Merge lp:~dave-cheney/juju-core/102-cmd-init-context into lp:~juju/juju-core/trunk

[Dave Cheney]

cmd: add cmd.Context to command.Init

Pass cmd.Context to command.Init. This is mostly unused, although most invocations of command.Run do not use their Context either.

https://codereview.appspot.com/6532045/

[William Reade (fwereade)]

If I were implementing it I think I would have gone for something more
like c.Config.Open(ctx) inside Run, but I can't come up with a really
convincing case for that being *better*. (OK, it'd be less work, but the
work's already done.) So: LGTM.

https://codereview.appspot.com/6532045/

Unmerged revisions

519. By Dave Cheney on 2012-09-18

context strawman

518. By Dave Cheney on 2012-09-18

add context to command.init

517. By Dave Cheney on 2012-09-18

cmd/juju: add juju set subcommand

This proposal only includes the command parsing, a following CL
will include --config parsing and config updating.

R=fwereade
CC=
https://codereview.appspot.com/6494131

516. By Aram Hăvărneanu on 2012-09-17

mstate: add services watcher

R=niemeyer
CC=
https://codereview.appspot.com/6496132

515. By Dave Cheney on 2012-09-17

mstate: fix ssh tests

Wait until the sshd process is listening before returning from sshDaemon()

R=rog
CC=
https://codereview.appspot.com/6497146

514. By Gustavo Niemeyer on 2012-09-17

mstate/watcher: fix trivial test race

R=dfc
CC=
https://codereview.appspot.com/6499126

513. By William Reade on 2012-09-17

update mstate charm usage

Service/Unit now have charm-related methods that match state

R=niemeyer
CC=
https://codereview.appspot.com/6506124

512. By Aram Hăvărneanu on 2012-09-17

mstate: improve error reporting in watcher test

R=niemeyer
CC=
https://codereview.appspot.com/6492131

511. By Aram Hăvărneanu on 2012-09-17

mstate: add machines watcher

R=niemeyer
CC=
https://codereview.appspot.com/6496131

510. By Dave Cheney on 2012-09-17

cmd: add FileVar flag and use it

PyJuJu had a nice construct that allowed a flag that was a file, or more
specifically the contents of a file to be handled nicely. As deploy ended
up implementing this, and I need it now for juju set, it made sense to
pretty it up.

R=niemeyer
CC=
https://codereview.appspot.com/6490121

=== modified file 'cmd/cmd.go'
--- cmd/cmd.go	2012-09-10 03:51:34 +0000
+++ cmd/cmd.go	2012-09-18 11:54:19 +0000
@@ -24,7 +24,7 @@
 
 	// Init initializes the Command before running. The command may add options
 	// to f before processing args.
-	Init(f *gnuflag.FlagSet, args []string) error
+	Init(f *gnuflag.FlagSet, args []string, ctx *Context) error
 
 	// Run will execute the Command as directed by the options and positional
 	// arguments passed to Init.
@@ -100,7 +100,7 @@
 func Main(c Command, ctx *Context, args []string) int {
 	f := gnuflag.NewFlagSet(c.Info().Name, gnuflag.ContinueOnError)
 	f.SetOutput(ioutil.Discard)
-	if err := c.Init(f, args); err != nil {
+	if err := c.Init(f, args, ctx); err != nil {
 		if err == gnuflag.ErrHelp {
 			ctx.Stderr.Write(c.Info().Help(f))
 			return 0
 
=== modified file 'cmd/filevar.go'
--- cmd/filevar.go	2012-09-17 14:05:50 +0000
+++ cmd/filevar.go	2012-09-18 11:54:19 +0000
@@ -3,19 +3,22 @@
 import (
 	"io"
 	"os"
+
+	"launchpad.net/gnuflag"
 )
 
 // FileVar represents a path to a file. If the flag is 
 // valid FileVar.ReadCloser will be non nil and FileVar
 // will be usable as an io.ReadCloser.
 type FileVar struct {
+	ctx *Context
 	io.ReadCloser
 	Path string
 }
 
-// Set opens the file. 
+// Set opens the file, resolving the path relative to Context.Dir
 func (f *FileVar) Set(v string) error {
-	file, err := os.Open(v)
+	file, err := os.Open(f.ctx.AbsPath(v))
 	if err != nil {
 		return err
 	}
@@ -28,3 +31,9 @@
 func (f *FileVar) String() string {
 	return f.Path
 }
+
+// AddFlags injects the command line flags into f.
+func (f *FileVar) AddFlags(fs *gnuflag.FlagSet, name, desc string, ctx *Context) {
+	f.ctx = ctx
+	fs.Var(f, name, desc)
+}
 
