154 lines
4.4 KiB
Go
154 lines
4.4 KiB
Go
/*
|
|
Copyright 2018 the Velero contributors.
|
|
|
|
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 clientmgmt
|
|
|
|
import (
|
|
"strings"
|
|
|
|
plugin "github.com/hashicorp/go-plugin"
|
|
"github.com/pkg/errors"
|
|
"github.com/sirupsen/logrus"
|
|
|
|
"github.com/vmware-tanzu/velero/pkg/plugin/framework"
|
|
)
|
|
|
|
type ProcessFactory interface {
|
|
newProcess(command string, logger logrus.FieldLogger, logLevel logrus.Level) (Process, error)
|
|
}
|
|
|
|
type processFactory struct {
|
|
}
|
|
|
|
func newProcessFactory() ProcessFactory {
|
|
return &processFactory{}
|
|
}
|
|
|
|
func (pf *processFactory) newProcess(command string, logger logrus.FieldLogger, logLevel logrus.Level) (Process, error) {
|
|
return newProcess(command, logger, logLevel)
|
|
}
|
|
|
|
type Process interface {
|
|
dispense(key kindAndName) (interface{}, error)
|
|
exited() bool
|
|
kill()
|
|
}
|
|
|
|
type process struct {
|
|
client *plugin.Client
|
|
protocolClient plugin.ClientProtocol
|
|
}
|
|
|
|
func newProcess(command string, logger logrus.FieldLogger, logLevel logrus.Level) (Process, error) {
|
|
builder := newClientBuilder(command, logger.WithField("cmd", command), logLevel)
|
|
|
|
// This creates a new go-plugin Client that has its own unique exec.Cmd for launching the plugin process.
|
|
client := builder.client()
|
|
|
|
// This launches the plugin process.
|
|
protocolClient, err := client.Client()
|
|
if err != nil {
|
|
if !strings.Contains(err.Error(), "unknown flag: --features") {
|
|
return nil, err
|
|
}
|
|
|
|
// Velero started passing the --features flag to plugins in v1.2, however existing plugins
|
|
// may not support that flag and may not silently ignore unknown flags. The plugin server
|
|
// code that we make available to plugin authors has since been updated to ignore unknown
|
|
// flags, but to avoid breaking plugins that haven't updated to that code and don't support
|
|
// the --features flag, we specifically handle not passing the flag if we can detect that
|
|
// it's not supported.
|
|
|
|
logger.Debug("Plugin process does not support the --features flag, removing it and trying again")
|
|
|
|
builder.commandArgs = removeFeaturesFlag(builder.commandArgs)
|
|
|
|
logger.Debugf("Updated command args after removing --features flag: %v", builder.commandArgs)
|
|
|
|
// re-get the client and protocol client now that --features has been removed
|
|
// from the command args.
|
|
client = builder.client()
|
|
protocolClient, err = client.Client()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
logger.Debug("Plugin process successfully started without the --features flag")
|
|
}
|
|
|
|
p := &process{
|
|
client: client,
|
|
protocolClient: protocolClient,
|
|
}
|
|
|
|
return p, nil
|
|
}
|
|
|
|
// removeFeaturesFlag looks for and removes the '--features' arg
|
|
// as well as the arg immediately following it (the flag value).
|
|
func removeFeaturesFlag(args []string) []string {
|
|
var commandArgs []string
|
|
var featureFlag bool
|
|
|
|
for _, arg := range args {
|
|
// if this arg is the flag name, skip it
|
|
if arg == "--features" {
|
|
featureFlag = true
|
|
continue
|
|
}
|
|
|
|
// if the last arg we saw was the flag name, then
|
|
// this arg is the value for the flag, so skip it
|
|
if featureFlag {
|
|
featureFlag = false
|
|
continue
|
|
}
|
|
|
|
// otherwise, keep the arg
|
|
commandArgs = append(commandArgs, arg)
|
|
}
|
|
|
|
return commandArgs
|
|
}
|
|
|
|
func (r *process) dispense(key kindAndName) (interface{}, error) {
|
|
// This calls GRPCClient(clientConn) on the plugin instance registered for key.name.
|
|
dispensed, err := r.protocolClient.Dispense(key.kind.String())
|
|
if err != nil {
|
|
return nil, errors.WithStack(err)
|
|
}
|
|
|
|
// Currently all plugins except for PluginLister dispense clientDispenser instances.
|
|
if clientDispenser, ok := dispensed.(framework.ClientDispenser); ok {
|
|
if key.name == "" {
|
|
return nil, errors.Errorf("%s plugin requested but name is missing", key.kind.String())
|
|
}
|
|
// Get the instance that implements our plugin interface (e.g. ObjectStore) that is a gRPC-based
|
|
// client
|
|
dispensed = clientDispenser.ClientFor(key.name)
|
|
}
|
|
|
|
return dispensed, nil
|
|
}
|
|
|
|
func (r *process) exited() bool {
|
|
return r.client.Exited()
|
|
}
|
|
|
|
func (r *process) kill() {
|
|
r.client.Kill()
|
|
}
|