deploy.go

// Copyright 2012, 2013 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.

package application

import (
	"archive/zip"
	"os"
	"path/filepath"
	"strings"

	"github.com/juju/cmd"
	"github.com/juju/errors"
	"github.com/juju/gnuflag"
	"gopkg.in/juju/charm.v6-unstable"
	"gopkg.in/juju/charmrepo.v2-unstable"
	"gopkg.in/juju/charmrepo.v2-unstable/csclient"
	"gopkg.in/juju/charmrepo.v2-unstable/csclient/params"
	"gopkg.in/juju/names.v2"
	"gopkg.in/macaroon-bakery.v1/httpbakery"
	"gopkg.in/macaroon.v1"

	"github.com/juju/juju/api"
	"github.com/juju/juju/api/annotations"
	"github.com/juju/juju/api/application"
	apicharms "github.com/juju/juju/api/charms"
	"github.com/juju/juju/api/modelconfig"
	apiparams "github.com/juju/juju/apiserver/params"
	"github.com/juju/juju/charmstore"
	"github.com/juju/juju/cmd/juju/block"
	"github.com/juju/juju/cmd/juju/common"
	"github.com/juju/juju/cmd/modelcmd"
	"github.com/juju/juju/constraints"
	"github.com/juju/juju/environs/config"
	"github.com/juju/juju/instance"
	"github.com/juju/juju/resource/resourceadapters"
	"github.com/juju/juju/storage"
)

var planURL = "https://api.jujucharms.com/omnibus/v2"

type CharmAdder interface {
	AddLocalCharm(*charm.URL, charm.Charm) (*charm.URL, error)
	AddCharm(*charm.URL, params.Channel) error
	AddCharmWithAuthorization(*charm.URL, params.Channel, *macaroon.Macaroon) error
	AuthorizeCharmstoreEntity(*charm.URL) (*macaroon.Macaroon, error)
}

type ApplicationAPI interface {
	AddMachines(machineParams []apiparams.AddMachineParams) ([]apiparams.AddMachinesResult, error)
	AddRelation(endpoints ...string) (*apiparams.AddRelationResults, error)
	AddUnits(application string, numUnits int, placement []*instance.Placement) ([]string, error)
	Expose(application string) error
	GetCharmURL(serviceName string) (*charm.URL, error)
	SetAnnotation(annotations map[string]map[string]string) ([]apiparams.ErrorResult, error)
	SetCharm(application.SetCharmConfig) error
	SetConstraints(application string, constraints constraints.Value) error
	Update(apiparams.ApplicationUpdate) error
}

type ModelAPI interface {
	ModelUUID() (string, bool)
	ModelGet() (map[string]interface{}, error)
}

// MeteredDeployAPI represents the methods of the API the deploy
// command needs for metered charms.
type MeteredDeployAPI interface {
	IsMetered(charmURL string) (bool, error)
	SetMetricCredentials(service string, credentials []byte) error
}

// DeployAPI represents the methods of the API the deploy
// command needs.
type DeployAPI interface {
	// TODO(katco): Pair DeployAPI down to only the methods required
	// by the deploy command.
	api.Connection
	CharmAdder
	MeteredDeployAPI
	ApplicationAPI
	ModelAPI

	// ApplicationClient
	CharmInfo(string) (*apicharms.CharmInfo, error)
	Deploy(application.DeployArgs) error
	Status(patterns []string) (*apiparams.FullStatus, error)

	Resolve(*config.Config, *charm.URL) (*charm.URL, params.Channel, []string, error)

	GetBundle(*charm.URL) (charm.Bundle, error)

	WatchAll() (*api.AllWatcher, error)

	// AddPendingResources(client.AddPendingResourcesArgs) (ids []string, _ error)
	// DeployResources(cmd.DeployResourcesArgs) (ids []string, _ error)
}

// The following structs exist purely because Go cannot create a
// struct with a field named the same as a method name. The DeployAPI
// needs to both embed a *<package>.Client and provide the
// api.Connection Client method.
//
// Once we pair down DeployAPI, this will not longer be a problem.

