Before you begin

1. Select or create a Cloud project with an App Engine app and enable billing, create a queue

2. Install Cloud SDK and configure gcloud

3. Configure the Slack app

   3.1 Create the app => random-picker

   3.2 Request mandatory scopes: chat:write, commands, usergroups:read, users:read

   3.3 Install the app

   3.4 Create Slash commands (name and URL) => /randompicker, /randompickerlater

Running your app

1. Export env vars :

• export SLACK_TOKEN=XXX where XXX is Bot User OAuth Access Token found in Slack app OAuth & Permissions page
• export PROJECT_NAME=XXX where XXX is the cloud project name
• export QUEUE_NAME=XXX where XXX is the queue name
• export LOCATION=XXX where XXX is the location (e.g. europe-west1)

2. Install your app dependencies using the npm command:

npm install

3. Run the app:

npm start

Deploying the app to App Engine

1. Replace env vars in app.yaml

2. In your terminal window, deploy the app to App Engine using the gcloud tool:

# on the command-line
gcloud app deploy

Using the Slash command

1. Type the command into your Slack channel:

/randompicker @engineering: pick someone randomly in @engineering group

/randompickerlater @engineering in 5s: pick someone randomly 5s later

2. Watch the logs to be sure the executions have completed

TODO

• La commande randompickerlater n'est pas vraiment utile en tant que telle, le but était de créer une commande pour planifier une tâche cron qui appellerait le picker. GCP ne semble pas proposer d'option (Cloud Scheduler ?) pour planifier des tâches cron de manière programmatique (c'est pour ça que j'utilise ici des Cloud Tasks). A creuser...
• ignore users option
• random with rotation (like Spotify)
• secure endpoints (OAuth?)
• control checks (e.g. endpoint parameters)
• call payfit API to ignore users in vacation => but no API!