Serverless Framework add Lambda to an Existing VPC and Subnet

An extension to the answer provided by @Nebulastic.

This is when you want to configure your VPC Lambda's to execute from more than one subnet for various Stages.

provider:
  name: aws
  vpc:
    securityGroupIds:
      - ${self:custom.securityGroupId.${self:provider.stage}}
    subnetIds:
      - ${self:custom.subnetId1.${self:provider.stage}}
      - ${self:custom.subnetId2.${self:provider.stage}}
      - ${self:custom.subnetId3.${self:provider.stage}}

custom:
  stage: ${opt:stage, self:provider.stage}

  securityGroupId:
    prod: sgId-prod
    test: sgId-test
    dev: sgId-dev
  subnetId1:
    prod: subnetId1-prod
    test: subnetId1-test
    dev: subnetId1-dev
  subnetId2:
    prod: subnetId2-prod
    test: subnetId2-test
    dev: subnetId2-dev
  subnetId2:
    prod: subnetId3-prod
    test: subnetId3-test
    dev: subnetId3-dev

Yes it is. The vpc configuration in serverless.yml just needs to reference existing subnets and security groups. Something like this:

vpc:
    securityGroupIds:
      - securityGroupId1
      - securityGroupId2
    subnetIds:
      - subnetId1
      - subnetId2

Take a look at https://serverless.com/framework/docs/providers/aws/guide/functions/#vpc-configuration

The following setup worked perfectly for me in Serverless version 1.51.0. I included staging variables, since my environments use different subnets and security groups for logical isolation. My network setup is an already existing VPC with subnets and security groups.

provider:
  name: aws
  ....
  ....
  vpc:
    securityGroupIds:
      - ${self:custom.securityGroupId.${self:provider.stage}}
    subnetIds:
      - ${self:custom.subnetId.${self:provider.stage}}

custom:
  stages:
    - tst
    - dev
    - prd
  securityGroupId:
    local: sg-local
    tst: sg-tst
    dev: sg-dev
    prd: sg-prd
  subnetId:
    local: subnet-local
    tst: subnet-tst
    dev: subnet-dev
    prd: subnet-prd


plugins:
  - serverless-stage-manager