type apiClient struct {
	*api.Client
}

type charmsClient struct {
	*apicharms.Client
}

type applicationClient struct {
	*application.Client
}

type modelConfigClient struct {
	*modelconfig.Client
}

type charmRepoClient struct {
	*charmrepo.CharmStore
}

type charmstoreClient struct {
	*csclient.Client
}

type annotationsClient struct {
	*annotations.Client
}

func (a *charmstoreClient) AuthorizeCharmstoreEntity(url *charm.URL) (*macaroon.Macaroon, error) {
	return authorizeCharmStoreEntity(a.Client, url)
}

type deployAPIAdapter struct {
	api.Connection
	*apiClient
	*charmsClient
	*applicationClient
	*modelConfigClient
	*charmRepoClient
	*charmstoreClient
	*annotationsClient
}

func (a *deployAPIAdapter) Client() *api.Client {
	return a.apiClient.Client
}

func (a *deployAPIAdapter) ModelUUID() (string, bool) {
	return a.apiClient.ModelUUID()
}

func (a *deployAPIAdapter) Deploy(args application.DeployArgs) error {
	for i, p := range args.Placement {
		if p.Scope == "model-uuid" {
			p.Scope = a.applicationClient.ModelUUID()
		}
		args.Placement[i] = p
	}

	return errors.Trace(a.applicationClient.Deploy(args))
}

func (a *deployAPIAdapter) Resolve(cfg *config.Config, url *charm.URL) (
	*charm.URL,
	params.Channel,
	[]string,
	error,
) {
	return resolveCharm(a.charmRepoClient.ResolveWithChannel, cfg, url)
}

func (a *deployAPIAdapter) Get(url *charm.URL) (charm.Charm, error) {
	return a.charmRepoClient.Get(url)
}

func (a *deployAPIAdapter) SetAnnotation(annotations map[string]map[string]string) ([]apiparams.ErrorResult, error) {
	return a.annotationsClient.Set(annotations)
}

type NewAPIRootFn func() (DeployAPI, error)

func NewDefaultDeployCommand() cmd.Command {
	return NewDeployCommandWithDefaultAPI([]DeployStep{
		&RegisterMeteredCharm{
			RegisterURL: planURL + "/plan/authorize",
			QueryURL:    planURL + "/charm",
		},
	})
}

func NewDeployCommandWithDefaultAPI(steps []DeployStep) cmd.Command {
	deployCmd := &DeployCommand{Steps: steps}
	cmd := modelcmd.Wrap(deployCmd)
	deployCmd.NewAPIRoot = func() (DeployAPI, error) {
		apiRoot, err := deployCmd.ModelCommandBase.NewAPIRoot()
		if err != nil {
			return nil, errors.Trace(err)
		}
		bakeryClient, err := deployCmd.BakeryClient()
		if err != nil {
			return nil, errors.Trace(err)
		}
		cstoreClient := newCharmStoreClient(bakeryClient).WithChannel(deployCmd.Channel)

		adapter := &deployAPIAdapter{
			Connection:        apiRoot,
			apiClient:         &apiClient{Client: apiRoot.Client()},
			charmsClient:      &charmsClient{Client: apicharms.NewClient(apiRoot)},
			applicationClient: &applicationClient{Client: application.NewClient(apiRoot)},
			modelConfigClient: &modelConfigClient{Client: modelconfig.NewClient(apiRoot)},
			charmstoreClient:  &charmstoreClient{Client: cstoreClient},
			annotationsClient: &annotationsClient{Client: annotations.NewClient(apiRoot)},
			charmRepoClient:   &charmRepoClient{CharmStore: charmrepo.NewCharmStoreFromClient(cstoreClient)},
		}

		return adapter, nil
	}
	return cmd
}

// NewDeployCommand returns a command to deploy services.
func NewDeployCommand(newAPIRoot NewAPIRootFn, steps []DeployStep) cmd.Command {
	return modelcmd.Wrap(&DeployCommand{
		Steps:      steps,
		NewAPIRoot: newAPIRoot,
	})
}

type DeployCommand struct {
	modelcmd.ModelCommandBase
	UnitCommandBase

	// CharmOrBundle is either a charm URL, a path where a charm can be found,
	// or a bundle name.
	CharmOrBundle string

