Merge pull request #5726 from hashicorp/b-plugins-via-init

Use init() to handle plugin invocation

client/logmon/plugin.go

@@ -2,12 +2,12 @@ package logmon
 
 import (
 	"context"
+	"os"
 	"os/exec"
 
 	hclog "github.com/hashicorp/go-hclog"
 	plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/nomad/client/logmon/proto"
-	"github.com/hashicorp/nomad/helper/discover"
 	"github.com/hashicorp/nomad/plugins/base"
 	"google.golang.org/grpc"
 )
@@ -16,7 +16,7 @@ import (
 // TODO: Integrate with base plugin loader
 func LaunchLogMon(logger hclog.Logger, reattachConfig *plugin.ReattachConfig) (LogMon, *plugin.Client, error) {
 	logger = logger.Named("logmon")
-	bin, err := discover.NomadExecutable()
+	bin, err := os.Executable()
 	if err != nil {
 		return nil, nil, err
 	}

client/logmon/z_logmon_cmd.go

+package logmon
+
+import (
+	"os"
+
+	hclog "github.com/hashicorp/go-hclog"
+	plugin "github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/nomad/plugins/base"
+)
+
+// Install a plugin cli handler to ease working with tests
+// and external plugins.
+// This init() must be initialized last in package required by the child plugin
+// process. It's recommended to avoid any other `init()` or inline any necessary calls
+// here. See eeaa95d commit message for more details.
+func init() {
+	if len(os.Args) > 1 && os.Args[1] == "logmon" {
+		logger := hclog.New(&hclog.LoggerOptions{
+			Level:      hclog.Trace,
+			JSONFormat: true,
+			Name:       "logmon",
+		})
+		plugin.Serve(&plugin.ServeConfig{
+			HandshakeConfig: base.Handshake,
+			Plugins: map[string]plugin.Plugin{
+				"logmon": NewPlugin(NewLogMon(logger)),
+			},
+			GRPCServer: plugin.DefaultGRPCServer,
+			Logger:     logger,
+		})
+		os.Exit(0)
+	}
+}

command/commands.go

@@ -5,7 +5,6 @@ import (
 	"os"
 
 	"github.com/hashicorp/nomad/command/agent"
-	"github.com/hashicorp/nomad/drivers/docker/docklog"
 	"github.com/hashicorp/nomad/version"
 	colorable "github.com/mattn/go-colorable"
 	"github.com/mitchellh/cli"
@@ -237,11 +236,6 @@ func Commands(metaPtr *Meta, agentUi cli.Ui) map[string]cli.CommandFactory {
 				Meta: meta,
 			}, nil
 		},
-		docklog.PluginName: func() (cli.Command, error) {
-			return &DockerLoggerPluginCommand{
-				Meta: meta,
-			}, nil
-		},
 		"eval": func() (cli.Command, error) {
 			return &EvalCommand{
 				Meta: meta,
@@ -262,11 +256,6 @@ func Commands(metaPtr *Meta, agentUi cli.Ui) map[string]cli.CommandFactory {
 				Meta: meta,
 			}, nil
 		},
-		"executor": func() (cli.Command, error) {
-			return &ExecutorPluginCommand{
-				Meta: meta,
-			}, nil
-		},
 		"fs": func() (cli.Command, error) {
 			return &AllocFSCommand{
 				Meta: meta,
@@ -372,11 +361,6 @@ func Commands(metaPtr *Meta, agentUi cli.Ui) map[string]cli.CommandFactory {
 				Meta: meta,
 			}, nil
 		},
-		"logmon": func() (cli.Command, error) {
-			return &LogMonPluginCommand{
-				Meta: meta,
-			}, nil
-		},
 		"logs": func() (cli.Command, error) {
 			return &AllocLogsCommand{
 				Meta: meta,