=== modified file 'cmd/juju/addunit.go'
--- cmd/juju/addunit.go	2012-09-03 17:35:44 +0000
+++ cmd/juju/addunit.go	2012-09-18 11:54:19 +0000
@@ -19,7 +19,7 @@
 	return &cmd.Info{"add-unit", "", "add a service unit", ""}
 }
 
-func (c *AddUnitCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *AddUnitCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	f.IntVar(&c.NumUnits, "n", 1, "number of service units to add")
 	f.IntVar(&c.NumUnits, "num-units", 1, "")
 
=== modified file 'cmd/juju/addunit_test.go'
--- cmd/juju/addunit_test.go	2012-09-12 22:31:00 +0000
+++ cmd/juju/addunit_test.go	2012-09-18 11:54:19 +0000
@@ -16,9 +16,10 @@
 
 func runAddUnit(c *C, args ...string) error {
 	com := &AddUnitCommand{}
-	err := com.Init(newFlagSet(), args)
+	ctx := &cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}}
+	err := com.Init(newFlagSet(), args, ctx)
 	c.Assert(err, IsNil)
-	return com.Run(&cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}})
+	return com.Run(ctx)
 }
 
 func (s *AddUnitSuite) TestAddUnit(c *C) {
 
=== modified file 'cmd/juju/bootstrap.go'
--- cmd/juju/bootstrap.go	2012-09-03 14:07:19 +0000
+++ cmd/juju/bootstrap.go	2012-09-18 11:54:19 +0000
@@ -17,7 +17,7 @@
 	return &cmd.Info{"bootstrap", "", "start up an environment from scratch", ""}
 }
 
-func (c *BootstrapCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *BootstrapCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	f.BoolVar(&c.UploadTools, "upload-tools", false, "upload local version of tools before bootstrapping")
 	if err := f.Parse(true, args); err != nil {
 
=== modified file 'cmd/juju/cmd_test.go'
--- cmd/juju/cmd_test.go	2012-09-17 15:30:34 +0000
+++ cmd/juju/cmd_test.go	2012-09-18 11:54:19 +0000
@@ -1,9 +1,9 @@
 package main
 
 import (
+	"bytes"
 	"net/http"
 	"os"
-	"path/filepath"
 	"reflect"
 
 	"launchpad.net/gnuflag"
@@ -52,7 +52,7 @@
 // testInit checks that a command initialises correctly
 // with the given set of arguments.
 func testInit(c *C, com cmd.Command, args []string, errPat string) {
-	err := com.Init(newFlagSet(), args)
+	err := com.Init(newFlagSet(), args, nil)
 	if errPat != "" {
 		c.Assert(err, ErrorMatches, errPat)
 	} else {
@@ -113,14 +113,15 @@
 	go func() {
 		// signal that we're done with this ops channel.
 		defer dummy.Listen(nil)
+		ctx := cmd.DefaultContext()
 
-		err := com.Init(newFlagSet(), args)
+		err := com.Init(newFlagSet(), args, ctx)
 		if err != nil {
 			errc <- err
 			return
 		}
 
-		err = com.Run(cmd.DefaultContext())
+		err = com.Run(ctx)
 		errc <- err
 	}()
 	return
@@ -213,9 +214,9 @@
 	}
 }
 
-func initDeployCommand(args ...string) (*DeployCommand, error) {
+func initDeployCommand(ctx *cmd.Context, args ...string) (*DeployCommand, error) {
 	com := &DeployCommand{}
-	return com, com.Init(newFlagSet(), args)
+	return com, com.Init(newFlagSet(), args, ctx)
 }
 
 func (*CmdSuite) TestDeployCommandInit(c *C) {
@@ -224,31 +225,31 @@
 
 	for _, t := range deployTests {
 		initExpectations(t.com)
-		com, err := initDeployCommand(t.args...)
+		com, err := initDeployCommand(nil, t.args...)
 		c.Assert(err, IsNil)
 		c.Assert(com, DeepEquals, t.com)
 	}
 
