{"componentChunkName":"component---src-templates-blog-post-js","path":"/lambda-training/","result":{"data":{"site":{"siteMetadata":{"title":"Nans' blogs"}},"markdownRemark":{"id":"afa18240-3db5-5fba-b3ab-4343c31dfc2c","excerpt":"Learn AWS Lambda and see real world example with serverless main documentation : https://serverless.com/ What is lambda functions\nlimited by time\nrun on demand…","html":"

Learn AWS Lambda and see real world example with serverless

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main documentation : https://serverless.com/

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What is lambda

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functions\nlimited by time\nrun on demand\nscaling is automated -> that’s why we call it “Serverless”

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Pricing

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AWS Lambda integrations

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Example : Thumbnail creation

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“Database Trigger-like” behavior for S3\nNew image in S3 -> trigger -> AWS Lambda function creates a thumbnail and push it to S3

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/!\\ the handler is the name of function that will be called in lambda\nThe instructor only did a “hello world”.

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The Serverless Framework

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Aims to ease the pain of creating, deploying, managing and debugging lambda functions.\nIntegrates with CI/CD tools.\nCloudFormation support (templates for deploying).

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npm install -g serverless
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IAM => Create a serverless-admin (new user). Programmatic access, and give administrator access. (not best practice though …)

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serverless config credentials --provider aws --key XXX --secret YYY --profile serverless-admin
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Hello world using the Serverless framework

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serverless or sls => list of commands.

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sls create --template aws-python --path hello-world-python
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serverless.yml add

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profile: serverless-admin\nregion: eu-west-3
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sls deploy -v
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the code is uploaded to s3, and then CloudFront is configured. IAM role is created for us.

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Running a function from the command line

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sls invoke -f hello -l
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 Updating the function

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change the print statement.

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sls deploy function -f hello
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=> how to integrate that with a proper CI/CD system ?

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Fetching function logs

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sls logs -f hello -t
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enables to stream function logs as they happen !

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 Remove the function

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sls remove
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add an IAM role statement to a function

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iamRoleStatements:\n  - Effect: \"Allow\"\n    Action:\n    - \"lambda\"\n    Resource:\n    - \"*\"
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VPC for lambda functions

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can launch a lambda in a VPC so that they can access EC2 instances or RDS instances.\n\n \n \n \n \n \ncan specify securityGroupIds and subnetsId in the serverless.yml file.

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Real world example : Service to create S3 image thumbnails

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Triggering a function from an s3 event :\n\n \n \n \n \n

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plugin :\nserverless-python-requirements\nit installs what’s written in requirements.txt file.\nPillow => import PIL

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Real world example : REST API with API Gateway and DynamoDB

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Lambda functions are stateless, they don’t keep anything in memory, so they will write to DynamoDB.

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package.json => like requirements.txt

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environment :\n  DYNAMODB_TABLE: ${self:service}-${opt:stage, self:provider.stage}
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POST on /todos => call create function\nthis is wired to the API gateway

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under resources, you can specify the cloud formation template

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response should always have a statusCode and a body.

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 Personal investigation : creating a full stack app

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If you want to build an app that can leverage that rest API that is written in Lambda, you can use aws-amplify : https://aws-amplify.github.io/docs/js/api.

","frontmatter":{"title":"Lambda training","date":"March 11, 2020","description":"Notes taken during AWS lambda training"}}},"pageContext":{"slug":"/lambda-training/","previous":{"fields":{"slug":"/aws-training/"},"frontmatter":{"title":"Formation AWS 09-10/03/2020","tags":["AWS","training","cloud","devOps"]}},"next":{"fields":{"slug":"/docker-training/"},"frontmatter":{"title":"Docker training","tags":["training","devOps"]}}}},"staticQueryHashes":["2841359383","3145232782"]}