Cut the comment bloat from the Podman playbooks

Comment blocks now stay within three lines and explain only the non-obvious. Long histories, include examples, and commented-out code are gone. No task, key, or value changed; the only data change is comment text inside the generated unit files.

tandoor/playbook.yml

@@ -1,28 +1,5 @@
 ---
-# Tandoor Recipes as a rootless Podman Quadlet unit, behind the shared Caddy
-# unit (see caddy/playbook.yml) and the shared Postgres unit
-# (postgres/playbook.yml).
-#
-# Connects as the container user and runs everything as that user: the Quadlet
-# units belong to it, so the connection's PAM session is what makes
-# `systemctl --user` work without any environment juggling.
-#
-# gather_facts is required: podman_user and the home directory come from the
-# user_id / user_dir facts.
-#
-# The rootless-Podman prerequisites (installing podman, enabling lingering, the
-# low-port sysctl, creating the Quadlet directory) are deliberately NOT applied
-# here. They are the shared task file at caddy/roles/podman/tasks/main.yaml, and
-# a host that has already run caddy/playbook.yml has them:
-#
-#   - name: Rootless Podman prerequisites
-#     ansible.builtin.include_tasks: "{{ playbook_dir }}/../caddy/roles/podman/tasks/main.yaml"
-#
-# The variables this play needs are duplicated at the top of vars/default.yml, so
-# it stands on its own. (Applying the commented include above would also need
-# podman_unprivileged_port_start, which lives in caddy/vars/default.yml.)
-#
-# Run with: ansible-playbook -u tanshu tandoor/playbook.yml
+# Requires caddy and postgres to have run first.
 - name: Deploy Tandoor as a rootless Podman Quadlet
   hosts: emily
   gather_facts: true
@@ -30,24 +7,11 @@
     - vars/default.yml
 
   pre_tasks:
-    # This must happen before the app unit is started, not after: the generated
-    # unit references {{ network_name }}.network, and Quadlet fails *unit
-    # generation* (so `systemctl --user start` reports "unit not found") when a
-    # referenced .network file does not exist yet. The same include writes the
-    # Caddy-side drop-in that attaches Caddy to this network, and the Postgres
-    # attach below needs the network unit to exist as well.
-    #
-    # network_name is a play var, so the include can see it directly.
+    # Quadlet needs the network unit before it generates the app unit.
     - name: Register Tandoor's network with Caddy
       ansible.builtin.include_tasks: "{{ playbook_dir }}/../caddy/roles/register/tasks/main.yaml"
 
   roles:
-    # Attaches this app's network to the shared Postgres unit, which is what
-    # makes POSTGRES_HOST=db resolve, and owns the "Restart Postgres" handler
-    # that postgres/roles/attach notifies. Runs first so the database is
-    # reachable before the app starts.
     - postgres
-    # The app: data directories, .env, the Quadlet unit, start + verify.
     - tandoor
-    # Appends this site's block to the shared Caddyfile and reloads Caddy.
     - caddy

tandoor/roles/caddy/handlers/main.yaml

@@ -1,27 +1,14 @@
 ---
-# Caddy is its own playbook (caddy/playbook.yml) and a rootless Quadlet unit
-# there. These handlers run as the connection user, so `systemctl --user` and
-# `podman exec` work without any XDG_RUNTIME_DIR juggling.
-
-# Notified by this role when the Caddyfile changes. A reload keeps existing
-# connections; a restart would briefly drop every hosted site.
-#
-# Note the config path: /etc/caddy/Caddyfile is the mount inside the container,
-# not {{ caddyfile_path }}, which is the host side of it.
+# A reload keeps existing connections. A restart would briefly drop every hosted site.
+# The config path is inside the container, not caddyfile_path on the host.
 - name: Reload Caddy configuration
   ansible.builtin.command: >-
     podman exec {{ caddy_name }} caddy reload --config /etc/caddy/Caddyfile
   changed_when: true
   listen: "Reload Caddy"
 
-# Notified by caddy/roles/register when this service's network unit, or the
-# drop-in that attaches Caddy to it, is written. Quadlet has no live equivalent
-# of `docker network connect`, so the container has to be recreated — a brief
-# restart of every hosted site, not just this one. See caddy/readme.md,
-# "Trade-off worth knowing".
-#
-# Defined after the reload above so that when both are notified the cheap
-# config reload happens first.
+# Quadlet has no live equivalent of network connect, so Caddy is recreated and every hosted site restarts.
+# Defined after the reload so the cheap reload runs first.
 - name: Restart Caddy
   ansible.builtin.systemd_service:
     name: "{{ caddy_name }}.service"