 	// test --config path
-	dir := c.MkDir()
-	path := filepath.Join(dir, "testconfig.yaml")
+	ctx := &cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}}
+	path := ctx.AbsPath("testconfig.yaml")
 	file, err := os.Create(path)
 	c.Assert(err, IsNil)
 	file.Close()
-	com, err := initDeployCommand("--config", path, "charm-name")
+	com, err := initDeployCommand(ctx, "--config", path, "charm-name")
 	c.Assert(err, IsNil)
 	defer com.Config.Close()
 	c.Assert(com.Config.Path, Equals, path)
 	c.Assert(com.Config.ReadCloser, NotNil)
 
 	// missing args
-	_, err = initDeployCommand()
+	_, err = initDeployCommand(ctx)
 	c.Assert(err, ErrorMatches, "no charm specified")
 
 	// bad unit count
-	_, err = initDeployCommand("charm-name", "--num-units", "0")
+	_, err = initDeployCommand(ctx, "charm-name", "--num-units", "0")
 	c.Assert(err, ErrorMatches, "must deploy at least one unit")
-	_, err = initDeployCommand("charm-name", "-n", "0")
+	_, err = initDeployCommand(ctx, "charm-name", "-n", "0")
 	c.Assert(err, ErrorMatches, "must deploy at least one unit")
 
 	// environment tested elsewhere
@@ -256,7 +257,7 @@
 
 func initAddUnitCommand(args ...string) (*AddUnitCommand, error) {
 	com := &AddUnitCommand{}
-	return com, com.Init(newFlagSet(), args)
+	return com, com.Init(newFlagSet(), args, nil)
 }
 
 func (*CmdSuite) TestAddUnitCommandInit(c *C) {
@@ -275,7 +276,7 @@
 
 func initExposeCommand(args ...string) (*ExposeCommand, error) {
 	com := &ExposeCommand{}
-	return com, com.Init(newFlagSet(), args)
+	return com, com.Init(newFlagSet(), args, nil)
 }
 
 func (*CmdSuite) TestExposeCommandInit(c *C) {
@@ -288,7 +289,7 @@
 
 func initUnexposeCommand(args ...string) (*UnexposeCommand, error) {
 	com := &UnexposeCommand{}
-	return com, com.Init(newFlagSet(), args)
+	return com, com.Init(newFlagSet(), args, nil)
 }
 
 func (*CmdSuite) TestUnexposeCommandInit(c *C) {
@@ -301,7 +302,7 @@
 
 func initGetCommand(args ...string) (*GetCommand, error) {
 	com := &GetCommand{}
-	return com, com.Init(newFlagSet(), args)
+	return com, com.Init(newFlagSet(), args, nil)
 }
 
 func (*CmdSuite) TestGetCommandInit(c *C) {
@@ -312,7 +313,7 @@
 
 func initSetCommand(args ...string) (*SetCommand, error) {
 	com := &SetCommand{}
-	return com, com.Init(newFlagSet(), args)
+	return com, com.Init(newFlagSet(), args, nil)
 }
 
 func (*CmdSuite) TestSetCommandInit(c *C) {
 
=== modified file 'cmd/juju/deploy.go'
--- cmd/juju/deploy.go	2012-09-17 14:05:50 +0000
+++ cmd/juju/deploy.go	2012-09-18 11:54:19 +0000
@@ -46,13 +46,13 @@
 	}
 }
 
-func (c *DeployCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *DeployCommand) Init(f *gnuflag.FlagSet, args []string, ctx *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	f.IntVar(&c.NumUnits, "n", 1, "number of service units to deploy for principal charms")
 	f.IntVar(&c.NumUnits, "num-units", 1, "")
 	f.BoolVar(&c.BumpRevision, "u", false, "increment local charm directory revision")
 	f.BoolVar(&c.BumpRevision, "upgrade", false, "")
-	f.Var(&c.Config, "config", "path to yaml-formatted service config")
+	c.Config.AddFlags(f, "config", "path to yaml-formatted service config", ctx)
 	f.StringVar(&c.RepoPath, "repository", os.Getenv("JUJU_REPOSITORY"), "local charm repository")
 	// TODO --constraints
 	if err := f.Parse(true, args); err != nil {
 
=== modified file 'cmd/juju/deploy_test.go'
--- cmd/juju/deploy_test.go	2012-09-12 22:31:00 +0000
+++ cmd/juju/deploy_test.go	2012-09-18 11:54:19 +0000
@@ -111,9 +111,10 @@
 
 func runDeploy(c *C, args ...string) error {
 	com := &DeployCommand{}
-	err := com.Init(newFlagSet(), args)
+	ctx := &cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}}
+	err := com.Init(newFlagSet(), args, ctx)
 	c.Assert(err, IsNil)
-	return com.Run(&cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}})
+	return com.Run(ctx)
 }
 
 func (s *DeploySuite) TestCharmDir(c *C) {
 
=== modified file 'cmd/juju/destroyenvironment.go'
--- cmd/juju/destroyenvironment.go	2012-09-06 10:44:58 +0000
+++ cmd/juju/destroyenvironment.go	2012-09-18 11:54:19 +0000
@@ -19,7 +19,7 @@
 	}
 }
 
