riweston / gcp-pubsub-acloudguru

README

Overview

This project is a rewrite of the original slackbot serving the same purpose of automatically re-activating user accounts, initiated from Slack and then processed using a serverless framework.

The reason for the rewrite is to achieve the following goals;

• Reduce nominal monthly costs
• Improve reportable metrics
• Implement trace logging for invidiual requests
• Improved scalability in the future

Repo

Summary

This repo is largely a monorepo design with all IaC and source code captured, here the only exception is the REST client https://github.com/riweston/acloudguru-client-go/ which is maintained separately.

HLD

The initial workflow is kicked from a user typing the command /acloudguru from Slack, this is then forwarded via the Slack API to GCP where it is processed accordingly.

Services

http-router

This service exists purely to handle the initial request from Slack, it must respond promptly or Slack will timeout. After confirming receipt of the request it forwards on the following useful attributes from the request for further processing

.user_id 			# This is the senders Slack ID, we'll use this later to lookup the senders email address
.response_url	# This gives us a unique identifier for logging additionally a URL to respond to our sender

These attributes are sent as a message to a pubsub topic for further processing

lookup-slack-id

This is a helper service to identify the email address of the sender using the Slack API. Using this we're able to forward on the now identified email address to main pubsub work-queue, we use these attributes

.user_email		# Email address, required by the ACloudGuru API for activation
.response_url	# Logging/response messages
.request_type	# This will just be 'activate' as we know any request from this service is an activation

house-keeping

This service is used is triggered from a new request coming through the request pubsub topic but doesn't require any context. Using environment variables configured at runtime this service will identify if there is capacity in the subscription or if the user(s) that haven't logged in for the most amount of time, but still have an ACloudGuru license activated, must be deactivated so as not to over-provision licenses.

In addition a variable is set to complete a housekeeping exercise that any users who haven't logged in within a given number of days will also have their accounts deactivated.

DAYS_CAP=			# Number of days since logging in before marking for deactivation
LICENSE_CAP=	# Number of licences before marking oldest accounts for deactivation

The DAYS_CAP variable is processed first to reduce the number of activated accounts, if this still doesn't bring the total number of licenses allocated below the LICENSE_CAP threshold then process this too.

Once the accounts for deactivation have been identified, they're sent on to the pubsub topic work-queue.

activate-deactivate

This service performs a few different tasks based on the .request_type attribute in the pubsub message. activate || deactivate are the 2 expected values, deactivate is relatively straightforward and for each user account a call is made to the ACloudGuru API. Activate works the same way but additionally the original sender is also sent a confirmation message over Slack using the .request_url attribute.