Documentation
¶
Overview ¶
Package hlog provides a set of http.Handler helpers for zerolog.
Example (Handler) ¶
//go:build !binary_log
// +build !binary_log
package main
import (
"net/http"
"os"
"time"
"net/http/httptest"
"github.com/rs/zerolog"
"github.com/rs/zerolog/hlog"
)
// fake alice to avoid dep
type middleware func(http.Handler) http.Handler
type alice struct {
m []middleware
}
func (a alice) Append(m middleware) alice {
a.m = append(a.m, m)
return a
}
func (a alice) Then(h http.Handler) http.Handler {
for i := range a.m {
h = a.m[len(a.m)-1-i](h)
}
return h
}
func init() {
zerolog.TimestampFunc = func() time.Time {
return time.Date(2001, time.February, 3, 4, 5, 6, 7, time.UTC)
}
}
func main() {
log := zerolog.New(os.Stdout).With().
Timestamp().
Str("role", "my-service").
Str("host", "local-hostname").
Logger()
c := alice{}
// Install the logger handler with default output on the console
c = c.Append(hlog.NewHandler(log))
// Install some provided extra handlers to set some request's context fields.
// Thanks to those handlers, all our logs will come with some pre-populated fields.
c = c.Append(hlog.RemoteAddrHandler("ip"))
c = c.Append(hlog.UserAgentHandler("user_agent"))
c = c.Append(hlog.RefererHandler("referer"))
//c = c.Append(hlog.RequestIDHandler("req_id", "Request-Id"))
// Here is your final handler
h := c.Then(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Get the logger from the request's context. You can safely assume it
// will be always there: if the handler is removed, hlog.FromRequest
// will return a no-op logger.
hlog.FromRequest(r).Info().
Str("user", "current user").
Str("status", "ok").
Msg("Something happened")
}))
http.Handle("/", h)
h.ServeHTTP(httptest.NewRecorder(), &http.Request{})
}
Output: {"level":"info","role":"my-service","host":"local-hostname","user":"current user","status":"ok","time":"2001-02-03T04:05:06Z","message":"Something happened"}
Index ¶
- func AccessHandler(f func(r *http.Request, status, size int, duration time.Duration)) func(next http.Handler) http.Handler
- func CtxWithID(ctx context.Context, id xid.ID) context.Context
- func CustomHeaderHandler(fieldKey, header string) func(next http.Handler) http.Handler
- func EtagHandler(fieldKey string) func(next http.Handler) http.Handler
- func FromRequest(r *http.Request) *zerolog.Logger
- func HTTPVersionHandler(fieldKey string) func(next http.Handler) http.Handler
- func HostHandler(fieldKey string, trimPort ...bool) func(next http.Handler) http.Handler
- func IDFromCtx(ctx context.Context) (id xid.ID, ok bool)
- func IDFromRequest(r *http.Request) (id xid.ID, ok bool)
- func MethodHandler(fieldKey string) func(next http.Handler) http.Handler
- func NewHandler(log zerolog.Logger) func(http.Handler) http.Handler
- func ProtoHandler(fieldKey string) func(next http.Handler) http.Handler
- func RefererHandler(fieldKey string) func(next http.Handler) http.Handler
- func RemoteAddrHandler(fieldKey string) func(next http.Handler) http.Handler
- func RemoteIPHandler(fieldKey string) func(next http.Handler) http.Handler
- func RequestHandler(fieldKey string) func(next http.Handler) http.Handler
- func RequestIDHandler(fieldKey, headerName string) func(next http.Handler) http.Handler
- func ResponseHeaderHandler(fieldKey, headerName string) func(next http.Handler) http.Handler
- func URLHandler(fieldKey string) func(next http.Handler) http.Handler
- func UserAgentHandler(fieldKey string) func(next http.Handler) http.Handler
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func AccessHandler ¶
func AccessHandler(f func(r *http.Request, status, size int, duration time.Duration)) func(next http.Handler) http.Handler
AccessHandler returns a handler that call f after each request.
func CustomHeaderHandler ¶
CustomHeaderHandler adds given header from request's header as a field to the context's logger using fieldKey as field key.
func EtagHandler ¶
EtagHandler adds Etag header from response's header as a field to the context's logger using fieldKey as field key.
func FromRequest ¶
FromRequest gets the logger in the request's context. This is a shortcut for log.Ctx(r.Context())
func HTTPVersionHandler ¶
HTTPVersionHandler is similar to ProtoHandler, but it does not store the "HTTP/" prefix in the protocol name.
func HostHandler ¶
HostHandler adds the request's host as a field to the context's logger using fieldKey as field key. If trimPort is set to true, then port is removed from the host.
func IDFromRequest ¶
IDFromRequest returns the unique id associated to the request if any.
func MethodHandler ¶
MethodHandler adds the request method as a field to the context's logger using fieldKey as field key.
func NewHandler ¶
NewHandler injects log into requests context.
func ProtoHandler ¶
ProtoHandler adds the requests protocol version as a field to the context logger using fieldKey as field Key.
func RefererHandler ¶
RefererHandler adds the request's referer as a field to the context's logger using fieldKey as field key.
func RemoteAddrHandler ¶
RemoteAddrHandler adds the request's remote address as a field to the context's logger using fieldKey as field key.
func RemoteIPHandler ¶
RemoteIPHandler is similar to RemoteAddrHandler, but logs only an IP, not a port.
func RequestHandler ¶
RequestHandler adds the request method and URL as a field to the context's logger using fieldKey as field key.
func RequestIDHandler ¶
RequestIDHandler returns a handler setting a unique id to the request which can be gathered using IDFromRequest(req). This generated id is added as a field to the logger using the passed fieldKey as field name. The id is also added as a response header if the headerName is not empty.
The generated id is a URL safe base64 encoded mongo object-id-like unique id. Mongo unique id generation algorithm has been selected as a trade-off between size and ease of use: UUID is less space efficient and snowflake requires machine configuration.
func ResponseHeaderHandler ¶
func URLHandler ¶
URLHandler adds the requested URL as a field to the context's logger using fieldKey as field key.
Types ¶
This section is empty.
Source Files
Directories