-func (c *DestroyEnvironmentCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *DestroyEnvironmentCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/juju/expose.go'
--- cmd/juju/expose.go	2012-09-03 17:35:44 +0000
+++ cmd/juju/expose.go	2012-09-18 11:54:19 +0000
@@ -18,7 +18,7 @@
 	return &cmd.Info{"expose", "", "expose a service", ""}
 }
 
-func (c *ExposeCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *ExposeCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/juju/expose_test.go'
--- cmd/juju/expose_test.go	2012-09-12 22:31:00 +0000
+++ cmd/juju/expose_test.go	2012-09-18 11:54:19 +0000
@@ -16,9 +16,10 @@
 
 func runExpose(c *C, args ...string) error {
 	com := &ExposeCommand{}
-	err := com.Init(newFlagSet(), args)
+	ctx := &cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}}
+	err := com.Init(newFlagSet(), args, ctx)
 	c.Assert(err, IsNil)
-	return com.Run(&cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}})
+	return com.Run(ctx)
 }
 
 func (s *ExposeSuite) assertExposed(c *C, service string) {
 
=== modified file 'cmd/juju/get.go'
--- cmd/juju/get.go	2012-09-14 05:28:04 +0000
+++ cmd/juju/get.go	2012-09-18 11:54:19 +0000
@@ -21,7 +21,7 @@
 	return &cmd.Info{"get", "", "get service config options", ""}
 }
 
-func (c *GetCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *GetCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	// TODO(dfc) add json formatting ?
 	c.out.AddFlags(f, "yaml", map[string]cmd.Formatter{
 
=== modified file 'cmd/juju/set.go'
--- cmd/juju/set.go	2012-09-13 07:22:45 +0000
+++ cmd/juju/set.go	2012-09-18 11:54:19 +0000
@@ -14,7 +14,7 @@
 	EnvName     string
 	ServiceName string
 	Options     []Option
-	ConfPath    string
+	Config      cmd.FileVar
 }
 
 type Option struct {
@@ -25,9 +25,9 @@
 	return &cmd.Info{"set", "", "set service config options", ""}
 }
 
-func (c *SetCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *SetCommand) Init(f *gnuflag.FlagSet, args []string, ctx *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
-	f.StringVar(&c.ConfPath, "config", "", "path to yaml-formatted service config")
+	c.Config.AddFlags(f, "config", "path to yaml-formatted service config", ctx)
 	if err := f.Parse(true, args); err != nil {
 		return err
 	}
 
=== modified file 'cmd/juju/status.go'
--- cmd/juju/status.go	2012-09-04 14:26:44 +0000
+++ cmd/juju/status.go	2012-09-18 11:54:19 +0000
@@ -24,7 +24,7 @@
 	}
 }
 
-func (c *StatusCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *StatusCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	c.out.AddFlags(f, "yaml", map[string]cmd.Formatter{
 		"yaml": cmd.FormatYaml,
 
=== modified file 'cmd/juju/unexpose.go'
--- cmd/juju/unexpose.go	2012-09-03 17:35:44 +0000
+++ cmd/juju/unexpose.go	2012-09-18 11:54:19 +0000
@@ -18,7 +18,7 @@
 	return &cmd.Info{"unexpose", "", "unexpose a service", ""}
 }
 
-func (c *UnexposeCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *UnexposeCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/juju/unexpose_test.go'
--- cmd/juju/unexpose_test.go	2012-09-12 22:31:00 +0000
+++ cmd/juju/unexpose_test.go	2012-09-18 11:54:19 +0000
@@ -16,9 +16,10 @@
 
 func runUnexpose(c *C, args ...string) error {
 	com := &UnexposeCommand{}
-	err := com.Init(newFlagSet(), args)
+	ctx := &cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}}
+	err := com.Init(newFlagSet(), args, ctx)
 	c.Assert(err, IsNil)
-	return com.Run(&cmd.Context{c.MkDir(), &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}})
+	return com.Run(ctx)
 }
 
 func (s *UnexposeSuite) assertExposed(c *C, service string, expected bool) {
 
=== modified file 'cmd/juju/upgradejuju.go'
--- cmd/juju/upgradejuju.go	2012-09-12 17:15:00 +0000
+++ cmd/juju/upgradejuju.go	2012-09-18 11:54:19 +0000
@@ -28,7 +28,7 @@
 	return &cmd.Info{"upgrade-juju", "", "upgrade the tools in a juju environment", ""}
 }
 
