Customize the configuration of the official PostgreSQL docker image - postgresql

Question

I am using the official postgresql docker image (version 9.4). I have extended the Dockerfile, so I can alter the settings in the postgresql.conf etc, using a bash script. It successfully adds and runs the script on entrypoint, for a single sed command. But when I put 2 or more sed commands, I get the following error:
/docker-entrypoint.sh: running /docker-entrypoint-initdb.d/config.sh
: No such file or directoryread
/var/lib/postgresql/data/postgresql.conf
I am trying on Windows 10, in combination with Vagrant and VirtualBox, using NFS file system on shared folders, via the vagrant-winnfsd plugin.
Why is this happening? How can I alter my bash script in order to work with more configuration settings? Is there a better way?
Dockerfile:
FROM postgres:9.4
RUN echo "Europe/Athens" > /etc/timezone \
&& dpkg-reconfigure -f noninteractive tzdata
RUN localedef -i el_GR -c -f UTF-8 -A /usr/share/locale/locale.alias el_GR.UTF-8
ADD config.sh /docker-entrypoint-initdb.d/
RUN chmod 755 /docker-entrypoint-initdb.d/config.sh
VOLUME ["/etc/postgresql", "/var/log/postgresql", "/var/lib/postgresql"]
config.sh:
#!/bin/bash
sed -i -e"s/^#logging_collector = off.*$/logging_collector = on/" /var/lib/postgresql/data/postgresql.conf
sed -i -e"s/^max_connections = 100.*$/max_connections = 1000/" /var/lib/postgresql/data/postgresql.conf
database.yml
postgres:
container_name: postgres-9.4
image: ***/postgres-9.4
volumes_from:
- postgres_data
ports:
- 5432:5432
environment:
- POSTGRES_USER=user
- POSTGRES_PASSWORD=password
- POSTGRES_DB=database
- USERMAP_UID=999
- USERMAP_GID=999
postgres_data:
container_name: postgres_data
image: ***/postgres-9.4
volumes:
- ./services/postgres:/etc/postgresql
- ./services/postgres:/var/lib/postgresql
- ./services/postgres/logs:/var/log/postgresql
command: "true"

Answer 1

You might want to try using a RUN statement to execute your bash script or just run sed directly with both commands combined with a semicolon:
RUN sed -i -e 's/^#\(logging_collector = \).*/\1on/; s/^\(max_connections = \).*/\11000/' \
/var/lib/postgresql/data/postgresql.conf
A more scalable solution would be to put the sed program in an external file, then use these statements:
ADD postgres-edit.sed /var/local
RUN sed -i -f /var/local/postgres-edit.sed /var/lib/postgresql/data/postgresql.conf
postgres-edit.sed:
# sed script to edit postgresql configuration
s/^#\(logging_collector = \).*/\1on/
s/^\(max_connections = \).*/\11000/

Answer 2

Seems like a duplicate of How to customize the configuration file of the official PostgreSQL docker image?.
Copy-paste of my answer at https://stackoverflow.com/a/40598124/385548.
Inject custom postgresql.conf into postgres Docker container
The default postgresql.conf file lives within the PGDATA dir (/var/lib/postgresql/data), which makes things more complicated especially when running postgres container for the first time, since the docker-entrypoint.sh wrapper invokes the initdb step for PGDATA dir initialization.
To customize PostgreSQL configuration in Docker consistently, I suggest using config_file postgres option together with Docker volumes like this:
Production database (PGDATA dir as Persistent Volume)
docker run -d \
-v $CUSTOM_CONFIG:/etc/postgresql.conf \
-v $CUSTOM_DATADIR:/var/lib/postgresql/data \
-e POSTGRES_USER=postgres \
-p 5432:5432 \
--name postgres \
postgres:9.6 postgres -c config_file=/etc/postgresql.conf
Testing database (PGDATA dir will be discarded after docker rm)
docker run -d \
-v $CUSTOM_CONFIG:/etc/postgresql.conf \
-e POSTGRES_USER=postgres \
--name postgres \
postgres:9.6 postgres -c config_file=/etc/postgresql.conf
Debugging
Remove the -d (detach option) from docker run command to see the server logs directly.
Connect to the postgres server with psql client and query the configuration:
docker run -it --rm --link postgres:postgres postgres:9.6 sh -c 'exec psql -h $POSTGRES_PORT_5432_TCP_ADDR -p $POSTGRES_PORT_5432_TCP_PORT -U postgres'
psql (9.6.0)
Type "help" for help.
postgres=# SHOW all;