autoscaling warmup for ec2/fargate

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Problem statement

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There are 2 parts in order to perform this process

1. rulegen serverless code to shedule cloudwatch events for autoscaling.

2. rulegen-scale serverless code which gets invoked by rulegen cloudwatch rules to perform autoscaling on defined autoscaling groups.

logical flow

• sheduled events for multiple resource and time, autoscaling will be defined by use in for of json as the syntax defined in rulegen

• This json will be uploaded to s3 bucket, before uploading bucket-arn and file name has to be defined in serverless.yml file as defined in rulegen

• On s3 bucket put event for that file rulegen lambda will generate cloudwatch event rules based on shedules and minimum count defined in json file by the user.

• This rules will trigger next lambda rulegen-scale which will perform task of modifing autoscaling minimum count of ec2/fargate and after updating autoscaling count, event rule will be removed as it was been made to run once only.

Flow Diagram

prerequisite

1. Nodejs
2. npm

To install nodejs click here

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Steps for implementation

1. Install serverless on your local device.

   • sudo npm install -G serverless

   • Now inside git repo directory run: npm i -D serverless-dotenv-plugin

2. Create a s3 bucket on your aws account where you will upload your sheduled scaling json file.

3. provide required example variables values at .env.dev file as follows

    ENV_AWS_REGION="<YOUR-REGION>"
    ENV_AWS_PROFILE="<YOUR-PROFILE>"
   
    BUCKET_NAME="shedule-event-ec2"
    BUCKET_FILE="test.json"
   

4. run serverless deploy

This now in you aws account in s3 bucket shedule-event-ec2 you can put scaling time shedules in file example/shedule.json

same can be written in yaml as well like: example/shedule.yml

like follows:

---
- service_type: fargate
  scaling_group_name: service/cluster-wp/fastapi
  shedule_table:
    date: 30/11/2021
    shedule:
    - start: '16:40:00'
      end: '16:57:00'
      count: 4
    - start: '16:55:00'
      end: '17:57:00'
      count: 6
- service_type: ec2
  scaling_group_name: scl
  shedule_table:
    date: 30/11/2021
    shedule:
    - start: '16:10:00'
      end: '17:37:00'
      count: 4
    - start: '17:35:00'
      end: '18:57:00'
      count: 6