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https://www.alexedwards.net/blog/serverless-api-with-go-and-aws-lambda
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Deploy with Ansible
ansible-playbook deploy.yml
- Initial setup of role
aws iam create-role --role-name lambda-books-executor --assume-role-policy-document file://./trust-policy.json --profile admin
aws iam attach-role-policy --role-name lambda-books-executor --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole --profile admin
- Build and prep code
env GOOS=linux GOARCH=amd64 go build -o /tmp/main
zip -j /tmp/main.zip /tmp/main
- ENV VARIABLES
ACCOUNT_ID=....
ZONE=us-east-1
- Deploy
aws lambda create-function --function-name books --runtime go1.x \
--role arn:aws:iam::${ACCOUNT_ID}:role/lambda-books-executor \
--handler main --zip-file fileb:///tmp/main.zip
- Test
# aws lambda invoke --function-name books /tmp/output.json && cat /tmp/output.json
aws lambda invoke --function-name books /dev/stdout
- Create DynamoDB
aws dynamodb create-table --table-name Books \
--attribute-definitions AttributeName=ISBN,AttributeType=S \
--key-schema AttributeName=ISBN,KeyType=HASH \
--provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5
- Provision some data
aws dynamodb put-item --table-name Books --item '{"ISBN": {"S": "978-1420931693"}, "Title": {"S": "The Republic"}, "Author": {"S": "Plato"}}'
aws dynamodb put-item --table-name Books --item '{"ISBN": {"S": "978-0486298238"}, "Title": {"S": "Meditations"}, "Author": {"S": "Marcus Aurelius"}}'
- Rebuild and redeploy
env GOOS=linux GOARCH=amd64 go build -o /tmp/main
zip -j /tmp/main.zip /tmp/main
aws lambda update-function-code --function-name books --zip-file fileb:///tmp/main.zip
- Add new policy to role for dynamodb access
aws iam put-role-policy --role-name lambda-books-executor \
--policy-name dynamodb-item-crud-role \
--policy-document file://./dynamodb-privilege-policy.json --profile admin
- Create API gateway
aws apigateway create-rest-api --name bookstore
REST_API_ID=....
- Get the id of the root API resource ("/")
aws apigateway get-resources --rest-api-id ${REST_API_ID}
ROOT_PATH_ID=....
- Create /books
aws apigateway create-resource --rest-api-id ${REST_API_ID} --parent-id ${ROOT_PATH_ID} --path-part books --profile admin
RESOURCE_ID=....
- Configure API gateway to respond to ANY HTTP method
aws apigateway put-method --rest-api-id ${REST_API_ID} \
--resource-id ${RESOURCE_ID} --http-method ANY \
--authorization-type NONE
- Connect the gateway to proxy with POST to the lambda function
aws apigateway put-integration --rest-api-id ${REST_API_ID} \
--resource-id ${RESOURCE_ID} --http-method ANY --type AWS_PROXY \
--integration-http-method POST \
--uri arn:aws:apigateway:${ZONE}:lambda:path/2015-03-31/functions/arn:aws:lambda:${ZONE}:${ACCOUNT_ID}:function:books/invocations
- Test API gateway
aws apigateway test-invoke-method --rest-api-id ${REST_API_ID} --resource-id ${RESOURCE_ID} --http-method "GET"
- Add/fix permissions on
- First build a GUID: https://www.guidgenerator.com/ GUID=....
aws lambda add-permission --function-name books --statement-id ${GUID} \
--action lambda:InvokeFunction --principal apigateway.amazonaws.com \
--source-arn arn:aws:execute-api:${ZONE}:${ACCOUNT_ID}:${REST_API_ID}/*/*/*
- Test API gateway
aws apigateway test-invoke-method --rest-api-id ${REST_API_ID} --resource-id ${RESOURCE_ID} --http-method "GET"
- Now fix the response for API gateway from lambda (in the Go code)
go get github.com/aws/aws-lambda-go/events
# Update the code to use the new structs
vi books/main.go
cd books && \
env GOOS=linux GOARCH=amd64 go build -o /tmp/main && \
zip -j /tmp/main.zip /tmp/main && \
aws lambda update-function-code --function-name books --zip-file fileb:///tmp/main.zip
- Test API gateway
aws apigateway test-invoke-method --rest-api-id ${REST_API_ID} --resource-id ${RESOURCE_ID} --http-method "GET" \
--path-with-query-string "/books?isbn=978-1420931693"
# Test book that isn't in the DB
aws apigateway test-invoke-method --rest-api-id ${REST_API_ID} --resource-id ${RESOURCE_ID} --http-method "GET" \
--path-with-query-string "/books?isbn=foobar"
- Query Cloudwatch
aws logs filter-log-events --log-group-name /aws/lambda/books \
--filter-pattern "ERROR"
- Create Deployment
aws apigateway create-deployment --rest-api-id ${REST_API_ID} \
--stage-name staging
- Test Deployment
curl https://${REST_API_ID}.execute-api.us-east-1.amazonaws.com/staging/books?isbn=978-1420931693
curl https://${REST_API_ID}.execute-api.us-east-1.amazonaws.com/staging/books?isbn=foobar
- Test creating a new book with POST
curl -i -H "Content-Type: application/json" -X POST \
-d '{"isbn":"978-0141439587", "title":"Emma", "author": "Jane Austen"}' \
https://${REST_API_ID}.execute-api.us-east-1.amazonaws.com/staging/books
- Test GET of that new book
curl https://${REST_API_ID}.execute-api.us-east-1.amazonaws.com/staging/books?isbn=978-0141439587
- Tail CloudWatch logs
cw tail -f /aws/lambda/books