Files
coder/coderd/httpmw/logger.go
2025-04-08 08:30:05 +00:00

128 lines
3.3 KiB
Go

package httpmw
import (
"context"
"fmt"
"net/http"
"time"
"cdr.dev/slog"
"github.com/coder/coder/v2/coderd/httpapi"
"github.com/coder/coder/v2/coderd/tracing"
)
func Logger(log slog.Logger) func(next http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
start := time.Now()
sw, ok := rw.(*tracing.StatusWriter)
if !ok {
panic(fmt.Sprintf("ResponseWriter not a *tracing.StatusWriter; got %T", rw))
}
httplog := log.With(
slog.F("host", httpapi.RequestHost(r)),
slog.F("path", r.URL.Path),
slog.F("proto", r.Proto),
slog.F("remote_addr", r.RemoteAddr),
// Include the start timestamp in the log so that we have the
// source of truth. There is at least a theoretical chance that
// there can be a delay between `next.ServeHTTP` ending and us
// actually logging the request. This can also be useful when
// filtering logs that started at a certain time (compared to
// trying to compute the value).
slog.F("start", start),
)
logContext := NewRequestLogger(httplog, r.Method, start)
ctx := WithRequestLogger(r.Context(), logContext)
next.ServeHTTP(sw, r.WithContext(ctx))
// Don't log successful health check requests.
if r.URL.Path == "/api/v2" && sw.Status == http.StatusOK {
return
}
// For status codes 500 and higher we
// want to log the response body.
if sw.Status >= http.StatusInternalServerError {
logContext.WithFields(
slog.F("response_body", string(sw.ResponseBody())),
)
}
logContext.WriteLog(r.Context(), sw.Status)
})
}
}
type RequestLogger interface {
WithFields(fields ...slog.Field)
WriteLog(ctx context.Context, status int)
}
type SlogRequestLogger struct {
log slog.Logger
written bool
message string
start time.Time
}
var _ RequestLogger = &SlogRequestLogger{}
func NewRequestLogger(log slog.Logger, message string, start time.Time) RequestLogger {
return &SlogRequestLogger{
log: log,
written: false,
message: message,
start: start,
}
}
func (c *SlogRequestLogger) WithFields(fields ...slog.Field) {
c.log = c.log.With(fields...)
}
func (c *SlogRequestLogger) WriteLog(ctx context.Context, status int) {
if c.written {
return
}
c.written = true
end := time.Now()
logger := c.log.With(
slog.F("took", end.Sub(c.start)),
slog.F("status_code", status),
slog.F("latency_ms", float64(end.Sub(c.start)/time.Millisecond)),
)
// We already capture most of this information in the span (minus
// the response body which we don't want to capture anyways).
tracing.RunWithoutSpan(ctx, func(ctx context.Context) {
// We should not log at level ERROR for 5xx status codes because 5xx
// includes proxy errors etc. It also causes slogtest to fail
// instantly without an error message by default.
if status >= http.StatusInternalServerError {
logger.Warn(ctx, c.message)
} else {
logger.Debug(ctx, c.message)
}
})
}
type logContextKey struct{}
func WithRequestLogger(ctx context.Context, rl RequestLogger) context.Context {
return context.WithValue(ctx, logContextKey{}, rl)
}
func RequestLoggerFromContext(ctx context.Context) RequestLogger {
val := ctx.Value(logContextKey{})
if logCtx, ok := val.(RequestLogger); ok {
return logCtx
}
return nil
}