roles/homeassistant: Deploy container with Podman

Installing Home Assistant in a Python virtualenv is rather tedious,
especially on non-x86 machines.  The main issue is Python packages that
include native extensions, as many of these do not have binary wheels
available for aarch64, etc. on PyPI.  Thus, to install these, they have
to be built from source, which then requires the appropriate development
packages to be installed.  Additionally, compiling native code on a
Raspberry Pi is excruciatingly slow.  I have considered various ways of
mitigating this, but all would require a substantial time investment,
both up front and ongoing, making them rather pointless.  Eventually, I
settled on just deploying the official Home Assistant container image
with Podman.

Although Podman includes a tool for generating systemd service unit
files for running containers, I ended up creating my own for several
reasons.  First and foremost, the generated unit files configure the
containers to run as *root*, but I wanted to run Home Assistant as an
unprivileged user.  Unfortunately, I could not seem to get the container
to work when dropping privileges using the `User` directive of the unit.
Fortunately, `podman` has `--uidmap` and `--gidmap` arguments, which I
was able to use to map UID/GID 0 in the container to the *homeassistant*
user on the host.  Another drawback of the generated unit files is that
they specify a "forking" type service, which is not really necessary.
Podman/conmon supports the systemd notify protocol, but the generator
has not been updated to make use of that yet.

Recent versions of Home Assistant are more strict with respect to how
reverse proxies are handled.  In order to use one, it must be explicitly
listed in the configuration file.  Therefore, the *homeassistant*
Ansible role will now create a stub `configuration.yaml`, based on the
one generated by Home Assistant itslf when it starts for the first time
on a new machine, that includes the appropriate configuration for a
reverse proxy running on the same machine.  The stub configuration will
not overwrite an existing configuration file, so it is only useful when
deploying Home Assistant for the first time on a new machine.

Overall, although I think a 300+ MB container image is ridiculous,
deploying Home Assistant this way should make it a lot easier to manage,
especially when updating.

roles/homeassistant/tasks/main.yml

@@ -3,11 +3,12 @@
   with_first_found:
   - '{{ ansible_architecture }}.yml'
   - defaults.yml
+  tags:
+  - always
 
-- name: ensure system dependencies are installed
+- name: ensure podman is installed
   package:
-    name: >-
-      {{ homeassistant_common_system_deps + homeassistant_arch_system_deps }}
+    name: '{{ homeassistant_podman_packages }}'
     state: present
   tags:
   - install
@@ -17,62 +18,73 @@
     name: homeassistant
     system: true
     home: /var/lib/homeassistant
+    createhome: false
+  register: homeassistant_user
+  tags:
+  - user
 
-- name: ensure homeassistant tmp dir exists
+- name: ensure homeassistant home directory exists
   file:
-    path: /var/lib/homeassistant/tmp
-    mode: '0700'
+    path: /var/lib/homeassistant
     owner: homeassistant
     group: homeassistant
-    state: directory
-
-- name: ensure homeassistant install dir exists
-  file:
-    path: /usr/local/homeassistant
     mode: '0755'
-    owner: homeassistant
-    group: homeassistant
     state: directory
-- name: ensure homeassistant is installed
-  environment:
-    TMPDIR: /var/lib/homeassistant/tmp
-  become: true
-  become_user: homeassistant
-  pip:
-    name: homeassistant
-    extra_args: >-
-      --prefer-binary
-    virtualenv: /usr/local/homeassistant
-    virtualenv_command: '/usr/bin/python3 -m venv'
+  tags:
+  - datadir
 
-- name: ensure selinux file context map is correct for home assistant dir
-  sefcontext:
-    ftype: a
-    setype: bin_t
-    target: /usr/local/homeassistant/bin(/.*)?
-    state: present
-  notify: relabel home assistant dir
-
-- name: ensure homeassistant entry point is installed
+- name: ensure stub home assistant configuration is set
   copy:
-    src: hass.sh
-    dest: /usr/local/bin/hass
-    setype: bin_t
-    mode: '0755'
+    src: '{{ item }}'
+    dest: /var/lib/homeassistant/{{ item|basename }}
+    owner: homeassistant
+    group: homeassistant
+    mode: '0644'
+    force: false
+  with_fileglob:
+  - 'stubs/*.yaml'
+  tags:
+  - config
+- name: ensure home assistant proxy settings are configured
+  copy:
+    src: http.yaml
+    dest: /var/lib/homeassistant/http.yaml
+    owner: homeassistant
+    group: homeassistant
+    mode: '0644'
   notify:
   - restart homeassistant
+  tags:
+  - config
+
+- name: ensure homeassistant container image is available
+  podman_image:
+    name: ghcr.io/home-assistant/{{ homeassistant_image_name }}
+    tag: stable
+    state: present
+  notify:
+  - restart homeassistant
+  tags:
+  - container-image
+  - container
+
 - name: ensure homeassistant systemd unit is installed
-  copy:
-    src: homeassistant.service
+  template:
+    src: homeassistant.service.j2
     dest: /etc/systemd/system/homeassistant.service
     mode: '0644'
   notify:
   - reload systemd
   - restart homeassistant
+  tags:
+  - service
+  - systemd
 - name: ensure homeassistant starts at boot
   service:
     name: homeassistant
     enabled: true
+  tags:
+  - service
 
 - name: ensure apache is configured to proxy for homeassistant
   template:
@@ -81,8 +93,13 @@
     mode: '0644'
   notify:
   - restart httpd
+  tags:
+  - apache
 - name: ensure selinux allows apache to proxy
   seboolean:
     name: httpd_can_network_connect
     state: true
     persistent: true
+  tags:
+  - selinux
+  - apache