Set Up Logs in Go
Structured logs allow you to send, view, and query logs sent from your applications within Sentry.
With Sentry Structured Logs, you can send text based log information from your applications to Sentry. Once in Sentry, these logs can be viewed alongside relevant errors, searched by text-string, or searched using their individual attributes.
Logs in Go are supported in Sentry Go SDK version 0.33.0 and above. To use integrations with other logging libraries, check their specific documentation pages for detailed requirements.
To enable logging, you need to initialize the SDK with the EnableLogs option set to true.
err := sentry.Init(sentry.ClientOptions{
Dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
// Enable printing of SDK debug messages.
// Useful when getting started or trying to figure something out.
Debug: true,
// Adds request headers and IP for users,
// visit: https://docs.sentry.io/platforms/go/data-management/data-collected/ for more info
SendDefaultPII: true,
EnableLogs: true,
// performance
EnableTracing: true,
// Set TracesSampleRate to 1.0 to capture 100%
// of transactions for tracing.
TracesSampleRate: 1.0,
// performance
})
if err != nil {
log.Fatalf("sentry.Init: %s", err)
}
// Flush buffered events before the program terminates.
// Set the timeout to the maximum duration the program can afford to wait.
defer sentry.Flush(2 * time.Second)
To filter logs, or update them before they are sent to Sentry, you can use the BeforeSendLog client option.
sentry.Init(sentry.ClientOptions{
Dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
EnableLogs: true,
BeforeSendLog: func(log *sentry.Log) *sentry.Log {
// filter out all trace logs
if log.Level == sentry.LogLevelTrace {
return nil
}
// filter all logs below warning
if log.Severity <= sentry.LogSeverityInfo {
return nil
}
return log
},
})
Once the feature is enabled on the SDK and the SDK is initialized, you can send logs by using the sentry.Logger API or our different integrations.
The sentry.Logger API exposes methods that support six different log levels:
tracedebuginfowarnerrorfatal
The methods support both fmt.Print and fmt.Printf like syntax. If you pass in format specifiers like %v, these will be sent to Sentry, and can be searched from within the Logs UI, and even added to the Logs views as a dedicated column.
func main() {
if err := sentry.Init(sentry.ClientOptions{
Dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
EnableLogs: true,
}); err != nil {
log.Fatalf("Sentry initialization failed: %v", err)
}
// Flush buffered events before the program terminates.
// Set the timeout to the maximum duration the program can afford to wait.
defer sentry.Flush(2 * time.Second)
// The SentryLogger requires context, to link logs with the appropriate traces. You can either create a new logger
// by providing the context, or use WithCtx() to pass the context inline.
ctx := context.Background()
logger := sentry.NewLogger(ctx)
// Or inline using WithCtx()
newCtx := context.Background()
// WithCtx() does not modify the original context attached on the logger.
logger.Info().WithCtx(newCtx).Emit("context passed")
// You can use the logger like [fmt.Print]
logger.Info().Emit("Hello ", "world!")
// Or like [fmt.Printf]
logger.Info().Emitf("Hello %v!", "world")
}
You can also pass additional permanent attributes to the logger via SetAttributes, or attach certain attributes to the LogEntry itself. These attributes do not persist after Emitting the LogEntry. All attributes will be searchable in the Logs UI.
logger.SetAttributes(
attribute.Int("key.int", 42),
attribute.Bool("key.boolean", true),
attribute.Float64("key.float", 42.4),
attribute.String("key.string", "string"),
)
logger.Warn().Emitf("I have params: %v and attributes", "example param")
// This entry would contain all attributes attached to the logger.
// However, it's also possible to overwrite them.
logger.Info().String("key.string", "newstring").Emit("overwriting key.string")
Currently, the attribute API supports only these value types: int, string, bool, and float.
The sentry.Logger implements the io.Writer interface, so you can easily inject the logger into your existing setup. However, to correctly link your traces you would need to create a new logger everytime you want to pass a new context. Due to this limitation we recommend using the sentry.Logger or any of the other supported integrations.
sentryLogger := sentry.NewLogger(ctx)
logger := log.New(sentryLogger, "", log.LstdFlags)
logger.Println("Implementing log.Logger")
If the Debug init option is set to true, calls to the sentry.Logger will also print to the console with the appropriate log level.
In order to properly attach the correct trace with each log entry, a context.Context is required. If you're using logs combined with tracing, you should pass the correct context to properly attach each trace with the appropriate logs.
Our documentation is open source and available on GitHub. Your contributions are welcome, whether fixing a typo (drat!) or suggesting an update ("yeah, this would be better").