-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
chore: add custom slog handler for cloud logging
- Loading branch information
Showing
4 changed files
with
214 additions
and
57 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,149 @@ | ||
| package log | ||
|
|
||
| import ( | ||
| "context" | ||
| "fmt" | ||
| "io" | ||
| "log/slog" | ||
| "runtime" | ||
|
|
||
| "cloud.google.com/go/logging" | ||
| "go.opentelemetry.io/otel/trace" | ||
| ) | ||
|
|
||
| const ( | ||
| cloudLoggingSourceKey = "logging.googleapis.com/sourceLocation" | ||
| cloudLoggingLabelsKey = "logging.googleapis.com/labels" | ||
| cloudLoggingTraceKey = "logging.googleapis.com/trace" | ||
| cloudLoggingTraceSpanKey = "logging.googleapis.com/spanId" | ||
| cloudLoggingTraceSampledKey = "logging.googleapis.com/trace_sampled" | ||
|
|
||
| cloudLoggingMessageKey = "message" | ||
| cloudLoggingSeverityKey = "severity" | ||
| cloudLoggingEnvironmentLabel = "env" | ||
| cloudLoggingServiceLabel = "app" | ||
| cloudLoggingTraceFormat = "projects/%s/traces/%s" | ||
| ) | ||
|
|
||
| type CloudLoggingHandler struct { | ||
| handler slog.Handler | ||
| environment string | ||
| service string | ||
| projectID string | ||
| } | ||
|
|
||
| type CloudLoggingHandlerOptions struct { | ||
| AddSource bool | ||
| Level slog.Level | ||
| Environment string | ||
| Service string | ||
| ProjectID string | ||
| ReplaceAttr func(groups []string, a slog.Attr) slog.Attr | ||
| } | ||
|
|
||
| // Ensure CloudLoggingHandler implements slog.Handler. | ||
| var _ slog.Handler = (*CloudLoggingHandler)(nil) | ||
|
|
||
| // NewCloudLoggingHandler creates a new CloudLoggingHandler. | ||
| func NewCloudLoggingHandler(out io.Writer, options *CloudLoggingHandlerOptions) *CloudLoggingHandler { | ||
| replaceAttr := func(groups []string, attr slog.Attr) slog.Attr { | ||
| cattr := attrReplacerForCloudLogging(groups, attr) | ||
| if options.ReplaceAttr != nil { | ||
| cattr = options.ReplaceAttr(groups, cattr) | ||
| } | ||
| return cattr | ||
| } | ||
|
|
||
| handler := slog.NewJSONHandler(out, &slog.HandlerOptions{ | ||
| AddSource: options.AddSource, | ||
| Level: options.Level, | ||
| ReplaceAttr: replaceAttr, | ||
| }) | ||
|
|
||
| return &CloudLoggingHandler{ | ||
| handler: handler, | ||
| environment: options.Environment, | ||
| service: options.Service, | ||
| projectID: options.ProjectID, | ||
| } | ||
| } | ||
|
|
||
| // Enabled implements the slog.Handler interface. | ||
| func (h *CloudLoggingHandler) Enabled(ctx context.Context, level slog.Level) bool { | ||
| return h.handler.Enabled(ctx, level) | ||
| } | ||
|
|
||
| // Handle implements the slog.Handler interface. | ||
| func (h *CloudLoggingHandler) Handle(ctx context.Context, record slog.Record) error { | ||
| record.AddAttrs( | ||
| slog.Group(cloudLoggingLabelsKey, | ||
| slog.String(cloudLoggingServiceLabel, h.service), | ||
| slog.String(cloudLoggingEnvironmentLabel, h.environment), | ||
| ), | ||
| ) | ||
| record.Level = h.toCloudLoggingLevel(record.Level) | ||
|
|
||
| // set trace | ||
| sc := trace.SpanContextFromContext(ctx) | ||
| if sc.IsValid() { | ||
| trace := fmt.Sprintf(cloudLoggingTraceFormat, h.projectID, sc.TraceID().String()) | ||
| record.AddAttrs( | ||
| slog.String(cloudLoggingTraceKey, trace), | ||
| slog.String(cloudLoggingTraceSpanKey, sc.SpanID().String()), | ||
| slog.Bool(cloudLoggingTraceSampledKey, sc.TraceFlags().IsSampled()), | ||
| ) | ||
| } | ||
|
|
||
| return h.handler.Handle(ctx, record) | ||
| } | ||
|
|
||
| // WithAttrs implements the slog.Handler interface. | ||
| func (h *CloudLoggingHandler) WithAttrs(attrs []slog.Attr) slog.Handler { | ||
| return h.handler.WithAttrs(attrs) | ||
| } | ||
|
|
||
| // WithGroup implements the slog.Handler interface. | ||
| func (h *CloudLoggingHandler) WithGroup(name string) slog.Handler { | ||
| return h.handler.WithGroup(name) | ||
| } | ||
|
|
||
| func (h *CloudLoggingHandler) toCloudLoggingLevel(level slog.Level) slog.Level { | ||
| switch level { | ||
| case SeverityDebug: | ||
| return slog.Level(logging.Debug) | ||
| case SeverityInfo: | ||
| return slog.Level(logging.Info) | ||
| case SeverityNotice: | ||
| return slog.Level(logging.Notice) | ||
| case SeverityWarning: | ||
| return slog.Level(logging.Warning) | ||
| case SeverityError: | ||
| return slog.Level(logging.Error) | ||
| case SeverityCritical: | ||
| return slog.Level(logging.Critical) | ||
| } | ||
| return slog.Level(logging.Info) | ||
| } | ||
|
|
||
| // attrReplacerForCloudLogging is default attribute replacer. | ||
| func attrReplacerForCloudLogging(_ []string, attr slog.Attr) slog.Attr { | ||
| switch attr.Key { | ||
| case slog.MessageKey: | ||
| attr.Key = cloudLoggingMessageKey | ||
| case slog.LevelKey: | ||
| attr.Key = cloudLoggingSeverityKey | ||
| attr.Value = slog.StringValue(logging.Severity(attr.Value.Any().(slog.Level)).String()) | ||
| case slog.SourceKey: | ||
| attr.Key = cloudLoggingSourceKey | ||
| // Replace the value of the "source" attribute with the value of the "sourceLocation" attribute. | ||
| const skip = 9 | ||
| _, file, line, ok := runtime.Caller(skip) | ||
| if !ok { | ||
| return attr | ||
| } | ||
| v := fmt.Sprintf("%s:%d", file, line) | ||
| attr.Value = slog.StringValue(v) | ||
| } | ||
|
|
||
| return attr | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters