Exporting views from Mysql using Docker commmand - mysql

Question

The code below extracts views separately from the database. However, I'm trying to get this to run in a single docker run or exec command.
Right now when I try, the pipe command and in combination with trying to escape quotes gives me errors.
mysql -u username INFORMATION_SCHEMA
--skip-column-names --batch
-e "select table_name from tables where table_type = 'VIEW'
and table_schema = 'database'"
| xargs mysqldump -u username database
> views.sql
Anyone know how to achieve this within one docker command?
For example:
docker exec -i $(docker-compose ps -q mysqldb) mysql ...
Much love.

Answer 1

You can run both the mysql client command and the mysqldump tool from somewhere that's not "on the database server". In your case, you can run them from the host that has the MySQL server, assuming you launched the database with options like docker run -p 3306:3306. It would look something like
mysql -h 127.0.0.1 -u username INFORMATION_SCHEMA \
--skip-column-names --batch \
-e "select table_name from tables where table_type = 'VIEW' and table_schema = 'database'" \
| xargs mysqldump -h 127.0.0.1 -u username database \
> views.sql
This avoids all of the shell quoting problems trying to feed this into docker exec, and also avoids the requirement to need root-level access on the host to do an administrative task (if you can run any Docker command at all then you can use docker run to add yourself to the host's /etc/sudoers, among other things).
I also agree with #MichaelBoesl's answer, though: this is long enough that trying to make it into a one-liner isn't really worth the trouble that the various quoting and escaping will bring. I'd probably write this into a script and put the SQL query into a file.
#!/bin/sh
: ${MYSQL_HOST:=127.0.0.1}
: ${MYSQL_USER:=username}
: ${MYSQL_DATABASE:=INFORMATION_SCHEMA}
cat >/tmp/dump_views.sql <<SQL
SELECT table_name
FROM tables
WHERE table_type='VIEW' AND table_schema='database';
SQL
mysql -h "$MYSQL_HOST" -u "$MYSQL_USER" --skip-column-names --batch \
"$MYSQL_DATABASE" </tmp/dump_views.sql \
| xargs mysqldump -h "$MYSQL_HOST" -u "$MYSQL_USER" "$MYSQL_DATABASE"

Answer 2

You can put all your commands into a bash script on the container and just execute the script!