worker/apiuniter: State to API migration

worker/apiuniter/context.go

 // Copyright 2012, 2013 Canonical Ltd.
 // Licensed under the AGPLv3, see LICENCE file for details.
 
 package apiuniter
 
 import (
         "bufio"
         "fmt"
         "io"
         "os"
@@ skipping 45 matching lines @@
         // relations contains the context for every relation the unit is a member
         // of, keyed on relation id.
         relations map[int]*ContextRelation
 
         // apiAddrs contains the API server addresses.
         apiAddrs []string
 }
 
 func NewHookContext(unit *uniter.Unit, id, uuid string, relationId int,
         remoteUnitName string, relations map[int]*ContextRelation,
-        apiAddrs []string) *HookContext {
+        apiAddrs []string) (*HookContext, error) {
         ctx := &HookContext{
                 unit:           unit,
                 id:             id,
                 uuid:           uuid,
                 relationId:     relationId,
                 remoteUnitName: remoteUnitName,
                 relations:      relations,
                 apiAddrs:       apiAddrs,
         }
         // Get and cache the addresses.
-        // We ignore the errors here, becasue we only
-        // care if the addresses are set or not, and
-        // we don't want them to change while a hook
-        // is executed.
-        ctx.publicAddress, _ = unit.PublicAddress()
-        ctx.privateAddress, _ = unit.PrivateAddress()
-        return ctx
+        var err error
+        ctx.publicAddress, err = unit.PublicAddress()
+        if err != nil && params.ErrCode(err) != params.CodeNoAddressSet {
+                return nil, err
+        }
+        ctx.privateAddress, err = unit.PrivateAddress()
+        if err != nil && params.ErrCode(err) != params.CodeNoAddressSet {
+                return nil, err
+        }
+        return ctx, nil
 }
 
 func (ctx *HookContext) UnitName() string {
         return ctx.unit.Name()
 }
 
 func (ctx *HookContext) PublicAddress() (string, bool) {
         return ctx.publicAddress, ctx.publicAddress != ""
 }
 
@@ skipping 280 matching lines @@
                         }
                 }
         }
         if member {
                 ctx.members[unit] = settings
         } else {
                 ctx.cache[unit] = settings
         }
         return settings, nil
 }