config dump endpoint for proxy

ocis-pkg/service/debug/option.go

@@ -20,6 +20,7 @@ type Options struct {
 	Zpages               bool
 	Health               func(http.ResponseWriter, *http.Request)
 	Ready                func(http.ResponseWriter, *http.Request)
+	ConfigDump           func(http.ResponseWriter, *http.Request)
 	CorsAllowedOrigins   []string
 	CorsAllowedMethods   []string
 	CorsAllowedHeaders   []string
@@ -100,6 +101,13 @@ func Ready(r func(http.ResponseWriter, *http.Request)) Option {
 	}
 }
 
+// ConfigDump to be documented.
+func ConfigDump(r func(http.ResponseWriter, *http.Request)) Option {
+	return func(o *Options) {
+		o.ConfigDump = r
+	}
+}
+
 // CorsAllowedOrigins provides a function to set the CorsAllowedOrigin option.
 func CorsAllowedOrigins(origins []string) Option {
 	return func(o *Options) {

ocis-pkg/service/debug/service.go

@@ -28,6 +28,10 @@ func NewService(opts ...Option) *http.Server {
 	mux.HandleFunc("/healthz", dopts.Health)
 	mux.HandleFunc("/readyz", dopts.Ready)
 
+	if dopts.ConfigDump != nil {
+		mux.HandleFunc("/config", dopts.ConfigDump)
+	}
+
 	if dopts.Pprof {
 		mux.HandleFunc("/debug/pprof/", pprof.Index)
 		mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)

proxy/pkg/server/debug/server.go

@@ -1,6 +1,7 @@
 package debug
 
 import (
+	"encoding/json"
 	"io"
 	"net/http"
 
@@ -22,6 +23,7 @@ func Server(opts ...Option) (*http.Server, error) {
 		debug.Zpages(options.Config.Debug.Zpages),
 		debug.Health(health(options.Config)),
 		debug.Ready(ready(options.Config)),
+		debug.ConfigDump(configDump(options.Config)),
 	), nil
 }
 
@@ -52,3 +54,17 @@ func ready(cfg *config.Config) func(http.ResponseWriter, *http.Request) {
 		}
 	}
 }
+
+// configDump implements the config dump
+func configDump(cfg *config.Config) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+
+		b, err := json.Marshal(cfg)
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+		}
+
+		_, _ = w.Write(b)
+	}
+}