	// Channel holds the charmstore channel to use when obtaining
	// the charm to be deployed.
	Channel params.Channel

	// Series is the series of the charm to deploy.
	Series string

	// Force is used to allow a charm to be deployed onto a machine
	// running an unsupported series.
	Force bool

	ApplicationName string
	Config          cmd.FileVar
	ConstraintsStr  string
	Constraints     constraints.Value
	BindToSpaces    string

	// TODO(axw) move this to UnitCommandBase once we support --storage
	// on add-unit too.
	//
	// Storage is a map of storage constraints, keyed on the storage name
	// defined in charm storage metadata.
	Storage map[string]storage.Constraints

	// BundleStorage maps application names to maps of storage constraints keyed on
	// the storage name defined in that application's charm storage metadata.
	BundleStorage map[string]map[string]storage.Constraints

	// Resources is a map of resource name to filename to be uploaded on deploy.
	Resources map[string]string

	Bindings map[string]string
	Steps    []DeployStep

	// NewAPIRoot stores a function which returns a new API root.
	NewAPIRoot NewAPIRootFn

	flagSet *gnuflag.FlagSet
}

const deployDoc = `
<charm or bundle> can be a charm/bundle URL, or an unambiguously condensed
form of it; assuming a current series of "trusty", the following forms will be
accepted:

For cs:trusty/mysql
  mysql
  trusty/mysql

For cs:~user/trusty/mysql
  ~user/mysql

For cs:bundle/mediawiki-single
  mediawiki-single
  bundle/mediawiki-single

The current series for charms is determined first by the 'default-series' model
setting, followed by the preferred series for the charm in the charm store.

In these cases, a versioned charm URL will be expanded as expected (for
example, mysql-33 becomes cs:precise/mysql-33).

Charms may also be deployed from a user specified path. In this case, the path
to the charm is specified along with an optional series.

  juju deploy /path/to/charm --series trusty

If '--series' is not specified, the charm's default series is used. The default
series for a charm is the first one specified in the charm metadata. If the
specified series is not supported by the charm, this results in an error,
unless '--force' is used.

  juju deploy /path/to/charm --series wily --force

Local bundles are specified with a direct path to a bundle.yaml file.
For example:

  juju deploy /path/to/bundle/openstack/bundle.yaml

If an 'application name' is not provided, the application name used is the
'charm or bundle' name.

Constraints can be specified by specifying the '--constraints' option. If the
application is later scaled out with ` + "`juju add-unit`" + `, provisioned machines
will use the same constraints (unless changed by ` + "`juju set-constraints`" + `).

Resources may be uploaded by specifying the '--resource' option followed by a
name=filepath pair. This option may be repeated more than once to upload more
than one resource.

  juju deploy foo --resource bar=/some/file.tgz --resource baz=./docs/cfg.xml

Where 'bar' and 'baz' are resources named in the metadata for the 'foo' charm.

When using a placement directive to deploy to an existing machine or container
('--to' option), the ` + "`juju status`" + ` command should be used for guidance. A few
placement directives are provider-dependent (e.g.: 'zone').

In more complex scenarios, Juju's network spaces are used to partition the
cloud networking layer into sets of subnets. Instances hosting units inside the
same space can communicate with each other without any firewalls. Traffic
crossing space boundaries could be subject to firewall and access restrictions.
Using spaces as deployment targets, rather than their individual subnets,
allows Juju to perform automatic distribution of units across availability zones
to support high availability for applications. Spaces help isolate applications
and their units, both for security purposes and to manage both traffic
segregation and congestion.

When deploying an application or adding machines, the 'spaces' constraint can
be used to define a comma-delimited list of required and forbidden spaces (the
latter prefixed with "^", similar to the 'tags' constraint).


