72 lines
2.2 KiB
Go
72 lines
2.2 KiB
Go
package middleware
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import (
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"context"
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"net/http"
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"time"
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chi_middleware "github.com/go-chi/chi/v5/middleware"
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"golang.org/x/exp/slog"
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)
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// Slogger is a slog-enabled logging middleware.
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// It logs the start and end of the request, and logs info
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// about the request itself, response status, and response time.
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// Slogger returns a log handler that uses the given slog logger as the base.
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func Slogger(sl *slog.Logger) func(next http.Handler) http.Handler {
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logger := sl.WithGroup("http")
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return func(next http.Handler) http.Handler {
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// this triple-nested function is strange, but basically the Slogger() call makes a new middleware function (above)
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// the middleware function returns a handler that calls the next handler in the chain(wrapping it)
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fn := func(w http.ResponseWriter, r *http.Request) {
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// wrap writer allows us to get info on the response from further handlers.
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ww := chi_middleware.NewWrapResponseWriter(w, r.ProtoMajor)
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t1 := time.Now()
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// attrs is stored to allow for the helpers to add additional elements to the main record.
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attrs := make([]slog.Attr, 0)
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// This function runs at the end and adds all the response details to the attrs before logging them.
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defer func() {
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attrs = append(attrs, slog.Int("status_code", ww.Status()))
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attrs = append(attrs, slog.Int("resp_size", ww.BytesWritten()))
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attrs = append(attrs, slog.Duration("duration", time.Since(t1)))
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attrs = append(attrs, slog.String("method", r.Method))
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logger.LogAttrs(r.Context(), slog.LevelInfo, r.RequestURI, attrs...)
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}()
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// embed the logger and the attrs for later items in the chain.
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ctx := context.WithValue(r.Context(), SloggerAttrsKey, attrs)
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ctx = context.WithValue(ctx, SloggerLogKey, logger)
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// push it to the request and serve the next handler
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r = r.WithContext(ctx)
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next.ServeHTTP(ww, r)
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}
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return http.HandlerFunc(fn)
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}
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}
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type slogKeyType int
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const (
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SloggerLogKey slogKeyType = iota
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SloggerAttrsKey
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)
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func AddSlogAttr(r *http.Request, attr slog.Attr) {
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ctx := r.Context()
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attrs, ok := ctx.Value(SloggerAttrsKey).([]slog.Attr)
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if !ok {
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return
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}
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attrs = append(attrs, attr)
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}
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// TODO: write rest of functions
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