Joseph Doherty
793 lines
37 KiB
C#
793 lines
37 KiB
C#
using System.Net;
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using System.Net.Http.Headers;
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using System.Text;
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using System.Text.Json;
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using System.Text.RegularExpressions;
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using Microsoft.Extensions.Logging;
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using Microsoft.Extensions.Options;
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using ZB.MOM.WW.ScadaBridge.Commons.Entities.ExternalSystems;
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using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories;
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using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Services;
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using ZB.MOM.WW.ScadaBridge.Commons.Types;
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using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;
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using ZB.MOM.WW.ScadaBridge.StoreAndForward;
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namespace ZB.MOM.WW.ScadaBridge.ExternalSystemGateway;
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/// <summary>
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/// HTTP/REST client that invokes external APIs.
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/// Dual call modes — Call (synchronous) and CachedCall (S&F on transient failure).
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/// Error classification applied to HTTP responses and exceptions.
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/// </summary>
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public class ExternalSystemClient : IExternalSystemClient
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{
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private readonly IHttpClientFactory _httpClientFactory;
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private readonly IExternalSystemRepository _repository;
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private readonly StoreAndForwardService? _storeAndForward;
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private readonly ILogger<ExternalSystemClient> _logger;
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private readonly ExternalSystemGatewayOptions _options;
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/// <summary>
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/// Initializes a new instance of the ExternalSystemClient.
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/// </summary>
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/// <param name="httpClientFactory">HTTP client factory for creating typed clients.</param>
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/// <param name="repository">External system repository for loading definitions.</param>
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/// <param name="logger">Logger instance.</param>
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/// <param name="storeAndForward">Store-and-forward service for buffering transient failures, or null if not available.</param>
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/// <param name="options">Configuration options, or null for defaults.</param>
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public ExternalSystemClient(
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IHttpClientFactory httpClientFactory,
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IExternalSystemRepository repository,
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ILogger<ExternalSystemClient> logger,
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StoreAndForwardService? storeAndForward = null,
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IOptions<ExternalSystemGatewayOptions>? options = null)
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{
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_httpClientFactory = httpClientFactory;
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_repository = repository;
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_logger = logger;
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_storeAndForward = storeAndForward;
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_options = options?.Value ?? new ExternalSystemGatewayOptions();
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}
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/// <inheritdoc />
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public async Task<ExternalCallResult> CallAsync(
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string systemName,
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string methodName,
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IReadOnlyDictionary<string, object?>? parameters = null,
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CancellationToken cancellationToken = default)
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{
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var (system, method) = await ResolveSystemAndMethodAsync(systemName, methodName, cancellationToken);
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if (system == null || method == null)
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{
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return new ExternalCallResult(false, null, $"External system '{systemName}' or method '{methodName}' not found");
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}
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try
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{
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var response = await InvokeHttpAsync(system, method, parameters, cancellationToken);
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return new ExternalCallResult(true, response, null);
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}
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catch (TransientExternalSystemException ex)
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{
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return new ExternalCallResult(false, null, $"Transient error: {ex.Message}");
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}
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catch (PermanentExternalSystemException ex)
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{
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return new ExternalCallResult(false, null, $"Permanent error: {ex.Message}");
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}
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}
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/// <inheritdoc />
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public async Task<ExternalCallResult> CachedCallAsync(
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string systemName,
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string methodName,
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IReadOnlyDictionary<string, object?>? parameters = null,
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string? originInstanceName = null,
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CancellationToken cancellationToken = default,
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TrackedOperationId? trackedOperationId = null,
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Guid? executionId = null,
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string? sourceScript = null,
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Guid? parentExecutionId = null)
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{
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var (system, method) = await ResolveSystemAndMethodAsync(systemName, methodName, cancellationToken);
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if (system == null || method == null)
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{
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return new ExternalCallResult(false, null, $"External system '{systemName}' or method '{methodName}' not found");
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}
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try
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{
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var response = await InvokeHttpAsync(system, method, parameters, cancellationToken);
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return new ExternalCallResult(true, response, null);
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}
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catch (PermanentExternalSystemException ex)
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{
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// Permanent failures returned to script, never buffered
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return new ExternalCallResult(false, null, $"Permanent error: {ex.Message}");
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}
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catch (TransientExternalSystemException)
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{
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// Transient failure — hand to S&F
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if (_storeAndForward == null)
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{
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return new ExternalCallResult(false, null, "Transient error and store-and-forward not available");
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}
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var payload = JsonSerializer.Serialize(new
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{
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SystemName = systemName,
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MethodName = methodName,
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Parameters = parameters
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});
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// attemptImmediateDelivery: false — this method already made the HTTP
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// attempt above; letting EnqueueAsync re-invoke the handler would
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// dispatch the same request a second time.