tandoor/roles/caddy/tasks/main.yaml

@@ -1,15 +1,4 @@
 ---
-# Append this site's block to the shared Caddyfile.
-#
-# The Caddyfile is a bind mount into the Caddy container, so Caddy sees the
-# change as soon as the file is written; the handler only asks Caddy to re-read
-# it. That is a reload, not a restart, so the other hosted sites are untouched.
-#
-# blockinfile is idempotent on its own via the marker, so there is no need to
-# slurp the file and compare first — which also matters because slurp *fails*
-# when the Caddyfile does not exist yet, on a host where the Caddy playbook has
-# not run.
-
 - name: "Add the {{ host }} site block to the Caddyfile"
   ansible.builtin.blockinfile:
     path: "{{ caddyfile_path }}"

tandoor/roles/postgres/handlers/main.yaml

@@ -1,13 +1,5 @@
 ---
-# Postgres is its own playbook (postgres/playbook.yml) and a rootless Quadlet
-# unit there. This handler runs as the connection user, so `systemctl --user`
-# works without setting XDG_RUNTIME_DIR.
-#
-# Required by postgres/roles/attach, which notifies it whenever this app's
-# drop-in changes: a new drop-in changes the generated unit, so Postgres must be
-# recreated to join the network — Quadlet has no live equivalent of
-# `podman network connect`. That is a few seconds of downtime for every attached
-# app, not just this one. See postgres/readme.md, "The trade-off".
+# A new drop-in changes the generated unit, so Postgres is recreated and every attached app restarts.
 - name: Restart Postgres
   ansible.builtin.systemd_service:
     name: "{{ postgres_unit }}"

tandoor/roles/postgres/tasks/main.yaml

@@ -1,26 +1,7 @@
 ---
-# Attach this app's network to the shared Postgres unit.
-#
-# Postgres knows nothing about its clients, exactly like Caddy: a service joins
-# by dropping 50-tandoor.conf and the shared 10-network-aliases.conf next to
-# postgres.container. The canonical way to do that is the shared include below —
-# it writes the same bytes every service writes, asserts that tandoor.network
-# already exists, and notifies the "Restart Postgres" handler defined in this
-# role.
-#
-# This runs in the roles phase, which is after the register include in
-# playbook.yml's pre_tasks has created tandoor.network.
-
 - name: Attach Tandoor to Postgres
   ansible.builtin.include_tasks: "{{ playbook_dir }}/../postgres/roles/attach/tasks/main.yaml"
 
-# On a first attach both drop-ins are new, so Postgres has to be recreated to
-# join tandoor_net — and that restart is a *handler*, which by default runs at
-# the end of the play, after the tandoor role has already started the app. The
-# app would then come up before `db` resolves, fail its own is-active check, and
-# fail the play on a machine where nothing is actually wrong.
-#
-# Flushing applies the new drop-in before the app starts. On later runs the
-# drop-ins are unchanged, nothing is pending, and this is a no-op.
+# The restart that joins Postgres to tandoor_net is a handler, so flush it before the app starts or its is-active check fails.
 - name: Apply the Postgres network change before starting Tandoor
   ansible.builtin.meta: flush_handlers

tandoor/roles/tandoor/tasks/main.yaml

@@ -1,10 +1,4 @@
 ---
-# Tandoor Recipes as a rootless Podman Quadlet unit.
-#
-# Everything here runs as {{ podman_user }} — the connection user. No become, no
-# XDG_RUNTIME_DIR: the SSH connection gave us a real PAM session, so systemd's
-# user manager is reachable through the standard environment.
-
 - name: Ensure the Tandoor data directories exist
   ansible.builtin.file:
     path: "{{ host_directory }}/{{ item }}"
@@ -13,16 +7,12 @@
     group: "{{ podman_user }}"
     mode: '0755'
   loop:
-    # mediafiles is the irreplaceable one; the other two are regenerated by the
-    # app and are bind-mounted anyway because the image expects them to exist.
+    # mediafiles is irreplaceable. The other two are regenerated and bind-mounted because the image expects them.
     - mediafiles
     - staticfiles
     - externalfiles
 
-# The app's secrets and database coordinates are consumed by systemd
-# (EnvironmentFile= in the Quadlet unit), not by Ansible, so this has to be
-# written before the unit starts. Mode 0600: it holds SECRET_KEY and the
-# postgres password.
+# systemd reads it through EnvironmentFile= before the unit starts, and it holds SECRET_KEY and the Postgres password.
 - name: Write the environment file
   ansible.builtin.template:
     src: tandoor.env.j2
@@ -52,9 +42,7 @@
         state: started
         daemon_reload: true
   rescue:
-    # systemd reports "control process exited with error code" and nothing
-    # else, which is useless for the usual failures (an unattached network, an
-    # unreachable database, a bad volume). Pull the real reason out.
+    # systemd only reports "control process exited with error code", so pull the real reason.
     - name: Collect Tandoor diagnostics
       ansible.builtin.command: "{{ item }}"
       loop:
@@ -73,16 +61,14 @@
       ansible.builtin.fail:
         msg: "Tandoor did not start — see the diagnostics above."
 
