Added POSTGRES_DB variable to optionally specify DB name

[rothgar]

POSTGRESS_DB defaults to POSTGRESS_USER if it's not specified.

Example run

docker run -d --name postgres -e POSTGRES_DB=testdb -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=password postgres

You can also connect to the db with

docker run --rm -it --name dbconnect --link postgres:db postgres sh -c 'exec psql -h "$DB_PORT_5432_TCP_ADDR" -p "$DB_PORT_5432_TCP_PORT" -d testdb -U postgres'

[yosifkit]

It seems that all but 8.4 got spaces instead of tabs on the : ${POSTGRES_DB:=$POSTGRES_USER} line; they should all be tabs like the rest of the lines. Other than that, this seems solid.

[rothgar]

Sorry about that. I wasn't showing tab characters so I didn't notice.

I just retabed all the files so they should have consistent formatting now.

[yosifkit]

LGTM

What do you think @tianon?

[tianon]

Missed one. 😉

[tianon]

Doesn't the logic down below this need to change too?

        gosu postgres postgres --single -jE <<-EOSQL
            $op USER "$POSTGRES_USER" WITH SUPERUSER $pass ;
        EOSQL

I'm +1 in general; I think this is a reasonable change.

[rothgar]

I fixed the missed variable in 9.1 and the template

@tianon Because there's only one db and one user I don't know if the logic needs to change. It worked in my test containers (specifying combinations of POSTGRES_USER, POSTGRES_DB, or none at all) by logging into the db with another container (see test above). But I'm not very familiar with postgres in general so there may be a better way.

[yosifkit]

Looks like the template is missing the change on the CREATE DATABASE line.

@tianon I don't see why the user creation/update would need to change. It will still have access to whatever database is created.

[rothgar]

@yosifkit fixed the template. Sorry, was doing that in a rush and didn't check everything.

[yosifkit]

It's all good. LGTM

ping @tianon

[tianon]

Can you confirm that all the following combinations work?

• POSTGRES_USER=postgres, POSTGRES_DB=postgres
• POSTGRES_USER=postgres, POSTGRES_DB=testdb
• POSTGRES_USER=testuser, POSTGRES_DB=postgres
• POSTGRES_USER=testuser, POSTGRES_DB=testdb

I just want to make sure we're covering our bases.

The change LGTM, but I'll feel better about merging if you can confirm you've tested all four possible permutations of these two interacting before we merge.

[md5]

It would be awesome to see those in the tests in official-images :)​

[rothgar]

I had to add another check to make sure the user was altered or created properly, but now all of these check out.

• ✔️POSTGRES_USER=postgres, POSTGRES_DB=postgres
• ✔️POSTGRES_USER=postgres, POSTGRES_DB=testdb
• ✔️POSTGRES_USER=testuser, POSTGRES_DB=postgres
• ✔️POSTGRES_USER=testuser, POSTGRES_DB=testdb
• ✔️POSTGRES_DB=testdb

It might not be ideal that the postgres database still exists no matter if you specify POSTGRES_DB to be something different or not. I could add DROP DATABASE IF EXISTS postgres if the user specifies a database but I'm not sure that would matter.

[yosifkit]

LGTM

[tianon]

Can we make this != instead of ! ... =? 😇

[rothgar]

That makes sense, I'll change it.

[md5]

LGTM

[maslick]

Is it possible to create multiple databases at startup?

docker-compose.yml

db:
    image: postgres
    environment:
        - POSTGRES_DB=db1
        - POSTGRES_DB=db2
        - POSTGRES_USER=user
        - POSTGRES_PASSWORD=pwd
        - POSTGRES_ROOT_PASSWORD=rootpwd

[yosifkit]

@maslickm, not with this environment variable, but you could add a simple sql script into /docker-entrypoint-initdb.d/ and it will be run just after initial database/user creation.