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//
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// The entity's MaxRetries is a non-nullable
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// int whose default is 0, and the Store-and-Forward engine interprets a
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// stored MaxRetries of 0 as "no limit" (retry forever) — see
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// StoreAndForwardMessage.MaxRetries ("0 = no limit") and the retry-sweep
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// guard `MaxRetries > 0 && ...`. Passing 0 verbatim would therefore turn
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// every unconfigured cached call into an unbounded retry loop. A 0 is
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// treated as "unset" and passed as null so the bounded S&F default
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// applies; the RetryDelay default of TimeSpan.Zero is likewise unset.
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await _storeAndForward.EnqueueAsync(
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StoreAndForwardCategory.ExternalSystem,
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systemName,
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payload,
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originInstanceName,
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system.MaxRetries > 0 ? system.MaxRetries : null,
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system.RetryDelay > TimeSpan.Zero ? system.RetryDelay : null,
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attemptImmediateDelivery: false,
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// Pin the S&F message id to the
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// TrackedOperationId so the retry loop can read it back via
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// StoreAndForwardMessage.Id and emit per-attempt + terminal
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// cached-call telemetry. Null -> S&F
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// mints its own GUID (legacy behaviour).
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messageId: trackedOperationId?.ToString(),
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// Thread the originating
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// script execution's ExecutionId + SourceScript onto the
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// buffered row so the retry-loop cached-call audit rows carry
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// the same provenance the script-side cached rows do.
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executionId: executionId,
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sourceScript: sourceScript,
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// Thread the spawning
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// inbound-API request's ExecutionId onto the buffered row so
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// the retry-loop cached-call audit rows correlate back to the
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// cross-execution chain. Null for a non-routed run.
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parentExecutionId: parentExecutionId);
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return new ExternalCallResult(true, null, null, WasBuffered: true);
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}
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}
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/// <summary>
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/// Delivers a buffered ExternalSystem call during a store-and-forward
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/// retry sweep. Returns true on success, false on permanent failure (the message
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/// is parked); throws <see cref="TransientExternalSystemException"/> on a
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/// transient failure so the engine retries. Deterministic-poison failures against
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/// the CURRENT method definition — malformed JSON, or an
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/// <see cref="ArgumentException"/> from an unresolvable <c>{param}</c> path
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/// template or an unsupported HTTP verb — return false (park immediately) rather
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/// than retry, because re-running the same stored payload can never succeed.
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/// </summary>
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/// <param name="message">The buffered message to deliver.</param>
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/// <param name="cancellationToken">Cancellation token.</param>
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/// <returns>True if delivered successfully, false if a permanent error occurred.</returns>
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public async Task<bool> DeliverBufferedAsync(
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StoreAndForwardMessage message, CancellationToken cancellationToken = default)
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{
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// A malformed (not just empty/null-fielded)
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// PayloadJson would otherwise throw `JsonException` here, which the S&F
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// engine treats as a transient failure and retries forever (poison
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// message). Re-running the same deserialization against the same payload
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// will throw deterministically, so JsonException is permanent — log,
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// and return false so the S&F engine parks the message instead.
