Failed to connect to authentik backend: authentik starting

[rhpeZ]

Describe the bug
Unable to access the web ui for Authentik, when looking in logs getting a "PostgreSQL connection failed, retrying. Name or service not known". Also, when doing a docker ps the worker component is constantly restarting after about 30 seconds

To Reproduce
Followed this guide for setting up Authentik.

Expected behavior
Web ui should be available to connect to and setup Authentik

Logs
[+] Running 4/4
✔ Container authentik-redis Recreated 0.3s
✔ Container authentik-postgresql Recreated 0.2s
✔ Container authentik-server Recreated 0.3s
✔ Container authentik-worker Recreated 0.3s
Attaching to authentik-postgresql, authentik-redis, authentik-server, authentik-worker
authentik-redis | Starting Redis Server
authentik-postgresql |
authentik-postgresql | PostgreSQL Database directory appears to contain a database; Skipping initialization
authentik-postgresql |
authentik-redis | 1:C 20 May 2025 15:03:15.594 # WARNING Memory overcommit must be enabled! Without it, a background save or replication may fail under low memory condition. Being disabled, it can also cause failures without low memory condition, see jemalloc/jemalloc#1328. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
authentik-postgresql | 2025-05-20 15:03:15.633 UTC [1] LOG: starting PostgreSQL 16.9 on x86_64-pc-linux-musl, compiled by gcc (Alpine 14.2.0) 14.2.0, 64-bit
authentik-postgresql | 2025-05-20 15:03:15.633 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
authentik-postgresql | 2025-05-20 15:03:15.633 UTC [1] LOG: listening on IPv6 address "::", port 5432
authentik-postgresql | 2025-05-20 15:03:15.639 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
authentik-postgresql | 2025-05-20 15:03:15.648 UTC [29] LOG: database system was shut down at 2025-05-20 15:03:14 UTC
authentik-postgresql | 2025-05-20 15:03:15.656 UTC [1] LOG: database system is ready to accept connections
authentik-server | {"event":"Loaded config","level":"debug","path":"inbuilt-default","timestamp":"2025-05-20T15:03:21Z"}
authentik-server | {"event":"Loaded config","level":"debug","path":"/authentik/lib/default.yml","timestamp":"2025-05-20T15:03:21Z"}
authentik-server | {"event":"Loaded config from environment","level":"debug","timestamp":"2025-05-20T15:03:21Z"}
authentik-server | {"event":"Starting Metrics server","level":"info","listen":"0.0.0.0:9300","logger":"authentik.router.metrics","timestamp":"2025-05-20T15:03:21Z"}
authentik-server | {"event":"Starting HTTP server","level":"info","listen":"0.0.0.0:9000","logger":"authentik.router","timestamp":"2025-05-20T15:03:21Z"}
authentik-worker | {"event": "Loaded config", "level": "debug", "logger": "authentik.lib.config", "timestamp": 1747753401.7073514, "file": "/authentik/lib/default.yml"}
authentik-worker | {"event": "Loaded environment variables", "level": "debug", "logger": "authentik.lib.config", "timestamp": 1747753401.7077928, "count": 7}
authentik-server | {"event": "Loaded config", "level": "debug", "logger": "authentik.lib.config", "timestamp": 1747753401.742738, "file": "/authentik/lib/default.yml"}
authentik-server | {"event": "Loaded environment variables", "level": "debug", "logger": "authentik.lib.config", "timestamp": 1747753401.7431855, "count": 7}
authentik-server | {"event":"Starting HTTPS server","level":"info","listen":"0.0.0.0:9443","logger":"authentik.router","timestamp":"2025-05-20T15:03:21Z"}
authentik-worker | {"event": "Starting authentik bootstrap", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753402.0593565}
authentik-server | {"event": "Starting authentik bootstrap", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753402.2168343}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753403.063988}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753403.2196019}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753404.0662575}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753404.2220685}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753405.069654}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753405.2246292}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753406.0717437}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753406.2270997}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753407.0741785}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753407.2296758}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753408.076667}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753408.232043}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753409.0795057}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753409.2348855}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753410.0819182}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753410.2373116}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753411.0847766}
authentik-server | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753411.2400072}
authentik-worker | {"event": "PostgreSQL connection failed, retrying... ([Errno -2] Name or service not known)", "level": "info", "logger": "authentik.lib.config", "timestamp": 1747753412.0872056}