command/docker_logger_plugin.go

-package command
-
-import (
-	"strings"
-
-	log "github.com/hashicorp/go-hclog"
-	plugin "github.com/hashicorp/go-plugin"
-	"github.com/hashicorp/nomad/drivers/docker/docklog"
-	"github.com/hashicorp/nomad/plugins/base"
-)
-
-type DockerLoggerPluginCommand struct {
-	Meta
-}
-
-func (e *DockerLoggerPluginCommand) Help() string {
-	helpText := `
-	This is a command used by Nomad internally to launch the docker logger process"
-	`
-	return strings.TrimSpace(helpText)
-}
-
-func (e *DockerLoggerPluginCommand) Synopsis() string {
-	return "internal - launch a docker logger plugin"
-}
-
-func (e *DockerLoggerPluginCommand) Run(args []string) int {
-	logger := log.New(&log.LoggerOptions{
-		Level:      log.Trace,
-		JSONFormat: true,
-		Name:       docklog.PluginName,
-	})
-
-	plugin.Serve(&plugin.ServeConfig{
-		HandshakeConfig: base.Handshake,
-		Plugins: map[string]plugin.Plugin{
-			docklog.PluginName: docklog.NewPlugin(docklog.NewDockerLogger(logger)),
-		},
-		GRPCServer: plugin.DefaultGRPCServer,
-		Logger:     logger,
-	})
-	return 0
-}

command/executor_plugin.go

-package command
-
-import (
-	"encoding/json"
-	"os"
-	"strings"
-
-	hclog "github.com/hashicorp/go-hclog"
-	log "github.com/hashicorp/go-hclog"
-	plugin "github.com/hashicorp/go-plugin"
-
-	"github.com/hashicorp/nomad/drivers/shared/executor"
-	"github.com/hashicorp/nomad/plugins/base"
-)
-
-type ExecutorPluginCommand struct {
-	Meta
-}
-
-func (e *ExecutorPluginCommand) Help() string {
-	helpText := `
-	This is a command used by Nomad internally to launch an executor plugin"
-	`
-	return strings.TrimSpace(helpText)
-}
-
-func (e *ExecutorPluginCommand) Synopsis() string {
-	return "internal - launch an executor plugin"
-}
-
-func (e *ExecutorPluginCommand) Run(args []string) int {
-	if len(args) != 1 {
-		e.Ui.Error("json configuration not provided")
-		return 1
-	}
-
-	config := args[0]
-	var executorConfig executor.ExecutorConfig
-	if err := json.Unmarshal([]byte(config), &executorConfig); err != nil {
-		return 1
-	}
-
-	f, err := os.OpenFile(executorConfig.LogFile, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0666)
-	if err != nil {
-		e.Ui.Error(err.Error())
-		return 1
-	}
-
-	// Create the logger
-	logger := log.New(&log.LoggerOptions{
-		Level:      hclog.LevelFromString(executorConfig.LogLevel),
-		JSONFormat: true,
-		Output:     f,
-	})
-
-	plugin.Serve(&plugin.ServeConfig{
-		HandshakeConfig: base.Handshake,
-		Plugins: executor.GetPluginMap(
-			logger,
-			executorConfig.FSIsolation,
-		),
-		GRPCServer: plugin.DefaultGRPCServer,
-		Logger:     logger,
-	})
-	return 0
-}

command/logmon_plugin.go

-package command
-
-import (
-	"strings"
-
-	hclog "github.com/hashicorp/go-hclog"
-	plugin "github.com/hashicorp/go-plugin"
-	"github.com/hashicorp/nomad/client/logmon"
-	"github.com/hashicorp/nomad/plugins/base"
-)
-
-type LogMonPluginCommand struct {
-	Meta
-}
-
-func (e *LogMonPluginCommand) Help() string {
-	helpText := `
-	This is a command used by Nomad internally to launch the logmon process"
-	`
-	return strings.TrimSpace(helpText)
-}
-
-func (e *LogMonPluginCommand) Synopsis() string {
-	return "internal - launch a logmon plugin"
-}
-
-func (e *LogMonPluginCommand) Run(args []string) int {
-	logger := hclog.New(&hclog.LoggerOptions{
-		Level:      hclog.Trace,
-		JSONFormat: true,
-		Name:       "logmon",
-	})
-	plugin.Serve(&plugin.ServeConfig{
-		HandshakeConfig: base.Handshake,
-		Plugins: map[string]plugin.Plugin{
-			"logmon": logmon.NewPlugin(logmon.NewLogMon(logger)),
-		},
-		GRPCServer: plugin.DefaultGRPCServer,
-		Logger:     logger,
-	})
-	return 0
-}

drivers/docker/docklog/plugin.go

@@ -2,12 +2,12 @@ package docklog
 
 import (
 	"context"
+	"os"
 	"os/exec"
 
