feat: allow locking maintenance mode

this enables manually turning it on

ansible/playbooks/pretix/lock-maintenance.yml

@@ -0,0 +1,8 @@
+---
+- hosts: "all"
+  remote_user: "ansible"
+  become: true
+
+  tasks:
+    - name: "lock and enable maintenance mode"
+      include_tasks: "$playbook_dir/../../../roles/pretix/tasks/lock-maintenance.yml"

ansible/playbooks/pretix/unlock-maintenance.yml

@@ -0,0 +1,8 @@
+---
+- hosts: "all"
+  remote_user: "ansible"
+  become: true
+
+  tasks:
+    - name: "unlock and redetermine maintenance mode"
+      include_tasks: "$playbook_dir/../../../roles/pretix/tasks/unlock-maintenance.yml"

ansible/roles/pretix/handlers/main.yml

@@ -18,9 +18,3 @@
     - "pretix-web.service"
     - "pretix-worker.service"
   listen: "restart pretix"
-
-- name: "ensure maintenance mode is in desired state and reload nginx"
-  ansible.builtin.service:
-    name: "pretix-maintenance.service" # This service reloads nginx
-    state: "started"
-  listen: "pretix reload nginx"

ansible/roles/pretix/tasks/lock-maintenance.yml

@@ -0,0 +1,14 @@
+---
+- name: "create pretix's maintenance lock"
+  ansible.builtin.file:
+    path: "/var/www/pretix/MAINTENANCE_MODE_LOCK"
+    state: "touch"
+  become: true
+  become_user: "pretix"
+
+- name: "ensure pretix's maintenance state is properly configured"
+  ansible.builtin.service:
+    name: "pretix-maintenance.service"
+    state: "started"
+  become: true
+  become_user: "root"

ansible/roles/pretix/tasks/main.yml

@@ -143,11 +143,14 @@
       group: "pretix"
       src: "pretix_maintenance.html.j2"
       dest: "/var/www/pretix/pretix-maintenance.html"
+    become: true
+    become_user: "pretix"
 
-  - name: "install maintenance script to be run my systemd services"
+  - name: "install maintenance script to be run by systemd services"
     ansible.builtin.template:
       src: "pretix-maintenance.sh.j2"
       dest: "/usr/local/bin/pretix-maintenance.sh"
+      mode: "755"
 
   - name: "prepare maintenance mode services"
     ansible.builtin.template:
@@ -167,19 +170,23 @@
       name: "pretix-maintenance.timer"
       state: "started"
       enabled: "yes"
-      # We do not need to start the service itself yet
 
-  # We do not simply reload nginx, but also run the previously defined systemd
-  # service to enable or disable maintenance mode - whichever is currently
-  # desired. This removes the need to specify during deploy whether we want
-  # maintenance mode on or off before we expose the service.
+  - name: "ensure maintenance mode is in right state"
+    ansible.builtin.service:
+      name: "pretix-maintenance.service"
+      state: "started"
+    changed_when: false
+    # Note: this should be run before reloading nginx, to prevent creating a
+    # short window of opportunity where people can buy tickets whilst
+    # maintenance mode should be on.
+
 - name: "set up nginx for pretix"
   block:
   - name: "place pretix's nginx configuration"
     ansible.builtin.template:
       src: "nginx.conf.j2"
       dest: "/etc/nginx/sites-available/pretix.{{ canonical_hostname }}.conf"
-    notify: "pretix reload nginx"
+    notify: "reload nginx"
 
   - name: "enable pretix's nginx configuration"
     ansible.builtin.file:
@@ -188,4 +195,4 @@
       state: "link"
     vars:
       filename: "pretix.{{ canonical_hostname }}.conf"
-    notify: "pretix reload nginx"
+    notify: "reload nginx"

ansible/roles/pretix/tasks/unlock-maintenance.yml

@@ -0,0 +1,14 @@
+---
+- name: "remove pretix's maintenance lock"
+  ansible.builtin.file:
+    path: "/var/www/pretix/MAINTENANCE_MODE_LOCK"
+    state: "absent"
+  become: true
+  become_user: "pretix"
+
+- name: "ensure pretix's maintenance state is properly configured"
+  ansible.builtin.service:
+    name: "pretix-maintenance.service"
+    state: "started"
+  become: true
+  become_user: "root"

ansible/roles/pretix/templates/nginx.conf.j2

@@ -17,10 +17,10 @@ server {
   # Security header file not included because frames
 
   location / {
-		if (-f /var/www/pretix/MAINTENANCE_MODE) {
-		    error_page 503 /var/www/pretix/pretix-maintenance.html;
-		    return 503;
-		}
+    if (-f /var/www/pretix/MAINTENANCE_MODE) {
+      error_page 503 =200 /pretix-maintenance.html;
+      return 503;
+    }
 
     proxy_pass http://localhost:8345/;
     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
@@ -56,4 +56,10 @@ server {
     expires 365d;
     add_header Cache-Control "public";
   }
+
+  # Expose 503 page
+  location = /pretix-maintenance.html {
+    root /var/www/pretix/;
+    internal; # Prevent direct access to the page
+  }
 }