Examples:
    juju deploy mysql --to 23       (deploy to machine 23)
    juju deploy mysql --to 24/lxd/3 (deploy to lxd container 3 on machine 24)
    juju deploy mysql --to lxd:25   (deploy to a new lxd container on machine 25)
    juju deploy mysql --to lxd      (deploy to a new lxd container on a new machine)

    juju deploy mysql --to zone=us-east-1a
    (provider-dependent; deploy to a specific AZ)

    juju deploy mysql --to host.maas
    (deploy to a specific MAAS node)

    juju deploy mysql -n 5 --constraints mem=8G
    (deploy 5 units to machines with at least 8 GB of memory)

    juju deploy haproxy -n 2 --constraints spaces=dmz,^cms,^database
    (deploy 2 units to machines that are part of the 'dmz' space but not of the
    'cmd' or the 'database' spaces)

See also:
    spaces
    constraints
    add-unit
    set-config
    get-config
    set-constraints
    get-constraints
`

// DeployStep is an action that needs to be taken during charm deployment.
type DeployStep interface {

	// Set flags necessary for the deploy step.
	SetFlags(*gnuflag.FlagSet)

	// RunPre runs before the call is made to add the charm to the environment.
	RunPre(MeteredDeployAPI, *httpbakery.Client, *cmd.Context, DeploymentInfo) error

	// RunPost runs after the call is made to add the charm to the environment.
	// The error parameter is used to notify the step of a previously occurred error.
	RunPost(MeteredDeployAPI, *httpbakery.Client, *cmd.Context, DeploymentInfo, error) error
}

// DeploymentInfo is used to maintain all deployment information for
// deployment steps.
type DeploymentInfo struct {
	CharmID         charmstore.CharmID
	ApplicationName string
	ModelUUID       string
	CharmInfo       *apicharms.CharmInfo
}

func (c *DeployCommand) Info() *cmd.Info {
	return &cmd.Info{
		Name:    "deploy",
		Args:    "<charm or bundle> [<application name>]",
		Purpose: "Deploy a new application or bundle.",
		Doc:     deployDoc,
	}
}

var (
	// charmOnlyFlags and bundleOnlyFlags are used to validate flags based on
	// whether we are deploying a charm or a bundle.
	charmOnlyFlags        = []string{"bind", "config", "constraints", "force", "n", "num-units", "series", "to", "resource"}
	bundleOnlyFlags       = []string{}
	modelCommandBaseFlags = []string{"B", "no-browser-login"}
)

func (c *DeployCommand) SetFlags(f *gnuflag.FlagSet) {
	// Keep above charmOnlyFlags and bundleOnlyFlags lists updated when adding
	// new flags.
	c.UnitCommandBase.SetFlags(f)
	c.ModelCommandBase.SetFlags(f)
	f.IntVar(&c.NumUnits, "n", 1, "Number of application units to deploy for principal charms")
	f.StringVar((*string)(&c.Channel), "channel", "", "Channel to use when getting the charm or bundle from the charm store")
	f.Var(&c.Config, "config", "Path to yaml-formatted application config")
	f.StringVar(&c.ConstraintsStr, "constraints", "", "Set application constraints")
	f.StringVar(&c.Series, "series", "", "The series on which to deploy")
	f.BoolVar(&c.Force, "force", false, "Allow a charm to be deployed to a machine running an unsupported series")
	f.Var(storageFlag{&c.Storage, &c.BundleStorage}, "storage", "Charm storage constraints")
	f.Var(stringMap{&c.Resources}, "resource", "Resource to be uploaded to the controller")
	f.StringVar(&c.BindToSpaces, "bind", "", "Configure application endpoint bindings to spaces")

	for _, step := range c.Steps {
		step.SetFlags(f)
	}
	c.flagSet = f
}

func (c *DeployCommand) Init(args []string) error {
	if c.Force && c.Series == "" && c.PlacementSpec == "" {
		return errors.New("--force is only used with --series")
	}
	switch len(args) {
	case 2:
		if !names.IsValidApplication(args[1]) {
			return errors.Errorf("invalid application name %q", args[1])
		}
		c.ApplicationName = args[1]
		fallthrough
	case 1:
		c.CharmOrBundle = args[0]
	case 0:
		return errors.New("no charm or bundle specified")
	default:
		return cmd.CheckEmpty(args[2:])
	}

	if err := c.parseBind(); err != nil {
		return err
	}
	return c.UnitCommandBase.Init(args)
}

