Solved Docker container fix IP ?

[spir0o]

Hi,
quick question :

I've linked a Firefly-docker with a MariaDB-docker using docker internal network (172.17.0.X). However each time I restart the NAS, the containers become different IPs and I have to manually change them in the environment variables. I know there is a possibility with bridges but I don't really understand how to set them up.

Would someone be kind enough to help me ?
Thanks in advance

 

[fredbert]

When I set up FreshRSS with PostgreSQL I used a link in the FreshRSS configuration that provided and alias to the PostgreSQL container. The alias is used by FreshRSS to refer to whatever IP is currently assigned to PostgreSQL.

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See sections 'Add the FreshRSS container to Docker' and 'Configuring FreshRSS' for how the link is setup and used. Probably similar for you?

 

[spir0o]

Thank you for your answer, fredbert.

But doesn't that require a specific formulation dependent on the client container (FreshRSS in your case) ? I don't see anything similar for Firefly.

 

[fredbert]

AFAIK the link adds an entry to /etc/hosts that gets updated by Docker so that the current linked container's IP is associated with the alias.

If I issue the command ping rss_psql_server from within a FreshRSS console then it will resolve to the current IP and ping it.

Edit: Adding a link is one of the tabs in Synology Docker's Edit window, or in the Advanced settings when creating a new container.

 

[spir0o]

Ahhh I understand.
I made a link with mariadb from firefly-docker, used that alias as IP in the environment variables and it worked ! Now I will test it with a restart.
Thanks a lot for your help

 

[Shadow]

docker network connect --ip <desired ip> <docket network name> <docker container name>

 

[spir0o]

Thank you Shadow.

The bridge solution was however enough for my problem