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CachedCallPayload? payload;
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try
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{
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payload = JsonSerializer.Deserialize<CachedCallPayload>(message.PayloadJson);
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}
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catch (JsonException ex)
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{
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_logger.LogError(
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ex,
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"Buffered ExternalSystem message {Id} has malformed JSON payload; parking.",
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message.Id);
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return false;
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}
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if (payload == null || string.IsNullOrEmpty(payload.SystemName) || string.IsNullOrEmpty(payload.MethodName))
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{
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_logger.LogError("Buffered ExternalSystem message {Id} has an unreadable payload; parking.", message.Id);
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return false;
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}
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var (system, method) = await ResolveSystemAndMethodAsync(
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payload.SystemName, payload.MethodName, cancellationToken);
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if (system == null || method == null)
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{
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_logger.LogError(
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"Buffered call to '{System}'/'{Method}' cannot be delivered — the system or method no longer exists; parking.",
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payload.SystemName, payload.MethodName);
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return false;
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}
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var parameters = payload.Parameters?.ToDictionary(kv => kv.Key, kv => (object?)kv.Value);
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try
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{
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await InvokeHttpAsync(system, method, parameters, cancellationToken);
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return true;
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}
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catch (PermanentExternalSystemException ex)
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{
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_logger.LogError(ex, "Buffered call to '{System}' failed permanently; parking.", payload.SystemName);
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return false;
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}
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catch (ArgumentException ex)
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{
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// N2: same poison-message shape as the JsonException catch above. BuildUrl's
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// {param} path-template substitution (placeholder with no matching/non-null
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// parameter) and ValidateHttpMethod both throw ArgumentException
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// deterministically for the SAME stored payload — the method definition
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// changed underneath the buffered call, and retrying can never succeed.
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// Return false so the S&F engine parks the message instead of counting the
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// throw as transient and burning MaxRetries.
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_logger.LogError(
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ex,
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"Buffered call to '{System}'/'{Method}' fails deterministically against the current method definition; parking.",
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payload.SystemName, payload.MethodName);
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return false;
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}
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// TransientExternalSystemException propagates — the S&F engine retries.
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}
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private sealed record CachedCallPayload(
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string SystemName,
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string MethodName,
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Dictionary<string, JsonElement>? Parameters);
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/// <summary>
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/// Executes the HTTP request against the external system.
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/// </summary>
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/// <param name="system">The external system definition.</param>
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/// <param name="method">The external system method to invoke.</param>
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/// <param name="parameters">Method parameters as a dictionary, or null if none.</param>
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/// <param name="cancellationToken">Cancellation token.</param>
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/// <returns>The response string, or null if no response body.</returns>
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internal async Task<string?> InvokeHttpAsync(
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ExternalSystemDefinition system,
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ExternalSystemMethod method,
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IReadOnlyDictionary<string, object?>? parameters,
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CancellationToken cancellationToken)
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{
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// Validate the verb against the documented set
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// (GET/POST/PUT/PATCH/DELETE)
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// BEFORE constructing the request. `new HttpMethod(string)` accepts any
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// token-character string (e.g. "FOO", "DLETE"), and the body-vs-query
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// branch below only knows POST/PUT/PATCH and GET/DELETE — so an
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// unsupported verb would dispatch silently with parameters sent to
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// neither body nor query, and the script would only see a remote 4xx.
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// Rejecting at the gateway entry surfaces the misconfiguration with a
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// clear ArgumentException naming the offending verb. Case-insensitive
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// match: the entity column carries free-form strings.
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ValidateHttpMethod(method.HttpMethod);
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var client = _httpClientFactory.CreateClient($"ExternalSystem_{system.Name}");
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// HttpClient.Timeout defaults to 100 seconds
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// and is enforced internally by SendAsync via its own private CTS — a
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// TaskCanceledException raised by that internal CTS does not trip
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// either the caller's token or the gateway's timeout CTS, so it falls
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// through the ordered catch filters below into the generic "connection
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// error" branch and is misclassified. Any operator-configured
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// DefaultHttpTimeout greater than 100 s would therefore be silently
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// clipped to 100 s, breaking the design's "timeout applies to the HTTP
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// request round-trip" guarantee. Disable the framework default so the
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// linked CancellationTokenSource(DefaultHttpTimeout) below is the sole
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// timeout source — DefaultHttpTimeout is then honoured verbatim for
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// every value, including ones well above 100 s. Setting this on the
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// factory-supplied HttpClient before any request is the safe time:
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// IHttpClientFactory rents typed clients backed by pooled message
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// handlers, but the HttpClient instance itself is per-call and the
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// Timeout property is per-instance.
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client.Timeout = Timeout.InfiniteTimeSpan;
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var url = BuildUrl(system.EndpointUrl, method.Path, parameters, method.HttpMethod, out var consumedParams);
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// The request and response own IDisposable resources (StringContent, the
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// response content stream). Dispose both, including on the exception paths.
