Execution failed due to configuration error: Invalid permissions on Lambda function

Question

I am building a serverless application using AWS Lambda and API Gateway via Visual Studio. I am working in C#, and using the serverless application model (SAM) in order to deploy my API. I build the code in Visual Studio, then deploy via publish to Lambda. This is working, except every time I do a new build, and try to execute an API call, I get this error:

Execution failed due to configuration error: Invalid permissions on Lambda function

Doing some research, I found this fix mentioned elsewhere (to be done via the AWS Console):

Fix: went to API Gateway > API name > Resources > Resource name > Method > Integration Request > Lambda Function and reselected my existing function, before "saving" it with the little checkmark.

Now this works for me, but it breaks the automation of using the serverless.template (JSON) to build out my API. Does anyone know how to fix this within the serverless.template file? So that I don't need to take action in the console to resolve? Here's a sample of one of my methods from the serverless.template file

{
  "AWSTemplateFormatVersion" : "2010-09-09",
  "Transform" : "AWS::Serverless-2016-10-31",
  "Description" : "An AWS Serverless Application.",

  "Resources" : {

    "Get" : {
      "Type" : "AWS::Serverless::Function",
      "Properties": {
        "VpcConfig":{
          "SecurityGroupIds" : ["sg-111a1476"],
          "SubnetIds" : [ "subnet-3029a769","subnet-5ec0b928"]
        },
        "Handler": "AWSServerlessInSiteDataGw::AWSServerlessInSiteDataGw.Functions::Get",
        "Runtime": "dotnetcore2.0",
        "CodeUri": "",
        "MemorySize": 256,
        "Timeout": 30,
        "Role": null,
        "Policies": [ "AWSLambdaBasicExecutionRole","AWSLambdaVPCAccessExecutionRole","AmazonSSMFullAccess"],
        "Events": {
          "PutResource": {
            "Type": "Api",
            "Properties": {
              "Path": "/",
              "Method": "GET"
            }
          }
        }
      }
    },

Thank you SO MUCH for this tip. I had no idea the AWS console seems to have this bug. I was able to fix it following your advice but also fixed my terraform code to add this in as well. — atom88, May 20 '20 at 19:15
Thank you sooo much for this post. I had a similar problem and was able to resolve it with the information provided in this post! — atom88, May 20 '20 at 20:32
fwiw, I had this error because I had the incorrect path set in the "`AWS::Serverless::Function` > Properties > Events > Event > path" of the sam template — mojave, Mar 02 '23 at 18:11

Muhammad Soliman · Answer 1 · 2020-01-15T01:55:11.407

30

You may have an issue in permission config, that's why API couldn't call your lambda. try to explicitly add to template.yaml file invoke permission to your lambda from apigateway as a principal here's a sample below:

  ConfigLambdaPermission:
    Type: "AWS::Lambda::Permission"
    DependsOn:
    - MyApiName
    - MyLambdaFunctionName
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !Ref MyLambdaFunctionName
      Principal: apigateway.amazonaws.com

Here's the issue that was reported in SAM github repo for complete reference and here is an example of hello SAM project

If you would like to add permission by AWS CLI for testing things out, you may want to use aws lambda add-permission. please visit official documentation website for more details.

edited Jan 15 '20 at 01:55

answered Jan 15 '20 at 01:48

Muhammad Soliman

21,644
6
109
75

I was specifying the property `SourceArn`, which I was defining incorrectly. Based on your answer, I checked the documentation and I decided to remove that property and then it started to work without any problems. I was using: `SourceArn: !Sub arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${ApiGateway}/*/POST/*"` No idea what was the problem. – Edenshaw Jul 28 '22 at 21:59
Checking the permissions on another lambda function that I linked to an API Gateway using the console: (If you go to your lambda and then got to **Configuration->Permissions->Policy Statements**) I saw that the format of the SourceARN is quite different: `arn:aws:execute-api:$AWS_REGION:$AWS_ACCOUNT:$API_ID/authorizers/$SOME_ID` the last part (SOME_ID) I don't know where that comes from or what it means, but clearly the format I was using is totally different, perhaps that was the reason of the _Invalid permissions on Lambda function_ error. – Edenshaw Jul 28 '22 at 22:14

score 17 · Answer 2 · answered Jan 07 '20 at 14:05

17

I had a similar issue - I deleted then re-installed a lambda function. My API Gateway was still pointing at the old one, so I had to go into the API Gateway and change my Resource Methods to alter the Integration Request setting to point to the new one (it may look like it's pointing to the correct one but wasn't in my case)

