More than one database for image based docker app


#1

I’m adapting an existing docker image to UCS.
Is there any way to use more than one database (either mysql or postgresql) for a docker image-based application? Our app follows a microservices design pattern and uses four different databases. Merging the databases into one is not desirable.
So, I’d like to have four of " DB_HOST, DB_PASSWORD, DB_NAME" etc.


#2

Hello @bheithecker,

the App Center does not support multi container setups for a single app at the moment. Nevertheless, as you wrote, the App Center allows to use one database outside the container.

I did not understand what you exactly need. Is it different database management systems (DBMS) or just other databases within the same DBMS? If it is the latter one, I believe this can be realized.

Best regards,
Nico


#3

This should be possible, although not conviniently. The App Center can install postgres and set up one database for you. If you want more, you would have to do it manually, probably best in the preinst script of the App.

This means that the user has to install the package univention-postgres prior to the App. A hint can be shown by using the parameter --error-file.

See https://wiki.univention.de/index.php/Docker_Apps/Container_Scripts and https://wiki.univention.de/index.php/Docker_Apps/Image_Based#Life_cycle

Kind regards,
Dirk Wiesenthal