Auto detect proxy settings for local provider

Auto detect proxy settings for local provider

Add methods to detect the proxy settings for both the
environment and apt.

The local provider now auto detects the proxy settings
during the environment Prepare call.

There were a few drive by fixes to use testbase commands
instead of duplication.

https://code.launchpad.net/~thumper/juju-core/local-provider-proxy-detection/+merge/202386

Requires: https://code.launchpad.net/~thumper/juju-core/config-proxy/+merge/202371

(do not edit description out of merge proposal)

[thumper, 2014-01-20 22:24:40]

Please take a look.

[wallyworld, 2014-01-20 22:43:21]

LGTM with additional tests

https://codereview.appspot.com/54720043/diff/1/juju/osenv/proxy_test.go
File juju/osenv/proxy_test.go (right):

https://codereview.appspot.com/54720043/diff/1/juju/osenv/proxy_test.go#newco...
juju/osenv/proxy_test.go:50: c.Assert(proxies.Ftp, gc.Equals, "")
There's no test that ftp proxy will return a value. The empty check is done
above, ftp proxy needs to be filled in here

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
File provider/local/environprovider_test.go (right):

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
provider/local/environprovider_test.go:156: message: "apt-proxies not used of
apt-http-proxy set",
if

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
provider/local/environprovider_test.go:170: message: "apt-proxies not used of
apt-https-proxy set",
if

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
provider/local/environprovider_test.go:184: message: "apt-proxies not used of
apt-ftp-proxy set",
if

https://codereview.appspot.com/54720043/diff/1/utils/apt.go
File utils/apt.go (right):

https://codereview.appspot.com/54720043/diff/1/utils/apt.go#newcode80
utils/apt.go:80: // ftp proxy settings.
This comment is not quite fully accurate/complete

https://codereview.appspot.com/54720043/diff/1/utils/apt_test.go
File utils/apt_test.go (right):

https://codereview.appspot.com/54720043/diff/1/utils/apt_test.go#newcode91
utils/apt_test.go:91: Ftp:   "none",
we need two tests - one for none and one for a value. There's no test that ftp
proxy will be correctly picked up

[thumper, 2014-01-21 00:54:47]

Please take a look.

https://codereview.appspot.com/54720043/diff/1/juju/osenv/proxy_test.go
File juju/osenv/proxy_test.go (right):

https://codereview.appspot.com/54720043/diff/1/juju/osenv/proxy_test.go#newco...
juju/osenv/proxy_test.go:50: c.Assert(proxies.Ftp, gc.Equals, "")
On 2014/01/20 22:43:21, wallyworld wrote:
> There's no test that ftp proxy will return a value. The empty check is done
> above, ftp proxy needs to be filled in here

Done.

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
File provider/local/environprovider_test.go (right):

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
provider/local/environprovider_test.go:156: message: "apt-proxies not used of
apt-http-proxy set",
On 2014/01/20 22:43:21, wallyworld wrote:
> if

Done.

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
provider/local/environprovider_test.go:170: message: "apt-proxies not used of
apt-https-proxy set",
On 2014/01/20 22:43:21, wallyworld wrote:
> if

Done.

https://codereview.appspot.com/54720043/diff/1/provider/local/environprovider...
provider/local/environprovider_test.go:184: message: "apt-proxies not used of
apt-ftp-proxy set",
On 2014/01/20 22:43:21, wallyworld wrote:
> if

Done.

https://codereview.appspot.com/54720043/diff/1/utils/apt.go
File utils/apt.go (right):

https://codereview.appspot.com/54720043/diff/1/utils/apt.go#newcode80
utils/apt.go:80: // ftp proxy settings.
On 2014/01/20 22:43:21, wallyworld wrote:
> This comment is not quite fully accurate/complete

Done.

https://codereview.appspot.com/54720043/diff/1/utils/apt_test.go
File utils/apt_test.go (right):

https://codereview.appspot.com/54720043/diff/1/utils/apt_test.go#newcode91
utils/apt_test.go:91: Ftp:   "none",
On 2014/01/20 22:43:21, wallyworld wrote:
> we need two tests - one for none and one for a value. There's no test that ftp
> proxy will be correctly picked up

Yes there is. This method gets the ftp proxy.  The test below tests no output.
Added a new test.