Add version output to CLIs

This change adds version output to the nvidia-continer-runtime,
nvidia-container-toolkit, and nvidia-ctk CLIs. The same version
is used in all cases and includes a version string and a git
revision if set.

The construction of the version string mirrors what is done in runc.

Signed-off-by: Evan Lezar <elezar@nvidia.com>

internal/info/version.go

@@ -0,0 +1,43 @@
+/**
+# Copyright (c) 2022, NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 info
+
+import "strings"
+
+// version must be set by go build's -X main.version= option in the Makefile.
+var version = "unknown"
+
+// gitCommit will be the hash that the binary was built from
+// and will be populated by the Makefile
+var gitCommit = ""
+
+// GetVersionParts returns the different version components
+func GetVersionParts() []string {
+	v := []string{version}
+
+	if gitCommit != "" {
+		v = append(v, "commit: "+gitCommit)
+	}
+
+	return v
+}
+
+// GetVersionString returns the string representation of the version
+func GetVersionString(more ...string) string {
+	v := append(GetVersionParts(), more...)
+	return strings.Join(v, "\n")
+}