PDNS_ Env variables are not applied

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Short description

The PowerDNS pdns-auth-49 Docker image does not automatically translate environment variables prefixed with PDNS_ into the /etc/powerdns/pdns.conf file, even though this behavior is expected and documented. This makes it necessary to manually append the required configurations to the pdns.conf file.

Environment

• Operating system: Ubuntu 22.04
• Software version: PowerDNS Authoritative Server 4.9.2
• Software source: Docker Hub (powerdns/pdns-auth-49)

Steps to reproduce

1. Use the docker-compose.yml file:

   services:
     powerdns:
       image: powerdns/pdns-auth-49:latest
       container_name: pdns
       restart: always
       ports:
         - "5353:53/tcp"
         - "5353:53/udp"
         - "8081:8081"
       environment:
         - PDNS_API=yes
         - PDNS_API_KEY=TestKey123
         - PDNS_WEBSERVER=yes
         - PDNS_WEBSERVER_ADDRESS=0.0.0.0
         - PDNS_WEBSERVER_PORT=8081
         - PDNS_WEBSERVER_ALLOW_FROM=0.0.0.0/0,::/0
         - PDNS_LAUNCH=gsqlite3
         - PDNS_GSQLITE3_DATABASE=/var/lib/powerdns/pdns.sqlite3
       volumes:
         - pdns_data:/var/lib/powerdns
   volumes:
     pdns_data:
   

2. Run:

   docker compose up -d
   docker exec -it pdns cat /etc/powerdns/pdns.conf
   
   local-address=0.0.0.0,::
   launch=gsqlite3
   gsqlite3-dnssec
   gsqlite3-database=/var/lib/powerdns/pdns.sqlite3
   include-dir=/etc/powerdns/pdns.d
   

Other information

To make the API work, I had to manually append the missing configurations to /etc/powerdns/pdns.conf:

docker exec -u root -it pdns sh -c "echo '
api=yes
webserver=yes
webserver-address=0.0.0.0
webserver-port=8081
api-key=TestKey123
webserver-allow-from=0.0.0.0/0,::/0
' >> /etc/powerdns/pdns.conf"