-func (c *UpgradeJujuCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *UpgradeJujuCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	addEnvironFlags(&c.EnvName, f)
 	var vers string
 	f.BoolVar(&c.UploadTools, "upload-tools", false, "upload local version of tools")
 
=== modified file 'cmd/juju/upgradejuju_test.go'
--- cmd/juju/upgradejuju_test.go	2012-09-12 17:15:00 +0000
+++ cmd/juju/upgradejuju_test.go	2012-09-18 11:54:19 +0000
@@ -164,12 +164,13 @@
 
 		// Run the command
 		com := &UpgradeJujuCommand{}
-		err = com.Init(newFlagSet(), test.args)
+		ctx := &cmd.Context{c.MkDir(), nil, ioutil.Discard, ioutil.Discard}
+		err = com.Init(newFlagSet(), test.args, ctx)
 		if test.expectInitErr != "" {
 			c.Check(err, ErrorMatches, test.expectInitErr)
 			continue
 		}
-		err = com.Run(&cmd.Context{c.MkDir(), nil, ioutil.Discard, ioutil.Discard})
+		err = com.Run(ctx)
 		if test.expectErr != "" {
 			c.Check(err, ErrorMatches, test.expectErr)
 			continue
@@ -212,9 +213,10 @@
 func (s *UpgradeJujuSuite) TestUpgradeJujuWithRealPutTools(c *C) {
 	s.Reset(c)
 	com := &UpgradeJujuCommand{}
-	err := com.Init(newFlagSet(), []string{"--upload-tools", "--dev"})
+	ctx := &cmd.Context{c.MkDir(), nil, ioutil.Discard, ioutil.Discard}
+	err := com.Init(newFlagSet(), []string{"--upload-tools", "--dev"}, ctx)
 	c.Assert(err, IsNil)
-	err = com.Run(&cmd.Context{c.MkDir(), nil, ioutil.Discard, ioutil.Discard})
+	err = com.Run(ctx)
 	c.Assert(err, IsNil)
 	p := environs.ToolsStoragePath(version.Current)
 	r, err := s.Conn.Environ.Storage().Get(p)
 
=== modified file 'cmd/jujuc/main_test.go'
--- cmd/jujuc/main_test.go	2012-08-07 16:23:28 +0000
+++ cmd/jujuc/main_test.go	2012-09-18 11:54:19 +0000
@@ -49,7 +49,7 @@
 		"remote", "", "test jujuc", "here is some documentation"}
 }
 
-func (c *RemoteCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *RemoteCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	f.StringVar(&c.msg, "error", "", "if set, fail")
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujuc/server/config-get.go'
--- cmd/jujuc/server/config-get.go	2012-07-31 21:36:59 +0000
+++ cmd/jujuc/server/config-get.go	2012-09-18 11:54:19 +0000
@@ -24,7 +24,7 @@
 	}
 }
 
-func (c *ConfigGetCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *ConfigGetCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	c.out.AddFlags(f, "smart", cmd.DefaultFormatters)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujuc/server/config-get_test.go'
--- cmd/jujuc/server/config-get_test.go	2012-07-31 21:36:59 +0000
+++ cmd/jujuc/server/config-get_test.go	2012-09-18 11:54:19 +0000
@@ -97,6 +97,6 @@
 	hctx := s.GetHookContext(c, -1, "")
 	com, err := hctx.NewCommand("config-get")
 	c.Assert(err, IsNil)
-	err = com.Init(dummyFlagSet(), []string{"multiple", "keys"})
+	err = com.Init(dummyFlagSet(), []string{"multiple", "keys"}, nil)
 	c.Assert(err, ErrorMatches, `unrecognized args: \["keys"\]`)
 }
 
=== modified file 'cmd/jujuc/server/juju-log.go'
--- cmd/jujuc/server/juju-log.go	2012-08-06 16:41:17 +0000
+++ cmd/jujuc/server/juju-log.go	2012-09-18 11:54:19 +0000
@@ -23,7 +23,7 @@
 	return &cmd.Info{"juju-log", "<message>", "write a message to the juju log", ""}
 }
 
