func (t *localServerSuite) TestAllocateAddressFailureToFindNetworkInterface(c *gc.C) {
	env := t.prepareEnviron(c)
	err := bootstrap.Bootstrap(envtesting.BootstrapContext(c), env, bootstrap.BootstrapParams{})
	c.Assert(err, jc.ErrorIsNil)

	instanceIds, err := env.StateServerInstances()
	c.Assert(err, jc.ErrorIsNil)

	instId := instanceIds[0]
	addr := network.Address{Value: "8.0.0.4"}

	// Invalid instance found
	err = env.AllocateAddress(instId+"foo", "", &addr, "foo", "bar")
	c.Assert(err, gc.ErrorMatches, ".*InvalidInstanceID.NotFound.*")

	// No network interface
	err = env.AllocateAddress(instId, "", &addr, "foo", "bar")
	c.Assert(errors.Cause(err), gc.ErrorMatches, "unexpected AWS response: network interface not found")

	// Nil or empty address given.
	err = env.AllocateAddress(instId, "", nil, "foo", "bar")
	c.Assert(errors.Cause(err), gc.ErrorMatches, "invalid address: nil or empty")

	err = env.AllocateAddress(instId, "", &network.Address{Value: ""}, "foo", "bar")
	c.Assert(errors.Cause(err), gc.ErrorMatches, "invalid address: nil or empty")
}

func (s *uniterResolver) nextOp(
	localState resolver.LocalState,
	remoteState remotestate.Snapshot,
	opFactory operation.Factory,
) (operation.Operation, error) {

	switch remoteState.Life {
	case params.Alive:
	case params.Dying:
		// Normally we handle relations last, but if we're dying we
		// must ensure that all relations are broken first.
		op, err := s.config.Relations.NextOp(localState, remoteState, opFactory)
		if errors.Cause(err) != resolver.ErrNoOperation {
			return op, err
		}

		// We're not in a hook error and the unit is Dying,
		// so we should proceed to tear down.
		//
		// TODO(axw) move logic for cascading destruction of
		//           subordinates, relation units and storage
		//           attachments into state, via cleanups.
		if localState.Started {
			return opFactory.NewRunHook(hook.Info{Kind: hooks.Stop})
		}
		fallthrough
	case params.Dead:
		// The unit is dying/dead and stopped, so tell the uniter
		// to terminate.
		return nil, resolver.ErrTerminate
	}

	// Now that storage hooks have run at least once, before anything else,
	// we need to run the install hook.
	// TODO(cmars): remove !localState.Started. It's here as a temporary
	// measure because unit agent upgrades aren't being performed yet.
	if !localState.Installed && !localState.Started {
		return opFactory.NewRunHook(hook.Info{Kind: hooks.Install})
	}

	if charmModified(localState, remoteState) {
		return opFactory.NewUpgrade(remoteState.CharmURL)
	}

	if localState.ConfigVersion != remoteState.ConfigVersion {
		return opFactory.NewRunHook(hook.Info{Kind: hooks.ConfigChanged})
	}

	op, err := s.config.Relations.NextOp(localState, remoteState, opFactory)
	if errors.Cause(err) != resolver.ErrNoOperation {
		return op, err
	}

	// UpdateStatus hook runs if nothing else needs to.
	if localState.UpdateStatusVersion != remoteState.UpdateStatusVersion {
		return opFactory.NewRunHook(hook.Info{Kind: hooks.UpdateStatus})
	}

	return nil, resolver.ErrNoOperation
}

// newState returns a new State that uses the given environment.
// The environment must have already been bootstrapped.
func newState(environ environs.Environ, mongoInfo *mongo.MongoInfo) (*state.State, error) {
	config := environ.Config()
	password := config.AdminSecret()
	if password == "" {
		return nil, fmt.Errorf("cannot connect without admin-secret")
	}
	modelTag := names.NewModelTag(config.UUID())

