juju: add NewConnFromState

juju/conn.go

 package juju
 
 import (
         "crypto/sha256"
         "encoding/hex"
         "fmt"
         "io"
         "io/ioutil"
         "launchpad.net/juju-core/charm"
         "launchpad.net/juju-core/environs"
@@ skipping 60 matching lines @@
                 Environ: environ,
                 State:   st,
         }
         if err := conn.updateSecrets(); err != nil {
                 conn.Close()
                 return nil, fmt.Errorf("unable to push secrets: %v", err)
         }
         return conn, nil
 }
 
+// NewConnFromState returns a Conn that uses an Environ
+// made by reading the environment configuration.
+// The resulting Conn uses the given State - closing
+// it will close that State.
+func NewConnFromState(st *state.State) (*Conn, error) {
+        cfg, err := st.EnvironConfig()
+        if err != nil {
+                return nil, err
+        }
+        environ, err := environs.New(cfg)
+        if err != nil {
+                return nil, err
+        }
+        return &Conn{
+                Environ: environ,
+                State:   st,
+        }, nil
+}
+
 // NewConnFromName returns a Conn pointing at the environName environment, or the
 // default environment if not specified.
 func NewConnFromName(environName string) (*Conn, error) {
         environ, err := environs.NewFromName(environName)
         if err != nil {
                 return nil, err
         }
         return NewConn(environ)
 }
 
@@ skipping 209 matching lines @@
         }
         if status != state.UnitError {
                 return fmt.Errorf("unit %q is not in an error state", unit)
         }
         mode := state.ResolvedNoHooks
         if retryHooks {
                 mode = state.ResolvedRetryHooks
         }
         return unit.SetResolved(mode)
 }