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using var request = new HttpRequestMessage(new HttpMethod(method.HttpMethod), url);
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// Apply authentication
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ApplyAuth(request, system);
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// For POST/PUT/PATCH, send parameters as JSON body
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if (method.HttpMethod.Equals("POST", StringComparison.OrdinalIgnoreCase) ||
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method.HttpMethod.Equals("PUT", StringComparison.OrdinalIgnoreCase) ||
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method.HttpMethod.Equals("PATCH", StringComparison.OrdinalIgnoreCase))
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{
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// Parameters consumed by `{param}` path-template substitution are
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// already carried in the URL — exclude them from the JSON body so a
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// path parameter is not duplicated as a body field.
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var bodyParameters = consumedParams.Count == 0
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? parameters
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: parameters?.Where(p => !consumedParams.Contains(p.Key))
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.ToDictionary(p => p.Key, p => p.Value);
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if (bodyParameters != null && bodyParameters.Count > 0)
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{
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request.Content = new StringContent(
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JsonSerializer.Serialize(bodyParameters),
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Encoding.UTF8,
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"application/json");
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}
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}
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// Enforce the per-call timeout (the design's "timeout applies to the HTTP
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// request round-trip" guarantee). Resolution order: a positive per-system
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// ExternalSystemDefinition.TimeoutSeconds wins; otherwise the configured
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// DefaultHttpTimeout is the effective round-trip limit. A linked CTS lets us
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// distinguish a timeout from a caller-initiated cancellation: only the
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// timeout is reclassified as transient.
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var effectiveTimeout = system.TimeoutSeconds > 0
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? TimeSpan.FromSeconds(system.TimeoutSeconds)
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: _options.DefaultHttpTimeout;
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using var timeoutCts = new CancellationTokenSource(effectiveTimeout);
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using var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(
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cancellationToken, timeoutCts.Token);
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HttpResponseMessage response;
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try
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{
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// ResponseHeadersRead returns as soon as the headers are in, so the
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// body is not eagerly buffered — the bounded read below streams it and
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// aborts once MaxResponseBodyBytes is exceeded, keeping a hostile or
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// misbehaving endpoint from inflating the active node's memory.
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response = await client.SendAsync(
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request, HttpCompletionOption.ResponseHeadersRead, linkedCts.Token);
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}
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catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
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{
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// The caller asked to abandon the work — do not reclassify as transient.
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throw;
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}
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catch (OperationCanceledException ex) when (timeoutCts.IsCancellationRequested)
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{
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// Our own timeout elapsed — a transient failure per the design.
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throw ErrorClassifier.AsTransient(
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$"Timeout calling {system.Name} after {effectiveTimeout.TotalSeconds:0.##}s", ex);
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}
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catch (Exception ex) when (ErrorClassifier.IsTransient(ex, cancellationToken))
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{
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throw ErrorClassifier.AsTransient($"Connection error to {system.Name}: {ex.Message}", ex);
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}
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using (response)
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{
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// The timeout also covers reading the response body (the design's
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// "round-trip" guarantee), so the linked token is used for the read too.
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string body;
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try
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{
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body = await ReadBodyBoundedAsync(
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response.Content, system.Name, _options.MaxResponseBodyBytes, linkedCts.Token);
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}
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catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
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{
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throw;
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}
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catch (OperationCanceledException ex) when (timeoutCts.IsCancellationRequested)
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{
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throw ErrorClassifier.AsTransient(
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$"Timeout reading response from {system.Name} after {effectiveTimeout.TotalSeconds:0.##}s", ex);
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}
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if (response.IsSuccessStatusCode)
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{
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return body;
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}
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// Bound the external error body before embedding it into a
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// script-visible message / event-log entry — a misbehaving or hostile
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// endpoint must not be able to inflate every error string.
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var errorBody = Truncate(body, MaxErrorBodyChars);
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if (ErrorClassifier.IsTransient(response.StatusCode))
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{
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// Transient failures are normal operation (handled by retry / S&F) —
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// record at debug level only so the event log is not noisy.
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_logger.LogDebug(
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"Transient HTTP {StatusCode} from external system {System} calling {Method}.",
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(int)response.StatusCode, system.Name, method.Name);
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throw ErrorClassifier.AsTransient(
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$"HTTP {(int)response.StatusCode} from {system.Name}: {errorBody}");
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}
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// The design requires permanent failures to be visible in Site Event
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// Logging — emit a warning so the gateway is not silent on a permanent
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// failure.
