Nice! I'm in the middle of making a release, but this will go into 0.4.5 :)

Heh. You're presuming it won't Break Everything. Waiting for 0.4.5 is a good idea :)

So, one potential issue with this is that both wget --quiet and curl --silent are both completely silent, and we still want to see log entries when something fails.

Curl has --show-error, to still print when something blows up, but wget doesn't have anything like it. The closest wget has is --no-verbose, which prints a single status line for all requests, in addition to any errors:

# curl -sS is silent, but still prints errors
$ curl -sSL 'http://httpbin.org/status/200'
$ curl -sSL 'http://httpbin.org/status/404'
$ curl -sSL 'http://httpbin.org/status/500'
$ curl -sSL 'http://example.invalid'
curl: (6) Could not resolve host: example.invalid

# wget -q is completely silent
$ wget -qO- 'http://httpbin.org/status/200'
$ wget -qO- 'http://httpbin.org/status/404'
$ wget -qO- 'http://httpbin.org/status/500'
$ wget -qO- 'http://example.invalid'

# wget -nv is almost silent, but prints on every request
$ wget -nv -O- 'http://httpbin.org/status/200'
2015-11-06 08:17:57 URL:http://httpbin.org/status/200 [0/0] -> "-" [1]
$ wget -nv -O- 'http://httpbin.org/status/400'
http://httpbin.org/status/404:
2015-11-06 08:18:00 ERROR 404: NOT FOUND.
$ wget -nv -O- 'http://httpbin.org/status/500'
http://httpbin.org/status/500:
2015-11-06 08:18:05 ERROR 500: INTERNAL SERVER ERROR.
$ wget -nv -O- 'http://example.invalid'
wget: unable to resolve host address 'example.invalid'

We can either:

• lose printing on errors with wget -q
• get a print on every request with wget -nv
• try to emulate curl's behavior with wget -nv ... 2>&1 | grep '^wget: '

And, if we need to be able to pass the output along, we can send stderr into a subshell, and stdout wherever

$ wget -nv -O - 'http://example.invalid' 2> >(grep '^wget: ') > /dev/null
wget: unable to resolve host address 'example.invalid'

I do a trick where I redirect all output to a temporary file, and if there is an error, I dump the contents of that file. See here and here.

Yeah, I need to revisit things, especially around what output goes where in the bats tests.

Dropping this PR's scope. We could probably make wget to work everywhere, but curl is way more developer friendly for us, especially its --show-error flag. Instead of excising it completely, let's just avoid using curl during bootstrapping, and keep the .deb package dependency on curl, so that we can use it once Dokku is installed.