Docker-compose mysql: import .sql - mysql

Question

My docker-compose script successfully manages to run a mysql/mariadb service, and copies my "init.sql" script containing the database schema to "/docker-entrypoint-initdb.d". However, the sql script is never executed like it should according to the docs.
There is no error, nothing in the logs. I checked that the sql file is copied at the right place in the container. I checked that the script runs with no errors on an empty database.
What am I missing? Is it even visible in the logs if the script was executed (and for some reason did nothing)?
(Edit: docker-compose version: 1.8.1, image mariadb:10.1.21)
# docker-compose.yml
version: '2'
volumes:
data-volume: {}
services:
mysql:
image: mariadb
ports:
- "3306:3306"
environment:
MYSQL_ROOT_PASSWORD: pwd
MYSQL_DATABASE: users_db
volumes:
- data-volume:/var/lib/mysql
- ./resources/docker-sql/init.sql:/docker-entrypoint-initdb.d/init.sql
backend:
image: myapp
ports:
- "8000:80"
depends_on:
- mysql
links:
- mysql

Answer 1

Looking at the source of the docker-entrypoint.sh file of the mariadb image, the script which is supposed to execute your init.sql, it becomes clear that
the script will only be executed when the container didn't contain a database before (line 76 of the script), and
there will a log output informing you that you script was called.
To achieve this with docker-compose you have to stop the service, remove the container (to get rid of the database) and start it again:
docker-compose stop
docker-compose rm
docker-compose start
Here is an example of the image's behavior, only with a .sh file instead of .sql:
$ cat hello.sh
echo "This is output of the hello script"
$ docker run -it -v `pwd`/hello.sh:/docker-entrypoint-initdb.d/hello.sh -v mariadb_test:/var/lib/mysql -e MYSQL_RANDOM_ROOT_PASSWORD=1 mariadb
Initializing database
2017-02-09 14:13:54 140617005938624 [Note] /usr/sbin/mysqld (mysqld 10.1.21-MariaDB-1~jessie) starting as process 63 ...
2017-02-09 14:13:54 140617005938624 [Note] InnoDB: Using mutexes to ref count buffer pool pages
2017-02-09 14:13:54 140617005938624 [Note] InnoDB: The InnoDB memory heap is disabled
2017-02-09 14:13:54 140617005938624 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
[...]
2017-02-09 14:14:03 139836212086528 [Note] InnoDB: Dumping buffer pool(s) not yet started
2017-02-09 14:14:03 139836971521984 [Note] Plugin 'FEEDBACK' is disabled.
2017-02-09 14:14:03 139836971521984 [Warning] 'user' entry 'root#830dbd0908f3' ignored in --skip-name-resolve mode.
2017-02-09 14:14:03 139836971521984 [Warning] 'proxies_priv' entry '#% root#830dbd0908f3' ignored in --skip-name-resolve mode.
2017-02-09 14:14:03 139836971521984 [Note] mysqld: ready for connections.
Version: '10.1.21-MariaDB-1~jessie' socket: '/var/run/mysqld/mysqld.sock' port: 0 mariadb.org binary distribution
Warning: Unable to load '/usr/share/zoneinfo/leap-seconds.list' as time zone. Skipping it.
GENERATED ROOT PASSWORD: dau6voh4eej2jooRohpiop4eh6ahl7Uz
2017-02-09 14:14:05 139836970654464 [Warning] 'proxies_priv' entry '#% root#830dbd0908f3' ignored in --skip-name-resolve mode.
/usr/local/bin/docker-entrypoint.sh: running /docker-entrypoint-initdb.d/hello.sh
This is output of the hello script
2017-02-09 14:14:05 139836970351360 [Note] mysqld: Normal shutdown
2017-02-09 14:14:05 139836970351360 [Note] Event Scheduler: Purging the queue. 0 events
2017-02-09 14:14:05 139836195301120 [Note] InnoDB: FTS optimize thread exiting.
2017-02-09 14:14:05 139836970351360 [Note] InnoDB: Starting shutdown...
2017-02-09 14:14:05 139836970351360 [Note] InnoDB: Waiting for page_cleaner to finish flushing of buffer pool
2017-02-09 14:14:07 139836970351360 [Note] InnoDB: Shutdown completed; log sequence number 1616829
2017-02-09 14:14:07 139836970351360 [Note] mysqld: Shutdown complete
MySQL init process done. Ready for start up.
[...]
You see somewhere in the log output the call and its stdout of the hello.sh script is buried. On subsequent starts of the container the script is not executed because the database is already created (in the local mariadb volume):
$ docker run -it -v `pwd`/hello.sh:/docker-entrypoint-initdb.d/hello.sh -v mariadb_test:/var/lib/mysql -e MYSQL_RANDOM_ROOT_PASSWORD=1 mariadb
2017-02-09 14:19:13 140155189532608 [Note] mysqld (mysqld 10.1.21-MariaDB-1~jessie) starting as process 1 ...
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Using mutexes to ref count buffer pool pages
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: The InnoDB memory heap is disabled
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Compressed tables use zlib 1.2.8
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Using Linux native AIO
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Using SSE crc32 instructions
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Initializing buffer pool, size = 256.0M
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Completed initialization of buffer pool
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Highest supported file format is Barracuda.
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: 128 rollback segment(s) are active.
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Waiting for purge to start
2017-02-09 14:19:13 140155189532608 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.6.34-79.1 started; log sequence number 1616839
2017-02-09 14:19:13 140154429736704 [Note] InnoDB: Dumping buffer pool(s) not yet started
2017-02-09 14:19:13 140155189532608 [Note] Plugin 'FEEDBACK' is disabled.
2017-02-09 14:19:13 140155189532608 [Note] Server socket created on IP: '::'.
2017-02-09 14:19:13 140155189532608 [Warning] 'proxies_priv' entry '#% root#830dbd0908f3' ignored in --skip-name-resolve mode.
2017-02-09 14:19:13 140155189532608 [Note] mysqld: ready for connections.
Version: '10.1.21-MariaDB-1~jessie' socket: '/var/run/mysqld/mysqld.sock' port: 3306 mariadb.org binary distribution

Answer 2

Maybe a little late, but I have found another more accurate solution.
Through depends_on and healthcheck, don't run backend until mysql dump has finished. The only detail is that you must run it with version 2.1.
# docker-compose.yml
version: '2.1'
volumes:
data-volume: {}
services:
mysql:
image: mariadb
ports:
- "3306:3306"
environment:
MYSQL_ROOT_PASSWORD: pwd
MYSQL_DATABASE: users_db
depends_on:
backend:
condition: service_healthy
volumes:
- data-volume:/var/lib/mysql
- ./resources/docker-sql/init.sql:/docker-entrypoint-initdb.d/init.sql
backend:
image: myapp
ports:
- "8000:80"
depends_on:
- mysql
links:
- mysql
healthcheck:
test: "/usr/bin/mysql --user=root --password=you_pass --database=your_db --execute \"SELECT * FROM last_table_of_your_dump;\""
interval: 10s
timeout: 3s
retries: 10