Make it possible to override base package URL location; switch default to GitHub

[Wing924]

Fixes #457, addresses RabbitMQ core team request to switch to Bintray/GitHub/Package Cloud from rabbitmq.com.

[Wing924]

@michaelklishin All tests are passed except lint test. But it seems not a part of my PR. Please check it.

[michaelklishin]

This looks differently from what was originally suggested. @jjasghar how are such attribute initialization issues typically resolved in modern Chef? This approach seems pretty hacky to me.

[Wing924]

@michaelklishin I tried lazy { ... }, but it don't work with embed string like "../#{node['rabbitmq'][...']}". If you have any better idea, please tell me.

[ghost]

There was already a back-and-forth on this issue back in 3.x. There was a change merged into 3.0.4 which moved URL string interpolation from from the attributes file into the recipe. However, the way it was done broke the ability to override package URL and use a local mirror.

Then later in 3.12.0 that behaviour was reverted and URL string interpolation was moved back into the attributes file which causes the behaviour that @Wing924 is trying to fix.

I believe the best approach is to do URL string interpolation in a recipe, while still allowing that to be overridden by an attribute if defined. It would look something like this:

attributes/default.rb:

default['rabbitmq']['version'] = '3.5.2'
default['rabbitmq']['deb_package'] = nil # override me if you have a local mirror

recipes/default.rb

default_deb_package = "https://www.rabbitmq.com/releases/rabbitmq-server/v#{node['rabbitmq']['version']}/"
deb_package = node['rabbitmq']['deb_package'] || default_deb_package
remote_file "#{Chef::Config[:file_cache_path]}/#{deb_package}" do
  source deb_package

[Wing924]

@michaelklishin
I updated my PR as @yardinicwaller commented. Can you please check this PR?

[michaelklishin]

@yardinicwaller thanks for the historical perspective and the suggestion. @Wing924 I'd need to investigate CI failures but let's change default URL to point to GitHub while we are at it. Thank you.

[michaelklishin]

It's a good opportunity to switch this URL away fro mrabbitmq.com/releases, say, to GitHub releases. GitHub offers better availability, a CDN and there are not plans to drop it as an artifact distribution mechanism, unlike rabbitmq.com/releases.

[michaelklishin]

CI failures should be addressed in master. @Wing924 please rebase/merge in master.

[michaelklishin]

@Wing924 actually, I'm happy to change download URL to point to GitHub or Bintray separately, so let's merge in master to get CI failure fixes and see.

@jjasghar do you have any objections to the approach in this PR?

[michaelklishin]

CI in master is green again.

[michaelklishin]

@Wing924 there is a CI failure that looks genuine:

* remote_file[/opt/kitchen/cache/rabbitmq-server_3.6.12-1_all.deb] action create_if_missing[2017-09-26T06:28:25+00:00] WARN: remote_file[/opt/kitchen/cache/rabbitmq-server_3.6.12-1_all.deb] cannot be downloaded from https://github.com/rabbitmq/rabbitmq-server/releases/download/v3.6.12/rabbitmq-server_3.6.12-1_all.deb: 404 "Not Found"

The correct URL is https://github.com/rabbitmq/rabbitmq-server/releases/download/rabbitmq_v3_6_12/rabbitmq-server_3.6.12-1_all.deb.

Bintray URLs should require no substitution: https://dl.bintray.com/rabbitmq/rabbitmq-server-deb/rabbitmq-server_3.6.12-1_all.deb.
We have plans to change Bintray repository for Debian packages to just deb but we can worry about that when it happens.

[michaelklishin]

OK, looks like afcc286 addresses the above comment.