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_logger.LogWarning(
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"Permanent HTTP {StatusCode} from external system {System} calling {Method}: {Error}",
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(int)response.StatusCode, system.Name, method.Name, errorBody);
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throw new PermanentExternalSystemException(
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$"HTTP {(int)response.StatusCode} from {system.Name}: {errorBody}",
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(int)response.StatusCode);
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}
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}
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/// <summary>
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/// Upper bound (characters) on an external error response body echoed into a
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/// script-visible error message.
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/// </summary>
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private const int MaxErrorBodyChars = 2048;
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/// <summary>
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/// Documented HTTP-verb allowlist. Matches the
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/// design doc's enumerated set (GET/POST/PUT/PATCH/DELETE) and
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/// the body-vs-query branching above; any addition here must update both.
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/// </summary>
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private static readonly HashSet<string> SupportedHttpMethods = new(StringComparer.OrdinalIgnoreCase)
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{
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"GET", "POST", "PUT", "PATCH", "DELETE",
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};
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/// <summary>
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/// Rejects HTTP verbs the gateway does not support. Throws
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/// <see cref="ArgumentException"/> for null/empty input or any string outside
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/// the documented allowlist. Case-insensitive — the entity column carries
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/// operator-authored strings.
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/// </summary>
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private static void ValidateHttpMethod(string httpMethod)
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{
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if (string.IsNullOrWhiteSpace(httpMethod))
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{
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throw new ArgumentException(
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"HTTP method must be one of GET/POST/PUT/PATCH/DELETE; got null or empty.",
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nameof(httpMethod));
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}
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if (!SupportedHttpMethods.Contains(httpMethod))
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{
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throw new ArgumentException(
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$"HTTP method '{httpMethod}' is not supported. Allowed verbs: GET, POST, PUT, PATCH, DELETE.",
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nameof(httpMethod));
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}
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}
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/// <summary>
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/// Reads an HTTP response body into a string while enforcing an upper size
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/// bound. When the <c>Content-Length</c> header is present it fails fast;
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/// otherwise the body is streamed in 16 KiB chunks and the read is aborted the
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/// moment the accumulated length exceeds <paramref name="maxBytes"/> (cap+1
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/// pattern), so the whole oversized body is never buffered. Oversize is a
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/// permanent failure — retrying will not shrink the response, and buffering it
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/// into store-and-forward would defeat the cap. Cancellation
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/// (<see cref="OperationCanceledException"/>) is allowed to propagate so the
|
|
/// caller's ordered timeout/cancellation catch filters classify it.
|
|
/// <para>
|
|
/// N4: the accumulated bytes are decoded using the response's declared charset
|
|
/// (<c>Content-Type: …; charset=…</c>) via <see cref="ResolveEncoding"/> — parity
|
|
/// with the pre-bounded-read <c>ReadAsStringAsync</c>. A null, empty, or
|
|
/// unrecognized charset falls back to UTF-8.
|
|
/// </para>
|
|
/// </summary>
|
|
private static async Task<string> ReadBodyBoundedAsync(
|
|
HttpContent content, string systemName, long maxBytes, CancellationToken token)
|
|
{
|
|
// Fast path: a declared Content-Length above the cap is rejected before a
|
|
// single body byte is read.
|
|
var declaredLength = content.Headers.ContentLength;
|
|
if (declaredLength.HasValue && declaredLength.Value > maxBytes)
|
|
{
|
|
throw new PermanentExternalSystemException(
|
|
$"Response from {systemName} exceeded the {maxBytes}-byte limit " +
|
|
$"(declared Content-Length {declaredLength.Value}).");
|
|
}
|
|
|
|
await using var stream = await content.ReadAsStreamAsync(token);
|
|
|
|
using var buffer = new MemoryStream();
|
|
var chunk = new byte[16 * 1024];
|
|
int read;
|
|
while ((read = await stream.ReadAsync(chunk.AsMemory(0, chunk.Length), token)) > 0)
|
|
{
|
|
buffer.Write(chunk, 0, read);
|
|
|
|
// cap+1: as soon as we hold more than maxBytes we know it is oversized,
|
|
// without reading the remainder of the stream.
|
|
if (buffer.Length > maxBytes)
|
|
{
|
|
throw new PermanentExternalSystemException(
|
|
$"Response from {systemName} exceeded the {maxBytes}-byte limit.");
|
|
}
|
|
}
|
|
|
|
// N4: honor the response's declared charset (parity with the pre-bounded-read
|
|
// ReadAsStringAsync). Unknown/invalid charset → UTF-8 fallback: mojibake beats
|
|
// failing the call over a cosmetic header.
