Aleksey Shakhmatov
cea75d198b
Introduces server/ sub-package as the server-side companion to the existing Client. Includes Router (over http.ServeMux with groups and mounting), graceful shutdown with signal handling, health endpoints (/healthz, /readyz), and built-in middlewares (RequestID, Recovery, Logging). Zero external dependencies. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
53 lines
1.4 KiB
Go
53 lines
1.4 KiB
Go
package server
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import (
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"context"
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"crypto/rand"
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"fmt"
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"net/http"
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)
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type requestIDKey struct{}
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// RequestID returns a middleware that assigns a unique request ID to each
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// request. If the incoming request already has an X-Request-Id header, that
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// value is used. Otherwise a new UUID v4 is generated via crypto/rand.
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//
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// The request ID is stored in the request context (retrieve with
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// RequestIDFromContext) and set on the response X-Request-Id header.
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func RequestID() Middleware {
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return func(next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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id := r.Header.Get("X-Request-Id")
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if id == "" {
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id = newUUID()
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}
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ctx := context.WithValue(r.Context(), requestIDKey{}, id)
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w.Header().Set("X-Request-Id", id)
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next.ServeHTTP(w, r.WithContext(ctx))
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})
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}
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}
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// RequestIDFromContext returns the request ID from the context, or an empty
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// string if none is set.
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func RequestIDFromContext(ctx context.Context) string {
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id, _ := ctx.Value(requestIDKey{}).(string)
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return id
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}
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// newUUID generates a UUID v4 string using crypto/rand.
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func newUUID() string {
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var uuid [16]byte
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_, _ = rand.Read(uuid[:])
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// Set version 4 (bits 12-15 of time_hi_and_version).
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uuid[6] = (uuid[6] & 0x0f) | 0x40
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// Set variant bits (10xx).
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uuid[8] = (uuid[8] & 0x3f) | 0x80
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return fmt.Sprintf("%x-%x-%x-%x-%x",
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uuid[0:4], uuid[4:6], uuid[6:8], uuid[8:10], uuid[10:16])
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}
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