Christopher Lord e74cf72d99 Plugin Metrics: Eliminate data race in plugin metrics middleware (#99396) ...

fix: eliminate data race in plugin metrics middleware

A data race was detected when multiple goroutines accessed the `MetricsMiddleware`
simultaneously. The race occurred because a single `MetricsMiddleware` instance
was being shared across goroutines while its `BaseHandler` field was being
modified during middleware chain setup.

Fix by creating a new `MetricsMiddleware` instance for each middleware chain,
while safely sharing the thread-safe Prometheus metrics and plugin registry.
This maintains proper metrics collection while eliminating the mutable shared
state that caused the race condition.

Original error was detected here:

```
WARNING: DATA RACE
Read at 0x00c0039c0790 by goroutine 4486:
  github.com/grafana/grafana-plugin-sdk-go/backend.(*ErrorSourceMiddleware).CallResource()
      /Users/clord/src/grafana/irm-devstack/.devenv/state/go/pkg/mod/github.com/grafana/grafana-plugin-sdk-go@v0.261.0/backend/error_source_middleware.go:93 +0x40
  github.com/grafana/grafana-plugin-sdk-go/backend.BaseHandler.CallResource()
  ...

```

2025-02-04 16:54:27 +00:00

..

caching_metrics.go

PublicDashboards: Variables refactor (#73476)

2023-08-25 13:56:02 -05:00

caching_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

caching_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

clear_auth_headers_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

clear_auth_headers_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

contextual_logger_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

cookies_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

cookies_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

forward_id_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

forward_id_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

grafana_request_id_header_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

grafana_request_id_header_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

httpclient_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

httpclient_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

logger_middleware.go

Plugins: Auto instrumentation improvements (#94193)

2024-10-15 14:02:34 +02:00

metrics_middleware_test.go

Plugins: Auto instrumentation improvements (#94193)

2024-10-15 14:02:34 +02:00

metrics_middleware.go

Plugin Metrics: Eliminate data race in plugin metrics middleware (#99396)

2025-02-04 16:54:27 +00:00

oauthtoken_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

oauthtoken_middleware.go

OAuth: Use the attached external session data in OAuthToken and OAuthTokenSync (#96655)

2024-11-27 11:06:39 +01:00

testing.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

tracing_header_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

tracing_header_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

tracing_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

tracing_middleware.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

usealertingheaders_middleware_test.go

query: handle the x-rule-uid header (#95223)

2024-10-23 10:49:54 +02:00

usealertingheaders_middleware.go

query: handle the x-rule-uid header (#95223)

2024-10-23 10:49:54 +02:00

user_header_middleware_test.go

Plugins: Use handler middleware from the SDK (#93445)

2024-09-30 16:33:15 +02:00

user_header_middleware.go

Authlib: Use types package rather than claims (#99243)

2025-01-21 12:06:55 +03:00