ansible/roles/pretix/templates/pretix-maintenance.sh.j2

@@ -1,8 +1,17 @@
 #!/usr/bin/env bash
 
 ##
+## ABSTRACT:
 ## This script checks the current UTC time, and based on that time
 ## enables or disables the pretix maintenance mode.
+## This script also respects a maintenance lock, meaning that if the lock exists,
+## maintenance mode will be enabled regardless of anything.
+## Enable the lock by simply creating the marker at MARKER_PATH defined below.
+##
+## PURPOSE:
+## The goal is to compensate for the report cut-off being different for Mollie and
+## Pretix, as described in https://github.com/svsticky/sadserver/issues/487
+## This improves the treasurer's quality of life.
 ##
 ## USAGE: pretix_maintenance.sh
 ##
@@ -12,13 +21,22 @@ set -eEfuo pipefail
 IFS=$'\n\t'
 
 MARKER_PATH='/var/www/pretix/MAINTENANCE_MODE'
+MARKER_LOCK_PATH="${MARKER_PATH}_LOCK"
+
+
+# If the maintenance lock exists, just ensure maintenance mode is enabled
+if [[ -f "$MARKER_LOCK_PATH" ]]; then
+  touch "$MARKER_PATH" # Enable maintenance mode
+  return
+fi
+
 
-HOUR=$(date -u +%H) # UTC hour
 DAY=$(date -u +%a) # UTC day
+HOUR=$(date -u +%H) # UTC hour
 
-if [[ "$DAY" == "su" && $HOUR -gt 21 || "$DAY" == "mo" && $HOUR -lt 5 ]]
-  then touch "$MARKER_PATH"; # Enable maintenance mode
-  else rm "$MARKER_PATH"; # Disable maintenance mode
+if [[ "$DAY" == "su" && $HOUR -gt 21 || "$DAY" == "mo" && $HOUR -lt 5 ]]; then
+  touch "$MARKER_PATH"; # Enable maintenance mode
+else
+  rm -f "$MARKER_PATH"; # Disable maintenance mode
 fi
 
-systemctl reload nginx # Apply changes

ansible/roles/pretix/templates/systemd/pretix-maintenance.service.j2

@@ -2,9 +2,9 @@
 
 [Unit]
 Description=Configure pretix maintenance mode
+# If, compared to UTC, we are between sunday 22:00 and monday 05:00, we want
+# maintenance mode enabled and otherwise not.
 OnFailure=failure-notificator@%n.service
 
 [Service]
-# If, compared to UTC, we are between sunday 22:00 and monday 05:00, we want
-# maintenance mode and otherwise not.
 ExecStart=/usr/local/bin/pretix-maintenance.sh

ansible/roles/pretix/templates/systemd/pretix-maintenance.timer.j2

@@ -2,7 +2,7 @@
 
 [Unit]
 Description=Weekly pretix maintenance
-#During week transitions, enable maintenance mode to make the treasurer's life easier
+# During week transitions, enable maintenance mode to make the treasurer's life easier
 
 [Timer]
 OnCalendar=Sun *-*-* 22:00:00 UTC

docs/pretix.md

@@ -0,0 +1,44 @@
+# Pretix
+
+## Maintenance mode
+
+Pretix has a weekly routine in enabling and disabling maintenance mode.
+The treasurer benefits from this, for the weekly reports from Mollie have a
+different cut-off then Pretix has, which can't be reconfigured. As such, Pretix
+will be brought in maintenance mode during this overlapping period, to make the
+book works way easier.
+
+Maintenance mode can be manually enabled for an arbitrarily long duration, but
+not disabled for an arbitrarily long duration, on purpose. This can be done
+with the two playbooks:
+
+```bash
+$ sadserver/ansible
+./deploy.py --to staging --playbook=playbooks/pretix/lock-maintenance.yml
+```
+
+```bash
+$ sadserver/ansible
+./deploy.py --to staging --playbook=playbooks/pretix/unlock-maintenance.yml
+```
+
+### How the maintenance mode works
+
+Maintenance mode is enabled when a marker file is present, indicating it is on.
+Nginx will respect this and return a 503 error page, preventing users from
+buying tickets. Admin panels and such are still available.
+
+This state is managed with a single script: `/usr/local/bin/pretix-maintenance.sh`.
+This script can be run as the systemd service `pretix-maintenance`, which is
+automatically run two times every week (at the start and end of the overlapping
+reporting period). Taking all things into account, this script ensures the
+maintenance mode is in the right state.
+
+If you wish to enable maintenance mode manually - and locking it, preventing
+the weekly service from touching the marker file - a playbook is available,
+placing a second marker file (lock) and running the same systemd service to
+ensure the maintenance mode is in the desired state. Running the other
+playbook, this lock file is removed and the systemd script is run again. Note
+that when this is done during the overlapping reporting period - when
+maintenance mode should be on - the maintenance marker still persists, but the
+lock is gone.