Unknown MySQL server host 'mariadb' about mailserver

[Wonderfall]

May you provide us with your docker-compose file?

[Toobian]

Sorry, i missed ><

version: "2"

services:
  mailserver:
    image: hardware/mailserver
    container_name: mailserver
    domainname: ***.net
    hostname: mail
    links:
      - mariadb:mariadb
    ports:
      - "25:25"
      - "143:143"
      - "465:465"
      - "587:587"
      - "993:993"
      - "4190:4190"
    environment:
      - OPENDKIM_KEY_LENGTH=4096
      - ADD_DOMAINS=***.net,***.fr
      - DBHOST=mariadb
      - DBUSER=postfix
      - DBNAME=postfix
      - DBPASS=***
    volumes:
      - /docker/mail:/var/mail
      - /docker/dovecot:/var/lib/dovecot
      - /docker/opendkim:/etc/opendkim/keys
      - /etc/localtime:/etc/localtime:ro
      - /docker/proxy/certs/mail.***.net:/etc/letsencrypt/live/mail.***.net
    networks:
      - mail-db

  postfixadmin:
    image: hardware/postfixadmin
    container_name: postfixadmin
    domainname: ***.net
    hostname: mail
    links:
      - mariadb:mariadb
    environment:
      - VIRTUAL_HOST=***.***.net
      - VIRTUAL_NETWORK=nginx-proxy
      - VIRTUAL_PORT=80
      - LETSENCRYPT_HOST=***.***.net
      - LETSENCRYPT_EMAIL=toobian@***.net
      - DBHOST=mariadb
      - DBUSER=postfix
      - DBNAME=postfix
      - DBPASS=***
    volumes:
      - /etc/localtime:/etc/localtime:ro
    networks:
      - proxy-tier
      - mail-db
  rainloop:
    image: wonderfall/rainloop
    container_name: rainloop
    links:
      - mailserver:mailserver
      - mariadb:mariadb
    environment:
      - VIRTUAL_HOST=webmail.***.net
      - LETSENCRYPT_HOST=webmail.***.net
      - LETSENCRYPT_EMAIL=toobian@***.net
      - VIRTUAL_NETWORK=nginx-proxy
      - VIRTUAL_PORT=80
      - GID=991
      - UID=991
    volumes:
      - /docker/rainloop:/rainloop/data
      - /etc/localtime:/etc/localtime:ro
    networks:
      - proxy-tier
      - mail-db

  mariadb:
    image: mariadb:10.1
    container_name: mariadb
    volumes:
      - /docker/mysql/db:/var/lib/mysql
      - /etc/localtime:/etc/localtime:ro
    environment:
      - MYSQL_ROOT_PASSWORD=***
      - MYSQL_DATABASE=postfix
      - MYSQL_USER=postfix
      - MYSQL_PASSWORD=***
    networks:
      - mail-db

networks:
  proxy-tier:
    external:
      name: nginx-proxy
  mail-db:
    external:
      name: mail-db

[Wonderfall]

Okay, this is interesting because I had similar troubles using docker-compose files second version.
Can't help you, I surrendered!

[hardware]

Postfix is isolated with unix chroot mecanism, so check that the mariadb hostname exist in this file /var/spool/postfix/etc/hosts so that DNS resolution works properly.

[Toobian]

Ok it's working when i add mariadb hostname and its ip address manually.

[hardware]

It is already the case here : https://github.com/hardware/mailserver/blob/master/rootfs/usr/local/bin/postfix#L7

[Toobian]

when i check /etc/hosts file, mariadb hostname is missing. For now i just add hostname in /var/spool/postfix/etc/hosts
If i restart container /etc/hosts will be reset, so i loose my modification.

[hardware]

check your docker-compose.yml file syntax, try with version 1.

[hardware]

Fix in c2c8a22

Can you confirm ? docker pull hardware/mailserver

[chmanie]

Hi, I found this issue while struggling with this in my own setup. Thank you for building this, it's been a great help so far!

I have a question regarding this:

Would it be a problem to run the postfix rewrite service in a non-chroot environment?

I changed the line in postfix' master.cf to

# service type  private unpriv  chroot  wakeup  maxproc command + args
rewrite   unix  -       -       n       -       -       trivial-rewrite

and it did work. Will there be any shortcomings or disadvantages due to this change?

Reading this it seems we might not even need chroot at all when running in an isolated docker environment (in my setup postfix is running in an own container).