feat: init support hgctl (#273)

Signed-off-by: bitliu <bitliu@tencent.com>

pkg/cmd/version/version.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2022 Alibaba Group Holding Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package version
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"sigs.k8s.io/yaml"
+)
+
+type Info struct {
+	Type           string `json:"type,omitempty" yaml:"type,omitempty"`
+	HigressVersion string `json:"higressVersion,omitempty" yaml:"higressVersion,omitempty"`
+	GitCommitID    string `json:"gitCommitID,omitempty" yaml:"gitCommitID,omitempty"`
+	GatewayVersion string `json:"gatewayVersion,omitempty" yaml:"gatewayVersion,omitempty"`
+}
+
+func Get() Info {
+	return Info{
+		HigressVersion: higressVersion,
+		GitCommitID:    gitCommitID,
+	}
+}
+
+var (
+	higressVersion string
+	gitCommitID    string
+)
+
+// Print shows the versions of the Envoy Gateway.
+func Print(w io.Writer, format string) error {
+	v := Get()
+	switch format {
+	case "json":
+		if marshalled, err := json.MarshalIndent(v, "", "  "); err == nil {
+			_, _ = fmt.Fprintln(w, string(marshalled))
+		}
+	case "yaml":
+		if marshalled, err := yaml.Marshal(v); err == nil {
+			_, _ = fmt.Fprintln(w, string(marshalled))
+		}
+	default:
+		_, _ = fmt.Fprintf(w, "HIGRESS_VERSION: %s\n", v.HigressVersion)
+		_, _ = fmt.Fprintf(w, "GIT_COMMIT_ID: %s\n", v.GitCommitID)
+	}
+
+	return nil
+}