django should wait for postgres to start up about docnow

[ryanfb]

Docker Compose doesn't have great built-in mechanisms for actually waiting for containers to completely start. The docs recommend using a wrapper like wait-for-it.sh or dockerize to wait on a port opening up, or you could probably use the example wait-for-postgres.sh script there: https://docs.docker.com/compose/startup-order/

[edsu]

Interesting! It looks like a timing issue -- docker-compose expresses the dependency that the django has on the db, but I think the container could be running without the db being fully up. I'm curious though, is the app running ok on http:/localhost:8000/ or did the django container quit? You can see if you do a:

docker ps -a

I did put a sleep in the django startup to try to accommodate for this, but maybe 5 seconds isn't enough ... and maybe there's a better way to do it...

[pbinkley]

I get this list:

CONTAINER ID        IMAGE                COMMAND                  CREATED              STATUS              PORTS                    NAMES
c9357c0d7b7d        docnow_trends        "/bin/bash -c 'sle..."   About a minute ago   Up About a minute                            docnow_trends_1
25f4ec315712        docnow_django        "/bin/bash -c 'sle..."   About a minute ago   Up About a minute   0.0.0.0:8000->8000/tcp   docnow_django_1
36f7bbe006e3        postgres             "docker-entrypoint..."   About a minute ago   Up About a minute   5432/tcp                 docnow_db_1
dcb21e9cd135        docnow_webpack       "npm run start"          About a minute ago   Up About a minute   0.0.0.0:3000->3000/tcp   docnow_webpack_1
a708b7a58dc3        redis                "docker-entrypoint..."   About a minute ago   Up About a minute   6379/tcp                 docnow_redis_1
5d18d6b298b2        catatnight/postfix   "/bin/sh -c '/opt/..."   About a minute ago   Up About a minute                            docnow_mail_1

I had already shut it down, so I deleted all the containers and images and restarted from scratch. This time the http server is responding at localhost:8000, and I get this error:

ProgrammingError at /

relation "docnow_user" does not exist
LINE 1: SELECT COUNT(*) AS "__count" FROM "docnow_user"
                                          ^

Request Method: 	GET
Request URL: 	http://localhost:8000/
Django Version: 	1.10.6
Exception Type: 	ProgrammingError
Exception Value: 	

relation "docnow_user" does not exist
LINE 1: SELECT COUNT(*) AS "__count" FROM "docnow_user"
                                          ^

Exception Location: 	/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py in execute, line 64
Python Executable: 	/usr/local/bin/python3.6
Python Version: 	3.6.1
Python Path: 	

['/usr/local/bin',
 '/code',
 '/usr/local/lib/python36.zip',
 '/usr/local/lib/python3.6',
 '/usr/local/lib/python3.6/lib-dynload',
 '/usr/local/lib/python3.6/site-packages']

Server time: 	Fri, 24 Mar 2017 19:53:18 +0000

[edsu]

Oh my bad, that is an error you are seeing in your web browser?

[edsu]

I'm not sure how you deleted all the containers and images, but it looks like the database hasn't been completely set up, which can happen if the django isn't able to synchronize the models to the database when it is starting.

Can you do this:

% git pull
% docker-compose down
% docker-compose build
% docker-compose up

and see if it works any better?

[pbinkley]

Yeah, that was an error served to the browser. And I destroyed the images and containers with these steps: https://gist.github.com/JeffBelback/5687bb02f3618965ca8f . I've pulled (now on 66c346f), and it works! I'm able to create an account and get the email confirmation etc. Thanks for the fix!

[edsu]

oh great! thanks for testing and working the kinks out

[edsu]

@ryanfb thanks for the pointers to solving this timing issue better than sleeping for longer and longer periods of time -- reopening this so that it can be fixed.

[justinlittman]

@edsu For SFM, we use appdeps.py (https://github.com/gwu-libraries/appdeps). For example, https://github.com/gwu-libraries/sfm-ui/blob/master/Dockerfile#L43.

[edsu]

Hey, thanks @justinlittman! Also, thanks for doing the work to share it as a reusable utility.