Keep container alive and linked using docker-compose

Question

I want to use docker-compose to compose together php and several databases (orientdb, neo4j, etc). Then get into the php container and use the shell to execute commands.

Individually, all of my container work swimmingly, and when I compose them together, they all run. However, I cannot for the life of me figure out how to keep the php container alive so I can get into it for testing.

For simplicity, I'll just use a single database: orient-db.

My docker-compose.yml file:

version: '2'
services:
  php:
    build: .
    links:
       - orientdb

  orientdb:
    image: orientdb:latest
    environment:
      ORIENTDB_ROOT_PASSWORD: rootpwd
    ports:
       - "2424:2424"
       - "2480:2480"

My "php" Dockerfile:

FROM php:5.6-cli
ADD . /spider
WORKDIR /spider
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/bin/ --filename=composer
RUN composer install --prefer-source --no-interaction

RUN yes | pecl install xdebug \
    && echo "zend_extension=$(find /usr/local/lib/php/extensions/ -name xdebug.so)" > /usr/local/etc/php/conf.d/xdebug.ini

I have tried (among other things):

• docker-compose up in one terminal and then docker attach in another
• enabling tty and stdin_open in my compose file
• using a /bin/bash command
• variations of CMD exec vendor/bin/phpunit -D FOREGROUND

And some references I've tried: - How to Keep Docker Container Running After Starting Services? - https://github.com/docker/compose/issues/1926 - https://github.com/docker/compose/issues/423

Any help would really be appreciated.

Thank you.

Answer 1

Had a similar issue with running a zsh shell on docker container running with compose, it would close with exit code 0 immediately after start.

@Spock's comment below the last answer is actually the key, at least for what I need.

Set your docker-compose command for the image to be:

command: tail -f /dev/null

This keeps the process alive but also allows it to shutdown gracefully.

Answer 2

Join entrypoint so that the process does not exit

version: "3.7"
services:
    debug-srv:
        container_name: "debug-srv"
        image: "alpine:latest"
        entrypoint: ["tail", "-f", "/dev/null"]
        networks:
            debug-net:
networks:
    debug-net:
        name: "debug-net"