-func (c *JujuLogCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *JujuLogCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	f.BoolVar(&c.Debug, "debug", false, "log at debug level")
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujuc/server/juju-log_test.go'
--- cmd/jujuc/server/juju-log_test.go	2012-08-01 15:48:38 +0000
+++ cmd/jujuc/server/juju-log_test.go	2012-09-18 11:54:19 +0000
@@ -82,6 +82,6 @@
 	ctx := &server.HookContext{}
 	com, err := ctx.NewCommand("juju-log")
 	c.Assert(err, IsNil)
-	err = com.Init(dummyFlagSet(), nil)
+	err = com.Init(dummyFlagSet(), nil, nil)
 	c.Assert(err, ErrorMatches, "no message specified")
 }
 
=== modified file 'cmd/jujuc/server/ports.go'
--- cmd/jujuc/server/ports.go	2012-07-30 14:30:00 +0000
+++ cmd/jujuc/server/ports.go	2012-09-18 11:54:19 +0000
@@ -28,7 +28,7 @@
 	return fmt.Errorf(`port must be in the range [1, 65535]; got "%v"`, value)
 }
 
-func (c *portCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *portCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	if err := f.Parse(true, args); err != nil {
 		return err
 	}
 
=== modified file 'cmd/jujuc/server/ports_test.go'
--- cmd/jujuc/server/ports_test.go	2012-07-30 14:30:00 +0000
+++ cmd/jujuc/server/ports_test.go	2012-09-18 11:54:19 +0000
@@ -58,7 +58,7 @@
 			hctx := s.GetHookContext(c, -1, "")
 			com, err := hctx.NewCommand(name)
 			c.Assert(err, IsNil)
-			err = com.Init(dummyFlagSet(), t.args)
+			err = com.Init(dummyFlagSet(), t.args, nil)
 			c.Assert(err, ErrorMatches, t.err)
 		}
 	}
 
=== modified file 'cmd/jujuc/server/relation-get.go'
--- cmd/jujuc/server/relation-get.go	2012-08-07 14:22:28 +0000
+++ cmd/jujuc/server/relation-get.go	2012-09-18 11:54:19 +0000
@@ -34,7 +34,7 @@
 	}
 }
 
-func (c *RelationGetCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *RelationGetCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	// TODO FWER implement --format shell lp:1033511
 	c.out.AddFlags(f, "smart", cmd.DefaultFormatters)
 	f.Var(c.relationIdValue(&c.RelationId), "r", "specify a relation by id")
 
=== modified file 'cmd/jujuc/server/relation-ids.go'
--- cmd/jujuc/server/relation-ids.go	2012-08-07 12:41:54 +0000
+++ cmd/jujuc/server/relation-ids.go	2012-09-18 11:54:19 +0000
@@ -30,7 +30,7 @@
 	}
 }
 
-func (c *RelationIdsCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *RelationIdsCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	c.out.AddFlags(f, "smart", cmd.DefaultFormatters)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujuc/server/relation-list.go'
--- cmd/jujuc/server/relation-list.go	2012-08-07 14:22:28 +0000
+++ cmd/jujuc/server/relation-list.go	2012-09-18 11:54:19 +0000
@@ -29,7 +29,7 @@
 	}
 }
 
-func (c *RelationListCommand) Init(f *gnuflag.FlagSet, args []string) (err error) {
+func (c *RelationListCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) (err error) {
 	c.out.AddFlags(f, "smart", cmd.DefaultFormatters)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujuc/server/relation-set.go'
--- cmd/jujuc/server/relation-set.go	2012-08-07 14:22:28 +0000
+++ cmd/jujuc/server/relation-set.go	2012-09-18 11:54:19 +0000
@@ -24,7 +24,7 @@
 	}
 }
 
-func (c *RelationSetCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *RelationSetCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	f.Var(c.relationIdValue(&c.RelationId), "r", "specify a relation by id")
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujuc/server/relation-set_test.go'
--- cmd/jujuc/server/relation-set_test.go	2012-08-07 14:22:28 +0000
+++ cmd/jujuc/server/relation-set_test.go	2012-09-18 11:54:19 +0000
@@ -152,7 +152,7 @@
 		hctx := s.GetHookContext(c, t.ctxrelid, "")
 		com, err := hctx.NewCommand("relation-set")
 		c.Assert(err, IsNil)
-		err = com.Init(dummyFlagSet(), t.args)
+		err = com.Init(dummyFlagSet(), t.args, nil)
 		if t.err == "" {
 			c.Assert(err, IsNil)
 			rset := com.(*server.RelationSetCommand)
 
