Update docker.io/library/postgres Docker tag to v16

By default the limit on file descriptors is at a 1024 hard limit and 520k hard limit.
Unsure how this affects nginx, but each client connection needs two file descriptors.
So let's try to set the limit of open files explicitly.

inventories/chaosknoten/host_vars/cloud.yaml

@@ -1,7 +1,7 @@
 # renovate: datasource=docker depName=git.hamburg.ccc.de/ccchh/oci-images/nextcloud
 nextcloud__version: 34
 # renovate: datasource=docker depName=docker.io/library/postgres
-nextcloud__postgres_version: 15.18
+nextcloud__postgres_version: 16.15
 nextcloud__fqdn: cloud.hamburg.ccc.de
 nextcloud__data_dir: /data/nextcloud
 nextcloud__extra_configuration: "{{ lookup('ansible.builtin.template', 'resources/chaosknoten/cloud/nextcloud/extra_configuration.config.php.j2') }}"

resources/chaosknoten/lists/docker_compose/compose.yaml.j2

@@ -62,7 +62,7 @@ services:
       - POSTGRES_DB=mailmandb
       - POSTGRES_USER=mailman
       - "POSTGRES_PASSWORD={{ secret__lists__postgres_password }}"
-    image: docker.io/library/postgres:12-alpine
+    image: docker.io/library/postgres:16-alpine
     volumes:
       - /opt/mailman/database:/var/lib/postgresql/data
     networks:

resources/chaosknoten/pretalx/docker_compose/compose.yaml.j2

@@ -3,7 +3,7 @@
 
 services:
   database:
-    image: docker.io/library/postgres:15-alpine
+    image: docker.io/library/postgres:16-alpine
     environment:
       - "POSTGRES_USER=pretalx"
       - "POSTGRES_PASSWORD={{ secret__pretalx_db_password }}"

resources/chaosknoten/public-reverse-proxy/nginx/nginx.conf

@@ -3,6 +3,7 @@
 
 user  nginx;
 worker_processes  auto;
+worker_rlimit_nofile  2050; # should be worker_connections*2 at least
 
 error_log  /var/log/nginx/error.log notice;
 pid        /var/run/nginx.pid;