	mongoInfo.Password = password
	opts := mongo.DefaultDialOpts()
	st, err := state.Open(modelTag, mongoInfo, opts, environs.NewStatePolicy())
	if errors.IsUnauthorized(errors.Cause(err)) {
		// We try for a while because we might succeed in
		// connecting to mongo before the state has been
		// initialized and the initial password set.
		for a := redialStrategy.Start(); a.Next(); {
			st, err = state.Open(modelTag, mongoInfo, opts, environs.NewStatePolicy())
			if !errors.IsUnauthorized(errors.Cause(err)) {
				break
			}
		}
		if err != nil {
			return nil, err
		}
	} else if err != nil {
		return nil, err
	}
	if err := updateSecrets(environ, st); err != nil {
		st.Close()
		return nil, fmt.Errorf("unable to push secrets: %v", err)
	}
	return st, nil
}

func (s *loginSuite) TestLoginAsDeactivatedUser(c *gc.C) {
	info, cleanup := s.setupServerWithValidator(c, nil)
	defer cleanup()

	info.Tag = nil
	info.Password = ""
	st, err := api.Open(info, fastDialOpts)
	c.Assert(err, jc.ErrorIsNil)
	defer st.Close()
	password := "password"
	u := s.Factory.MakeUser(c, &factory.UserParams{Password: password, Disabled: true})

	_, err = st.Client().Status([]string{})
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: `unknown object type "Client"`,
		Code:    "not implemented",
	})

	// Since these are user login tests, the nonce is empty.
	err = st.Login(u.Tag(), password, "")
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: "invalid entity name or password",
		Code:    "unauthorized access",
	})

	_, err = st.Client().Status([]string{})
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: `unknown object type "Client"`,
		Code:    "not implemented",
	})
}

func (s *loginSuite) TestLoginAsDeactivatedUser(c *gc.C) {
	info, srv := newServer(c, s.State)
	defer assertStop(c, srv)
	info.ModelTag = s.State.ModelTag()

	st := s.openAPIWithoutLogin(c, info)
	password := "password"
	u := s.Factory.MakeUser(c, &factory.UserParams{Password: password, Disabled: true})

	_, err := st.Client().Status([]string{})
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: `unknown object type "Client"`,
		Code:    "not implemented",
	})

	// Since these are user login tests, the nonce is empty.
	err = st.Login(u.Tag(), password, "", nil)
	assertInvalidEntityPassword(c, err)

	_, err = st.Client().Status([]string{})
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: `unknown object type "Client"`,
		Code:    "not implemented",
	})
}

// Run implements Command.Run
func (c *killCommand) Run(ctx *cmd.Context) error {
	controllerName := c.ControllerName()
	store := c.ClientStore()
	if !c.assumeYes {
		if err := confirmDestruction(ctx, controllerName); err != nil {
			return err
		}
	}

	// Attempt to connect to the API.
	api, err := c.getControllerAPI()
	switch {
	case err == nil:
		defer api.Close()
	case errors.Cause(err) == common.ErrPerm:
		return errors.Annotate(err, "cannot destroy controller")
	default:
		if errors.Cause(err) != modelcmd.ErrConnTimedOut {
			logger.Debugf("unable to open api: %s", err)
		}
		ctx.Infof("Unable to open API: %s\n", err)
		api = nil
	}

	// Obtain controller environ so we can clean up afterwards.
	controllerEnviron, err := c.getControllerEnviron(ctx, store, controllerName, api)
	if err != nil {
		return errors.Annotate(err, "getting controller environ")
	}
	// If we were unable to connect to the API, just destroy the controller through
	// the environs interface.
	if api == nil {
		ctx.Infof("Unable to connect to the API server. Destroying through provider.")
		return environs.Destroy(controllerName, controllerEnviron, store)
	}

	// Attempt to destroy the controller and all environments.
	err = api.DestroyController(true)
	if err != nil {
		ctx.Infof("Unable to destroy controller through the API: %s.  Destroying through provider.", err)
		return environs.Destroy(controllerName, controllerEnviron, store)
	}

	ctx.Infof("Destroying controller %q\nWaiting for resources to be reclaimed", controllerName)

	updateStatus := newTimedStatusUpdater(ctx, api, controllerEnviron.Config().UUID())
	for ctrStatus, envsStatus := updateStatus(0); hasUnDeadModels(envsStatus); ctrStatus, envsStatus = updateStatus(2 * time.Second) {
		ctx.Infof(fmtCtrStatus(ctrStatus))
		for _, envStatus := range envsStatus {
			ctx.Verbosef(fmtModelStatus(envStatus))
		}
	}