type ModelConfigGetter interface {
	ModelGet() (map[string]interface{}, error)
}

var getModelConfig = func(api ModelConfigGetter) (*config.Config, error) {
	// Separated into a variable for easy overrides
	attrs, err := api.ModelGet()
	if err != nil {
		return nil, errors.Wrap(err, errors.New("cannot fetch model settings"))
	}

	return config.New(config.NoDefaults, attrs)
}

func (c *DeployCommand) deployBundle(
	ctx *cmd.Context,
	filePath string,
	data *charm.BundleData,
	channel params.Channel,
	apiRoot DeployAPI,
	bundleStorage map[string]map[string]storage.Constraints,
) error {
	// TODO(ericsnow) Do something with the CS macaroons that were returned?
	if _, err := deployBundle(
		filePath,
		data,
		channel,
		apiRoot,
		ctx,
		bundleStorage,
	); err != nil {
		return errors.Trace(err)
	}
	ctx.Infof("Deploy of bundle completed.")
	return nil
}

func (c *DeployCommand) deployCharm(
	id charmstore.CharmID,
	csMac *macaroon.Macaroon,
	series string,
	ctx *cmd.Context,
	apiRoot DeployAPI,
) (rErr error) {
	charmInfo, err := apiRoot.CharmInfo(id.URL.String())
	if err != nil {
		return err
	}

	numUnits := c.NumUnits
	if charmInfo.Meta.Subordinate {
		if !constraints.IsEmpty(&c.Constraints) {
			return errors.New("cannot use --constraints with subordinate application")
		}
		if numUnits == 1 && c.PlacementSpec == "" {
			numUnits = 0
		} else {
			return errors.New("cannot use --num-units or --to with subordinate application")
		}
	}
	serviceName := c.ApplicationName
	if serviceName == "" {
		serviceName = charmInfo.Meta.Name
	}

	var configYAML []byte
	if c.Config.Path != "" {
		configYAML, err = c.Config.Read(ctx)
		if err != nil {
			return errors.Trace(err)
		}
	}

	bakeryClient, err := c.BakeryClient()
	if err != nil {
		return errors.Trace(err)
	}

	uuid, ok := apiRoot.ModelUUID()
	if !ok {
		return errors.New("API connection is controller-only (should never happen)")
	}

	deployInfo := DeploymentInfo{
		CharmID:         id,
		ApplicationName: serviceName,
		ModelUUID:       uuid,
		CharmInfo:       charmInfo,
	}

	for _, step := range c.Steps {
		err = step.RunPre(apiRoot, bakeryClient, ctx, deployInfo)
		if err != nil {
			return errors.Trace(err)
		}
	}

	defer func() {
		for _, step := range c.Steps {
			err = errors.Trace(step.RunPost(apiRoot, bakeryClient, ctx, deployInfo, rErr))
			if err != nil {
				rErr = err
			}
		}
	}()

	if id.URL != nil && id.URL.Schema != "local" && len(charmInfo.Meta.Terms) > 0 {
		ctx.Infof("Deployment under prior agreement to terms: %s",
			strings.Join(charmInfo.Meta.Terms, " "))
	}

	ids, err := resourceadapters.DeployResources(
		serviceName,
		id,
		csMac,
		c.Resources,
		charmInfo.Meta.Resources,
		apiRoot,
	)
	if err != nil {
		return errors.Trace(err)
	}

	return errors.Trace(apiRoot.Deploy(application.DeployArgs{
		CharmID:          id,
		Cons:             c.Constraints,
		ApplicationName:  serviceName,
		Series:           series,
		NumUnits:         numUnits,
		ConfigYAML:       string(configYAML),
		Placement:        c.Placement,
		Storage:          c.Storage,
		Resources:        ids,
		EndpointBindings: c.Bindings,
	}))
}

const parseBindErrorPrefix = "--bind must be in the form '[<default-space>] [<endpoint-name>=<space> ...]'. "