=== modified file 'cmd/jujuc/server/server_test.go'
--- cmd/jujuc/server/server_test.go	2012-08-18 09:09:37 +0000
+++ cmd/jujuc/server/server_test.go	2012-09-18 11:54:19 +0000
@@ -24,7 +24,7 @@
 	return &cmd.Info{"remote", "", "act at a distance", "blah doc"}
 }
 
-func (c *RpcCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *RpcCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	f.StringVar(&c.Value, "value", "", "doc")
 	f.BoolVar(&c.Slow, "slow", false, "doc")
 	if err := f.Parse(true, args); err != nil {
 
=== modified file 'cmd/jujuc/server/unit-get.go'
--- cmd/jujuc/server/unit-get.go	2012-07-31 21:36:59 +0000
+++ cmd/jujuc/server/unit-get.go	2012-09-18 11:54:19 +0000
@@ -24,7 +24,7 @@
 	}
 }
 
-func (c *UnitGetCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *UnitGetCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	c.out.AddFlags(f, "smart", cmd.DefaultFormatters)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujuc/server/unit-get_test.go'
--- cmd/jujuc/server/unit-get_test.go	2012-07-31 21:36:59 +0000
+++ cmd/jujuc/server/unit-get_test.go	2012-09-18 11:54:19 +0000
@@ -83,7 +83,7 @@
 	hctx := s.GetHookContext(c, -1, "")
 	com, err := hctx.NewCommand("unit-get")
 	c.Assert(err, IsNil)
-	err = com.Init(dummyFlagSet(), []string{"protected-address"})
+	err = com.Init(dummyFlagSet(), []string{"protected-address"}, nil)
 	c.Assert(err, ErrorMatches, `unknown setting "protected-address"`)
 }
 
@@ -91,6 +91,6 @@
 	hctx := s.GetHookContext(c, -1, "")
 	com, err := hctx.NewCommand("unit-get")
 	c.Assert(err, IsNil)
-	err = com.Init(dummyFlagSet(), []string{"private-address", "blah"})
+	err = com.Init(dummyFlagSet(), []string{"private-address", "blah"}, nil)
 	c.Assert(err, ErrorMatches, `unrecognized args: \["blah"\]`)
 }
 
=== modified file 'cmd/jujud/bootstrap.go'
--- cmd/jujud/bootstrap.go	2012-09-09 20:10:46 +0000
+++ cmd/jujud/bootstrap.go	2012-09-18 11:54:19 +0000
@@ -21,7 +21,7 @@
 }
 
 // Init initializes the command for running.
-func (c *BootstrapCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *BootstrapCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	stateInfoVar(f, &c.StateInfo, "zookeeper-servers", []string{"127.0.0.1:2181"}, "address of zookeeper to initialize")
 	f.StringVar(&c.InstanceId, "instance-id", "", "instance id of this machine")
 	yamlBase64Var(f, &c.EnvConfig, "env-config", "", "initial environment configuration (yaml, base64 encoded)")
 
=== modified file 'cmd/jujud/machine.go'
--- cmd/jujud/machine.go	2012-09-12 15:35:55 +0000
+++ cmd/jujud/machine.go	2012-09-18 11:54:19 +0000
@@ -25,7 +25,7 @@
 }
 
 // Init initializes the command for running.
-func (a *MachineAgent) Init(f *gnuflag.FlagSet, args []string) error {
+func (a *MachineAgent) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	a.Conf.addFlags(f)
 	f.IntVar(&a.MachineId, "machine-id", -1, "id of the machine to run")
 	if err := f.Parse(true, args); err != nil {
 
=== modified file 'cmd/jujud/provisioning.go'
--- cmd/jujud/provisioning.go	2012-08-27 23:27:57 +0000
+++ cmd/jujud/provisioning.go	2012-09-18 11:54:19 +0000
@@ -31,7 +31,7 @@
 }
 
 // Init initializes the command for running.
-func (a *ProvisioningAgent) Init(f *gnuflag.FlagSet, args []string) error {
+func (a *ProvisioningAgent) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	a.Conf.addFlags(f)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/jujud/unit.go'
--- cmd/jujud/unit.go	2012-09-12 17:26:56 +0000
+++ cmd/jujud/unit.go	2012-09-18 11:54:19 +0000
@@ -25,7 +25,7 @@
 }
 
