[chef-dev] Re: [chef] Re: How do I know if my application has really been "provisioned"? a suggestion

[Bryan Berry < >]

Hey Cassiano,

I think the mechanism used to verify whether the application has been
fully provisioned will vary by application. For that reason I think
the using an optional :before block to gather info and an :after block
with arbitrary ruby code to check the state of the system will give us
the flexibility we need.

On Sun, Dec 9, 2012 at 4:09 PM, Cassiano Leal 
<
 >
 wrote:
> I had to deal with a similar problem in some capistrano recipes for
> deploying JBoss applications.
>
> The approach I used was to monitor the "deployments" directory in JBoss and
> check for an "artifact.deployed" file with a timestamp greater than that of
> "artifact.ear". It's been working beautifully, but your solution of checking
> the tiestamp in the logs might be more robust.
>
> --
> Cassiano Leal
>
> On Sunday, December 9, 2012 at 10:22, Bryan Berry wrote:
>
> I have been struggling lately w/ the problem of how to know whether or
> not my servers have been fully provisioned. This is a problem that
> affects both cookbook testing and orchestration.
>
> I have numerous java applications that have long startup times. I
> believe Rails 3 apps also have long startup times. For example,
> elasticsearch takes > 5s to start up fully. However Chef does not
> natively have a way to determine when elasticsearch has fully started
> up. All Chef can know is the exit code returned by `service
> elasticsearch start` and its various platform equivalents. Why is this
> an issue? Well, I don't want to run my minitest-handler integration
> tests until elasticsearch is actually functional. Also, if I am
> testing a multiple VM setup where another VM depends on elasticsearch,
> I need to know when elasticsearch has completed startup.
>
> Erik Hollensbe is doing some freaking awesome work on workflow
> orchestration w/ chef-workflow and I think it illustrates the problem
> here
>
> require 'chef-workflow/helper'
> class MyTest < MiniTest::Unit::VagrantTestCase
> def before
> @json_msg = '{ 'id': "dumb message json msg"}'
> end
> def setup
> provision('elasticsearch')
> provision('logstash')
> wait_for('elasticsearch')
> wait_for('logstash')
> inject_logstash_message(@json_msg)
> end
>
> def test_message_indexed_elasticsearch
> assert es_has_message?(@json_msg)
> end
> end
>
> If I understand Erik's code correctly, the `wait_for('elasticsearch')`
> only waits for the vagrant provisioner to return. The vagrant
> provisioner in turn only waits for `service elasticsearch start` to
> return a non-zero exit-code.
>
> We need an optional way to determine whether an server has been
> complete provisioned, or that all the resources have entered a "done"
> state. The only way I know that elasticsearch has started
> successfully is if I see in the log "Elasticsearch has started" w/ a
> timestamp more recent than when I started the service.
>
> Here is my idea, pls tell me if it is crazy.
>
> I think that the service resource should have an additional attribute
> "done" that takes two ruby blocks, named before and after. The first
> block would return a hash with the results of the block.
>
> # Warning much of the Ruby code here maybe horribly incorrect.
>
> def get_current_offset(file_name)
> { :offset => ::File.seek(file_name, EOF).get_offset }
> end
>
> def es_started?(params)
> !::File.open(params[:log_file], params[:offset],
> 'r').grep(params[:started_text]).empty?
> end
>
> log_file = '/usr/local/var/log/elasticsearch.log'
> started_test = "elasticsearch has started successfully"
> timeout = 60
>
> service "elasticsearch" do
> done(
> :before => { get_current_offset(logfile) },
> :after => { es_started?(:log_file => log_file, :offset
> => @before_results[:offset]
> :timeout => 60
> )
> end
>
> The before block would run before the service is actually actioned.
> Now Chef would need some additional machinery to collect all the done
> :after blocks and the related @before_results. This could be done by
> chef_handler but may be better as part of chef itself. Let's call it
> the done_handler for now. This done_handler would mark the time before
> it starts handling any done_after blocks, then loop through the
> collected done_after blocks for the specified timeout. Once all blocks
> are complete it would continue onto other handlers, such as the
> minitest_handler.
>
> I think this done_handler could be part of something called "wait_mode"
>
>