Skip to content

Fix NatsUri not reflecting host/port changes from OnConnectingAsync hook #997

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 3 commits into
base: main
Choose a base branch
from
Open

Fix NatsUri not reflecting host/port changes from OnConnectingAsync hook #997

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
2bfc6a3
Fix NatsUri not reflecting host/port changes from OnConnectingAsync hook
tormoder Nov 10, 2025
d3c6351
Preserve and log resolved URI after OnConnectingAsync hook
tormoder Nov 18, 2025
9009ae3
Merge branch 'main' into fork/tormoder/connect-socket-fix-uri-assignm…
mtmk Nov 24, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 25 additions & 6 deletions src/NATS.Client.Core/NatsConnection.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,7 @@ public partial class NatsConnection : INatsConnection
private CancellationTokenSource? _pingTimerCancellationTokenSource;
private volatile NatsUri? _currentConnectUri;
private volatile NatsUri? _lastSeedConnectUri;
private volatile NatsUri? _lastAttemptResolvedUri;
private NatsReadProtocolProcessor? _socketReader;
private TaskCompletionSource _waitForOpenConnection;
private UserCredentials? _userCredentials;
Expand Down Expand Up @@ -381,22 +382,33 @@ private async ValueTask InitialConnectAsync()
_userCredentials = new UserCredentials(Opts.AuthOpts);
}

var attemptedUris = new List<NatsUri>();

foreach (var uri in uris)
{
try
{
await ConnectSocketAsync(uri).ConfigureAwait(false);
var resolvedUri = await ConnectSocketAsync(uri).ConfigureAwait(false);
attemptedUris.Add(resolvedUri);
_currentConnectUri = resolvedUri; // set only after success
break;
}
catch (Exception ex)
{
_logger.LogError(NatsLogEvents.Connection, ex, "Fail to connect NATS {Url}", uri);
var failedResolvedUri = _lastAttemptResolvedUri ?? uri; // local cache from ConnectSocketAsync
attemptedUris.Add(failedResolvedUri);
_logger.LogError(NatsLogEvents.Connection, ex, "Fail to connect NATS {Url}", failedResolvedUri);
_currentConnectUri = null; // ensure cleared on failure
}
finally
{
_lastAttemptResolvedUri = null;
}
}

if (_socketConnection == null)
{
var exception = new NatsException("can not connect uris: " + string.Join(",", uris.Select(x => x.ToString())));
var exception = new NatsException("can not connect uris: " + string.Join(",", attemptedUris.Select(x => x.ToString())));
lock (_gate)
{
ConnectionState = NatsConnectionState.Closed; // allow retry connect
Expand Down Expand Up @@ -459,7 +471,7 @@ private async ValueTask InitialConnectAsync()
}
}

private async Task ConnectSocketAsync(NatsUri uri)
private async Task<NatsUri> ConnectSocketAsync(NatsUri uri)
{
var target = (uri.Host, uri.Port);
if (OnConnectingAsync != null)
Expand All @@ -468,10 +480,16 @@ private async Task ConnectSocketAsync(NatsUri uri)
target = await OnConnectingAsync(target).ConfigureAwait(false);
if (target.Host != uri.Host || target.Port != uri.Port)
{
uri = uri with { Uri = new UriBuilder(uri.Uri) { Host = target.Host, Port = target.Port, }.Uri };
var modifiedUri = new UriBuilder(uri.Uri) { Host = target.Host, Port = target.Port }.Uri;
var newUri = new NatsUri(modifiedUri.ToString(), uri.IsSeed, uri.Uri.Scheme);
_logger.LogDebug(NatsLogEvents.Connection, "OnConnectingAsync override: {Original} -> {Resolved}", uri.Uri, newUri.Uri);
uri = newUri;
}
}

// Keep for failure logging.
_lastAttemptResolvedUri = uri;

var connectionFactory = Opts.SocketConnectionFactory ?? (uri.IsWebSocket ? WebSocketFactory.Default : TcpFactory.Default);
_logger.LogInformation(NatsLogEvents.Connection, "Connect to NATS using {FactoryType} {Uri}", connectionFactory.GetType().Name, uri);
using var timeoutCts = new CancellationTokenSource(Opts.ConnectTimeout);
Expand Down Expand Up @@ -501,7 +519,8 @@ private async Task ConnectSocketAsync(NatsUri uri)
_socketConnection = _socketConnection with { InnerSocket = await OnSocketAvailableAsync(_socketConnection.InnerSocket).ConfigureAwait(false) };
}

_currentConnectUri = uri;
// Caller assigns _currentConnectUri.
return uri;
}

private async ValueTask SetupReaderWriterAsync(bool reconnect)
Expand Down
Loading