open-nomad/client/driver/utils.go

109 lines
3 KiB
Go

package driver
import (
"fmt"
"io"
"net"
"os"
"github.com/hashicorp/go-multierror"
"github.com/hashicorp/go-plugin"
"github.com/hashicorp/nomad/client/config"
"github.com/hashicorp/nomad/client/driver/executor"
"github.com/hashicorp/nomad/client/driver/syslog"
)
// createExecutor launches an executor plugin and returns an instance of the
// Executor interface
func createExecutor(config *plugin.ClientConfig, w io.Writer,
clientConfig *config.Config) (executor.Executor, *plugin.Client, error) {
config.HandshakeConfig = HandshakeConfig
config.Plugins = GetPluginMap(w)
config.MaxPort = clientConfig.ClientMaxPort
config.MinPort = clientConfig.ClientMinPort
// setting the setsid of the plugin process so that it doesn't get signals sent to
// the nomad client.
if config.Cmd != nil {
isolateCommand(config.Cmd)
}
executorClient := plugin.NewClient(config)
rpcClient, err := executorClient.Client()
if err != nil {
return nil, nil, fmt.Errorf("error creating rpc client for executor plugin: %v", err)
}
raw, err := rpcClient.Dispense("executor")
if err != nil {
return nil, nil, fmt.Errorf("unable to dispense the executor plugin: %v", err)
}
executorPlugin := raw.(executor.Executor)
return executorPlugin, executorClient, nil
}
func createLogCollector(config *plugin.ClientConfig, w io.Writer,
clientConfig *config.Config) (syslog.LogCollector, *plugin.Client, error) {
config.HandshakeConfig = HandshakeConfig
config.Plugins = GetPluginMap(w)
config.MaxPort = clientConfig.ClientMaxPort
config.MinPort = clientConfig.ClientMinPort
if config.Cmd != nil {
isolateCommand(config.Cmd)
}
syslogClient := plugin.NewClient(config)
rpcCLient, err := syslogClient.Client()
if err != nil {
return nil, nil, fmt.Errorf("error creating rpc client for syslog plugin: %v", err)
}
raw, err := rpcCLient.Dispense("syslogcollector")
if err != nil {
return nil, nil, fmt.Errorf("unable to dispense the syslog plugin: %v", err)
}
logCollector := raw.(syslog.LogCollector)
return logCollector, syslogClient, nil
}
// getFreePort returns a free port ready to be listened on between upper and
// lower bounds
func getFreePort(lowerBound uint, upperBound uint) (net.Addr, error) {
for i := lowerBound; i <= upperBound; i++ {
addr, err := net.ResolveTCPAddr("tcp", fmt.Sprintf("localhost:%v", i))
if err != nil {
return nil, err
}
l, err := net.ListenTCP("tcp", addr)
if err != nil {
continue
}
defer l.Close()
return l.Addr(), nil
}
return nil, fmt.Errorf("No free port found")
}
// killProcess kills a process with the given pid
func killProcess(pid int) error {
proc, err := os.FindProcess(pid)
if err != nil {
return err
}
return proc.Kill()
}
// destroyPlugin kills the plugin with the given pid and also kills the user
// process
func destroyPlugin(pluginPid int, userPid int) error {
var merr error
if err := killProcess(pluginPid); err != nil {
merr = multierror.Append(merr, err)
}
if err := killProcess(userPid); err != nil {
merr = multierror.Append(merr, err)
}
return merr
}