Make volumes, ports and labels explicitly configurable

Author: mhutter

README.md

@@ -20,16 +20,28 @@ Generic role for creating systemd services to manage docker containers.
 ```
 
 This will create:
-- a file containing the env vars (either `/etc/sysconfig/mysql` or `/etc/default/mysql`)
-- a systemd unit which starts and stops the container
+
+* A file containing the env vars (either `/etc/sysconfig/mysql` or `/etc/default/mysql`).
+* A systemd unit which starts and stops the container. The unit will be called
+  `<name>_container.service` to avoid name clashes.
 
 ### Role variables
 
 * `name` (**required**) - name of the service
+
+#### Docker container specifics
+
 * `image` (**required**) - Docker image the service uses
-* `args` - arbitrary list of arguments to the `docker run` command; Put port
-  bindings, mounts etc here
+* `args` - arbitrary list of arguments to the `docker run` command
+* `cmd` - optional command to the container run command (the part after the
+  image name)
 * `env` - key/value pairs of ENV vars that need to be present
+* `volumes` (default: _[]_) - List of `-v` arguments
+* `ports` (default: _[]_) - List of `-p` arguments
+* `labels` (default: _[]_) - List of `-l` arguments
+
+#### Systemd service specifics
+
 * `enabled` (default: _yes_) - whether the service should be enabled
 * `masked` (default: _no_) - whether the service should be masked
 * `state` (default: _started_) - state the service should be in

defaults/main.yml

@@ -1,4 +1,7 @@
 ---
+volumes: []
+labels: []
+ports: []
 enabled: yes
 masked: no
 state: started

templates/unit.j2

@@ -1,3 +1,7 @@
+# {{ ansible_managed }}
+{% macro params(name, vals) %}
+{% for v in vals %}-{{ name }} {{ v }} {% endfor %}
+{% endmacro %}
 [Unit]
 After=docker.service
 PartOf=docker.service
@@ -8,7 +12,7 @@ Requires=docker.service
 EnvironmentFile={{ sysconf_dir }}/{{ name }}
 {% endif %}
 ExecStartPre=-/usr/bin/docker rm -f {{ name }}
-ExecStart=/usr/bin/docker run --name {{ name }} --rm {% if env is defined %}--env-file {{ sysconf_dir }}/{{ name }}{% endif %} {{ (args | trim) if args is defined }} {{ image }}
+ExecStart=/usr/bin/docker run --name {{ name }} --rm {% if env is defined %}--env-file {{ sysconf_dir }}/{{ name }} {% endif %}{{ params('v', volumes) }}{{ params('p', ports) }}{{ params('l', labels) }}{{ args | default('') |trim }} {{ image }} {{ cmd | default('') | trim }}
 ExecStop=/usr/bin/docker stop {{ name }}
 
 SyslogIdentifier={{ name }}