Serverless Fast Deploy Plugin

Fast Serverless deployments for large packages

Requirements:

• Serverless v1.12.x or higher.
• AWS provider

How it works

I found that while working with Python libraries such Numpy and Pandas, my deploys became very slow and expensive (I work off a mobile data plan) due to the increased package size. This plugin deploys a specialized Lambda always you to only deploy the files that are most likely to change. It does this by merging the incoming files with the latest existing package on S3. So now when I deploy a change, I am sending a few KB across the wire each time, not 50 MB.

Caveats

A note about merging the update package with the base package

y first attempt was to just use the latest existing deployment package on S3, unpack that and create a new package with the update files. This was a bit “slow”, so now I create a base package which is the full previous deployment package without the files described by the custom.fastDeploy.include property. This means that I can simply append the new files, resulting in an even faster deploy. The unfortunately side effect being that if you change the custom.fastDeploy.include property, you need to do a full deployment before doing your next FastDeploy.

The creation of the base deployment package also means that the first FastDeploy will be slightly slower than subsequent deployments.

Custom deployment bucket

At the moment this plugin bypasses all of the standard deployment lifecycle stages, so I am not yet able to get hold of the auto generated deployment bucket. As such this plugin only works if you have created a custom deployment bucket and configured it via the provider.deploymentBucket property.

IAM Role

The FastDeploy Lambda requires the following permissions on the deployment bucket. Either this can be added to the services default role, or you can create a new role and configure it via the custom.fastDeploy.role property.

Updates to CloudFormation configuration requires a full deployment

Much like Serverless’s function deployment feature, any updates to the CloudFormation stack requires a full deployment.

- Effect: Allow
  Action:
    - s3:GetObject
    - s3:PutObject
  Resource: arn:aws:s3:::aronim-serverless/*
- Effect: Allow
  Action:
    - s3:ListBucket
  Resource: arn:aws:s3:::aronim-serverless     

Setup

Install via npm in the root of your Serverless service:

npm install serverless-plugin-fastdeploy --save-dev

• Add the plugin to the plugins array in your Serverless serverless.yml:

plugins:
  - serverless-plugin-fastdeploy

Run

sls fastdeploy

Configuration

The custom.fastDeploy.include property describes which files to include in the update package, and exclude from the base package. This can be an array if you are just working in single module project, or an object if you are working with a multi-module project.

Available custom properties:

custom:
  fastDeploy:
    memorySize: 512    # Optional. Default: 512MB
    timeout: 30        # Optional. Default: 30sec
    include:           # Required. No Default
      - src/*.js       # Example
    role:              # Optional. Uses service default role if one is provided
      - FastDeployRole # Example

service: ServerlessFastDeployExample

plugins:
  - serverless-plugin-fastdeploy

provider:
  ...
  role: DefaultRole
  deploymentBucket: aronim-serverless

custom:
  fastDeploy:
    include:
      - package_one/**
      - package_two/**

######      
# OR #      
###### 
 
custom:
  fastDeploy:
    include:
      ".": service_one/**
      "../../modules/module-two": module_two/**     

resources:
  Resources:
    DefaultRole:
      Type: AWS::IAM::Role
      Properties:
        Path: /
        RoleName: ${self:service}-${self:provider.stage}
        AssumeRolePolicyDocument:
          Version: "2012-10-17"
          Statement:
            - Effect: Allow
              Principal:
                Service:
                  - lambda.amazonaws.com
              Action: sts:AssumeRole
        Policies:
          - PolicyName: ${self:service}-${self:provider.stage}
            PolicyDocument:
              Version: "2012-10-17"
              Statement:
                - Effect: Allow
                  Action:
                    - logs:CreateLogGroup
                    - logs:CreateLogStream
                    - logs:PutLogEvents
                  Resource: arn:aws:logs:${self:provider.region}:*:log-group:/aws/lambda/*:*:*
                - Effect: Allow
                  Action:
                    - s3:GetObject
                    - s3:PutObject
                  Resource: arn:aws:s3:::aronim-serverless/*
                - Effect: Allow
                  Action:
                    - s3:ListBucket
                  Resource: arn:aws:s3:::aronim-serverless     

Cost

Since we are deploying an additional Lambda, there are some neglible cost implications. The default memory allocated to the FastDeploy Lambda is 512MB, but this can be increased or decreased using the custom.fastDeploy.memory property.

Acknowledgements

A big thank you to FidelLimited, I blatently plagiarized their WarmUp plugin for the basis of the FastDeploy Lambda :-) As they say “Mimicry is the highest form of flattery”.

Contribute

Help us making this plugin better and future proof.

• Clone the code
• Install the dependencies with npm install
• Create a feature branch git checkout -b new_feature
• Lint with standard npm run lint

License

This software is released under the MIT license. See the license file for more details.