ansible-mesos-playbook
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An ansible playbook for launching a mesos cluster with docker and marathon support.
ansible-mesos-playbook
An ansible playbook for launching a mesos cluster with native docker and mesos executors, along with Marathon), Consul and HAProxy support. Run this on Ubuntu 14.04 LTS (preferred) or Centos/RHEL 6. Read the blog post for a descriptive overview.
Getting Started
- Install ansible, version >= 1.7.
- Install librarian-ansible via
gem install librarian-ansible
- Run
librarian-ansible install
- Spin up a bunch of Ubuntu 14.04 servers, say 5, on your favorite cloud provider.
-
cp hosts.sample hosts
and update themesos_masters
andmesos_slaves
groups. -
cp ansible.cfg.sample ansible.cfg
to ensure librarian_roles is in the ansible path (ansible.cfg
is git-ignored). - Run
ansible-playbook playbook.yml
.
The Setup
- zookeeper, haproxy, mesos-master, consul and marathon with ha mode run on nodes in the mesos_primaries group. The zoo_id host variable is used to configure zookeeper, and consul_bootstrap is set on one node to initialize the cluster.
- mesos-slave runs in the mesos_workers group and are passed the list of mesos_primaries for coordination.
- Docker and native mesos are configured as containerizers on mesos-slaves.
- A cron job on each master is set up to query the marathon api and configure HAProxy.
- HAProxy routes a frontend (listening on port 80) to backends based on marathon tasks.
- Consul for service discovery. It's not hooked into any other services, just part of the default setup.
- You probably want to tweak the HAProxy configuration script (in /opt/marathon/bin) for your needs. With the current setup you can have a wildcard dns prefix route to a backend matching the marathon name: i.e. www.example.com would do a least-connection proxy to the www task.
Altering the Playbook
There are a variety of tweaks you can make to this playbook for your needs.
- Don't want Marathon, Consul or HAProxy? Simply remove roles from mesos_primaries.yml
- Don't want to overload the primaries? Simply add new groups and remap roles appropriately.
Troubelshooting
If you have trouble, /var/log/syslog
on Ubuntu and /var/log/messages
on RHEL is your friend. For Zookeeper, try /var/log/zookeeper/zookeeper.log
. You can try re-running the playbook; the roles aren't perfect but most are idempotent.
Ansible lets you perform actions on groups of servers. You can try query or restart zookeeper and/or mesos:
$ ansible mesos_primaries -a "sudo status zookeeper"
$ ansible mesos_primaries -a "sudo restart zookeeper"
Notes
Currently this installs Mesos 0.20.1 with Marathon 0.7.3.
Launching a Container
POST to /v2/apps:
{
"id": "mlh",
"container": {
"docker": {
"image": "mhamrah/mesos-sample",
"network": "BRIDGE",
"portMappings": [
{ "containerPort": 8080, "hostPort": 0, "protocol": "tcp" }
]
},
"type": "DOCKER"
},
"cpus": 0.5,
"mem": 512,
"instances": 1
}