ec2: added security group configuration

ec2: added security group configuration

Added a configuration option to enable and disable the
usage of one security group per machine in EC2. Currently
only the configuration change is not used, only hints
in ec2.go.

https://code.launchpad.net/~themue/juju-core/go-ec2-security-group-config/+merge/127318

(do not edit description out of merge proposal)

[TheMue, 2012-10-01 15:55:32]

Please take a look.

[niemeyer, 2012-10-01 19:05:26]

This is going in the right direction, but this problem is not specific to EC2,
so we can take another step forward and have it ready for the next providers. I
suggest introducing:

    firewall-mode: default / global

With an internal API such as:

    func (c *Config) FirewallMode() FirewallMode { ... }

    type FirewallMode string

    const (
            FwDefault FirewallMode = "default"
            FwGlobal  FirewallMode = "global"
    )

[TheMue, 2012-10-02 13:44:36]

Please take a look.

[niemeyer, 2012-10-02 13:52:38]

LGTM, but please add a test where indicated.

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go
File environs/config/config.go (right):

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go#ne...
environs/config/config.go:10: // per machine of global.
// FirewallMode defines the way in which the environment
// handles opening and closing of firewall ports.

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go#ne...
environs/config/config.go:13: const (
// FwDefault is the environment-specific default mode.

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go#ne...
environs/config/config.go:14: FwDefault FirewallMode = "default"
<empty line>
// FwGlobal requests the use of a single firewall group for all machines.
// When ports are opened for one machine, all machines will have the same
// port opened.

https://codereview.appspot.com/6596051/diff/3001/environs/config/config_test.go
File environs/config/config_test.go (right):

https://codereview.appspot.com/6596051/diff/3001/environs/config/config_test....
environs/config/config_test.go:133: },
We need a test here.

[TheMue, 2012-10-02 15:33:18]

Please take a look.

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go
File environs/config/config.go (right):

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go#ne...
environs/config/config.go:10: // per machine of global.
On 2012/10/02 13:52:39, niemeyer wrote:
> // FirewallMode defines the way in which the environment
> // handles opening and closing of firewall ports.

Done.

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go#ne...
environs/config/config.go:13: const (
On 2012/10/02 13:52:39, niemeyer wrote:
> // FwDefault is the environment-specific default mode. 

Done.

https://codereview.appspot.com/6596051/diff/3001/environs/config/config.go#ne...
environs/config/config.go:14: FwDefault FirewallMode = "default"
On 2012/10/02 13:52:39, niemeyer wrote:
> <empty line>
> // FwGlobal requests the use of a single firewall group for all machines.
> // When ports are opened for one machine, all machines will have the same
> // port opened.

Done.

[niemeyer, 2012-10-02 15:53:23]

LGTM

https://codereview.appspot.com/6596051/diff/3002/environs/config/config.go
File environs/config/config.go (right):

https://codereview.appspot.com/6596051/diff/3002/environs/config/config.go#ne...
environs/config/config.go:78: return nil, fmt.Errorf("invalid firewall mode %q
in environment configuration", firewallMode)
Good catch.

This should follow the existing convention above:

"invalid firewall mode in environment configuration: %q"

[TheMue, 2012-10-02 16:40:52]

*** Submitted:

ec2: added security group configuration

Added a configuration option to enable and disable the
usage of one security group per machine in EC2. Currently
only the configuration change is not used, only hints
in ec2.go.

R=niemeyer
CC=
https://codereview.appspot.com/6596051

https://codereview.appspot.com/6596051/diff/3002/environs/config/config.go
File environs/config/config.go (right):

https://codereview.appspot.com/6596051/diff/3002/environs/config/config.go#ne...
environs/config/config.go:78: return nil, fmt.Errorf("invalid firewall mode %q
in environment configuration", firewallMode)
On 2012/10/02 15:53:23, niemeyer wrote:
> Good catch.
> 
> This should follow the existing convention above:
> 
> "invalid firewall mode in environment configuration: %q"

Done.