Unable to utilize external gems with foreman-hooks

Support
1

I’m trying to use ruby-kafka gem alongside foreman-hooks, but I’m unable to do so.

My hook script looks something like this:

#!/usr/local/rvm/rubies/ruby-2.7.1/bin/ruby

require 'kafka'
kafka = Kafka.new([ENV['KAFKA_BROKER']])

host_info = $stdin.read
hook_event = ARGV[0]

kafka.deliver_message(host_info, key: hook_event, topic: ENV['KAFKA_TOPIC'])

When trying to update the host using the API get the following response back:

"Hook: /usr/share/foreman/config/hooks/host/managed/postupdate/1000-post-update.rb task failed with the following error: Hook failure running/usr/share/foreman/config/hooks/host/managed/postupdate/1000-post-update.rb postupdate becky-lidstone.xxx.cloud: Ignoring bcrypt-3.1.12 because its extensions are not built. Try: gem pristine bcrypt --version 3.1.12\nIgnoring ffi-1.11.3 because its extensions are not built. Try: gem pristine ffi --version 1.11.3\nIgnoring nio4r-2.3.1 because its extensions are not built. Try: gem pristine nio4r --version 2.3.1\nIgnoring nokogiri-1.8.4 because its extensions are not built. Try: gem pristine nokogiri --version 1.8.4\nNOTE: Gem::Specification#rubyforge_project= is deprecated with no replacement. It will be removed on or after 2019-12-01.\nGem::Specification#rubyforge_project= called from /opt/theforeman/tfm/root/usr/share/gems/specifications/passenger-4.0.18.gemspec:19.\nIgnoring passenger-4.0.18 because its extensions are not built. Try: gem pristine passenger --version 4.0.18\nIgnoring pg-1.1.4 because its extensions are not built. Try: gem pristine pg --version 1.1.4\nIgnoring rkerberos-0.1.5 because its extensions are not built. Try: gem pristine rkerberos --version 0.1.5\nIgnoring unf_ext-0.0.7.2 because its extensions are not built. Try: gem pristine unf_ext --version 0.0.7.2\nIgnoring unicode-0.4.4.4 because its extensions are not built. Try: gem pristine unicode --version 0.4.4.4\nIgnoring websocket-driver-0.7.0 because its extensions are not built. Try: gem pristine websocket-driver --version 0.7.0\n/usr/local/rvm/rubies/ruby-2.7.1/lib/ruby/2.7.0/rubygems/core_ext/kernel_require.rb:92:in require’: cannot load such file – kafka (LoadError)\n\tfrom /usr/local/rvm/rubies/ruby-2.7.1/lib/ruby/2.7.0/rubygems/core_ext/kernel_require.rb:92:in require'\n\tfrom /usr/share/foreman/config/hooks/host/managed/postupdate/1000-post-update.rb:3:in '\n"`

I tried the steps mentioned in this post: Post but it doesn’t work.

Foreman is running ruby 2.0.0 while the script uses ruby 2.7.1 (since ruby-kaka requires ruby >= 2.2). I could update foreman to ruby 2.7.1 but I’m not sure how to do that, and I’m wary that I might break it.

2

Close, but not quite. Foreman itself runs using the the rh-ruby25 SCL on EL7. The “fun” that Ruby is, is it sets GEM_HOME and GEM_PATH as an environment variable. That is set to the rh-ruby25 path, which is why it can’t find all the native gems.

The typical solution to this is clean those variables. I don’t know if it works inside the script though. If it doesn’t you may need a small bash wrapper for your actual hook that does so.

A cleaner long term solution is to submit a patch to the plugin to do so.

You can also make sure the kafka gem is available in the rh-ruby25 SCL and use #!/usr/bin/env ruby (which will give you Ruby 2.5).

1 Like
3

Thanks! Just wondering, if I change those variables to point to the native gem path, will it interfere with Foreman?

4

Inside the script: no
Outside of the script: yes - this can break Foreman.

Here is a code sample how we clean the env in our installer:

5

Ahh, thanks. I’m pretty new to the Ruby (and Foreman) ecosystem, so I’m still getting used to it. Much appreciated. I’ll try your suggestions and see if they work.

6

FYI we are working on foreman_webhooks plugin which will make this kind of stuff much easeier. You could take your integration to a separate VM/container into a clean environment easily. Stay tuned for the next release!

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