Docker Postgres file illegal option - - postgresql

Question

I want to put variables inside my CMD of a Dockerfile that has a Postgres container with certificates needed for SSL. I am using this Dockerfile as build context from a docker-compose.yml file that this database as one service and an app
db.Dockerfile
FROM postgres:14.5-alpine
ENV EXT_KEY .key
COPY ./.docker/dev/init-database.sh /docker-entrypoint-initdb.d/
COPY ./.docker/dev/migrations/database_schema.tar ./
COPY ./.docker/dev/certs/out/postgresdb$EXT_KEY /var/lib/postgresql
COPY ./.docker/dev/certs/out/postgresdb.crt /var/lib/postgresql
COPY ./.docker/dev/certs/out/myCA.crt /var/lib/postgresql
COPY ./.docker/dev/certs/out/myCA.crl /var/lib/postgresql
COPY ./.docker/dev/certs/out/news_user$EXT_KEY ./
COPY ./.docker/dev/certs/out/news_user.crt ./
RUN chown 0:70 /var/lib/postgresql/postgresdb$EXT_KEY && chmod 640 /var/lib/postgresql/postgresdb$EXT_KEY
RUN chown 0:70 /var/lib/postgresql/postgresdb.crt && chmod 640 /var/lib/postgresql/postgresdb.crt
RUN chown 0:70 /var/lib/postgresql/myCA.crt && chmod 640 /var/lib/postgresql/myCA.crt
RUN chown 0:70 /var/lib/postgresql/myCA.crl && chmod 640 /var/lib/postgresql/myCA.crl
RUN chown 0:70 ./news_user$EXT_KEY && chmod 640 ./news_user$EXT_KEY
RUN chown 0:70 ./news_user.crt && chmod 640 ./news_user.crt
RUN chown postgres:postgres /docker-entrypoint-initdb.d/init-database.sh
EXPOSE 5432
USER postgres
ENTRYPOINT ["docker-entrypoint.sh"]
CMD [ "-c", "ssl=on" , "-c", "ssl_cert_file=/var/lib/postgresql/postgresdb.crt", "-c",\
"ssl_key_file=/var/lib/postgresql/postgresdb.${EXT_KEY}", "-c",\
"ssl_ca_file=/var/lib/postgresql/myCA.crt", "-c", "ssl_crl_file=/var/lib/postgresql/myCA.crl" ]
docker-compose.yml
version: "3.8"
services:
news_database:
build:
context: ../..
dockerfile: ./.docker/dev/db.Dockerfile
container_name: news_database
restart: unless-stopped
env_file:
- .env
ports:
- "5432:5432"
volumes:
- news_db:/var/lib/postgresql/data
news_app:
...
volumes:
news_db:
driver: local
When I run this the variable is not present in the CMD and therefore the container fails
Attempt 1
I tried changing the final command from array to string format
CMD -c ssl=on -c ssl_cert_file=/var/lib/postgresql/postgresdb.crt -c ssl_key_file=/var/lib/postgresql/postgresdb.key -c ssl_ca_file=/var/lib/postgresql/myCA.crt -c ssl_crl_file=/var/lib/postgresql/myCA.crl
It gives me an /bin/sh: illegal option - error
Attempt 2
I removed the entrypoint completely and tried directly calling postgres with a CMD
CMD postgres -c ssl=on -c ssl_cert_file=/var/lib/postgresql/postgresdb.crt -c ssl_key_file=/var/lib/postgresql/postgresdb.key -c ssl_ca_file=/var/lib/postgresql/myCA.crt -c ssl_crl_file=/var/lib/postgresql/myCA.crl
It immediately gives me another error when I run it via docker-compose
postgres: could not access the server configuration file "/var/lib/postgresql/data/postgresql.conf": No such file or directory
All I want is to have variables inside that CMD, can someone kindly tell me a way to make this work?

Answer 1

Your ENTRYPOINT instruction is specified as JSON array, meaning it's in exec form - no shell will be invoked for the execution of docker-entrypoint.sh. As there is no shell invoked, there won't be any environment variable expansion.
To make it work, try this:
ENTRYPOINT [ "sh", "-c", \
"docker-entrypoint.sh \
-c ssl=on \
-c ssl_cert_file=/var/lib/postgresql/postgresdb.crt \
-c ssl_key_file=/var/lib/postgresql/postgresdb${EXT_KEY} \
-c ssl_ca_file=/var/lib/postgresql/myCA.crt \
-c ssl_crl_file=/var/lib/postgresql/myCA.crl \
${0} ${#}" ]