Deploy API Gateway from Command Line - bash

Question

I am trying for two days to deploy a POST Rest API, which would be the trigger for an already existing Lambda function on AWS, through a bash script using the aws-cli. The thing is that I am able to upload and deploy the API but it doesn't work. I tested my Lambda fuction through the test feature on AWS itself and it works. But when I call the API it returns this as header
{"x-amzn-ErrorType":"InternalServerErrorException"}
and this as body
{
"message": "Internal server error"
}
and this is the log I find on API Gateway test functionality
Execution log for request ba8d70b6-bb5e-49c5-9ff4-7927983c51d8
Thu Nov 26 16:41:55 UTC 2020 : Starting execution for request: ba8d70b6-bb5e-49c5-9ff4-7927983c51d8
Thu Nov 26 16:41:55 UTC 2020 : HTTP Method: POST, Resource Path: /provoletta
Thu Nov 26 16:41:55 UTC 2020 : Method request path: {}
Thu Nov 26 16:41:55 UTC 2020 : Method request query string: {}
Thu Nov 26 16:41:55 UTC 2020 : Method request headers: {}
Thu Nov 26 16:41:55 UTC 2020 : Method request body before transformations: {
"device": {
"uuid": "4",
"lastPosition": "4",
"lastSeen": "4",
"raspberryId": "4",
"roomNumber": "34"
}
}
Thu Nov 26 16:41:55 UTC 2020 : Endpoint request URI: https://lambda.us-east-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:us-east-1:***:function:provoletta/invocations
Thu Nov 26 16:41:55 UTC 2020 : Endpoint request headers: {x-amzn-lambda-integration-tag=ba8d70b6-bb5e-49c5-9ff4-7927983c51d8, Authorization=************************************************************************************************************************************************************************************************************************************************************************************************************************53a5a7, X-Amz-Date=20201126T164155Z, x-amzn-apigateway-api-id=eca0u6a3ed, X-Amz-Source-Arn=arn:aws:execute-api:us-east-1:***:eca0u6a3ed/test-invoke-stage/POST/provoletta, Accept=application/json, User-Agent=AmazonAPIGateway_eca0u6a3ed, X-Amz-Security-Token=*** [TRUNCATED]
Thu Nov 26 16:41:55 UTC 2020 : Endpoint request body after transformations: {
"device": {
"uuid": "4",
"lastPosition": "4",
"lastSeen": "4",
"raspberryId": "4",
"roomNumber": "34"
}
}
Thu Nov 26 16:41:55 UTC 2020 : Sending request to https://lambda.us-east-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:us-east-1:***:function:provoletta/invocations
Thu Nov 26 16:41:55 UTC 2020 : Execution failed due to configuration error: Invalid permissions on Lambda function
Thu Nov 26 16:41:55 UTC 2020 : Method completed with status: 500
This is how I am trying to create and build the API through bash script
#!/bin/sh
api_id=$(aws apigateway create-rest-api --name 'provoletta' --query 'id' --output text)
resource_id=$(aws apigateway get-resources --rest-api-id $api_id --query 'items' --output text)
resource_id=${resource_id::-2}
result_id=$(aws apigateway create-resource --rest-api-id $api_id --parent-id $resource_id --path-part provoletta --query 'id' --output text)
aws apigateway put-method \
--rest-api-id $api_id \
--region $AWS_REGION \
--resource-id $result_id \
--http-method POST \
--authorization-type "NONE"
aws apigateway put-method-response \
--region $AWS_REGION \
--rest-api-id $api_id \
--resource-id $result_id \
--http-method POST \
--status-code 200
aws apigateway put-integration \
--region $AWS_REGION \
--rest-api-id $api_id \
--resource-id $result_id \
--http-method POST \
--type AWS \
--integration-http-method POST \
--uri arn:aws:apigateway:$AWS_REGION:lambda:path/2015-03-31/functions/arn:aws:lambda:$AWS_REGION:$ACCOUNT_ID:function:provoletta/invocations \
--request-templates '{"application/x-www-form-urlencoded":"{\"body\": $input.json(\"$\")}"}'
aws apigateway put-integration-response \
--region $AWS_REGION \
--rest-api-id $api_id \
--resource-id $result_id \
--http-method POST \
--status-code 200 \
--selection-pattern ""
aws apigateway create-deployment --rest-api-id $api_id --stage-name provoletta
If I create an API for the same Lambda function on API Gateway console itself it works without problems. So, what's the problem with this script?

Answer 1

It looks like a permission problem. Specifically, it looks like you did not give permission for the API Gateway to invoke your Lambda function:
Execution failed due to configuration error: Invalid permissions on Lambda function.
To fix this you should "add permissions" to your Lambda as described in the AWS CLI documentation.
Based on your "code", this might already do the trick, assuming your Lambda function is called provoletta:
aws lambda add-permission \
--region $AWS_REGION \
--function-name provoletta \
--action lambda:InvokeFunction \
--statement-id AllowGatewayToInvokeFunction \
--principal apigateway.amazonaws.com