Version and Deployment (please complete the following information):
Setup using docker compose and using latest versions provided in the docker-compose.yml

services:
  postgresql:
    image: docker.io/library/postgres:16-alpine
    container_name: authentik-postgresql
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -d $${POSTGRES_DB} -U $${POSTGRES_USER}"]
      start_period: 20s
      interval: 30s
      retries: 5
      timeout: 5s
    volumes:
      - ./database_postgresql:/var/lib/postgresql/data
    environment:
      - POSTGRES_DB=${POSTGRES_DB}
      - POSTGRES_USER=${POSTGRES_USER}
      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}



  redis:
    image: docker.io/library/redis:alpine
    container_name: authentik-redis
    command: --save 60 1 --loglevel warning
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "redis-cli ping | grep PONG"]
      start_period: 20s
      interval: 30s
      retries: 5
      timeout: 3s
    volumes:
      - ./config_redis:/data



  server:
    image: ghcr.io/goauthentik/server:2025.4.1
    container_name: authentik-server
    restart: unless-stopped
    command: server
    environment:
      - AUTHENTIK_REDIS__HOST=authentik-redis
      - AUTHENTIK_POSTGRESQL__HOST=authentik-postgresql
      - AUTHENTIK_POSTGRESQL__NAME=${POSTGRES_DB}
      - AUTHENTIK_POSTGRESQL__USER=${POSTGRES_USER}
      - AUTHENTIK_POSTGRESQL__PASSWORD=${POSTGRES_PASSWORD}
      - AUTHENTIK_ERROR_REPORTING__ENABLED=true
      - AUTHENTIK_SECRET_KEY=${AUTHENTIK_SECRET_KEY}
    labels:      
      - "traefik.enable=true"
      - "traefik.http.routers.authentik.rule=Host(`my.domain.name`)"
      - "traefik.http.routers.authentik.entrypoints=https"
      - "traefik.http.routers.authentik.tls=true"
      - "traefik.http.services.authentik.loadbalancer.server.port=9000"
    volumes:
      - ./authentik_media:/media
      - ./authentik_custom_templates:/templates
    depends_on:
      postgresql:
        condition: service_healthy
      redis:
        condition: service_healthy
    networks:
      - backend
      - frontend



  worker:
    image: ghcr.io/goauthentik/server:2025.4.1
    container_name: authentik-worker
    restart: unless-stopped
    command: worker
    environment:
      - AUTHENTIK_REDIS__HOST=redis
      - AUTHENTIK_POSTGRESQL__HOST=postgresql
      - AUTHENTIK_POSTGRESQL__NAME=${POSTGRES_DB}
      - AUTHENTIK_POSTGRESQL__USER=${POSTGRES_USER}
      - AUTHENTIK_POSTGRESQL__PASSWORD=${POSTGRES_PASSWORD}
      - AUTHENTIK_ERROR_REPORTING__ENABLED=true
      - AUTHENTIK_SECRET_KEY=${AUTHENTIK_SECRET_KEY}
    user: root
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - ./authentik_media:/media
      - ./authentik_certs:/certs
      - ./authentik_custom_templates:/templates
    depends_on:
      postgresql:
        condition: service_healthy
      redis:
        condition: service_healthy
    networks:
      - backend

networks:
  frontend:
    external: true
  backend:
    external: true

[dominic-r]

It's a DNS resolution error as postgres is not added to any common docker network. You're resolving as postgresql which is the hostname of a container in the stack. You'd need to add the backend network to both postgres and redis as done on the worker with:

    networks:
      - backend

[dominic-r]

I'd recommend visiting our docs at https://docs.goauthentik.io for up-to-date configuration guides