Using Default NAT can't resolve hostnames

[AshranPewter]

Hi All,

I'm trying to get my docker containers to talk to one another without using their IP addresses (they change when restarting sometimes) and without using links (since this has or will be taken away soon).

For reference I'm using TS-453Bmini with linuxserver nzbget, sonarr, radarr containers.
Using NAT and then exposing internal container ports to external ones.
I've set the hostname for nzbget to nzbget and put that in the hostname but it won't connect.

Anyone have any ideas as to why?

Thanks!
AshranPewter

[AshranPewter]

Just thought I'd let you know of a solution to this.

I installed Portainer according to this reddit post:

I would follow this guide for some good recommendations on how to setup Docker apps on QNAP.

https://www.linuxserver.io/2017/09/17/h ... s-on-qnap/

Then for Portainer install I use the following command line:

docker run -d -p 9000:9000 --name=portainer \
--net=host --restart on-failure \
-e PUID=<your docker user UID> \
-e PGID=<your docker user GUID> \
-v /share/<your docker data diretory>/portainer:/data \
-v /var/run/docker.sock:/var/run/docker.sock portainer/portainer

Code: Select all

---
version: '2'

services:

  nzbget:
    image: linuxserver/nzbget:latest
    container_name: nzbget
    hostname: nzbget
    ports:
      - "6789:6789"
    environment:
      PUID: ${PUID}
      PGID: ${PGID}
    volumes:
      - ${CONFIG}/nzbget:/config
      - ${DOWNLOAD}/complete:/downloads
      - ${DOWNLOAD}/incomplete:/incomplete-downloads
      - ${DOWNLOAD}/watch:/watch
    restart: unless-stopped

  sonarr:
    image: linuxserver/sonarr:latest
    container_name: sonarr
    hostname: sonarr
    ports:
      - "8989:8989"
    environment:
      PUID: ${PUID}
      PGID: ${PGID}
    volumes:
      - ${CONFIG}/sonarr:/config
      - ${DOWNLOAD}/complete:/downloads
      - ${DATA}/tv:/tv
      - ${DATA}/anime:/anime
    restart: unless-stopped

  radarr:
    image: linuxserver/radarr:latest
    container_name: radarr
    hostname: radarr
    ports:
      - "7878:7878"
    environment:
      PUID: ${PUID}
      PGID: ${PGID}
    volumes:
      - ${CONFIG}/radarr:/config
      - ${DOWNLOAD}/complete:/downloads
      - ${DATA}/movies:/movies
    restart: unless-stopped

  lidarr:
    image: linuxserver/lidarr:latest
    container_name: lidarr
    hostname: lidarr
    ports:
      - "8686:8686"
    environment:
      PUID: ${PUID}
      PGID: ${PGID}
    volumes:
      - ${CONFIG}/lidarr:/config
      - /etc/localtime:/etc/localtime:ro
      - ${DOWNLOAD}/complete:/downloads
      - ${DATA}/music:/music
    restart: unless-stopped

  mylar:
    image: linuxserver/mylar:latest
    container_name: mylar
    hostname: mylar
    ports:
      - "8090:8090"
    environment:
      PUID: ${PUID}
      PGID: ${PGID}
    volumes:
      - ${CONFIG}/mylar:/config
      - ${DOWNLOAD}/complete:/downloads
      - ${DATA}/comics:/comics
    restart: unless-stopped

  nzbhydra:
    image: linuxserver/hydra2:latest
    container_name: nzbhydra
    hostname: nzbhydra
    ports:
      - "5076:5076"
    environment:
      PUID: ${PUID}
      PGID: ${PGID}
    volumes:
      - ${CONFIG}/nzbhydra2:/config
      - ${DOWNLOAD}/complete:/downloads
    restart: unless-stopped

  ombi:
    image: linuxserver/ombi
    container_name: ombi
    hostname: ombi
    ports:
      - "3579:3579"
    environment:
      PUID: ${PUID}
      PGID: ${PGID}
    volumes:
      - ${CONFIG}/ombi:/config
    restart: unless-stopped

Note that the tabs are important since the file is yaml (docker-compose.yaml)

Using docker-compose (or within portainer, stacks) lets you create a set of images that then can talk to another easily because it automatically creates a user-defined bridge network that has a DNS server incorporated into it and also deploys all of these images automatically. So now I can just type in 'nzbget' into the hostname and it works. The ${DATA}, ${CONFIG} etc are Environment variables (env), they allow me to change the location of the files when I want easily, DATA stores the data files, CONFIG is appdata, DOWNLOAD is where the downloads go, PUID/PGID are user id and group id, explained in the post above and are something that linuxserver images have to allow for images to not have admin issues with folders/files.

There is something called watchtower that I don't use that would update images automatically, I think this is bad practice without a backup because an updated image could break your configs due to not updating properly.

You could also add in torrenting into this pretty easily following the template and the original template is based off of https://github.com/duhio/docker-compose-usenet which uses sabnzbd (which is python based vs nzbget which is c++). This also has the ability to create a reverse proxy so you can do things like sonarr.hostname.com, but I don't have a domain setup yet and don't really need one.

Hope this helps someone.

[oyvindo]

There must bean easier way to achieve this than to install Portainer?
I have nothing against Portainer, but it is not convenient if to write a tutorial assuming the reader is willing or able to install Portainer just to accomplish something so fundamental.

So, does anyone know how to assign hostname to a container during installation in Container Station?