// parseBind parses the --bind option. Valid forms are:
// * relation-name=space-name
// * extra-binding-name=space-name
// * space-name (equivalent to binding all endpoints to the same space, i.e. application-default)
// * The above in a space separated list to specify multiple bindings,
//   e.g. "rel1=space1 ext1=space2 space3"
func (c *DeployCommand) parseBind() error {
	bindings := make(map[string]string)
	if c.BindToSpaces == "" {
		return nil
	}

	for _, s := range strings.Split(c.BindToSpaces, " ") {
		s = strings.TrimSpace(s)
		if s == "" {
			continue
		}

		v := strings.Split(s, "=")
		var endpoint, space string
		switch len(v) {
		case 1:
			endpoint = ""
			space = v[0]
		case 2:
			if v[0] == "" {
				return errors.New(parseBindErrorPrefix + "Found = without endpoint name. Use a lone space name to set the default.")
			}
			endpoint = v[0]
			space = v[1]
		default:
			return errors.New(parseBindErrorPrefix + "Found multiple = in binding. Did you forget to space-separate the binding list?")
		}

		if !names.IsValidSpace(space) {
			return errors.New(parseBindErrorPrefix + "Space name invalid.")
		}
		bindings[endpoint] = space
	}
	c.Bindings = bindings
	return nil
}

func (c *DeployCommand) Run(ctx *cmd.Context) error {
	var err error
	c.Constraints, err = common.ParseConstraints(ctx, c.ConstraintsStr)
	if err != nil {
		return err
	}
	apiRoot, err := c.NewAPIRoot()
	if err != nil {
		return errors.Trace(err)
	}
	defer apiRoot.Close()

	deploy, err := findDeployerFIFO(
		c.maybeReadLocalBundle,
		c.maybeReadLocalCharm,
		c.maybePredeployedLocalCharm,
		c.maybeReadCharmstoreBundleFn(apiRoot),
		c.charmStoreCharm, // This always returns a deployer
	)
	if err != nil {
		return errors.Trace(err)
	}

	return block.ProcessBlockedError(deploy(ctx, apiRoot), block.BlockChange)
}

func findDeployerFIFO(maybeDeployers ...func() (deployFn, error)) (deployFn, error) {
	for _, d := range maybeDeployers {
		if deploy, err := d(); err != nil {
			return nil, errors.Trace(err)
		} else if deploy != nil {
			return deploy, nil
		}
	}
	return nil, errors.NotFoundf("suitable deployer")
}

type deployFn func(*cmd.Context, DeployAPI) error

func (c *DeployCommand) validateBundleFlags() error {
	if flags := getFlags(c.flagSet, charmOnlyFlags); len(flags) > 0 {
		return errors.Errorf("Flags provided but not supported when deploying a bundle: %s.", strings.Join(flags, ", "))
	}
	return nil
}

func (c *DeployCommand) validateCharmFlags() error {
	if flags := getFlags(c.flagSet, bundleOnlyFlags); len(flags) > 0 {
		return errors.Errorf("Flags provided but not supported when deploying a charm: %s.", strings.Join(flags, ", "))
	}
	return nil
}

func (c *DeployCommand) maybePredeployedLocalCharm() (deployFn, error) {
	// If the charm's schema is local, we should definitively attempt
	// to deploy a charm that's already deployed in the
	// environment.
	userCharmURL, err := charm.ParseURL(c.CharmOrBundle)
	if err != nil {
		return nil, errors.Trace(err)
	} else if userCharmURL.Schema != "local" {
		logger.Debugf("cannot interpret as a redeployment of a local charm from the controller")
		return nil, nil
	}

	return func(ctx *cmd.Context, api DeployAPI) error {
		formattedCharmURL := userCharmURL.String()
		ctx.Infof("Located charm %q.", formattedCharmURL)
		ctx.Infof("Deploying charm %q.", formattedCharmURL)
		return errors.Trace(c.deployCharm(
			charmstore.CharmID{URL: userCharmURL},
			(*macaroon.Macaroon)(nil),
			userCharmURL.Series,
			ctx,
			api,
		))
	}, nil
}

func (c *DeployCommand) maybeReadLocalBundle() (deployFn, error) {
	bundleFile := c.CharmOrBundle
	var (
		bundleFilePath                string
		resolveRelativeBundleFilePath bool
	)

