github.com/ranjib/nomad@v0.1.1-0.20160225204057-97751b02f70b/client/driver/utils.go (about)

     1  package driver
     2  
     3  import (
     4  	"fmt"
     5  	"io"
     6  	"os"
     7  	"strings"
     8  
     9  	"github.com/hashicorp/go-multierror"
    10  	"github.com/hashicorp/go-plugin"
    11  	"github.com/hashicorp/nomad/client/config"
    12  	"github.com/hashicorp/nomad/client/driver/executor"
    13  	"github.com/hashicorp/nomad/client/driver/logging"
    14  )
    15  
    16  // createExecutor launches an executor plugin and returns an instance of the
    17  // Executor interface
    18  func createExecutor(config *plugin.ClientConfig, w io.Writer,
    19  	clientConfig *config.Config) (executor.Executor, *plugin.Client, error) {
    20  	config.HandshakeConfig = HandshakeConfig
    21  	config.Plugins = GetPluginMap(w)
    22  	config.MaxPort = clientConfig.ClientMaxPort
    23  	config.MinPort = clientConfig.ClientMinPort
    24  
    25  	// setting the setsid of the plugin process so that it doesn't get signals sent to
    26  	// the nomad client.
    27  	if config.Cmd != nil {
    28  		isolateCommand(config.Cmd)
    29  	}
    30  
    31  	executorClient := plugin.NewClient(config)
    32  	rpcClient, err := executorClient.Client()
    33  	if err != nil {
    34  		return nil, nil, fmt.Errorf("error creating rpc client for executor plugin: %v", err)
    35  	}
    36  
    37  	raw, err := rpcClient.Dispense("executor")
    38  	if err != nil {
    39  		return nil, nil, fmt.Errorf("unable to dispense the executor plugin: %v", err)
    40  	}
    41  	executorPlugin := raw.(executor.Executor)
    42  	return executorPlugin, executorClient, nil
    43  }
    44  
    45  func createLogCollector(config *plugin.ClientConfig, w io.Writer,
    46  	clientConfig *config.Config) (logging.LogCollector, *plugin.Client, error) {
    47  	config.HandshakeConfig = HandshakeConfig
    48  	config.Plugins = GetPluginMap(w)
    49  	config.MaxPort = clientConfig.ClientMaxPort
    50  	config.MinPort = clientConfig.ClientMinPort
    51  	if config.Cmd != nil {
    52  		isolateCommand(config.Cmd)
    53  	}
    54  
    55  	syslogClient := plugin.NewClient(config)
    56  	rpcCLient, err := syslogClient.Client()
    57  	if err != nil {
    58  		return nil, nil, fmt.Errorf("error creating rpc client for syslog plugin: %v", err)
    59  	}
    60  
    61  	raw, err := rpcCLient.Dispense("syslogcollector")
    62  	if err != nil {
    63  		return nil, nil, fmt.Errorf("unable to dispense the syslog plugin: %v", err)
    64  	}
    65  	logCollector := raw.(logging.LogCollector)
    66  	return logCollector, syslogClient, nil
    67  }
    68  
    69  // killProcess kills a process with the given pid
    70  func killProcess(pid int) error {
    71  	proc, err := os.FindProcess(pid)
    72  	if err != nil {
    73  		return err
    74  	}
    75  	return proc.Kill()
    76  }
    77  
    78  // destroyPlugin kills the plugin with the given pid and also kills the user
    79  // process
    80  func destroyPlugin(pluginPid int, userPid int) error {
    81  	var merr error
    82  	if err := killProcess(pluginPid); err != nil {
    83  		merr = multierror.Append(merr, err)
    84  	}
    85  
    86  	if err := killProcess(userPid); err != nil {
    87  		merr = multierror.Append(merr, err)
    88  	}
    89  	return merr
    90  }
    91  
    92  // validateCommand validates that the command only has a single value and
    93  // returns a user friendly error message telling them to use the passed
    94  // argField.
    95  func validateCommand(command, argField string) error {
    96  	trimmed := strings.TrimSpace(command)
    97  	if len(trimmed) == 0 {
    98  		return fmt.Errorf("command empty: %q", command)
    99  	}
   100  
   101  	if len(trimmed) != len(command) {
   102  		return fmt.Errorf("command contains extra white space: %q", command)
   103  	}
   104  
   105  	split := strings.Split(trimmed, " ")
   106  	if len(split) != 1 {
   107  		return fmt.Errorf("command contained more than one input. Use %q field to pass arguments", argField)
   108  	}
   109  
   110  	return nil
   111  }