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>
56 lines
1.4 KiB
Go
56 lines
1.4 KiB
Go
package server
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import (
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"encoding/json"
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"net/http"
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)
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// ReadinessChecker is a function that reports whether a dependency is ready.
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// Return nil if healthy, or an error describing the problem.
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type ReadinessChecker func() error
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// HealthHandler returns an http.Handler that exposes liveness and readiness
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// endpoints:
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//
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// - GET /healthz — liveness check, always returns 200 OK
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// - GET /readyz — readiness check, returns 200 if all checkers pass, 503 otherwise
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func HealthHandler(checkers ...ReadinessChecker) http.Handler {
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mux := http.NewServeMux()
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mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, _ *http.Request) {
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w.Header().Set("Content-Type", "application/json")
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w.WriteHeader(http.StatusOK)
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_ = json.NewEncoder(w).Encode(healthResponse{Status: "ok"})
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})
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mux.HandleFunc("GET /readyz", func(w http.ResponseWriter, _ *http.Request) {
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w.Header().Set("Content-Type", "application/json")
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var errs []string
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for _, check := range checkers {
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if err := check(); err != nil {
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errs = append(errs, err.Error())
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}
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}
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if len(errs) > 0 {
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w.WriteHeader(http.StatusServiceUnavailable)
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_ = json.NewEncoder(w).Encode(healthResponse{
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Status: "unavailable",
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Errors: errs,
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})
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return
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}
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w.WriteHeader(http.StatusOK)
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_ = json.NewEncoder(w).Encode(healthResponse{Status: "ok"})
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})
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return mux
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}
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type healthResponse struct {
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Status string `json:"status"`
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Errors []string `json:"errors,omitempty"`
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}
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