Bridge

Bridge is a bastion host that is the starting point for ops operations in OpenDev. It is the server from which Ansible is run, and contains a centralized database that contains secure information such as passwords. The bridge server contains all of the ansible playbooks as well as the scripts to create new servers.

Many of the systems in OpenDev are still configured using puppet, although the trend is away from Puppet to Ansible. For the hosts still using puppet, the process is still driven by Ansible.

At a Glance

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Ansible Hosts

In OpenDev, all host configuration is done via ansible playbooks.

Puppet Hosts

For hosts still using puppet, ansible drives the running of puppet apply on hosts in the inventory in the puppet group. That process first copies appropriate hiera data files to each host.

Hiera uses a systemwide configuration file in /etc/puppet/hiera.yaml.

The hiera configuration is placed by ansible into common.yaml in /etc/puppet/hieradata/production on each puppet host. The values are simple key-value pairs in yaml format. The keys needed are the keys referenced in site.pp, their values are typically obvious (strings, lists of strings). /etc/puppet/hieradata/ and below should be owned by puppet:puppet and have mode 0711.

Below the hieradata directory, there should be a common.yaml file where settings that should be available to all servers in the infrastructure go, and then two directories full of files. The first is fqdn which should contain a yaml file for every server in the infrastructure named ${fqdn_of_server}.yaml. That file has secrets that are only for that server. Additionally, some servers can have a $group defined in manifests/site.pp. There can be a correspondingly named yaml file in the group directory that contains secrets to be made available to each server in the group.

All of the actual yaml files should have mode 0600 and be owned by root.

Adding a node

Adding a new node should be done using the /opt/system-config/launch/launch-node.py script (see system-config: launch/README.rst for full details). If the host is put into the puppet group in the Ansible inventory, puppet will be run on on the host.

Running Ansible on Nodes

Each service that has been migrated fully to Ansible has its own playbook in system-config: playbooks named service_{ service_name }.yaml.

Because the playbooks are normally run by zuul, to run them manually, first run the utility disable-ansible as root. That will touch the file /home/zuul/DISABLE-ANSIBLE. We use the utility to avoid mistyping the lockfile name. Then make sure no jobs are currently executing ansible. Ensure that /home/zuul/src/opendev.org/opendev/system-config and /home/zuul/src/opendev.org/openstack/project-config are in the appropriate states, then run:

cd /home/zuul/src/opendev.org/opendev/system-config
ansible-playbook --limit="$HOST:localhost" playbooks/service-$SERVICE.yaml

as root, where $HOST is the host you want to run puppet on. The :localhost is important as some of the plays depend on performing a task on the localhost before continuing to the host in question, and without it in the limit section, the tasks for the host will have undefined values.

When done, don’t forget to remove /home/zuul/DISABLE-ANSIBLE

Running Puppet on Nodes

In OpenDev, puppet is run by ansible from a Zuul job running on bridge which in turn runs a single run of puppet apply on each host using puppet.

The entry point for this process is system-config: playbooks/remote_puppet_else.yaml

If an admin needs to run puppet by hand, it’s a simple matter of following the instructions in Running Ansible on Nodes but using playbooks/remote_puppet_else.yaml as the playbook.

Alternately, if local iteration is desired, it’s possible to log in to the server in question and running puppet apply /opt/system-config/manifests/site.pp.

There is also a script, tools/kick.sh that takes the host as an argument and runs the above command.

Testing new puppet code can be done via puppet apply –noop or by constructing a VM with a puppet install in it and just running puppet apply on the code in question. This should actually make it fairly easy to test how production works in a more self-contained manner.

Disabling Ansible on Nodes

In the case of needing to disable the running of ansible on a node, it’s a simple matter of adding an entry to the ansible inventory “disabled” group. See the Disable/Enable Ansible section for more details.