	bundleData, err := charmrepo.ReadBundleFile(bundleFile)
	if err != nil {
		// We may have been given a local bundle archive or exploded directory.
		bundle, url, pathErr := charmrepo.NewBundleAtPath(bundleFile)
		if charmrepo.IsInvalidPathError(pathErr) {
			return nil, errors.Errorf(""+
				"The charm or bundle %q is ambiguous.\n"+
				"To deploy a local charm or bundle, run `juju deploy ./%[1]s`.\n"+
				"To deploy a charm or bundle from the store, run `juju deploy cs:%[1]s`.",
				c.CharmOrBundle,
			)
		}
		if pathErr != nil {
			// If the bundle files existed but we couldn't read them,
			// then return that error rather than trying to interpret
			// as a charm.
			if info, statErr := os.Stat(c.CharmOrBundle); statErr == nil {
				if info.IsDir() {
					if _, ok := pathErr.(*charmrepo.NotFoundError); !ok {
						return nil, pathErr
					}
				}
			}

			logger.Debugf("cannot interpret as local bundle: %v", err)
			return nil, nil
		}

		bundleData = bundle.Data()
		bundleFile = url.String()
		if info, err := os.Stat(bundleFile); err == nil && info.IsDir() {
			bundleFilePath = bundleFile
		}
	} else {
		resolveRelativeBundleFilePath = true
	}

	if err := c.validateBundleFlags(); err != nil {
		return nil, errors.Trace(err)
	}

	return func(ctx *cmd.Context, apiRoot DeployAPI) error {
		// For local bundles, we extract the local path of the bundle
		// directory.
		if resolveRelativeBundleFilePath {
			bundleFilePath = filepath.Dir(ctx.AbsPath(bundleFile))
		}

		return errors.Trace(c.deployBundle(
			ctx,
			bundleFilePath,
			bundleData,
			c.Channel,
			apiRoot,
			c.BundleStorage,
		))
	}, nil
}

func (c *DeployCommand) maybeReadLocalCharm() (deployFn, error) {
	// Charm may have been supplied via a path reference.
	ch, curl, err := charmrepo.NewCharmAtPathForceSeries(c.CharmOrBundle, c.Series, c.Force)
	// We check for several types of known error which indicate
	// that the supplied reference was indeed a path but there was
	// an issue reading the charm located there.
	if charm.IsMissingSeriesError(err) {
		return nil, err
	} else if charm.IsUnsupportedSeriesError(err) {
		return nil, errors.Errorf("%v. Use --force to deploy the charm anyway.", err)
	} else if errors.Cause(err) == zip.ErrFormat {
		return nil, errors.Errorf("invalid charm or bundle provided at %q", c.CharmOrBundle)
	} else if _, ok := err.(*charmrepo.NotFoundError); ok {
		return nil, errors.Wrap(err, errors.NotFoundf("charm or bundle at %q", c.CharmOrBundle))
	} else if err != nil && err != os.ErrNotExist {
		// If we get a "not exists" error then we attempt to interpret
		// the supplied charm reference as a URL elsewhere, otherwise
		// we return the error.
		return nil, errors.Trace(err)
	} else if err != nil {
		logger.Debugf("cannot interpret as local charm: %v", err)
		return nil, nil
	}

	return func(ctx *cmd.Context, apiRoot DeployAPI) error {
		if curl, err = apiRoot.AddLocalCharm(curl, ch); err != nil {
			return errors.Trace(err)
		}

		id := charmstore.CharmID{
			URL: curl,
			// Local charms don't need a channel.
		}

		ctx.Infof("Deploying charm %q.", curl.String())
		return errors.Trace(c.deployCharm(
			id,
			(*macaroon.Macaroon)(nil), // local charms don't need one.
			curl.Series,
			ctx,
			apiRoot,
		))
	}, nil
}

func (c *DeployCommand) maybeReadCharmstoreBundleFn(apiRoot DeployAPI) func() (deployFn, error) {
	return func() (deployFn, error) {
		userRequestedURL, err := charm.ParseURL(c.CharmOrBundle)
		if err != nil {
			return nil, errors.Trace(err)
		}

		modelCfg, err := getModelConfig(apiRoot)
		if err != nil {
			return nil, errors.Trace(err)
		}

