worker: new package to factor out some common code from workers

worker: new package to factor out some common code from workers

Also simplify workers a little.

https://code.launchpad.net/~rogpeppe/juju-core/045-worker-wait-for-environ/+merge/122300

(do not edit description out of merge proposal)

[rog, 2012-08-31 15:19:11]

Please take a look.

[niemeyer, 2012-08-31 15:57:17]

Several great improvement here. Thanks.

LGTM assuming you find these sensible enough:

https://codereview.appspot.com/6501072/diff/2001/state/watcher/watcher.go
File state/watcher/watcher.go (right):

https://codereview.appspot.com/6501072/diff/2001/state/watcher/watcher.go#new...
state/watcher/watcher.go:15: type Errorer interface {
Errer feels a lot better as a name for this.

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go
File worker/environ.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go#newcode18
worker/environ.go:18: case <-stop:
s/stop/dying/, so we can use ErrDying below correctly.

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go#newcode22
worker/environ.go:22: return nil, w.Err()
MustErr, I suppose?

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go#newcode24
worker/environ.go:24: var err error
d

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go#newcode29
worker/environ.go:29: log.Printf("firewaller loaded invalid environment
configuration: %v", err)
s/firewaller //

https://codereview.appspot.com/6501072/diff/2001/worker/environ_test.go
File worker/environ_test.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/environ_test.go#newco...
worker/environ_test.go:54: c.Assert(err, IsNil)
Can't Assert within a goroutine. It will not stop the test and the done below
will never be executed.

https://codereview.appspot.com/6501072/diff/2001/worker/firewaller/firewaller.go
File worker/firewaller/firewaller.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/firewaller/firewaller...
worker/firewaller/firewaller.go:60: return nil
tomb.ErrDying

https://codereview.appspot.com/6501072/diff/2001/worker/provisioner/provision...
File worker/provisioner/provisioner.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/provisioner/provision...
worker/provisioner/provisioner.go:69: return nil
tomb.ErrDying

[rog, 2012-08-31 16:17:10]

*** Submitted:

worker: new package to factor out some common code from workers

Also simplify workers a little.

R=niemeyer
CC=
https://codereview.appspot.com/6501072

https://codereview.appspot.com/6501072/diff/2001/state/watcher/watcher.go
File state/watcher/watcher.go (right):

https://codereview.appspot.com/6501072/diff/2001/state/watcher/watcher.go#new...
state/watcher/watcher.go:15: type Errorer interface {
On 2012/08/31 15:57:17, niemeyer wrote:
> Errer feels a lot better as a name for this.

Done.

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go
File worker/environ.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go#newcode18
worker/environ.go:18: case <-stop:
On 2012/08/31 15:57:17, niemeyer wrote:
> s/stop/dying/, so we can use ErrDying below correctly.

Done.

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go#newcode22
worker/environ.go:22: return nil, w.Err()
On 2012/08/31 15:57:17, niemeyer wrote:
> MustErr, I suppose?

Done.

https://codereview.appspot.com/6501072/diff/2001/worker/environ.go#newcode29
worker/environ.go:29: log.Printf("firewaller loaded invalid environment
configuration: %v", err)
On 2012/08/31 15:57:17, niemeyer wrote:
> s/firewaller //

Done.

https://codereview.appspot.com/6501072/diff/2001/worker/environ_test.go
File worker/environ_test.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/environ_test.go#newco...
worker/environ_test.go:54: c.Assert(err, IsNil)
On 2012/08/31 15:57:17, niemeyer wrote:
> Can't Assert within a goroutine. It will not stop the test and the done below
> will never be executed.

Done.

https://codereview.appspot.com/6501072/diff/2001/worker/firewaller/firewaller.go
File worker/firewaller/firewaller.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/firewaller/firewaller...
worker/firewaller/firewaller.go:60: return nil
On 2012/08/31 15:57:17, niemeyer wrote:
> tomb.ErrDying

Done.

https://codereview.appspot.com/6501072/diff/2001/worker/provisioner/provision...
File worker/provisioner/provisioner.go (right):

https://codereview.appspot.com/6501072/diff/2001/worker/provisioner/provision...
worker/provisioner/provisioner.go:69: return nil
On 2012/08/31 15:57:17, niemeyer wrote:
> tomb.ErrDying

Done.