docker 权限被拒绝 mysql 映像中的 shell 脚本放置在 docker-entrypoint-initdb.d

Question

FROM mysql:latest
RUN set -ex && apt-get update \
    && apt-get dist-upgrade -y \
    && apt-get install -y --no-install-recommends \
    curl unzip
ADD my.sh  /docker-entrypoint-initdb.d
RUN chown -R mysql:mysql /docker-entrypoint-initdb.d/
RUN chmod -R 777 docker-entrypoint-initdb.d

Content of my.sh file are:

#!/bin/bash

mkdir try1

The my.sh file has a command to create a directory and when the entrypoint.sh of the image runs this file, it throws a permission denied error. I have changed the owner of the directory as well. What could be the reason.

Answer 1

Script in docker-entrypoint-initdb.d will be executed by mysql account, not by root , see source code .

You could verify it by change my.sh as next:

#!/bin/bash

echo "start"
pwd
id
mkdir try1
echo "done"

Then, the error log will be:

/usr/local/bin/docker-entrypoint.sh: running /docker-entrypoint-initdb.d/my.sh
start
/
uid=999(mysql) gid=999(mysql) groups=999(mysql)
mkdir: cannot create directory 'try1': Permission denied

You could see the user which run current my.sh is mysql , while you currently want to setup try1 folder in / , surely you won't have permission.