 // Init initializes the command for running.
-func (a *UnitAgent) Init(f *gnuflag.FlagSet, args []string) error {
+func (a *UnitAgent) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	a.Conf.addFlags(f)
 	f.StringVar(&a.UnitName, "unit-name", "", "name of the unit to run")
 	if err := f.Parse(true, args); err != nil {
 
=== modified file 'cmd/jujud/util_test.go'
--- cmd/jujud/util_test.go	2012-09-12 17:10:28 +0000
+++ cmd/jujud/util_test.go	2012-09-18 11:54:19 +0000
@@ -12,7 +12,7 @@
 func initCmd(c cmd.Command, args []string) error {
 	f := gnuflag.NewFlagSet("", gnuflag.ContinueOnError)
 	f.SetOutput(ioutil.Discard)
-	return c.Init(f, args)
+	return c.Init(f, args, nil)
 }
 
 // CheckAgentCommand is a utility function for verifying that common agent
 
=== modified file 'cmd/jujud/version.go'
--- cmd/jujud/version.go	2012-08-16 17:09:22 +0000
+++ cmd/jujud/version.go	2012-09-18 11:54:19 +0000
@@ -15,7 +15,7 @@
 	return &cmd.Info{"version", "", "print the current version", ""}
 }
 
-func (v *VersionCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (v *VersionCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	v.out.AddFlags(f, "smart", cmd.DefaultFormatters)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/output_test.go'
--- cmd/output_test.go	2012-08-07 16:23:28 +0000
+++ cmd/output_test.go	2012-09-18 11:54:19 +0000
@@ -16,7 +16,7 @@
 	return &cmd.Info{"output", "<something>", "I like to output", "output"}
 }
 
-func (c *OutputCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *OutputCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	c.out.AddFlags(f, "smart", cmd.DefaultFormatters)
 	if err := f.Parse(true, args); err != nil {
 		return err
 
=== modified file 'cmd/supercommand.go'
--- cmd/supercommand.go	2012-05-18 09:52:31 +0000
+++ cmd/supercommand.go	2012-09-18 11:54:19 +0000
@@ -75,7 +75,7 @@
 }
 
 // Init initializes the command for running.
-func (c *SuperCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *SuperCommand) Init(f *gnuflag.FlagSet, args []string, ctx *Context) error {
 	if c.Log != nil {
 		c.Log.AddFlags(f)
 	}
@@ -90,7 +90,7 @@
 	if c.subcmd, found = c.subcmds[subargs[0]]; !found {
 		return fmt.Errorf("unrecognized command: %s %s", c.Info().Name, subargs[0])
 	}
-	return c.subcmd.Init(f, subargs[1:])
+	return c.subcmd.Init(f, subargs[1:], ctx)
 }
 
 // Run executes the subcommand that was selected in Init.
 
=== modified file 'cmd/supercommand_test.go'
--- cmd/supercommand_test.go	2012-06-21 20:40:39 +0000
+++ cmd/supercommand_test.go	2012-09-18 11:54:19 +0000
@@ -10,7 +10,7 @@
 	jc := &cmd.SuperCommand{Name: "jujutest"}
 	tc := &TestCommand{Name: "defenestrate"}
 	jc.Register(tc)
-	return jc, tc, jc.Init(dummyFlagSet(), args)
+	return jc, tc, jc.Init(dummyFlagSet(), args, nil)
 }
 
 type SuperCommandSuite struct{}
@@ -19,7 +19,7 @@
 
 func (s *SuperCommandSuite) TestDispatch(c *C) {
 	jc := &cmd.SuperCommand{Name: "jujutest"}
-	err := jc.Init(dummyFlagSet(), []string{})
+	err := jc.Init(dummyFlagSet(), []string{}, nil)
 	c.Assert(err, ErrorMatches, `no command specified`)
 	info := jc.Info()
 	c.Assert(info.Name, Equals, "jujutest")
 
=== modified file 'cmd/util_test.go'
--- cmd/util_test.go	2012-09-10 03:51:34 +0000
+++ cmd/util_test.go	2012-09-18 11:54:19 +0000
@@ -36,7 +36,7 @@
 	return &cmd.Info{c.Name, "<something>", c.Name + " the juju", c.Name + "-doc"}
 }
 
-func (c *TestCommand) Init(f *gnuflag.FlagSet, args []string) error {
+func (c *TestCommand) Init(f *gnuflag.FlagSet, args []string, _ *cmd.Context) error {
 	if !c.Minimal {
 		f.StringVar(&c.Option, "option", "", "option-doc")
 	}