Many hosts have a read-only root filesystem, as well as some other
read-only paths that need to be remounted before configuration changes
can be made. The `remount.yml` playbook can be used to remount select
filesystems as either read-write or read-only (the default). It is
intended to be used before and after other playbooks, to ensure the
filesystems are in the correct state.
The *postfix* role installs and configures the Postfix MTA. It currently
supports a number of modes, including direct transfer and relay. Relay
mode supports STARTTLS security and PLAIN authentication.
Since the location of the configuration drop-in directory can vary by
distribution, it is important to expand the `zbx_agent_config_dir`
variable in the `Include` parameter.
Apparently, the `vault_password_file` setting in `ansible.cfg` overrides
the `--vault-password-file` command-line argument, which breaks the
Jenkins `ansiblePlaybook` task.
The host *zbx0.pyrocufflink.blue* (a Raspberry Pi) runs the Zabbix
server and web UI. It has a reserved IPv4 address to simplify reverse
DNS management for now, since Samba's dynamic DNS client does not
register PTR records.
The *zabbix-agent* role installs the Zabbix monitoring agent on the
managed node, and sets it up to communicate with the Zabbix server
specified by the `zabbix_server` variable. This role "should" be
compatible with most distributions; it has been tested with Fedora and
Gentoo.
The *zabbix-server* role deploys the Zabbix server database, daemon, and
web interface. It requires the *apache* role to configure Apache HTTPD
to serve the web UI.
The *apache* role installs and configures the Apache HTTPD server and
its *mod_ssl* module. It currently only works on Fedora/RHEL-based
distributions.
These IPv6 reverse DNS zones are managed by the Samba AD DCs for the
*pyrocufflink.blue* domain. These zones correspond to the IPv6 prefixes
used by the "blue" network.
The `ad` identity mapper backend is apparently the only one that can
use shell, home directory, etc. attributes from the directory now (as of
Samba 4.6).
Many hosts (should) have `/tmp` mounted with the `noexec` flag, which
prevents Ansible modules written there from running. To work around
this, the `remote_tmp` configuration option should be set to a path
under `/var/tmp`, which is not mounted noexec.
Using a dedicated slave node instead of a Docker container has a few
advantages:
* Persistent configuration is possible, without making weird assumptions
(e.g. Jenkins UID/GID) in the Dockerfile
* Can limit concurrent deployments by controlling executor count on the
node
The *ssh-hostkeys* role is used to manage the global SSH host key
database. This file is consulted by the `ssh` command when verifying
remote host keys on first connect. If the host key is found here, it is
copied to the user's host key database file without prompting for
verification.
The *jenkins-slave* role prepares a host to have the Jenkins slave
agent deployed on it. Deploying the agent itself is done by the Jenkins
master, through the web UI.
Dustin