feat: expose interLink server version via API

cmd/interlink/main.go

@@ -193,6 +193,7 @@ func main() {
 	mutex.HandleFunc("/pinglink", interLinkAPIs.Ping)
 	mutex.HandleFunc("/getLogs", interLinkAPIs.GetLogsHandler)
 	mutex.HandleFunc("/updateCache", interLinkAPIs.UpdateCacheHandler)
+	mutex.HandleFunc("/version", api.VersionHandler(interlink.Version))
 
 	interLinkEndpoint := ""
 	switch {

cmd/virtual-kubelet/set-version.sh

@@ -8,4 +8,9 @@ var (
 	KubeletVersion = "$KUBELET_VERSION"
 )
 EOF
+cat << EOF > pkg/interlink/version.go
+package interlink
+
+var Version = "$KUBELET_VERSION"
+EOF
 fi

pkg/interlink/api/version.go

@@ -0,0 +1,24 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+// VersionHandler reports the version of the running interLink server.
+func VersionHandler(version string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			w.Header().Set("Allow", http.MethodGet)
+			w.WriteHeader(http.StatusMethodNotAllowed)
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		if err := json.NewEncoder(w).Encode(struct {
+			Version string `json:"version"`
+		}{Version: version}); err != nil {
+			return
+		}
+	}
+}

pkg/interlink/api/version_test.go

@@ -0,0 +1,30 @@
+package api
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestVersionHandlerReturnsRunningVersion(t *testing.T) {
+	recorder := httptest.NewRecorder()
+	request := httptest.NewRequest(http.MethodGet, "/version", nil)
+
+	VersionHandler("1.2.3").ServeHTTP(recorder, request)
+
+	require.Equal(t, http.StatusOK, recorder.Code)
+	require.Equal(t, "application/json", recorder.Header().Get("Content-Type"))
+	require.JSONEq(t, `{"version":"1.2.3"}`, recorder.Body.String())
+}
+
+func TestVersionHandlerRejectsNonGetRequests(t *testing.T) {
+	recorder := httptest.NewRecorder()
+	request := httptest.NewRequest(http.MethodPost, "/version", nil)
+
+	VersionHandler("1.2.3").ServeHTTP(recorder, request)
+
+	require.Equal(t, http.StatusMethodNotAllowed, recorder.Code)
+	require.Equal(t, http.MethodGet, recorder.Header().Get("Allow"))
+}

pkg/interlink/version.go

@@ -0,0 +1,4 @@
+package interlink
+
+// Version is the version of the running interLink server.
+var Version = "test"