|
|
return ResolveEncoding(content.Headers.ContentType?.CharSet)
|
|
.GetString(buffer.GetBuffer(), 0, (int)buffer.Length);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Resolves the declared response charset to an <see cref="Encoding"/>, tolerating
|
|
/// the quoted form some servers emit (<c>charset="iso-8859-1"</c>). Null, empty,
|
|
/// or unrecognized values fall back to UTF-8.
|
|
/// </summary>
|
|
private static Encoding ResolveEncoding(string? charset)
|
|
{
|
|
if (string.IsNullOrWhiteSpace(charset))
|
|
{
|
|
return Encoding.UTF8;
|
|
}
|
|
|
|
try
|
|
{
|
|
return Encoding.GetEncoding(charset.Trim().Trim('"'));
|
|
}
|
|
catch (ArgumentException)
|
|
{
|
|
return Encoding.UTF8;
|
|
}
|
|
}
|
|
|
|
private static string Truncate(string value, int maxChars)
|
|
{
|
|
if (string.IsNullOrEmpty(value) || value.Length <= maxChars)
|
|
{
|
|
return value;
|
|
}
|
|
|
|
return value.Substring(0, maxChars) + $"… [truncated, {value.Length} chars total]";
|
|
}
|
|
|
|
/// <summary>
|
|
/// Matches a `{param}` path-template placeholder. The name must be a valid
|
|
/// identifier (letter/underscore start, then letters/digits/underscores) so the
|
|
/// pattern cannot accidentally swallow JSON-ish braces in a hand-authored path.
|
|
/// </summary>
|
|
private static readonly Regex PathParamRegex = new(
|
|
@"\{([A-Za-z_][A-Za-z0-9_]*)\}", RegexOptions.Compiled);
|
|
|
|
private static string BuildUrl(
|
|
string baseUrl,
|
|
string path,
|
|
IReadOnlyDictionary<string, object?>? parameters,
|
|
string httpMethod,
|
|
out ISet<string> consumedParams)
|
|
{
|
|
consumedParams = new HashSet<string>(StringComparer.Ordinal);
|
|
|
|
// A method that targets the base URL itself has an empty (or "/") path.
|
|
// Appending a trailing "/" in that case yields ".../api/" which some
|
|
// servers treat as a distinct resource — only append a segment when the
|
|
// method actually defines a non-empty relative path.
|
|
var trimmedBase = baseUrl.TrimEnd('/');
|
|
var trimmedPath = path.Trim().TrimStart('/');
|
|
|
|
// Substitute `{param}` placeholders in the path with escaped parameter
|
|
// values. Each substituted name is recorded so it is excluded from BOTH
|
|
// the query string (GET/DELETE) and the JSON body (POST/PUT/PATCH) — a
|
|
// path parameter must not be duplicated. A placeholder with no matching
|
|
// parameter (or a null value) is an authoring error: throw a clear
|
|
// ArgumentException naming it, mirroring ValidateHttpMethod.
|
|
if (trimmedPath.Length > 0 && trimmedPath.Contains('{'))
|
|
{
|
|
var consumed = consumedParams;
|
|
trimmedPath = PathParamRegex.Replace(trimmedPath, match =>
|
|
{
|
|
var name = match.Groups[1].Value;
|
|
if (parameters == null ||
|
|
!parameters.TryGetValue(name, out var value) ||
|
|
value == null)
|
|
{
|
|
throw new ArgumentException(
|
|
$"Path template parameter '{{{name}}}' has no value — supply a non-null '{name}' parameter for this method.",
|
|
nameof(path));
|
|
}
|
|
|
|
consumed.Add(name);
|
|
return Uri.EscapeDataString(value.ToString() ?? string.Empty);
|
|
});
|
|
}
|
|
|
|
var url = string.IsNullOrEmpty(trimmedPath)
|
|
? trimmedBase
|
|
: trimmedBase + "/" + trimmedPath;
|
|
|
|
// For GET/DELETE, append parameters as query string
|
|
if ((httpMethod.Equals("GET", StringComparison.OrdinalIgnoreCase) ||
|
|
httpMethod.Equals("DELETE", StringComparison.OrdinalIgnoreCase)) &&
|
|
parameters != null && parameters.Count > 0)
|
|
{
|
|
var consumed = consumedParams;
|
|
var queryString = string.Join("&",
|
|
parameters.Where(p => p.Value != null && !consumed.Contains(p.Key))
|
|
.Select(p => $"{Uri.EscapeDataString(p.Key)}={Uri.EscapeDataString(p.Value?.ToString() ?? "")}"));
|
|
|
|
// Only append "?" when the effective query string is non-empty — a method
|
|
// whose parameter values are all null produces no query string, and the
|
|
// URL must then be identical to the no-parameters case rather than ending
|
|
// in a bare "?".
