Add an AuthenticationProvider interface.

Add an AuthenticationProvider interface.

To be used by the provisioner.  Very simple implementation now to mirror what
is currently happening.  We can add caching and re-getting the information as
we desire.

https://code.launchpad.net/~thumper/juju-core/provisioner-auth-provider/+merge/171006

Requires: https://code.launchpad.net/~thumper/juju-core/lxc-broker/+merge/170713

(do not edit description out of merge proposal)

[thumper, 2013-06-24 02:27:34]

Please take a look.

[dave_cheney.net, 2013-06-24 06:30:32]

LGTM.

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
File worker/provisioner/authentication.go (right):

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:15: // AuthenticationProvider defines the
single function that the provisioner
/s/function/method, only types with receivers can fulfil interfaces

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:27: return &simpleAuth{stateInfo, apiInfo},
nil
return &simpleAuth{stateInfo, apiInfo}, err

In the unlikely case of an error, the heap allocation of the simpleAuth won't be
noticable.

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:41: return nil, nil, fmt.Errorf("cannot set
password for machine %v: %v", machine, err)
cannot set mongo password ? there must be a million different username/password
combinations, I don't think it hurts to give a hint which is wrong.

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:43: stateInfo := *auth.stateInfo
stateInfo := &auth.StateInfo {
    Tag: machine.Tag(),
    Password: password, 
}

etc

[thumper, 2013-06-24 22:48:52]

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
File worker/provisioner/authentication.go (right):

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:15: // AuthenticationProvider defines the
single function that the provisioner
On 2013/06/24 06:30:32, dfc wrote:
> /s/function/method, only types with receivers can fulfil interfaces

Done.

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:27: return &simpleAuth{stateInfo, apiInfo},
nil
On 2013/06/24 06:30:32, dfc wrote:
> return &simpleAuth{stateInfo, apiInfo}, err
> 
> In the unlikely case of an error, the heap allocation of the simpleAuth won't
be
> noticable. 

I thought it was idiomatic go to make sure that if you have an error, the other
return params are nil or zero initialized.

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:41: return nil, nil, fmt.Errorf("cannot set
password for machine %v: %v", machine, err)
On 2013/06/24 06:30:32, dfc wrote:
> cannot set mongo password ? there must be a million different
username/password
> combinations, I don't think it hurts to give a hint which is wrong.

Done.

https://codereview.appspot.com/10478043/diff/1/worker/provisioner/authenticat...
worker/provisioner/authentication.go:43: stateInfo := *auth.stateInfo
On 2013/06/24 06:30:32, dfc wrote:
> stateInfo := &auth.StateInfo {
>     Tag: machine.Tag(),
>     Password: password, 
> }
> 
> etc

However we are copying some of the fields from stateInfo.  This is the same code
that was elsewhere, just moved here.

[wallyworld, 2013-06-24 23:32:24]

LGTM. If Dave is happy, I'm happy