142 lines
4.0 KiB
Go
142 lines
4.0 KiB
Go
//
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// Custom Structured Logger
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// ========================
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// This example demonstrates how to use middleware.RequestLogger,
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// middleware.LogFormatter and middleware.LogEntry to build a structured
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// logger using the amazing sirupsen/logrus package as the logging
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// backend.
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//
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// Also: check out https://github.com/pressly/lg for an improved context
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// logger with support for HTTP request logging, based on the example
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// below.
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//
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package main
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import (
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"fmt"
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"net/http"
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"time"
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"github.com/go-chi/chi"
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"github.com/go-chi/chi/middleware"
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"github.com/sirupsen/logrus"
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)
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func main() {
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// Setup the logger backend using sirupsen/logrus and configure
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// it to use a custom JSONFormatter. See the logrus docs for how to
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// configure the backend at github.com/sirupsen/logrus
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logger := logrus.New()
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logger.Formatter = &logrus.JSONFormatter{
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// disable, as we set our own
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DisableTimestamp: true,
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}
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// Routes
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r := chi.NewRouter()
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r.Use(middleware.RequestID)
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r.Use(NewStructuredLogger(logger))
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r.Use(middleware.Recoverer)
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r.Get("/", func(w http.ResponseWriter, r *http.Request) {
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w.Write([]byte("welcome"))
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})
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r.Get("/wait", func(w http.ResponseWriter, r *http.Request) {
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time.Sleep(1 * time.Second)
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LogEntrySetField(r, "wait", true)
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w.Write([]byte("hi"))
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})
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r.Get("/panic", func(w http.ResponseWriter, r *http.Request) {
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panic("oops")
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})
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http.ListenAndServe(":3333", r)
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}
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// StructuredLogger is a simple, but powerful implementation of a custom structured
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// logger backed on logrus. I encourage users to copy it, adapt it and make it their
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// own. Also take a look at https://github.com/pressly/lg for a dedicated pkg based
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// on this work, designed for context-based http routers.
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func NewStructuredLogger(logger *logrus.Logger) func(next http.Handler) http.Handler {
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return middleware.RequestLogger(&StructuredLogger{logger})
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}
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type StructuredLogger struct {
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Logger *logrus.Logger
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}
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func (l *StructuredLogger) NewLogEntry(r *http.Request) middleware.LogEntry {
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entry := &StructuredLoggerEntry{Logger: logrus.NewEntry(l.Logger)}
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logFields := logrus.Fields{}
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logFields["ts"] = time.Now().UTC().Format(time.RFC1123)
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if reqID := middleware.GetReqID(r.Context()); reqID != "" {
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logFields["req_id"] = reqID
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}
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scheme := "http"
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if r.TLS != nil {
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scheme = "https"
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}
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logFields["http_scheme"] = scheme
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logFields["http_proto"] = r.Proto
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logFields["http_method"] = r.Method
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logFields["remote_addr"] = r.RemoteAddr
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logFields["user_agent"] = r.UserAgent()
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logFields["uri"] = fmt.Sprintf("%s://%s%s", scheme, r.Host, r.RequestURI)
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entry.Logger = entry.Logger.WithFields(logFields)
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entry.Logger.Infoln("request started")
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return entry
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}
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type StructuredLoggerEntry struct {
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Logger logrus.FieldLogger
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}
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func (l *StructuredLoggerEntry) Write(status, bytes int, elapsed time.Duration) {
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l.Logger = l.Logger.WithFields(logrus.Fields{
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"resp_status": status, "resp_bytes_length": bytes,
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"resp_elapsed_ms": float64(elapsed.Nanoseconds()) / 1000000.0,
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})
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l.Logger.Infoln("request complete")
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}
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func (l *StructuredLoggerEntry) Panic(v interface{}, stack []byte) {
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l.Logger = l.Logger.WithFields(logrus.Fields{
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"stack": string(stack),
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"panic": fmt.Sprintf("%+v", v),
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})
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}
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// Helper methods used by the application to get the request-scoped
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// logger entry and set additional fields between handlers.
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//
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// This is a useful pattern to use to set state on the entry as it
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// passes through the handler chain, which at any point can be logged
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// with a call to .Print(), .Info(), etc.
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func GetLogEntry(r *http.Request) logrus.FieldLogger {
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entry := middleware.GetLogEntry(r).(*StructuredLoggerEntry)
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return entry.Logger
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}
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func LogEntrySetField(r *http.Request, key string, value interface{}) {
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if entry, ok := r.Context().Value(middleware.LogEntryCtxKey).(*StructuredLoggerEntry); ok {
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entry.Logger = entry.Logger.WithField(key, value)
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}
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}
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func LogEntrySetFields(r *http.Request, fields map[string]interface{}) {
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if entry, ok := r.Context().Value(middleware.LogEntryCtxKey).(*StructuredLoggerEntry); ok {
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entry.Logger = entry.Logger.WithFields(fields)
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}
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}
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