esl-erlang-compat is not needed for 'esl install method'

[chrisduong]

Hi,

It happened accidentally when I installed RabbitMQ v3.6.1, and I saw the repeated error in the startup_log.

Error in log handler

Event: {info_report,<0.9.0>,
{<0.32.0>,progress,
[{supervisor,{local,kernel_safe_sup}},
{started,[{pid,<0.313.0>},
{name,pg_local},
{mfargs,{pg_local,start_link,[]}},
{restart_type,permanent},
{shutdown,4294967295},
{child_type,worker}]}]}}
Error: function_clause
Stack trace: [{error_logger_file_h,write_event,
[{<0.46.0>,"/var/log/rabbitmq/[email protected]",[]},
{info_report,<0.9.0>,
{<0.32.0>,progress,
[{supervisor,{local,kernel_safe_sup}},
{started,
[{pid,<0.313.0>},
{name,pg_local},
{mfargs,{pg_local,start_link,[]}},
{restart_type,permanent},
{shutdown,4294967295},
{child_type,worker}]}]}}],
[{file,"error_logger_file_h.erl"},{line,113}]},
{error_logger_file_h,handle_event,2,
[{file,"error_logger_file_h.erl"},{line,78}]},
{rabbit_error_logger_file_h,safe_handle_event,3,
[{file,"src/rabbit_error_logger_file_h.erl"},{line,121}]},
{gen_event,server_update,4,[{file,"gen_event.erl"},{line,522}]},
{gen_event,server_notify,4,[{file,"gen_event.erl"},{line,504}]},
{gen_event,server_notify,4,[{file,"gen_event.erl"},{line,506}]},
{gen_event,handle_msg,5,[{file,"gen_event.erl"},{line,266}]},
{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,239}]}]

And the log is never written into RABBITMQ_LOGS, it is alway empty.

I suspect that the version of Erlang in Epel repo is not updated as 'esl-erlang' repo. So I switch to use the repo by overriding the attribute ['erlang']['install_method'] = 'esl'. And RabbitMQ starting without an error message with the latest Erlang version 18.3, not the old one R16B-03.16 from Epel repo.

Interestingly, I think I find an unnecessary snippet in this cookbook (which can cause trouble later).

if node['erlang']['install_method'] == 'esl'
    remote_file "#{Chef::Config[:file_cache_path]}/esl-erlang-compat.rpm" do
      source "#{node['rabbitmq']['esl-erlang_package_url']}#{node['rabbitmq']['esl-erlang_package']}"
    end
    rpm_package "#{Chef::Config[:file_cache_path]}/esl-erlang-compat.rpm"
  end

We actually don't need to install esl-erlang-compat, since the package esl-erlang from esl-erlang repo already provides the erlang package.

[root@node1 ~]# rpm -qf /bin/erl
esl-erlang-18.3-1.x86_64

I think it is because the RabbitMQ docs for installing Erlang is not updated with 'esl-erlang' packaging system. And it is true, the package esl-erlang-compat-R16B03.noarch from the above snippet contains no files.

[root@node1 ~]# rpm -ql esl-erlang-compat-R16B03.noarch
(contains no files)

I don't have much time to dig deeper but I think we can remove the code to install esl-erlang-compat when using install_method is esl.

[michaelklishin]

esl-erlang-compat is necessary because the ESL RPM package provides a package named esl-erlang (or at least it used to do that) and RabbitMQ expects it to be erlang.

In a somewhat related note, this cookbook should consider supporting RabbitMQ provided RPM packages of Erlang.

[chrisduong]

Hi,

The erlang-solution repo actually install erlang package for RabbitMQ also.

[root@node1 ~]# yum info erlang
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile

• base: centos-hcm.viettelidc.com.vn
• epel: ftp.cuhk.edu.hk
• extras: centos-hcm.viettelidc.com.vn
• updates: centos-hcm.viettelidc.com.vn
  Available Packages
  Name : erlang
  Arch : x86_64
  Version : 18.3
  Release : 1.el7.centos
  Size : 16 k
  Repo : erlang_solutions/7/x86_64
  Summary : General-purpose programming language and runtime environment
  URL : http://www.erlang.org
  License : ERPL
  Description : Erlang is a general-purpose programming language and runtime
  : environment. Erlang has built-in support for concurrency,
  : distribution and fault tolerance. Erlang is used in several large
  : telecommunication systems from Ericsson.

As from RabbitMQ official docs.

Install Erlang

Before installing RabbitMQ, you must install Erlang. We strongly recommend using a packaged version. There are three suggested sources for Erlang packages:

Erlang Solutions produces packages that are usually up to date. They produce two sets of packages - ones which are split up and are more convenient to use if you can add a yum repository, and a monolithic package which might be easier if you have to download manually.

We can simple use yum repository to install all erlang packages for RabbitMQ. This way is more simple.

[chrisduong]

Sorry, I clicked the wrong button.

[michaelklishin]

@chrisduong have you actually tried using the split up RPM package? It's an endless stream of headaches and dependency woes. That's the only reason why our team provides Erlang RPM builds in the first place.

[chrisduong]

@michaelklishin, thanks for clearing my mind. Since we are using erlang cookbook - going with ''esl-erlang" package (instead of split-up erlang packages). that's the reason we have to install 'esl-erlang-compat' so we can install RabbitMQ later.

Thanks for supporting esl-erlang-compat package.