	ctx.Infof("All hosted models reclaimed, cleaning up controller machines")

	return environs.Destroy(controllerName, controllerEnviron, store)
}

func (s *loginSuite) TestBadLogin(c *gc.C) {
	// Start our own server so we can control when the first login
	// happens. Otherwise in JujuConnSuite.SetUpTest api.Open is
	// called with user-admin permissions automatically.
	info, cleanup := s.setupServerWithValidator(c, nil)
	defer cleanup()

	adminUser := s.AdminUserTag(c)

	for i, t := range []struct {
		tag      names.Tag
		password string
		err      error
		code     string
	}{{
		tag:      adminUser,
		password: "wrong password",
		err: &rpc.RequestError{
			Message: "invalid entity name or password",
			Code:    "unauthorized access",
		},
		code: params.CodeUnauthorized,
	}, {
		tag:      names.NewUserTag("unknown"),
		password: "password",
		err: &rpc.RequestError{
			Message: "invalid entity name or password",
			Code:    "unauthorized access",
		},
		code: params.CodeUnauthorized,
	}} {
		c.Logf("test %d; entity %q; password %q", i, t.tag, t.password)
		func() {
			// Open the API without logging in, so we can perform
			// operations on the connection before calling Login.
			st := s.openAPIWithoutLogin(c, info)
			defer st.Close()

			_, err := apimachiner.NewState(st).Machine(names.NewMachineTag("0"))
			c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
				Message: `unknown object type "Machiner"`,
				Code:    "not implemented",
			})

			// Since these are user login tests, the nonce is empty.
			err = st.Login(t.tag, t.password, "", nil)
			c.Assert(errors.Cause(err), gc.DeepEquals, t.err)
			c.Assert(params.ErrCode(err), gc.Equals, t.code)

			_, err = apimachiner.NewState(st).Machine(names.NewMachineTag("0"))
			c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
				Message: `unknown object type "Machiner"`,
				Code:    "not implemented",
			})
		}()
	}
}

func rebootstrap(cfg *config.Config, ctx *cmd.Context, cons constraints.Value) (environs.Environ, error) {
	progress("re-bootstrapping environment")
	// Turn on safe mode so that the newly bootstrapped instance
	// will not destroy all the instances it does not know about.
	cfg, err := cfg.Apply(map[string]interface{}{
		"provisioner-safe-mode": true,
	})
	if err != nil {
		return nil, errors.Annotate(err, "cannot enable provisioner-safe-mode")
	}
	env, err := environs.New(cfg)
	if err != nil {
		return nil, err
	}
	instanceIds, err := env.StateServerInstances()
	switch errors.Cause(err) {
	case nil, environs.ErrNoInstances:
		// Some providers will return a nil error even
		// if there are no live state server instances.
		break
	case environs.ErrNotBootstrapped:
		return nil, errors.Trace(err)
	default:
		return nil, errors.Annotate(err, "cannot determine state server instances")
	}
	if len(instanceIds) > 0 {
		instances, err := env.Instances(instanceIds)
		switch errors.Cause(err) {
		case nil, environs.ErrPartialInstances:
			return nil, fmt.Errorf("old bootstrap instances %q still seems to exist; will not replace", instances)
		case environs.ErrNoInstances:
			// No state server instances, so keep running.
			break
		default:
			return nil, errors.Annotate(err, "cannot detect whether old instance is still running")
		}
	}
	// Remove the storage so that we can bootstrap without the provider complaining.
	if env, ok := env.(environs.EnvironStorage); ok {
		if err := env.Storage().Remove(common.StateFile); err != nil {
			return nil, errors.Annotate(err, fmt.Sprintf("cannot remove %q from storage", common.StateFile))
		}
	}

	// TODO If we fail beyond here, then we won't have a state file and
	// we won't be able to re-run this script because it fails without it.
	// We could either try to recreate the file if we fail (which is itself
	// error-prone) or we could provide a --no-check flag to make
	// it go ahead anyway without the check.

