Covers 6 implementation layers: ClientKind enum + INatsClient interface,
event infrastructure with Channel<T>, system event publishing, request-reply
monitoring services, import/export model with ACCOUNT client, and response
routing with latency tracking.
Wire up the config parsing infrastructure into the server:
- NatsServer: add ReloadConfig() with digest-based change detection,
diff/validate, CLI override preservation, and side-effect triggers
- Program.cs: two-pass CLI parsing — load config file first, then
apply CLI args on top with InCmdLine tracking for reload precedence
- SIGHUP handler upgraded from stub warning to actual reload
- Remove config file "not yet supported" warning from StartAsync
- Add integration tests for config loading, CLI overrides, and
reload validation
Port of Go server/reload.go option interface and diffing logic. Compares
NatsOptions property-by-property to detect changes, tags each with category
flags (logging, auth, TLS, non-reloadable), validates that non-reloadable
options (Host, Port, ServerName) are not changed at runtime, and provides
MergeCliOverrides to ensure CLI flags always take precedence over config
file values during hot reload.
- Add MaxIncludeDepth = 10 constant and thread _includeDepth through ParserState
constructors, ProcessInclude, ParseFile (private overload), and ParseEnvValue
to prevent StackOverflowException from recursive includes
- Fix PopContext to check _ctxs.Count <= 1 instead of == 0 so the root context
is never popped, replacing silent crash with clear InvalidOperationException
- Add else throw in SetValue so unknown context types surface as bugs rather
than silently dropping values
Wire OcspPeerVerify into the client-cert validation callback in
TlsHelper so revocation is checked online when the flag is set.
Add TlsHelper.BuildCertificateContext to build an
SslStreamCertificateContext with offline:false, enabling the runtime
to fetch and staple OCSP responses during the TLS handshake.
NatsServer applies the context at startup when OcspConfig.Mode is not
Never. Ten unit tests cover the config defaults, mode ordinals, and
the null-return invariants of BuildCertificateContext.
Implements NatsConfParser with Parse, ParseFile, and ParseFileWithDigest
methods. Supports nested maps/arrays, variable resolution with block
scoping and environment fallback, bcrypt password literals, integer
suffix multipliers, include directives, and cycle detection.
Adds LogOverrides property to NatsOptions and a --log_level_override=namespace=level CLI flag that wires Serilog MinimumLevel.Override entries so operators can tune verbosity per .NET namespace without changing the global log level.
Implement NatsJwt static class with Ed25519 signature verification,
base64url decoding, and JWT parsing. Add UserClaims and AccountClaims
with all NATS-specific fields (permissions, bearer tokens, limits,
signing keys, revocations). Includes 44 tests covering decode, verify,
nonce verification, and full round-trip signing with real NKey keypairs.
Port Go server/subject_transform.go to .NET. Implements a compiled
transform engine that parses source patterns with wildcards and
destination templates with function tokens at Create() time, then
evaluates them efficiently at Apply() time without runtime regex.
Supports all 9 transform functions: wildcard/$N, partition (FNV-1a),
split, splitFromLeft, splitFromRight, sliceFromLeft, sliceFromRight,
left, and right. Used for stream mirroring, account imports/exports,
and subject routing.
Load the server TLS certificate from disk during each /varz request to
read its NotAfter date and expose it as tls_cert_not_after. Also wire
OcspPeerVerify from NatsOptions into the tls_ocsp_peer_verify field.
Both fields were already declared in the Varz model but left unpopulated.
Adds Microsoft.Extensions.Hosting.WindowsServices package and a --service
CLI flag to Program.cs that logs service mode activation, enabling future
Windows Service lifecycle management.
Adds 10 new fields to NatsOptions (ClientAdvertise, TraceVerbose, MaxTracedMsgLen,
DisableSublistCache, ConnectErrorReports, ReconnectErrorReports, NoHeaderSupport,
MaxClosedClients, NoSystemAccount, SystemAccount) plus InCmdLine tracking set.
Moves MaxClosedClients from a private constant in NatsServer to a configurable option.
Introduces NATS.Server.Tls.OcspMode (Auto/Always/Must/Never matching
Go ocsp.go constants) and OcspConfig with Mode and OverrideUrls. Adds
OcspConfig? and OcspPeerVerify to NatsOptions for stapling configuration
and peer certificate revocation checking. Covered by 12 new unit tests.
Adds the IAccountResolver interface (FetchAsync, StoreAsync, IsReadOnly)
and a MemAccountResolver backed by ConcurrentDictionary for in-memory
JWT storage in tests and simple operator deployments.
Reference: golang/nats-server/server/accounts.go:4035+
Port the NATS configuration file lexer from Go's conf/lex.go to C#.
The lexer is a state-machine tokenizer that supports the NATS config
format: key-value pairs with =, :, or whitespace separators; nested
maps {}; arrays []; single and double quoted strings with escape
sequences; block strings (); variables $VAR; include directives;
comments (# and //); booleans; integers with size suffixes (kb, mb, gb);
floats; ISO8601 datetimes; and IP addresses.
Avoids re-serializing the same ServerInfo JSON on every new connection. The
cache is rebuilt when the ephemeral port is resolved. Connections that carry a
per-connection nonce (NKey auth) continue to serialize individually so the nonce
is included correctly.
Reconcile close reason tracking: feature branch's MarkClosed() and
ShouldSkipFlush/FlushAndCloseAsync now use main's ClientClosedReason
enum. ClosedState enum retained for forward compatibility.
Reject connections that send no_responders:true without headers:true,
since the 503 HMSG response requires header support. Add three tests:
connection rejection, acceptance with headers, and 503 delivery flow.
When a client sends CONNECT {"verbose":true}, the server now responds
with +OK\r\n after successfully processing CONNECT, PING, SUB, UNSUB,
and PUB/HPUB commands, matching the Go NATS server behavior.
Joseph Doherty