Running a custom script using entrypoint in docker-compose

Question

I modified the docker-compose.yml file as given on https://hub.docker.com/_/solr/ by adding a volumes configuration and a change in entrypoint. The modified file is as given:

version: '3'
services:
  solr:
    image: solr
    ports:
     - "8983:8983"
    volumes:
      - ./solr/init.sh:/init.sh
      - ./solr/data:/opt/solr/server/solr/mycores
    entrypoint:
      - init.sh
      - docker-entrypoint.sh
      - solr-precreate
      - mycore

I need to run this 'init.sh' before entrypoint starts, to prepare my files inside container.

But I get following errors:

ERROR: for solr_solr_1 Cannot start service solr: oci runtime error: container_linux.go:247: starting container process caused "exec: \"init.sh\": executable file not found in $PATH"

Earlier I found about official image hooks in neo4j from here. Is there a similar thing I can use here also?

Update 1: From comments below, I realized that dockerfile set WORKDIR /opt/solr due to which executable file not found in $PATH. So I tested by providing the absolute path to entrypoint by using /init.sh. But this also gives error, but a different one:

standard_init_linux.go:178: exec user process caused "exec format error"

Answer 1

It looks like you need to map your volume to /docker-entrypoint-initdb.d/

version: '3'
services:
  solr:
    image: solr
    ports:
     - "8983:8983"
    volumes:
      - ./solr/init.sh:/docker-entrypoint-initdb.d/init.sh
      - ./solr/data:/opt/solr/server/solr/mycores
    entrypoint:
      - docker-entrypoint.sh
      - init

From

https://hub.docker.com/_/solr/

Extending the image The docker-solr image has an extension mechanism. At run time, before starting Solr, the container will execute scripts in the /docker-entrypoint-initdb.d/ directory. You can add your own scripts there either by using mounted volumes or by using a custom Dockerfile. These scripts can for example copy a core directory with pre-loaded data for continuous integration testing, or modify the Solr configuration.

The docker-entrypoint.sh seems to be responsible for running the sh scripts based on the arguments passed to it. So init is the first argument which in turn tries to run init.sh

docker-compose logs solr | head

Update 1:

I had struggled to get this to work and finally figured out why my docker-compose was not working while the docker run -v pointing to the /docker-entrypoint-initdb.d/init.sh was working.

It turns out that removing the entrypoint tree was the solution. Here's my final docker-compose:

version: '3'
services:
  solr:
    image: solr:6.6-alpine
    ports:
     - "8983:8983"
    volumes:
      - ./solr/data/:/opt/solr/server/solr/
      - ./solr/config/init.sh:/docker-entrypoint-initdb.d/init.sh

my ./solr/config/init.sh

#!/bin/bash
echo "running"
touch /opt/solr/server/solr/test.txt;
echo "test" > /opt/solr/server/solr/test.txt;

Answer 2

An alternative solution that worked for me was modifying entrypoint by placing /bin/sh.It looked a bit like this afterwards

version: '3'
services:
  web:
    build: .
    volumes:
    - .:/code
    entrypoint :  
    - /bin/sh
    - ./test.sh
    ports:
    - "5000:5000 

where test.sh is the required bash script to be run inside the container.