Docker compose MySql initialisation scripts not executing - mysql

Question

I am having a problem having the mysql container to run my initialisation scripts.
I have two files create.sql and insert.sql, which I use to initialise the database.
I create the images using the command docker-compose.yml and it runs successfully and creates the images.
I am facing two problems.
When I run the docker-compose up command, the mysql container is created and started successfully. However the two initialisation scripts (create.sql and insert.sql) don't run on the database.
I explicitly use the docker run command to run the created mysql container. In this scenario the initialisation scripts run successfully.
I am using Docker version 18.09.0 and docker-compose version 1.23.1 and ubuntu 16.04 LTS
I am new to docker and can't seem to figure out the problem.
The following are the files I am using to create images.
docker-compose.yml file.
version: '3'
services:
demo-mysql:
image: demo-mysql
build: ./demo-mysql
volumes:
- /mnt/data/mysql-data:/var/lib/mysql
ports:
- 3306:3306
environment:
- MYSQL_ROOT_PASSWORD=root
- MYSQL_DATABASE=demo
- MYSQL_PASSWORD=root
demo-api:
image: demo-api-1.0
build: ./api
depends_on:
- demo-mysql
ports:
- 8080:8080
environment:
- DATABASE_HOST=demo-mysql
- DATABASE_USER=root
- DATABASE_PASSWORD=root
- DATABASE_NAME=demo
- DATABASE_PORT=3306
demo1-app:
image: demo1-app-1.0
build: ./demo1
depends_on:
- demo-mysql
ports:
- 8090:8090
environment:
- DATABASE_HOST=demo-mysql
- DATABASE_USER=root
- DATABASE_PASSWORD=root
- DATABASE_NAME=demo
- DATABASE_PORT=3306
The following is the Dockerfile for the spring boot project
FROM java:8
VOLUME /tmp
ARG DATA_PATH=/src/main/resources
ARG APP_PORT=8080
EXPOSE ${APP_PORT}
ADD /build/libs/demo-api.jar demo-api.jar
ENTRYPOINT ["java","-jar","demo-api.jar"]
The following is the Dockerfile I used to create my mysql image
FROM mysql:5.7
ENV MYSQL_DATABASE=demo \
MYSQL_USER=root \
MYSQL_ROOT_PASSWORD=root
ADD ./1.0/create.sql /docker-entrypoint-initdb.d
ADD ./1.0/insert.sql /docker-entrypoint-initdb.d
EXPOSE 3306

Answer 1

From documentation (https://hub.docker.com/_/mysql/)
Initializing a fresh instance
When a container is started for the first time, a new database with
the specified name will be created and initialized with the provided
configuration variables. Furthermore, it will execute files with
extensions .sh, .sql and .sql.gz that are found in
/docker-entrypoint-initdb.d.
I suspect that, because of the persisted volume
volumes:
- /mnt/data/mysql-data:/var/lib/mysql
when docker starts the mysql image, there is already a DB. So the image isn't "fresh" and the scripts are not run.
Update:
we can confirm this suspect looking at the source code of the docker-entrypoint.sh here: https://github.com/docker-library/mysql/blob/696fc899126ae00771b5d87bdadae836e704ae7d/5.7/docker-entrypoint.sh
if [ ! -d "$DATADIR/mysql" ]; then
...
...
ls /docker-entrypoint-initdb.d/ > /dev/null
for f in /docker-entrypoint-initdb.d/*; do
process_init_file "$f" "${mysql[#]}"
done
The scripts run only if the "$DATADIR/mysql" is not present already.
btw, I personally consider a better design to have the "application" create the database schema, preload the required application data, manage schema migrations etc... at startup, but this another topic :)