Redis docker container not recognizing copied files

Question

I'm trying to run multiple redis containers that use the same Dockerfile to setup their start scripts containing their start parameters like passwords, host binding, log levels, etc.

start-cache.sh

#!/bin/bash

set -o errexit
set -o pipefail
set -o nounset

redis-server --bind ${CACHE_REDIS_HOST} --save 60 1 --loglevel warning --requirepass ${CACHE_REDIS_PASSWORD}

The second one looks exactly like that but with tweaked parameters ofc.

My dockerfile utilizing these start scripts looks like this:

FROM redis:7.2.1-alpine

COPY ./compose/local/redis/cache/start-cache.sh /start-cache
RUN sed -i 's/\r$//g' /start-cache
RUN chmod +x /start-cache

COPY ./compose/local/redis/media/start-media.sh /start-media
RUN sed -i 's/\r$//g' /start-media
RUN chmod +x /start-media

My docker compose utilizing the Dockerfile looks like this:

  ....
  media-cache:
    container_name: 'media_cache'
    build:
      context: .
      dockerfile: ./compose/local/redis/Dockerfile
    command: /start-media
    env_file:
      - .env
    ports:
      - 6371:6379
    volumes:
      - ./data/mediaRedis:/data
      - ./compose/local/redis/redis.conf:/etc/redis/redis.conf
    restart: always

  db-cache:
    container_name: 'db_cache'
    build:
      context: .
      dockerfile: ./compose/local/redis/Dockerfile
    command: /start-cache
    env_file:
      - .env
    ports:
      - 6370:6379
    volumes:
      - ./data/dbRedis:/data
      - ./compose/local/redis/redis.conf:/etc/redis/redis.conf
    restart: always
  ....

Don't believe it has any relevancy for my problem but just so it's out of the way, the redis.conf looks like this:

bind 0.0.0.0

My docker compose spits out the following errors concerning my redis containers before having both containers exit with code 0:

/usr/local/bin/docker-entrypoint.sh: exec: line 24: /start-media: not found

/usr/local/bin/docker-entrypoint.sh: exec: line 24: /start-cache: not found

Thanks in advance.

Answer 1

The "shebang" line at the very start of your script says it uses /bin/bash. Alpine Linux doesn't normally contain bash or any other GNU tools.

Your script isn't using any shell features that aren't part of the POSIX shell standard, except for some set options that won't matter here. You can change the script to use plain /bin/sh, and remove the set options

#!/bin/sh
exec redis-server \
  --bind ${CACHE_REDIS_HOST} \
  --save 60 1 \
  --loglevel warning \
  --requirepass ${CACHE_REDIS_PASSWORD}

You can also provide these options directly in the Compose command: without using a script, if you'd prefer. The redis image knows how to inject a redis-server command if it's not explicitly specified, so you might be able to say

services:
  media-cache:
    image: redis:7.2.1-alpine
    command: >
      --bind 0.0.0.0
      --save 60 1
      --loglevel warning
      --requirepass ${CACHE_REDIS_PASSWORD}
    env_file:
      - .env
    ports:
      - 6371:6379
    volumes:
      - ./data/mediaRedis:/data
      - ./compose/local/redis/redis.conf:/etc/redis/redis.conf
    restart: always

With this specific construction, the $CACHE_REDIS_PASSWORD would need to be in the host environment or a .env file; it is processed before the Compose environment: or env_file: directives are read.