answered Jan 07 '20 at 14:05

Liam

5,033
2
30
39

2

I had the same case. Thank you for this note! – Df.fpm Apr 17 '20 at 12:08
1

Unfortunately that is not a valid solution as this represent an underlying bug with AWS. Also if you have a Cloudformation template you cannot modify resources into the console. – Matteo Aug 12 '20 at 01:02

score 9 · Answer 3 · answered Feb 25 '19 at 14:49

9

I was having the same issue but I was deploying through Terraform. After a suggestion from another user, I reselected my Lambda function in the Integration part of the API Gateway, and then checked what changed in my Lambda permissions. Turns out I needed to add a "*" where I was putting the stage name in the source_arn section of the API Gateway trigger in my Lambda resource. Not sure how SAM compares to Terraform but perhaps you can change the stage name or just try this troubleshooting technique that I tried.

My SO posting: AWS API Gateway and Lambda function deployed through terraform -- Execution failed due to configuration error: Invalid permissions on Lambda function

answered Feb 25 '19 at 14:49

transposeglobal

491
4
14

1

I had a similar terraform deployment error to and was able to fix it by adding in the additional permission in my terraform code. I found I had to go into the lambda function and look at the effective policy to see the difference. I discovered that with the policy has the "statement ID" it's one that was done via terraform, and when it has a GUID looking ID it's one done via the console. This helped me figure out the correct one to add. – atom88 May 20 '20 at 19:16
1

It would seem this is a bug based on this post: https://github.com/terraform-providers/terraform-provider-aws/issues/9972 – atom88 May 20 '20 at 20:31
1

Thank you sooo much for this post. I had a similar problem and was able to resolve it with the information provided in this post! – atom88 May 20 '20 at 20:32

Daniel TZ · Answer 4 · 2020-09-15T07:06:12.090

Same error, and the solution was simple: clearing and applying the "Lambda Function" mapping again in the integration setting of the API Gateway.

My mapping looks like this: MyFunction-894AR653OJX:test where "test" is the alias to point to the right version of my lambda

The problem was caused by removing the ALIAS "test" on the lambda, and recreating it on another version (after publishing). It seems that the API gateway internally still links to the `old' ALIAS instance. You would expect that the match is purely done on name...

Bonus: so, via the AWS console you cannot move that ALIAS, but you can do this via the AWS CLI, using the following command:

aws lambda --profile <YOUR_PROFILE> update-alias --function-name <FUNCTION_NAME> --name <ALIAS_NAME> --function-version <VERSION_NUMBER>

score 2 · Answer 5 · answered May 31 '20 at 08:30

2

I had the same issue. I changed the integration to mock first, i.e unsetting the integration type to Lambda, and then after one deployment, set the integration type to lambda again. It worked flawlessly thereafter.

I hope it helps.

answered May 31 '20 at 08:30

Dikshit Kathuria

1,182
12
15

score 2 · Answer 6 · answered Sep 15 '20 at 06:51

Facing the same issue, I figured out the problem is : API Gateway is not able to invoke the Lambda function as I couldn't see any CloudWatch logs for the lambda Function.

So firstly I went through API Gateway console and under the Integration Request - gave the full ARN for the Lambda Function. and it is started working.

Secondly, through the CloudFormation

x-amazon-apigateway-integration:
        credentials:
          Fn::Sub: "${ApiGatewayLambdaRole.Arn}"
        type: "aws"
        uri:
          Fn::Sub: "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${lambda_function.Arn}/invocations"

I was missing credentials and your answer helped me see that. Cheers! — rainabba, Apr 14 '21 at 23:42

score 1 · Answer 7 · answered May 21 '20 at 05:47

1

I had the same problem so I deleted then created the stack and it worked.

answered May 21 '20 at 05:47

T. Cervenka

301
1
2
11

Zambonilli · Answer 8 · 2021-07-13T02:13:35.767

1

The documentation for AWS lambda resource permissions shows 3 levels of access you can filter or wildcard, /*/*/*, which is documented as $stage/$method/$path. However, their example and most examples online only use 2 levels and I was bashing my head against the wall using 3 only to get Access Denied. I changed down to 2 levels and lambda then created the trigger. Hopefully, this will save someone from throwing their computer against the wall.

edited Jul 13 '21 at 02:13

answered Jul 13 '21 at 01:52

Zambonilli

4,358
1
18
18

This saved me hours, it looks like it's two levels like you say: `arn:partition:execute-api:region:account-id:api-id/stage/route-key` https://docs.aws.amazon.com/apigateway/latest/developerguide/arn-format-reference.html – OrderAndChaos Apr 11 '23 at 12:52

mud · Answer 9 · 2022-01-14T01:12:26.490

Looks like "Execution failed due to configuration error: Invalid permissions on Lambda function" is a catch all for multiple things :D

I deployed a stack with CloudFormation templates and hit this issue.

