teleport/lib/utils/ver.go

/*
Copyright 2018 Gravitational, Inc.

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 utils

import (
	"github.com/gravitational/trace"

	"github.com/coreos/go-semver/semver"
)

// CheckVersions compares client and server versions and makes sure that the
// client version is greater than or equal to the minimum version supported
// by the server.
func CheckVersions(clientVersion, minClientVersion string) error {
	clientSemver, err := semver.NewVersion(clientVersion)
	if err != nil {
		return trace.Wrap(err, "unsupported version format, need semver format: %q, e.g 1.0.0", clientVersion)
	}

	minClientSemver, err := semver.NewVersion(minClientVersion)
	if err != nil {
		return trace.Wrap(err, "unsupported version format, need semver format: %q, e.g 1.0.0", minClientVersion)
	}

	if clientSemver.Compare(*minClientSemver) < 0 {
		return trace.BadParameter(`Detected potentially incompatible client and server versions.
Minimum client version supported by the server is %v but you are using %v.
Please upgrade tsh to %v or newer or use the --skip-version-check flag to bypass this check.`, minClientVersion, clientVersion, minClientVersion)
	}

	return nil
}