	args := bootstrap.BootstrapParams{Constraints: cons}
	if err := bootstrap.Bootstrap(envcmd.BootstrapContextNoVerify(ctx), env, args); err != nil {
		return nil, errors.Annotate(err, "cannot bootstrap new instance")
	}
	return env, nil
}

// WaitForAgentInitialisation polls the bootstrapped controller with a read-only
// command which will fail until the controller is fully initialised.
// TODO(wallyworld) - add a bespoke command to maybe the admin facade for this purpose.
func WaitForAgentInitialisation(ctx *cmd.Context, c *modelcmd.ModelCommandBase, controllerName, hostedModelName string) error {
	// TODO(katco): 2016-08-09: lp:1611427
	attempts := utils.AttemptStrategy{
		Min:   bootstrapReadyPollCount,
		Delay: bootstrapReadyPollDelay,
	}
	var (
		apiAttempts int
		err         error
	)

	// Make a best effort to find the new controller address so we can print it.
	addressInfo := ""
	controller, err := c.ClientStore().ControllerByName(controllerName)
	if err == nil && len(controller.APIEndpoints) > 0 {
		addr, err := network.ParseHostPort(controller.APIEndpoints[0])
		if err == nil {
			addressInfo = fmt.Sprintf(" at %s", addr.Address.Value)
		}
	}

	ctx.Infof("Contacting Juju controller%s to verify accessibility...", addressInfo)
	apiAttempts = 1
	for attempt := attempts.Start(); attempt.Next(); apiAttempts++ {
		err = tryAPI(c)
		if err == nil {
			ctx.Infof("Bootstrap complete, %q controller now available.", controllerName)
			ctx.Infof("Controller machines are in the %q model.", bootstrap.ControllerModelName)
			ctx.Infof("Initial model %q added.", hostedModelName)
			break
		}
		// As the API server is coming up, it goes through a number of steps.
		// Initially the upgrade steps run, but the api server allows some
		// calls to be processed during the upgrade, but not the list blocks.
		// Logins are also blocked during space discovery.
		// It is also possible that the underlying database causes connections
		// to be dropped as it is initialising, or reconfiguring. These can
		// lead to EOF or "connection is shut down" error messages. We skip
		// these too, hoping that things come back up before the end of the
		// retry poll count.
		errorMessage := errors.Cause(err).Error()
		switch {
		case errors.Cause(err) == io.EOF,
			strings.HasSuffix(errorMessage, "connection is shut down"),
			strings.HasSuffix(errorMessage, "no api connection available"),
			strings.Contains(errorMessage, "spaces are still being discovered"):
			ctx.Verbosef("Still waiting for API to become available")
			continue
		case params.ErrCode(err) == params.CodeUpgradeInProgress:
			ctx.Verbosef("Still waiting for API to become available: %v", err)
			continue
		}
		break
	}
	return errors.Annotatef(err, "unable to contact api server after %d attempts", apiAttempts)
}

// Run implements Command.Run
func (c *killCommand) Run(ctx *cmd.Context) error {
	controllerName := c.ControllerName()
	store := c.ClientStore()
	if !c.assumeYes {
		if err := confirmDestruction(ctx, controllerName); err != nil {
			return err
		}
	}

	// Attempt to connect to the API.
	api, err := c.getControllerAPI()
	switch {
	case err == nil:
		defer api.Close()
	case errors.Cause(err) == common.ErrPerm:
		return errors.Annotate(err, "cannot destroy controller")
	default:
		if errors.Cause(err) != modelcmd.ErrConnTimedOut {
			logger.Debugf("unable to open api: %s", err)
		}
		ctx.Infof("Unable to open API: %s\n", err)
		api = nil
	}

	// Obtain controller environ so we can clean up afterwards.
	controllerEnviron, err := c.getControllerEnviron(ctx, store, controllerName, api)
	if err != nil {
		return errors.Annotate(err, "getting controller environ")
	}
	// If we were unable to connect to the API, just destroy the controller through
	// the environs interface.
	if api == nil {
		ctx.Infof("Unable to connect to the API server, destroying through provider")
		return environs.Destroy(controllerName, controllerEnviron, store)
	}