I was using the stage name in the SourceArn for the AWS::Lambda::Permission segment.

when i changed that to a * AWS was a bit more explicit about the cause, which in my case happened to be an invalid Handler reference (I was using Java, the handler had moved package) in the AWS::Lambda::Function section.

Also, when i hit my API GW i got this message

{
    "message": "Internal server error"
}

It was only when I was at the console and sent through the payload as a test for the resource that I got the permissions error.

If I check the Cloudwatch logs for the API GW when I configured that, it does indeed mention the true cause even when the Stage Name is explicit.

Lambda execution failed with status 200 due to customer function error: No public method named ...

score 1 · Answer 10 · answered Mar 14 '22 at 13:59

In my case, I got the error because the Lambda function had been renamed. Double-check your configuration just in case.

Technically, the error message was correct—there was no function, and therefore no permissions. A helpful message would, of course, have been useful.

atom88 · Answer 11 · 2020-05-20T20:29:02.850

I had a similar problem and was using Terraform. It needed the policy with the "POST" in it. For some reason the /*/ (wildcard) policy didn't work?

Here's the policy and the example terraform I used to solve the issue.

Many thanks to all above.

Here is what my Lambda function policy JSON looked like and the terraform:

    {
      "Version": "2012-10-17",
      "Id": "default",
      "Statement": [
        {
          "Sid": "AllowAPIGatewayInvoke",
          "Effect": "Allow",
          "Principal": {
            "Service": "apigateway.amazonaws.com"
          },
          "Action": "lambda:InvokeFunction",
          "Resource": "arn:aws:lambda:us-east-1:999999999999:function:MY-APP",
          "Condition": {
            "ArnLike": {
              "AWS:SourceArn": "arn:aws:execute-api:us-east-1:999999999999:d85kyq3jx3/test/*/MY-APP"
            }
          }
        },
        {
          "Sid": "e841fc76-c755-43b5-bd2c-53edf052cb3e",
          "Effect": "Allow",
          "Principal": {
            "Service": "apigateway.amazonaws.com"
          },
          "Action": "lambda:InvokeFunction",
          "Resource": "arn:aws:lambda:us-east-1:999999999999:function:MY-APP",
          "Condition": {
            "ArnLike": {
              "AWS:SourceArn": "arn:aws:execute-api:us-east-1:999999999999:d85kyq3jx3/*/POST/MY-APP"
            }
          }
        }
      ]
    }

    add in a terraform like this:


    //************************************************
    // allows you to read in the ARN and parse out needed info, like region, and account
    //************************************************
    data "aws_arn" "api_gw_deployment_arn" {
        arn = aws_api_gateway_deployment.MY-APP_deployment.execution_arn 
    }

    //************************************************
    // Add in this to support API GW testing in AWS Console.
    //************************************************
    resource "aws_lambda_permission" "apigw-post" {
        statement_id  = "AllowAPIGatewayInvokePOST"
        action        = "lambda:InvokeFunction"
        //function_name = aws_lambda_function.lambda-MY-APP.arn
        function_name = module.lambda.function_name
        principal     = "apigateway.amazonaws.com"

        // "arn:aws:execute-api:us-east-1:473097069755:708lig5xuc/dev/POST1/cloudability-church-ws"
        source_arn = "arn:aws:execute-api:${data.aws_arn.api_gw_deployment_arn.region}:${data.aws_arn.api_gw_deployment_arn.account}:${aws_api_gateway_deployment.MY-APP_deployment.rest_api_id}/*/POST/${var.api_gateway_root_path}"
    }

It would seem this is a bug based on this post: https://github.com/terraform-providers/terraform-provider-aws/issues/9972 — atom88, May 20 '20 at 20:31

score 0 · Answer 12 · answered Dec 15 '22 at 12:29

In my case I used Lambda path, that doesn't starts with a '/', like Path: "example/path" in my template.yaml. As a result AWS generate incorrect permission for this lambda:

{
 "ArnLike": {
  "AWS:SourceArn": "arn:aws:execute-api:{Region}:{AccountId}:{ApiId}/*/GETexample/path/*"
 }
}

So I fixed it by adding '/' to my lambda path in the template.

Execution failed due to configuration error: Invalid permissions on Lambda function

12 Answers12

Linked