Discourse: move from Bitnami chart to launcher-built image

The Bitnami chart and images stop at 3.5.0. Run Discourse 2026.10.0 from
an image built with the official launcher, on PostgreSQL 18, reusing the
existing uploads volume, Redis and secrets.

Update the Dex sign-in step for the new image paths, drop the removed
LDAP setting, and keep chat off now that it is bundled in core. The image
adds a real-IP rule so visitors are not all rate limited as the ingress.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tasks/discourse.yaml

@@ -1,90 +1,57 @@
 ---
 # tasks file for discourse
+#
+# Discourse runs from an image built with the official launcher; the Bitnami
+# chart stops at 3.5.0. To upgrade, change params.version in
+# files/discourse/web_only.yml, then from a discourse_docker checkout:
+#   cp <role>/files/discourse/web_only.yml containers/web_only.yml
+#   launcher build --set base_image=<base_image from templates/web.template.yml>-web-only \
+#     --tag gitea.eom.dev/devops/discourse-web:<version> web_only --output=type=docker
+# Push it, update the image tag in files/discourse/discourse-web.yaml, and re-run.
+#
+# Pushing through the gitea ingress needs proxy-body-size raised and
+# proxy-request-buffering "off" for the push, then restored. With buffering on,
+# ingress-nginx writes layers to its node's small disk; on 2026-11-08 that caused
+# DiskPressure, evicted the MetalLB speaker, and took the public sites down.
+#
+# Redis, the secrets, the uploads PVC, the Service and the Ingress still come from
+# the original Helm release, which must stay installed but is no longer upgraded.
+- name: Deploy PostgreSQL 18 for Discourse
+  kubernetes.core.k8s:
+    state: present
+    src: "{{ role_path }}/files/discourse/postgres18.yaml"
+
 - name: Deploy Discourse
-  kubernetes.core.helm:
-    name: discourse
-    chart_ref: bitnami/discourse
-    release_namespace: discourse
-    create_namespace: true
-    values:
-      auth:
-        email: discourse@eom.dev
-        username: discourse_admin
-        password: "{{ discourse_admin_password }}"
-      host: "https://discourse.eom.dev"
-      siteName: 'Discourse'
-      smtp:
-        enabled: true
-        host: "postfix.eom.dev"
-        port: "587"
-        protocol: "tls"
-        user: "discourse"
-        password: "{{ discourse_admin_password }}"
-      image:
-        debug: false
-        repository: bitnamilegacy/discourse
-        tag: 3.4.7-debian-12-r0
-      service:
-        externalTrafficPolicy: Local
-      discourse:
-        skipInstall: false
-        plugins:
-          - https://github.com/discourse/discourse-adplugin
-          - https://github.com/discourse/discourse-subscriptions
-          - https://github.com/discourse/discourse-activity-pub
-          - https://github.com/discourse/discourse-openid-connect
-          # discourse-ldap-auth removed: its login cannot be disabled by setting,
-          # and sign-in goes through Dex (discourse-openid-connect) only.
-          - https://github.com/discourse/discourse-math
-          - https://github.com/discourse/discourse-post-voting
-          - https://github.com/discourse/discourse-prometheus
-          - https://github.com/discourse/discourse-reactions
-        command:
-          - /bin/bash
-        args:
-          - -c
-          - |
-            rm -r /opt/bitnami/discourse/plugins/chat
-            chown -R discourse:root /opt/bitnami/discourse/plugins
-            /opt/bitnami/scripts/discourse/entrypoint.sh /opt/bitnami/scripts/discourse/run.sh
-        persistPlugins: false
-        compatiblePlugins: true
-        resourcesPreset: none
-      persistence:
-        size: 2Ti
-      ingress:
-        enabled: true
-        ingressClassName: "nginx"
-        hostname: discourse.eom.dev
-        annotations: 
-          cert-manager.io/cluster-issuer: ca-issuer
-          nginx.ingress.kubernetes.io/proxy-set-header: "X-Forwarded-Proto $scheme"
-        tls: true
-      postgresql:
-        enabled: true
-        image:
-          repository: bitnamilegacy/postgresql
-        auth:
-          enablePostgresUser: true
-          postgresPassword: "{{ discourse_admin_password }}"
-          password: "{{ discourse_admin_password }}"
-        primary:
-          persistence:
-            size: 2Ti
-      redis:
-        enabled: true
-        image:
-          repository: bitnamilegacy/redis
-        auth:
-          password: "{{ discourse_admin_password }}"
+  kubernetes.core.k8s:
+    state: present
+    src: "{{ role_path }}/files/discourse/discourse-web.yaml"
+    wait: true
+    wait_condition:
+      type: Available
+      status: "True"
+    wait_timeout: 1800
+
+- name: Point the Discourse Service at the launcher-built pods
+  kubernetes.core.k8s:
+    state: present
+    merge_type: merge
+    definition:
+      apiVersion: v1
+      kind: Service
+      metadata:
+        name: discourse
+        namespace: discourse
+      spec:
+        selector:
+          app.kubernetes.io/name: discourse-web
+          app.kubernetes.io/instance: null
 
 - name: Find the Discourse pod
   kubernetes.core.k8s_info:
     kind: Pod
     namespace: discourse
     label_selectors:
-      - app.kubernetes.io/instance=discourse
-      - app.kubernetes.io/name=discourse
+      - app.kubernetes.io/name=discourse-web
     field_selectors:
       - status.phase=Running
   register: discourse_pods
@@ -103,8 +70,7 @@
     pod: "{{ discourse_pods.resources[0].metadata.name }}"
     container: discourse
     command: >-
-      bash -c 'cd /opt/bitnami/discourse && PATH=/opt/bitnami/ruby/bin:$PATH
-      RAILS_ENV=production bundle exec ruby -e
-      "require \"/opt/bitnami/discourse/config/environment\"; load \"/tmp/discourse-sso.rb\""'
+      bash -c 'cd /var/www/discourse && su discourse -c
+      "RAILS_ENV=production bundle exec rails runner /tmp/discourse-sso.rb"'
   register: discourse_sso
   changed_when: false