	// Attempt to destroy the controller and all environments.
	err = api.DestroyController(true)
	if err != nil {
		ctx.Infof("Unable to destroy controller through the API: %s\nDestroying through provider", err)
		return environs.Destroy(controllerName, controllerEnviron, store)
	}

	ctx.Infof("Destroying controller %q\nWaiting for resources to be reclaimed", controllerName)

	uuid := controllerEnviron.Config().UUID()
	if err := c.WaitForModels(ctx, api, uuid); err != nil {
		c.DirectDestroyRemaining(ctx, api)
	}
	return environs.Destroy(controllerName, controllerEnviron, store)
}

// TODO: The following functions can be moved later.
// ErrorEqual returns a boolean indicating whether err1 is equal to err2.
func ErrorEqual(err1, err2 error) bool {
	e1 := errors.Cause(err1)
	e2 := errors.Cause(err2)

	if e1 == e2 {
		return true
	}

	if e1 == nil || e2 == nil {
		return e1 == e2
	}

	return e1.Error() == e2.Error()
}

// filesystemParamsBySource separates the filesystem parameters by filesystem source.
func filesystemParamsBySource(
	environConfig *config.Config,
	baseStorageDir string,
	params []storage.FilesystemParams,
	managedFilesystemSource storage.FilesystemSource,
) (map[string][]storage.FilesystemParams, map[string]storage.FilesystemSource, error) {
	// TODO(axw) later we may have multiple instantiations (sources)
	// for a storage provider, e.g. multiple Ceph installations. For
	// now we assume a single source for each provider type, with no
	// configuration.
	filesystemSources := make(map[string]storage.FilesystemSource)
	for _, params := range params {
		sourceName := string(params.Provider)
		if _, ok := filesystemSources[sourceName]; ok {
			continue
		}
		if params.Volume != (names.VolumeTag{}) {
			filesystemSources[sourceName] = managedFilesystemSource
			continue
		}
		filesystemSource, err := filesystemSource(
			environConfig, baseStorageDir, sourceName, params.Provider,
		)
		if errors.Cause(err) == errNonDynamic {
			filesystemSource = nil
		} else if err != nil {
			return nil, nil, errors.Annotate(err, "getting filesystem source")
		}
		filesystemSources[sourceName] = filesystemSource
	}
	paramsBySource := make(map[string][]storage.FilesystemParams)
	for _, params := range params {
		sourceName := string(params.Provider)
		filesystemSource := filesystemSources[sourceName]
		if filesystemSource == nil {
			// Ignore nil filesystem sources; this means that the
			// filesystem should be created by the machine-provisioner.
			continue
		}
		err := filesystemSource.ValidateFilesystemParams(params)
		switch errors.Cause(err) {
		case nil:
			paramsBySource[sourceName] = append(paramsBySource[sourceName], params)
		default:
			return nil, nil, errors.Annotatef(err, "invalid parameters for filesystem %s", params.Tag.Id())
		}
	}
	return paramsBySource, filesystemSources, nil
}

func (t *localServerSuite) TestAllocateAddressIPAddressInUseOrEmpty(c *gc.C) {
	env, instId := t.setUpInstanceWithDefaultVpc(c)

	addr := network.Address{Value: "8.0.0.4"}
	mockAssign := func(ec2Inst *amzec2.EC2, netId string, addr network.Address) error {
		return &amzec2.Error{Code: "InvalidParameterValue"}
	}
	t.PatchValue(&ec2.AssignPrivateIPAddress, mockAssign)

	err := env.AllocateAddress(instId, "", addr, "foo", "bar")
	c.Assert(errors.Cause(err), gc.Equals, environs.ErrIPAddressUnavailable)

	err = env.AllocateAddress(instId, "", network.Address{}, "foo", "bar")
	c.Assert(errors.Cause(err), gc.Equals, environs.ErrIPAddressUnavailable)
}

