IT LIVES (er, the Uniter, that is)

worker/uniter/hook/hook.go

 // hook provides types and constants that define the hooks known to Juju,
 // and implements persistence of hook execution state.
 package hook
 
 import (
         "errors"
         "fmt"
         "launchpad.net/juju-core/trivial"
         "os"
 )
@@ skipping 70 matching lines @@
         // for the member units, but these are communicated only when already
         // known to the producer: their presence should never be assumed. The
         // field is only set when Kind identifies a relation hook.
         Members map[string]map[string]interface{}
 }
 
 // Status defines the stages of execution through which a hook passes.
 type Status string
 
 const (
-        // StatusStarted indicates that the unit agent intended to run the hook.
-        // This status implies that a hook *may* have been interrupted and have
-        // failed to complete all required operations, and that therefore the
-        // proper response is to treat it as a hook execution failure and punt
-        // to the user for manual resolution.
-        StatusStarted Status = "started"
+        // Queued indicates that the hook should be executed at the earliest
+        // opportunity.
+        Queued Status = "queued"
 
-        // StatusSucceeded indicates that the hook itself completed successfully,
-        // but that local state (ie relation membership) may not have been
-        // synchronized, and that recovery should therefore be performed.
-        StatusSucceeded Status = "succeeded"
+        // Pending indicates that execution of the hook is pending. A hook
+        // that fails should keep this status until it is successfully re-
+        // executed or skipped.
+        Pending Status = "pending"
 
-        // StatusCommitted indicates that the last hook ran successfully and that
-        // local state has been synchronized.
-        StatusCommitted Status = "committed"
+        // Committing indicates that execution of the hook has successfully
+        // completed, or that the hook has been skipped, but that persistent
+        // local state has not been synchronized with the change embodied by
+        // the hook.
+        Committing Status = "committing"
+
+        // Complete indicates that all operations associated with the hook have
+        // succeeded.
+        Complete Status = "complete"
 )
 
 // valid will return true if the Status is known.
 func (status Status) valid() bool {
         switch status {
-        case StatusStarted, StatusSucceeded, StatusCommitted:
+        case Queued, Pending, Committing, Complete:
                 return true
         }
         return false
 }
 
 // State holds details necessary for executing a hook, and the
 // status of the execution.
 type State struct {
         Info   Info
         Status Status
@@ skipping 65 matching lines @@
 
 // state defines the hook state serialization.
 type state struct {
         Kind          Kind
         RelationId    int      `yaml:"relation-id,omitempty"`
         RemoteUnit    string   `yaml:"remote-unit,omitempty"`
         ChangeVersion int      `yaml:"change-version,omitempty"`
         Members       []string `yaml:"members,omitempty"`
         Status        Status
 }