hook

func (*Context) AllRelationUnits ¶

func (ctxt *Context) AllRelationUnits(relationName string) (map[string][]string, error)

AllRelationUnits returns a map from all the relation ids for the relation with the given name to all the units with that name

func (*Context) ClosePort ¶

func (ctxt *Context) ClosePort(proto string, port int) error

func (*Context) CommandName ¶

func (ctxt *Context) CommandName(name string) string

CommandName returns a value that can be used to make runhook run the given command when passed as its first argument. The command name is relative to the registry from which ctxt was created. TODO better explanation and an example.

func (*Context) GetAllConfig ¶

func (ctxt *Context) GetAllConfig() (map[string]interface{}, error)

func (*Context) GetAllRelation ¶

func (ctxt *Context) GetAllRelation() (map[string]string, error)

GetAllRelation returns all the settings for the relation and unit that triggered the hook execution. It is equivalent to GetAllRelationUnit(RelationId, RemoteUnit).

func (*Context) GetAllRelationUnit ¶

func (ctxt *Context) GetAllRelationUnit(relationId, unit string) (map[string]string, error)

GetAllRelationUnit returns all the settings from the given unit associated with the relation with the given id.

func (*Context) GetConfig ¶

func (ctxt *Context) GetConfig(key string) (interface{}, error)

GetConfig returns the charm configuration value for the given key. Both int- and float-typed values will be returned as float64.

func (*Context) GetRelation ¶

func (ctxt *Context) GetRelation(key string) (string, error)

GetRelation returns the value with the given key from the relation and unit that triggered the hook execution. It is equivalent to GetRelationUnit(RelationId, RemoteUnit, key).

func (*Context) GetRelationUnit ¶

func (ctxt *Context) GetRelationUnit(relationId, unit, key string) (string, error)

GetRelationUnit returns the value with the given key from the given unit associated with the relation with the given id.

func (*Context) IsRelationHook ¶

func (ctxt *Context) IsRelationHook() bool

func (*Context) LocalState ¶

func (ctxt *Context) LocalState(name string, ptr interface{}) error

LocalState reads charm local state for the given name (which should be valid to use as a file name) and uses it to fill out the value pointed to by ptr, which should be a pointer to a pointer to a type that's marshallable and unmarshallable as JSON.

When the hook has completed, the value will be saved back to the same place, making it persistent.

The first time LocalState is called in a hook, the element pointed to by ptr is allocated with new, and then filled by JSON unmarshalling, or left zero if there's no existing state. When LocalState is called again, the element pointed to by ptr will be set to the previously allocated value.

For example:

func someHook(ctxt *hook.Context) error {
	type myState struct {
		Called int
	}
	var state *myState
	if err := ctxt.LocalState(&state, "some-hook"); err != nil {
		return err
	}
	if !state.Called {
		ctxt.Logf("someHook has never been called before")
	}
	state.Called = true
}

func (*Context) Logf ¶

func (ctxt *Context) Logf(f string, a ...interface{}) error

Log logs a message through the juju logging facility.

func (*Context) OpenPort ¶

func (ctxt *Context) OpenPort(proto string, port int) error

func (*Context) PrivateAddress ¶

func (ctxt *Context) PrivateAddress() (string, error)

PrivateAddress returns the private address of the local unit.

func (*Context) PublicAddress ¶

func (ctxt *Context) PublicAddress() (string, error)

PublicAddress returns the public address of the local unit.

func (*Context) RelationIds ¶

func (ctxt *Context) RelationIds(relationName string) ([]string, error)

RelationIds returns all the relation ids associated with the relation with the given name,

func (*Context) RelationUnits ¶

func (ctxt *Context) RelationUnits(relationId string) ([]string, error)

func (*Context) SetRelation ¶

func (ctxt *Context) SetRelation(keyvals ...string) error

SetRelation sets the given key-value pairs on the current relation instance.

func (*Context) SetRelationWithId ¶

func (ctxt *Context) SetRelationWithId(relationId string, keyvals ...string) error

SetRelationWithId sets the given key-value pairs on the relation with the given id.

func (*Context) StateDir ¶

func (ctxt *Context) StateDir() string

StateDir returns the path to the directory where local state for the given context will be stored. The directory is not guaranteed to exist.

func (*Context) UnitTag ¶

func (ctxt *Context) UnitTag() string

UnitTag returns the tag of the current unit, useful for using as a file name.

func (*Registry) LocalContext ¶

func (r *Registry) LocalContext(ctxt *Context) *Context

LocalContext transforms an existing context into a context with state local to r.

func (*Registry) NewRegistry ¶

func (r *Registry) NewRegistry(localStateName string) *Registry

NewRegistry returns a sub-registry of r. Local state stored by hooks registered with that will be stored relative to the given name within r; likewise new registries created by NewRegistry on it will store local state relatively to r.

This enables hierarchical local storage for charm hooks.

func (*Registry) Register ¶

func (r *Registry) Register(name string, f func(ctxt *Context) error)

Register registers the given function to be called when the charm hook with the given name is invoked. The function must not use its provided Context after it returns.

If more than one function is registered for a given hook, each function will be called in turn until one returns an error; the context's local state will be saved with SaveState after each call.

func (*Registry) RegisterCommand ¶

func (r *Registry) RegisterCommand(name string, f func())

RegisterCommand registers the given function to be called when the hook is invoked with a first argument of "cmd". The name is relative to the registry's state namespace. It will panic if the same name is registered more than once in the same Registry.

When the function is called, os.Args will be set up as if the function is main - the "cmd-" command selector will be removed.

func (*Registry) RegisteredHooks ¶

func (r *Registry) RegisteredHooks() []string

RegisteredHooks returns the names of all currently registered hooks.