func (*rpcSuite) TestTransformErrors(c *gc.C) {
	root := &Root{
		errorInst: &ErrorMethods{&codedError{"message", "code"}},
	}
	tfErr := func(err error) error {
		c.Check(err, gc.NotNil)
		if e, ok := err.(*codedError); ok {
			return &codedError{
				m:    "transformed: " + e.m,
				code: "transformed: " + e.code,
			}
		}
		return fmt.Errorf("transformed: %v", err)
	}
	client, srvDone, _, _ := newRPCClientServer(c, root, tfErr, false)
	defer closeClient(c, client, srvDone)
	// First, we don't transform methods we can't find.
	err := client.Call(rpc.Request{"foo", 0, "", "bar"}, nil, nil)
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: `unknown object type "foo"`,
		Code:    rpc.CodeNotImplemented,
	})

	err = client.Call(rpc.Request{"ErrorMethods", 0, "", "NoMethod"}, nil, nil)
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: "no such request - method ErrorMethods.NoMethod is not implemented",
		Code:    rpc.CodeNotImplemented,
	})

	// We do transform any errors that happen from calling the RootMethod
	// and beyond.
	err = client.Call(rpc.Request{"ErrorMethods", 0, "", "Call"}, nil, nil)
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: "transformed: message",
		Code:    "transformed: code",
	})

	root.errorInst.err = nil
	err = client.Call(rpc.Request{"ErrorMethods", 0, "", "Call"}, nil, nil)
	c.Assert(err, jc.ErrorIsNil)

	root.errorInst = nil
	err = client.Call(rpc.Request{"ErrorMethods", 0, "", "Call"}, nil, nil)
	c.Assert(errors.Cause(err), gc.DeepEquals, &rpc.RequestError{
		Message: "transformed: no error methods",
	})

}

// setStatus inteprets the supplied params as documented on the type.
func setStatus(st *State, params setStatusParams) (err error) {
	defer errors.DeferredAnnotatef(&err, "cannot set status")

	// TODO(fwereade): this can/should probably be recording the time the
	// status was *set*, not the time it happened to arrive in state.
	// We should almost certainly be accepting StatusInfo in the exposed
	// SetStatus methods, for symetry with the Status methods.
	now := time.Now().UnixNano()
	doc := statusDoc{
		Status:     params.status,
		StatusInfo: params.message,
		StatusData: escapeKeys(params.rawData),
		Updated:    now,
	}
	probablyUpdateStatusHistory(st, params.globalKey, doc)

	// Set the authoritative status document, or fail trying.
	buildTxn := updateStatusSource(st, params.globalKey, doc)
	if params.token != nil {
		buildTxn = buildTxnWithLeadership(buildTxn, params.token)
	}
	err = st.run(buildTxn)
	if cause := errors.Cause(err); cause == mgo.ErrNotFound {
		return errors.NotFoundf(params.badge)
	}
	return errors.Trace(err)
}

func (s *relationsSuite) TestNextOpNothing(c *gc.C) {
	unitTag := names.NewUnitTag("wordpress/0")
	abort := make(chan struct{})

	var numCalls int32
	unitEntity := params.Entities{Entities: []params.Entity{params.Entity{Tag: "unit-wordpress-0"}}}
	apiCaller := mockAPICaller(c, &numCalls,
		uniterApiCall("Life", unitEntity, params.LifeResults{Results: []params.LifeResult{{Life: params.Alive}}}, nil),
		uniterApiCall("JoinedRelations", unitEntity, params.StringsResults{Results: []params.StringsResult{{Result: []string{}}}}, nil),
		uniterApiCall("GetPrincipal", unitEntity, params.StringBoolResults{Results: []params.StringBoolResult{{Result: "", Ok: false}}}, nil),
	)
	st := uniter.NewState(apiCaller, unitTag)
	r, err := relation.NewRelations(st, unitTag, s.stateDir, s.relationsDir, abort)
	c.Assert(err, jc.ErrorIsNil)
	assertNumCalls(c, &numCalls, 2)

	localState := resolver.LocalState{
		State: operation.State{
			Kind: operation.Continue,
		},
	}
	remoteState := remotestate.Snapshot{}
	relationsResolver := relation.NewRelationsResolver(r)
	_, err = relationsResolver.NextOp(localState, remoteState, &mockOperations{})
	c.Assert(errors.Cause(err), gc.Equals, resolver.ErrNoOperation)
}

