HAProxy support for Mesos in vSphere Big Data Extensions

I realized late last night the current vSphere Big Data Extensions fling does not have HAProxy built into it for the Mesos cluster deployments. After a bit of reading and testing new pieces inside the Chef recipes, I have added support so that HAProxy is running on all of the Mesos nodes. The first thing is to add the HAProxy package to the /opt/serengeti/chef/cookbooks/mesos/recipes/install.rb file:

 72   %w( unzip libcurl haproxy ).each do |pkg|
 73     yum_package pkg do
 74       action :install
 75     end
 76   end

There is also a script that Mesosphere provides to modify the HAProxy configuration file and reload the rules when changes occur. You can find instructions on the file and how to incorporate it on the Mesosphere page.

Note: I had to edit ‘sudo’ out of the lines inside the script in order for Chef to execute it properly.

After copying the file haproxy-marathon-bridge into my Chef server, I added the following code to the same install.rb file to get things all setup and configured properly:

 82   directory "/etc/haproxy-marathon-bridge" do
 83     owner 'root'
 84     group 'root'
 85     mode '0755'
 86     action :create
 87   end
 88 
 89   template '/usr/local/bin/haproxy-marathon-bridge' do
 90     source 'haproxy-marathon-bridge.erb'
 91     action :create
 92   end
 93 
 94   master_ips = mesos_masters_ip
 95   slave_ips = mesos_slaves_ip
 96 
 97   all_ips = master_ips
 98   all_ips += slave_ips
 99   
100   template '/etc/haproxy-marathon-bridge/marathons' do
101     source 'marathons.erb'
102     variables(
103       haproxy_server_list: all_ips
104     )
105     action :create
106   end
107   
108   execute 'configure haproxy' do
109     command 'chkconfig haproxy on; service haproxy start'
110   end
111   
112   execute 'setup haproxy-marathon-bridge' do
113     command 'chmod 755 /usr/local/bin/haproxy-marathon-bridge; /usr/local/bin/haproxy-marathon-bridge install_cronjob'
114   end

There is also a bit of supporting code needed for lines 94-98 above that were added to /opt/serengeti/chef/cookbooks/mesos/libraries/default.rb:

  1 module Mesosphere
  2 
  3   def mesos_masters_ip
  4     servers = all_providers_fqdn_for_role("mesos_master")
  5     Chef::Log.info("Mesos master nodes in cluster #{node[:cluster_name]} are: #{servers.inspect}")
  6     servers
  7   end
  8 
  9   def mesos_slaves_ip
 10     servers = all_providers_fqdn_for_role("mesos_slave")
 11     Chef::Log.info("Mesos slave nodes in cluster #{node[:cluster_name]} are: #{servers.inspect}")
 12     servers
 13   end
 14 
 15 end
 16 
 17 class Chef::Recipe; include Mesosphere; end

The last thing needed is a new template file for the /etc/haproxy-marathon-bridge/marathons file that is needed by the script provided by Mesosphere. I created the file /opt/serengeti/chef/cookbooks/mesos/templates/default/marathons.erb:

  1 # Configuration file for haproxy-marathon-bridge script
  2 <%
  3   ha_url_list = []
  4   @haproxy_server_list.each do |ha_server|
  5     ha_url_list << "#{ha_server}"
  6   end
  7 %>
  8 <%= ha_url_list.join(":8080\n") + ":8080" %>

At this point, all of the modifications can be uploaded to the Chef server with the command knife cookbook upload -a and a new cluster can be deployed with HAProxy support.

After deploying a nginx workload, you scale it out and check the /etc/haproxy/haproxy.cfg file on a master node and see entries like:

[root@hadoopvm388 haproxy]# cat haproxy.cfg global
  daemon
  log 127.0.0.1 local0
  log 127.0.0.1 local1 notice
  maxconn 4096
defaults
  log            global
  retries             3
  maxconn          2000
  timeout connect  5000
  timeout client  50000
  timeout server  50000
listen stats
  bind 127.0.0.1:9090
  balance
  mode http
  stats enable
  stats auth admin:admin
listen nginx-80
  bind 0.0.0.0:80
  mode tcp
  option tcplog
  balance leastconn
  server nginx-10 hadoopvm382.localdomain:31000 check
  server nginx-9 hadoopvm390.localdomain:31000 check
  server nginx-8 hadoopvm387.localdomain:31000 check
  server nginx-7 hadoopvm389.localdomain:31000 check
  server nginx-6 hadoopvm386.localdomain:31000 check
  server nginx-5 hadoopvm383.localdomain:31000 check
  server nginx-4 hadoopvm378.localdomain:31001 check
  server nginx-3 hadoopvm381.localdomain:31000 check
  server nginx-2 hadoopvm385.localdomain:31000 check
  server nginx-1 hadoopvm378.localdomain:31000 check

Enjoy!