feat(api): add /version endpoint

Fixes #3332

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Added a dedicated API endpoint for overview modal.
 - Individual alert details are now lazy-loaded to improve performance
   when dealing with a huge number of alerts per group.
+- Added `/version` endpoint returning karma and Go runtime version #3332.
 
 ### Changed
 

cmd/karma/main.go

@@ -114,6 +114,7 @@ func setupRouter(router *chi.Mux, historyPoller *historyPoller) {
 	allowAuthBypass := []string{
 		getViewURL("/health"),
 		getViewURL("/metrics"),
+		getViewURL("/version"),
 	}
 	if config.Config.Authentication.Header.Name != "" {
 		config.Config.Authentication.Enabled = true
@@ -131,6 +132,7 @@ func setupRouter(router *chi.Mux, historyPoller *historyPoller) {
 		router.Get(getViewURL(""), redirectIndex)
 	}
 	router.Get(getViewURL("/"), index)
+	router.Get(getViewURL("/version"), versionHandler)
 	router.Get(getViewURL("/health"), pong)
 	router.Get(getViewURL("/robots.txt"), robots)
 	router.Get(getViewURL("/metrics"), http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

cmd/karma/views.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"runtime"
 	"sort"
 	"strings"
 	"time"
@@ -39,6 +40,20 @@ func badRequestJSON(w http.ResponseWriter, error string) {
 	_, _ = w.Write(out)
 }
 
+type KarmaVersion struct {
+	Version string `json:"version"`
+	Golang  string `json:"golang"`
+}
+
+func versionHandler(w http.ResponseWriter, r *http.Request) {
+	ver := KarmaVersion{
+		Version: version,
+		Golang:  runtime.Version(),
+	}
+	data, _ := json.MarshalIndent(ver, "", "  ")
+	_, _ = w.Write(data)
+}
+
 func pong(w http.ResponseWriter, r *http.Request) {
 	_, _ = w.Write([]byte("Pong\n"))
 }

cmd/karma/views_test.go

@@ -89,6 +89,18 @@ func TestRobots(t *testing.T) {
 	}
 }
 
+func TestVersion(t *testing.T) {
+	mockConfig()
+	r := testRouter()
+	setupRouter(r, nil)
+	req := httptest.NewRequest("GET", "/version", nil)
+	resp := httptest.NewRecorder()
+	r.ServeHTTP(resp, req)
+	if resp.Code != http.StatusOK {
+		t.Errorf("GET /version returned status %d", resp.Code)
+	}
+}
+
 func TestHealthPrefix(t *testing.T) {
 	os.Setenv("LISTEN_PREFIX", "/prefix")
 	defer os.Unsetenv("LISTEN_PREFIX")