Database Lab access using the pgai Ruby gem

@mbobin created the pgai Ruby Gem that greatly simplifies access to a database clone, with support for:

• Access to all database clones listed in the Postgres.ai instances page;
• Multiple psql sessions on the same clone.

If you have AllFeaturesUser psql access, you can follow the steps below to configure the pgai Gem:

1. To get started, you need to gather some values from the Postgres.ai instances page:

   1. Go to the instance that you want to configure and the on right side of the screen.

   2. Under Connection, select Connect. The menu might be collapsed.

      A dialog with everything that’s needed for configuration appears, using this format:

      dblab init --url "http://127.0.0.1:1234" --token TOKEN --environment-id <environment-id>
      

      ssh -NTML 1234:localhost:<environment-port> <postgresai-user>@<postgresai-proxy> -i ~/.ssh/id_rsa
      

2. Add the following snippet to your SSH configuration file at ~/.ssh/config, replacing the variable values:

   Host pgai-proxy
     HostName <postgresai-proxy>
     User <postgresai-user>
     IdentityFile ~/.ssh/id_ed25519
   

3. Run the following command so you can accept the server key fingerprint:

   ssh pgai-proxy
   

4. Run the following commands:

   gem install pgai
   
   # Grab an access token: https://console.postgres.ai/gitlab/tokens
   # GITLAB_USER is your GitLab handle
   pgai config --dbname=gitlabhq_dblab --prefix=$GITLAB_USER --proxy=pgai-proxy
   
   # Grab the respective port values from https://console.postgres.ai/gitlab/instances
   # for the instances you'll be using (in this case, for the `main` database instance)
   pgai env add --alias main --id <environment-id> --port <environment-port>
   

5. Once this one-time configuration is done, you can use pgai connect to connect to a particular database. For instance, to connect to the main database:

   pgai connect main
   

6. Once done with the clone, you can destroy it:

   pgai destroy main