Category: Serverless

AWS Function

If you are using AWS as a service provider then all function that you are using on AWS platform is known as AWS lambda function.

Serverless

Configuration

All of the lambda functions that we have created can be found in serverless.yml file under functions property.

How to generate serverless file for our Application?

Getting started with Serverless Framework and AWS

Open your Terminal and choose a specific folder

Execute the following command

# Install the serverless cli
npm install -g serverless

# Or, update the serverless cli from a previous version

npm update -g serverless

After that severless-cli has been successfully installed on your system.we can create our project using following command

# Create and deploy a new service/project

serverless

Note: Before going for serverless framework make sure your system should have Node 6 or higher on Your machine, if not then first do that.
After that during the process, it will ask a few questions just follow them

1. It will ask you log in on serverless or if you no account then create account 
2. Ask you to give permission for connecting with AWS
3. Then after on AWS account, it will ask to your account user Iamrole assign it and then after it will generate Access key ID  and Secret access key 
4. Your terminal will ask for that Access key ID  and Secret access key just enter this information and after that, your project has been successfully created.

After that our Serverless has been successfully created now we have to follow steps for creating our Lambda function and deploy on AWS using serverless framework.

Configuration

service: serverlessex
# app and org for use with dashboard.serverless.com
app: server-app
org: dheerajkumar

# You can pin your service to only deploy with a specific Serverless version
# Check out our docs for more details
# frameworkVersion: "=X.X.X"
provider:
  name: aws
  runtime: nodejs10.x
# you can also these properties 
#  memorySize:512
#  timeout:10
#  versionfunctions:false
#  tracing:true

functions:
  hello:
    handler: handler.hello

handler: property points file and module containing the code you want to run in your function.
During creating a lambda function it will be a common need that we have to maintain folder structure so we have to provide path of lambda function inside our serverless file.
This property is declared inside functions like
permissions: Every AWS lambda function needs permission to interact with other AWS infrastructure resources within your account.

These roles are set via an AWS IAMRole.

We can set permission policy statements within this role via the property.

provider.iamRoleStatements property.

Environmental Variables: We can add an environment variable configuration to a specific function in serverless.yml by adding an environment object in the function configuration like 

functions:
  hello:

    handler: handler.hello
#    Define function environment variables here
#    environment:
#      variable2: value2

Note: Using an environment variable in a function applies changes to that particular function. But, if we want to apply changes for all functions in our project then we have to need to declare environment variable in provider.

provider:
  name: aws
  runtime: nodejs10.x

# you can also these properties 
#  memorySize:512
#  timeout:10
#  versionfunctions:false
#  tracing:true

# you can define service wide environment variables here
#  environment:
#    variable1: value1

If an environment variable with the same key is defined in the provider level as well as function level then function level key will overwrite the provider level.