// APICall places a call to the remote machine.
//
// This fills out the rpc.Request on the given facade, version for a given
// object id, and the specific RPC method. It marshalls the Arguments, and will
// unmarshall the result into the response object that is supplied.
func (s *state) APICall(facade string, version int, id, method string, args, response interface{}) error {
	retrySpec := retry.CallArgs{
		Func: func() error {
			return s.client.Call(rpc.Request{
				Type:    facade,
				Version: version,
				Id:      id,
				Action:  method,
			}, args, response)
		},
		IsFatalError: func(err error) bool {
			err = errors.Cause(err)
			ec, ok := err.(hasErrorCode)
			if !ok {
				return true
			}
			return ec.ErrorCode() != params.CodeRetry
		},
		Delay:       100 * time.Millisecond,
		MaxDelay:    1500 * time.Millisecond,
		MaxDuration: 10 * time.Second,
		BackoffFunc: retry.DoubleDelay,
		Clock:       s.clock,
	}
	err := retry.Call(retrySpec)
	return errors.Trace(err)
}

func (s *LogReaderSuite) TestNextError(c *gc.C) {
	cUUID := "feebdaed-2f18-4fd2-967d-db9663db7bea"
	stub := &testing.Stub{}
	conn := &mockConnector{stub: stub}
	jsonReader := mockStream{stub: stub}
	conn.ReturnConnectStream = jsonReader
	failure := errors.New("an error")
	stub.SetErrors(nil, failure)
	var cfg params.LogStreamConfig
	stream, err := logstream.Open(conn, cfg, cUUID)
	c.Assert(err, gc.IsNil)

	var nextErr error
	done := make(chan struct{})
	go func() {
		_, nextErr = stream.Next()
		c.Check(errors.Cause(nextErr), gc.Equals, failure)
		close(done)
	}()
	select {
	case <-done:
	case <-time.After(coretesting.LongWait):
		c.Errorf("timed out waiting for record")
	}
	stub.CheckCallNames(c, "ConnectStream", "ReadJSON")
}

func (s *machineSuite) TestEntitySetPassword(c *gc.C) {
	entity, err := apiagent.NewState(s.st).Entity(s.machine.Tag())
	c.Assert(err, jc.ErrorIsNil)

	err = entity.SetPassword("foo")
	c.Assert(err, gc.ErrorMatches, "password is only 3 bytes long, and is not a valid Agent password")
	err = entity.SetPassword("foo-12345678901234567890")
	c.Assert(err, jc.ErrorIsNil)
	err = entity.ClearReboot()
	c.Assert(err, jc.ErrorIsNil)

	err = s.machine.Refresh()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(s.machine.PasswordValid("bar"), jc.IsFalse)
	c.Assert(s.machine.PasswordValid("foo-12345678901234567890"), jc.IsTrue)

	// Check that we cannot log in to mongo with the correct password.
	// This is because there's no mongo password set for s.machine,
	// which has JobHostUnits
	info := s.MongoInfo(c)
	// TODO(dfc) this entity.Tag should return a Tag
	tag, err := names.ParseTag(entity.Tag())
	c.Assert(err, jc.ErrorIsNil)
	info.Tag = tag
	info.Password = "foo-12345678901234567890"
	err = tryOpenState(s.State.ModelTag(), info)
	c.Assert(errors.Cause(err), jc.Satisfies, errors.IsUnauthorized)
}

// FingerprintMatches determines whether or not the identified file's
// fingerprint matches the expected fingerprint.
func (fpm FingerprintMatcher) FingerprintMatches(filename string, expected charmresource.Fingerprint) (bool, error) {
	open := fpm.Open
	if open == nil {
		open = func(filename string) (io.ReadCloser, error) { return os.Open(filename) }
	}
	generateFingerprint := fpm.GenerateFingerprint
	if generateFingerprint == nil {
		generateFingerprint = charmresource.GenerateFingerprint
	}

	file, err := open(filename)
	if os.IsNotExist(errors.Cause(err)) {
		return false, nil
	}
	if err != nil {
		return false, errors.Trace(err)
	}
	defer file.Close()

	fp, err := generateFingerprint(file)
	if err != nil {
		return false, errors.Trace(err)
	}
	matches := (fp.String() == expected.String())
	return matches, nil
}