		// Charm or bundle has been supplied as a URL so we resolve and
		// deploy using the store.
		storeCharmOrBundleURL, channel, _, err := apiRoot.Resolve(modelCfg, userRequestedURL)
		if charm.IsUnsupportedSeriesError(err) {
			return nil, errors.Errorf("%v. Use --force to deploy the charm anyway.", err)
		} else if err != nil {
			return nil, errors.Trace(err)
		} else if storeCharmOrBundleURL.Series != "bundle" {
			logger.Debugf(
				`cannot interpret as charmstore bundle: %v (series) != "bundle"`,
				storeCharmOrBundleURL.Series,
			)
			return nil, nil
		}

		if err := c.validateBundleFlags(); err != nil {
			return nil, errors.Trace(err)
		}

		return func(ctx *cmd.Context, apiRoot DeployAPI) error {
			bundle, err := apiRoot.GetBundle(storeCharmOrBundleURL)
			if err != nil {
				return errors.Trace(err)
			}
			ctx.Infof("Located bundle %q", storeCharmOrBundleURL)
			data := bundle.Data()

			return errors.Trace(c.deployBundle(
				ctx,
				"", // filepath
				data,
				channel,
				apiRoot,
				c.BundleStorage,
			))
		}, nil
	}
}

func (c *DeployCommand) charmStoreCharm() (deployFn, error) {
	userRequestedURL, err := charm.ParseURL(c.CharmOrBundle)
	if err != nil {
		return nil, errors.Trace(err)
	}

	return func(ctx *cmd.Context, apiRoot DeployAPI) error {
		// resolver.resolve potentially updates the series of anything
		// passed in. Store this for use in seriesSelector.
		userRequestedSeries := userRequestedURL.Series

		modelCfg, err := getModelConfig(apiRoot)
		if err != nil {
			return errors.Trace(err)
		}

		// Charm or bundle has been supplied as a URL so we resolve and deploy using the store.
		storeCharmOrBundleURL, channel, supportedSeries, err := apiRoot.Resolve(modelCfg, userRequestedURL)
		if charm.IsUnsupportedSeriesError(err) {
			return errors.Errorf("%v. Use --force to deploy the charm anyway.", err)
		} else if err != nil {
			return errors.Trace(err)
		}

		if err := c.validateCharmFlags(); err != nil {
			return errors.Trace(err)
		}

		selector := seriesSelector{
			charmURLSeries:  userRequestedSeries,
			seriesFlag:      c.Series,
			supportedSeries: supportedSeries,
			force:           c.Force,
			conf:            modelCfg,
			fromBundle:      false,
		}

		// Get the series to use.
		series, err := selector.charmSeries()
		if charm.IsUnsupportedSeriesError(err) {
			return errors.Errorf("%v. Use --force to deploy the charm anyway.", err)
		}

		// Store the charm in the controller
		curl, csMac, err := addCharmFromURL(apiRoot, storeCharmOrBundleURL, channel)
		if err != nil {
			if err1, ok := errors.Cause(err).(*termsRequiredError); ok {
				terms := strings.Join(err1.Terms, " ")
				return errors.Errorf(`Declined: please agree to the following terms %s. Try: "juju agree %s"`, terms, terms)
			}
			return errors.Annotatef(err, "storing charm for URL %q", storeCharmOrBundleURL)
		}

		formattedCharmURL := curl.String()
		ctx.Infof("Located charm %q.", formattedCharmURL)
		ctx.Infof("Deploying charm %q.", formattedCharmURL)
		id := charmstore.CharmID{
			URL:     curl,
			Channel: channel,
		}
		return errors.Trace(c.deployCharm(
			id,
			csMac,
			series,
			ctx,
			apiRoot,
		))
	}, nil
}

// getFlags returns the flags with the given names. Only flags that are set and
// whose name is included in flagNames are included.
func getFlags(flagSet *gnuflag.FlagSet, flagNames []string) []string {
	flags := make([]string, 0, flagSet.NFlag())
	flagSet.Visit(func(flag *gnuflag.Flag) {
		for _, name := range flagNames {
			if flag.Name == name {
				flags = append(flags, flagWithMinus(name))
			}
		}
	})
	return flags
}

func flagWithMinus(name string) string {
	if len(name) > 1 {
		return "--" + name
	}
	return "-" + name
}