|
|
if (queryString.Length > 0)
|
|
{
|
|
url += "?" + queryString;
|
|
}
|
|
}
|
|
|
|
return url;
|
|
}
|
|
|
|
private void ApplyAuth(HttpRequestMessage request, ExternalSystemDefinition system)
|
|
{
|
|
// Distinguish "intentionally unauthenticated" (AuthType = none)
|
|
// from "AuthConfiguration is missing or empty for a type that requires it"
|
|
// (deployment glitch, decryption failure, operator typo). The unauthenticated
|
|
// case is silent; the requires-creds-but-empty case logs a Warning so an
|
|
// operator debugging a recurring 401 sees the cause inside ScadaBridge instead
|
|
// of having to read the remote system's logs. The value of AuthConfiguration
|
|
// is NEVER logged.
|
|
var authType = system.AuthType?.Trim().ToLowerInvariant() ?? string.Empty;
|
|
|
|
if (string.IsNullOrEmpty(system.AuthConfiguration))
|
|
{
|
|
if (authType is "apikey" or "basic")
|
|
{
|
|
_logger.LogWarning(
|
|
"ApplyAuth: External system '{System}' has AuthType '{AuthType}' but AuthConfiguration is empty; request will be sent without an auth header.",
|
|
system.Name, system.AuthType);
|
|
}
|
|
return;
|
|
}
|
|
|
|
// A config whose trimmed value starts with '{' is the structured JSON form
|
|
// promised by the entity doc-comment and the Central UI placeholders. Parse
|
|
// it first; only a non-JSON value falls through to the legacy colon-split.
|
|
var isJson = system.AuthConfiguration.TrimStart().StartsWith('{');
|
|
Dictionary<string, string?>? jsonFields = null;
|
|
var jsonParsed = isJson && TryParseJsonAuth(system.AuthConfiguration, out jsonFields);
|
|
|
|
switch (authType)
|
|
{
|
|
case "apikey":
|
|
// JSON form: {"header"?: string, "key": string} (default header X-API-Key).
|
|
if (isJson)
|
|
{
|
|
if (jsonParsed &&
|
|
jsonFields!.TryGetValue("key", out var jsonKey) &&
|
|
!string.IsNullOrEmpty(jsonKey))
|
|
{
|
|
var header = jsonFields.TryGetValue("header", out var h) && !string.IsNullOrEmpty(h)
|
|
? h!
|
|
: "X-API-Key";
|
|
request.Headers.TryAddWithoutValidation(header, jsonKey);
|
|
}
|
|
else
|
|
{
|
|
// Malformed JSON, or JSON with no usable "key": send without a
|
|
// header and warn (the value is never logged). Never throw.
|
|
_logger.LogWarning(
|
|
"ApplyAuth: External system '{System}' AuthType 'apikey' AuthConfiguration is malformed JSON (expected {{\"header\"?:...,\"key\":...}}); request will be sent without an auth header.",
|
|
system.Name);
|
|
}
|
|
break;
|
|
}
|
|
|
|
// Legacy config format: "HeaderName:KeyValue" or just "KeyValue" (default header: X-API-Key)
|
|
var parts = system.AuthConfiguration.Split(':', 2);
|
|
if (parts.Length == 2)
|
|
{
|
|
request.Headers.TryAddWithoutValidation(parts[0], parts[1]);
|
|
}
|
|
else
|
|
{
|
|
request.Headers.TryAddWithoutValidation("X-API-Key", system.AuthConfiguration);
|
|
}
|
|
break;
|
|
|
|
case "basic":
|
|
// JSON form: {"username": string, "password": string}.
