How to add a custom environment variables to docker-ejabberd - docker

Question

I am running docker-ejabberd on ECS and all works fine. Now i want to replace the my_sql user/pass that exists on the ejabberd.yml file with the environment variables been passed to the image while running the container. There is no clear way described even on the docker-ejabberd wiki or anywhere on how to do that simply. Does anyone face a similar situation and how to do that?
For example in the ejabberd.yml i have this section:
sql_server: ${MYSQL_SERVER}
sql_database: ${MYSQL_DATABASE_NAME}
sql_username: ${MYSQL_USERNAME}
sql_password: ${MYSQL_PASSWORD}
sql_port: ${MYSQL_PORT}
I want to pass those vars as env vars while docker run and then replace them before the container run.
Side note: We are using ECS and passing the variables through the task defination without any issue.
I went through some topics recommend using the ENTRY_POINT command to run a script that replaces the file before running the container but not sure if that's a good idea.
Also, I have an idea of replacing the variables in this ejabberd.yml file in the CICD pipeline just before building the image and while getting the code from the git repository and create the image on AWS ECR?

Answer 1

i want to replace the my_sql user/pass that exists on the ejabberd.yml file with the environment variables been passed to the image while running the container.
The ejabberd.yml file is read and parsed by the yconf library (https://github.com/processone/yconf) , and I doubt it supports such a thing.
I went through some topics recommend using the ENTRY_POINT command to run a script that replaces the file before running the container but not sure if that's a good idea.
Following that recomendation, if you don't want to mess with the whole ejabberd.yml and let a script manipulate it, you can ensure that only those specific options are parametrized:
You can define those vars using a script in a small file, and then include options from that small file into ejabberd.yml using
https://docs.ejabberd.im/admin/configuration/file-format/#include-additional-files
For example, in your ejabberd.yml, put something like this:
include_config_file:
/etc/ejabberd/database.yml:
allow_only: [sql_server, sql_database, sql_username, sql_password, sql_port]
Then write your script, that generates that small file, for example:
$ generate-database-config.sh
$ cat /etc/ejabberd/database.yml
sql_server: "localhost"
sql_database: "ejaup"
sql_username: "ejabberd_test"
sql_password: "ejabberd_test"
sql_port: 3306