 	hclog "github.com/hashicorp/go-hclog"
 	plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/nomad/drivers/docker/docklog/proto"
-	"github.com/hashicorp/nomad/helper/discover"
 	"github.com/hashicorp/nomad/plugins/base"
 	"google.golang.org/grpc"
 )
@@ -17,7 +17,7 @@ const PluginName = "docker_logger"
 // LaunchDockerLogger launches an instance of DockerLogger
 func LaunchDockerLogger(logger hclog.Logger) (DockerLogger, *plugin.Client, error) {
 	logger = logger.Named(PluginName)
-	bin, err := discover.NomadExecutable()
+	bin, err := os.Executable()
 	if err != nil {
 		return nil, nil, err
 	}

drivers/docker/docklog/z_docker_logger_cmd.go

+package docklog
+
+import (
+	"os"
+
+	log "github.com/hashicorp/go-hclog"
+	plugin "github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/nomad/plugins/base"
+)
+
+// Install a plugin cli handler to ease working with tests
+// and external plugins.
+// This init() must be initialized last in package required by the child plugin
+// process. It's recommended to avoid any other `init()` or inline any necessary calls
+// here. See eeaa95d commit message for more details.
+func init() {
+	if len(os.Args) > 1 && os.Args[1] == PluginName {
+		logger := log.New(&log.LoggerOptions{
+			Level:      log.Trace,
+			JSONFormat: true,
+			Name:       PluginName,
+		})
+
+		plugin.Serve(&plugin.ServeConfig{
+			HandshakeConfig: base.Handshake,
+			Plugins: map[string]plugin.Plugin{
+				PluginName: NewPlugin(NewDockerLogger(logger)),
+			},
+			GRPCServer: plugin.DefaultGRPCServer,
+			Logger:     logger,
+		})
+		os.Exit(0)
+	}
+}

drivers/shared/executor/utils.go

@@ -3,13 +3,13 @@ package executor
 import (
 	"encoding/json"
 	"fmt"
+	"os"
 	"os/exec"
 
 	"github.com/golang/protobuf/ptypes"
 	hclog "github.com/hashicorp/go-hclog"
 	plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/nomad/drivers/shared/executor/proto"
-	"github.com/hashicorp/nomad/helper/discover"
 	"github.com/hashicorp/nomad/plugins/base"
 )
 
@@ -32,7 +32,7 @@ func CreateExecutor(logger hclog.Logger, driverConfig *base.ClientDriverConfig,
 	if err != nil {
 		return nil, nil, fmt.Errorf("unable to create executor config: %v", err)
 	}
-	bin, err := discover.NomadExecutable()
+	bin, err := os.Executable()
 	if err != nil {
 		return nil, nil, fmt.Errorf("unable to find the nomad binary: %v", err)
 	}

drivers/shared/executor/z_executor_cmd.go

+package executor
+
+import (
+	"encoding/json"
+	"os"
+
+	hclog "github.com/hashicorp/go-hclog"
+	log "github.com/hashicorp/go-hclog"
+	plugin "github.com/hashicorp/go-plugin"
+
+	"github.com/hashicorp/nomad/plugins/base"
+)
+
+// Install a plugin cli handler to ease working with tests
+// and external plugins.
+// This init() must be initialized last in package required by the child plugin
+// process. It's recommended to avoid any other `init()` or inline any necessary calls
+// here. See eeaa95d commit message for more details.
+func init() {
+	if len(os.Args) > 1 && os.Args[1] == "executor" {
+		if len(os.Args) != 3 {
+			hclog.L().Error("json configuration not provided")
+			os.Exit(1)
+		}
+
+		config := os.Args[2]
+		var executorConfig ExecutorConfig
+		if err := json.Unmarshal([]byte(config), &executorConfig); err != nil {
+			os.Exit(1)
+		}
+
+		f, err := os.OpenFile(executorConfig.LogFile, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0666)
+		if err != nil {
+			hclog.L().Error(err.Error())
+			os.Exit(1)
+		}
+
+		// Create the logger
+		logger := log.New(&log.LoggerOptions{
+			Level:      hclog.LevelFromString(executorConfig.LogLevel),
+			JSONFormat: true,
+			Output:     f,
+		})
+
+		plugin.Serve(&plugin.ServeConfig{
+			HandshakeConfig: base.Handshake,
+			Plugins: GetPluginMap(
+				logger,
+				executorConfig.FSIsolation,
+			),
+			GRPCServer: plugin.DefaultGRPCServer,
+			Logger:     logger,
+		})
+		os.Exit(0)
+	}
+}