Droplet State Checks

[pearkes]

The addition of #30 made me think of this.

Basically, during FindDroplet, we already retrieve the details of a droplet. This includes the Droplet's "status". For example, if a Droplet is shutdown it's status is off.

So, we know that some commands require certain state before working properly.

I added several middleware's: CheckDropletInactive and CheckDropletActive. This simply looks at the droplet_status injected during FindDroplet, and if it's not active/inactive, raises an error to the user.

This might be overkill and too hand-holdy. I can't really decide, but I thought I would write it anyway to show what it's like. I'm personally a bit on the fence about including it.

[pearkes]

Realized I don't give a concrete example above. Here's one:

$ tugboat start foobar
Droplet name provided. Finding droplet ID...done, 100823 (foobar)
Droplet must be in an 'off' state for this operation to be successful.

[blom]

I like it! It saves us from making an unnecessary API call and therefore reduces the time before tugboat exits. Since we get the status information for free in FindDroplet, I'm all for this. I would have worded the messages "must be on/off" instead of "must be in an on/off state", but that is just my personal preference.

sequence_restart_droplet seems to be missing use CheckDropletActive?

[pearkes]

Yea, that state wording is a little confusing isn't it. I'm going to correct that.

For sequence_restart_droplet, I figured because the API just starts Droplets that are off that we'd do that same. Does that make sense? Or better to be consistent?

[blom]

LGTM. Good point about restart, and I agree. Since DigitalOcean will start a stopped droplet here, we should probably not override that behaviour.

[pearkes]

Ok, cool. I'm convinced. Merging!