Deploying Sentry on Heroku

For a recent personal project, I've been using Sentry to monitor errors and suchlike. I was hosting this on my VPS, but the app it is monitoring is hosted on Heroku, so I thought that (a) it would make more sense to have the monitoring In The Cloud (TM), and (b) it would be an interesting exercise with Heroku, which I have been enjoying using a great deal.

It turns out to be pretty simple, and I've made a git repo available to make it even easier.  Just follow these steps:

1. Clone my GitHub repository:

   git clone https://github.com/OddBloke/heroku-sentry.git

2. Generate a secret key and set it as SENTRY_KEY in sentry.conf.py. See point 11 here for a good example of how to generate a good key.
3. Install the Heroku Toolbelt.
4. Sign up for a Heroku account.
5. Log in to your Heroku account from the CLI:

   heroku login

6. Navigate to your clone of the git repo and create a new Heroku app:

   heroku apps:create

   This command creates a heroku remote in the git repo, which we will use in a minute.
7. Take the URL it spits out (which will be something like http://floating-earth-1234.herokuapp.com/) and set that as SENTRY_URL_PREFIX in sentry.conf.py.
8. Commit your changes:

   git commit --all -m "Personalise."

9. Push your repository up to Heroku:

   git push heroku master

   If all goes according to plan, this will cause Heroku to deploy, and you will see the output as it installs Sentry and all of its requirements. Finally, it will tell you that your app is deployed to Heroku, but we're not quite done.
10. We need to configure a database for Sentry to use. We're going to use the new Heroku Postgres offering, which is currently in public beta: 

    heroku addons:add heroku-postgresql:dev

11. The previous command will have given you a database name, something like HEROKU_POSTGRESQL_CHARCOAL. Tell Heroku to use this database: heroku pg:promote HEROKU_POSTGRESQL_CHARCOAL
12. Finally, we need to run the Sentry setup script, create a default user and tell Sentry to use it: 

    heroku run sentry --config=sentry.conf.py upgrade
    heroku run sentry --config=sentry.conf.py createsuperuser
    heroku run sentry --config=sentry.conf.py repair --owner=JustCreatedSuperuser

    You should use the name of the super-user you create with the second command as the --owner argument to the third command.

Voila!  You should now be able to see Sentry by pointing your browser at the URL you used for SENTRY_URL_PREFIX earlier.

If you have any problems, you can check out your logs using heroku logs.

One final note: Heroku doesn't provide SMTP for you, so you'll also have to modify the SMTP settings to point at your own mail server (or play around with the Heroku add-ons that do provide it).