-# Quadlet honours [Install] WantedBy= when it generates the unit, so
-# `systemctl --user enable` is neither needed nor possible on a generated unit.
+# Quadlet honours [Install] WantedBy=, so `systemctl --user enable` is not needed on a generated unit.
 - name: Verify Tandoor is running
   ansible.builtin.command: "systemctl --user is-active {{ unit_name }}"
   register: tandoor_active
   changed_when: false
   failed_when: tandoor_active.stdout != 'active'
 
-# `db` is the alias the environment file actually asks for; the container name
-# is checked too because it is what the Quadlet network gives us for free.
+# The environment file asks for `db`; the container name is checked too because the network provides it.
 - name: Confirm Tandoor can resolve its database
   ansible.builtin.command: >-
     podman exec {{ container_name }} getent hosts {{ item }}
@@ -100,15 +86,8 @@
       {{ item.stdout | default('(no answer)') }}
   loop: "{{ tandoor_db_lookup.results }}"
 
-# `is-active` says the container is running; it does not say the app can serve.
-# Tandoor's entrypoint runs Django migrations before gunicorn answers, and until
-# it does the image's own nginx returns 502 to Caddy — which Caddy relays as-is,
-# complete with `server: nginx`. That is exactly the confusing "nginx 502" a
-# first deploy shows after a play that reported success.
-#
-# python3 is used rather than curl or wget because this is a Django image: the
-# interpreter is guaranteed present, the others are not. A 502 raises HTTPError,
-# so the retry loop holds until a real page comes back.
+# `is-active` only says the container is running. Tandoor migrates before gunicorn answers, and its nginx returns 502 until then.
+# The probe uses python3 because the Django image guarantees it and may not ship curl or wget.
 - name: Wait for Tandoor to serve HTTP
   ansible.builtin.command: >-
     podman exec {{ container_name }}

tandoor/vars/default.yml

@@ -1,50 +1,29 @@
 ---
-# ---------------------------------------------------------------------------
-# Rootless Podman / Quadlet
-# ---------------------------------------------------------------------------
-# Duplicated on purpose from caddy/vars/default.yml: a play cannot include that
-# file wholesale, because it also sets `host_directory` — to the Caddy data
-# directory — and every playbook defines that for itself. Keep these three in
-# sync with caddy/vars/default.yml. (Its fourth, podman_unprivileged_port_start,
-# belongs to the podman tasks, which this play does not run: Tandoor listens on
-# 80 inside the container and publishes nothing host-side.)
-#
-# podman_user is derived from the connection: this play carries no become, so
-# the Quadlet units belong to whoever Ansible connects as. Requires gather_facts
-# (set in playbook.yml).
+# Duplicated from caddy/vars/default.yml on purpose, so keep them in sync.
+# podman_user comes from the connection user, so the play needs gather_facts.
 podman_user: "{{ ansible_facts['user_id'] }}"
 podman_data_dir: "{{ ansible_facts['user_dir'] }}/podman-data"
 quadlet_dir: "{{ ansible_facts['user_dir'] }}/.config/containers/systemd"
 
-# ---------------------------------------------------------------------------
-# Tandoor
-# ---------------------------------------------------------------------------
 host: recipes.tanshu.com
 
 container_name: tandoor
 unit_name: "{{ container_name }}.service"
 
-# Fully qualified on purpose: rootless Podman resolves short names against
-# unqualified-search-registries, and there is no TTY to answer a prompt when
-# the systemd unit starts.
+# Fully qualified because rootless Podman would otherwise prompt for a registry, and a unit has no TTY.
 image: docker.io/vabene1111/recipes:latest
 
-# The Quadlet file is <network_name>.network. caddy/roles/register pins the
-# Podman network name to <network_name>_net (so: tandoor.network, tandoor_net).
+# caddy/roles/register pins the Podman network to <network_name>_net, so the Quadlet file is tandoor.network.
 network_name: "{{ container_name }}"
 
 host_directory: "{{ podman_data_dir }}/{{ container_name }}"
 
-# Port Caddy proxies to, inside the container (the image's own nginx).
+# The port Caddy proxies to inside the container, where the image's own nginx listens.
 container_port: 80
 
-# The shared Postgres unit this app attaches itself to (postgres/playbook.yml).
-# roles/postgres owns this app's drop-ins there and the "Restart Postgres"
-# handler that applies them.
 postgres_container: postgres
 postgres_unit: "{{ postgres_container }}.service"
 
-# The shared Caddy unit and its Caddyfile, both owned by caddy/playbook.yml.
 caddy_name: caddy
 caddyfile_path: "{{ podman_data_dir }}/{{ caddy_name }}/conf/Caddyfile"