[chef-dev] bug: 'notifies' ran even when bash script didn't run when 'creates' presents

[Nuo Yan < >]

We found that it started to happen recently (but we are not 100% sure if it happened before) that when using the 'bash' resource, 'notifies' gets executed even when the script didn't run because of what's specified in "creates" already exists.

For example, for this block in the nginx::source recipe:

bash "compile_nginx_source" do

  cwd Chef::Config[:file_cache_path]

  code <<-EOH

    tar zxf nginx-#{nginx_version}.tar.gz

    cd nginx-#{nginx_version} && ./configure #{configure_flags}

    make && make install

  EOH

  creates node[:nginx][:src_binary]

  notifies :restart, "service[nginx]"

end

If the file referred in node[:nginx][:src_binary] exists, it doesn't run the script to compile nginx, which is right, but it still executes the notification which restarts nginx, which is not cool.

We worked around this easily by putting a not_if block in it, but we think this is a chef bug that should be fixed (we are on 10.16.0 and 10.16.2). We think whether or not "notifies" get triggered should be consistent with whether the code(script) ran. If 'creates' presents and the code may not run in some conditions, then in those conditions 'notifies' shouldn't get triggered by default. This nginx example is an example of the use case, if it's already compiled, there is no reason to restart it. I try to think about other use cases and it seems to me that in very rare cases you want 'notifies' to trigger even when anything else is not executed. As the result I think at least the default should be the common case, where "notifies" doesn't trigger if "creates" presents and when the code did not run because of being protected by "creates."

Let me know what you think.

Thanks,

Nuo