|
|
if (isJson)
|
|
{
|
|
if (jsonParsed &&
|
|
jsonFields!.TryGetValue("username", out var jsonUser) &&
|
|
!string.IsNullOrEmpty(jsonUser))
|
|
{
|
|
var password = jsonFields.TryGetValue("password", out var p) ? p ?? string.Empty : string.Empty;
|
|
var jsonEncoded = Convert.ToBase64String(
|
|
Encoding.UTF8.GetBytes($"{jsonUser}:{password}"));
|
|
request.Headers.Authorization = new AuthenticationHeaderValue("Basic", jsonEncoded);
|
|
}
|
|
else
|
|
{
|
|
_logger.LogWarning(
|
|
"ApplyAuth: External system '{System}' AuthType 'basic' AuthConfiguration is malformed JSON (expected {{\"username\":...,\"password\":...}}); request will be sent without an Authorization header.",
|
|
system.Name);
|
|
}
|
|
break;
|
|
}
|
|
|
|
// Legacy config format: "username:password"
|
|
var basicParts = system.AuthConfiguration.Split(':', 2);
|
|
if (basicParts.Length == 2)
|
|
{
|
|
var encoded = Convert.ToBase64String(
|
|
Encoding.UTF8.GetBytes($"{basicParts[0]}:{basicParts[1]}"));
|
|
request.Headers.Authorization = new AuthenticationHeaderValue("Basic", encoded);
|
|
}
|
|
else
|
|
{
|
|
// Malformed Basic config (no ':' separator) means the
|
|
// request goes out with no Authorization header. Warn so the
|
|
// failure mode is visible inside ZB.MOM.WW.ScadaBridge.
|
|
_logger.LogWarning(
|
|
"ApplyAuth: External system '{System}' AuthType 'basic' AuthConfiguration is malformed (expected 'username:password'); request will be sent without an Authorization header.",
|
|
system.Name);
|
|
}
|
|
break;
|
|
|
|
case "none":
|
|
// Documented sentinel for unauthenticated systems — silent by design.
|
|
break;
|
|
|
|
default:
|
|
// Unknown AuthType silently fell through here before. Warn.
|
|
_logger.LogWarning(
|
|
"ApplyAuth: External system '{System}' has unknown AuthType '{AuthType}'; request will be sent without an auth header. Allowed values: apikey, basic, none.",
|
|
system.Name, system.AuthType);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Parses a structured JSON <c>AuthConfiguration</c> into a case-insensitive
|
|
/// field map (e.g. <c>{"header":"X-Auth","key":"..."}</c> or
|
|
/// <c>{"username":"u","password":"p"}</c>). Returns <c>false</c> on malformed
|
|
/// JSON (<see cref="JsonException"/>) instead of throwing, so the caller can
|
|
/// fall through to the "send without header" warning path. Values are never
|
|
/// logged.
|
|
/// </summary>
|
|
private static bool TryParseJsonAuth(string config, out Dictionary<string, string?> fields)
|
|
{
|
|
try
|
|
{
|
|
fields = JsonSerializer.Deserialize<Dictionary<string, string?>>(
|
|
config,
|
|
new JsonSerializerOptions { PropertyNameCaseInsensitive = true })
|
|
?? new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
|
|
|
|
// Normalize to case-insensitive so "Header"/"header" both resolve.
|
|
if (!ReferenceEquals(fields.Comparer, StringComparer.OrdinalIgnoreCase))
|
|
{
|
|
fields = new Dictionary<string, string?>(fields, StringComparer.OrdinalIgnoreCase);
|
|
}
|
|
return true;
|
|
}
|
|
catch (JsonException)
|
|
{
|
|
fields = new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
private async Task<(ExternalSystemDefinition? system, ExternalSystemMethod? method)> ResolveSystemAndMethodAsync(
|
|
string systemName,
|
|
string methodName,
|
|
CancellationToken cancellationToken)
|
|
{
|
|
// Name-keyed repository lookups instead of
|
|
// fetch-all-then-filter — definitions are resolved on every hot-path call
|
|
// (a script's ExternalSystem.Call()), so the repository performs an indexed
|
|
// query rather than loading every system / every method into memory.
|
|
var system = await _repository.GetExternalSystemByNameAsync(systemName, cancellationToken);
|
|
if (system == null)
|
|
return (null, null);
|
|
|
|
var method = await _repository.GetMethodByNameAsync(system.Id, methodName, cancellationToken);
|
|
|
|
return (system, method);
|
|
}
|
|
}
|