I already had an API Gateway API as the trigger for my AWS Lambda function. However when I tried to add another API as a trigger to the same AWS Lambda, it threw an error saying that
There was an error creating the trigger: An integration is already present on this method.
Even when I delete the trigger already present from the configuration window of Lambda, it still shows that the trigger is present.
How can I add multiple API Gateway APIs as triggers for the same lambda function ?
You can setup it via API Gateway console.
Create the Lambda function via Lambda without providing a trigger
Go to API Gateway Console
Create an API.
Create a resource and method
Select the Lambda function you want to trigger by the method
Create an other API/method
Select the Lambda function you want to trigger by the method
Since you are creating the trigger/integration via API Gateway Console, API Gateway will setup the proper permission to allow API Gateway to invoke your Lambda function on multiple APIs/methods.
In the API Gateway, we cannot make entries with the same resource name. When you have created a trigger it's already created and again you are trying to create another one. So we have to clear the previous one and then try again or else we can update it going into the API Gateway interface.
Related
I have an AWS Lambda function that takes in and processes logs from CloudWatch Logs that are sent to specific log groups. The thing is, I may need to add more triggers as more log groups are created. The only way I have found to create a trigger for a specific log group is to use the AWS Lambda console and the AWS CloudFront console. Is it possible to create a trigger for an AWS Lambda function programmatically? For instance, in some Java code?
Yes, one of the common ways of triggering server-less functions is using endpoints. I believe you can expose an API endpoint from the Function's console using a an API Gateway, and call this endpoint URL from your java code or whatever programmatic entity you wish.
I have a lambda function exposed via API gateway but when I try to request it using fetch it is saying that I am forbidden to access it. How do I allow my function to call another function via API gateway?
There can be multiple reasons for it.
Check whether your API gateway endpoint is open or not. While specifying trigger for lambda you must have selected one option for security. You can edit this in API gateway Method Execution tab under Authorization Settings, select Authorization : None and API key required: false
You might not have enabled CORS on your api and due to that your api is not available on cross regions.
Your api gateway is not having access to lambda function. You can do that by attaching IAM role to your API gateway API which can trigger your lambda function.
I am using Strong loop in AWS Lambda and i want to trigger it somehow. The only available option right now is APi Gateway. Is there a way to create one resource and pass all its requests to single lambda function?
I want to achieve something like this
/api/* --> Lambda Function
Does AWS support this?
This is supported by API gateway proxy resource. You can create a special path parameter {proxy+} which represents any child resource of a parent API. The ANY method can be used to catch all http methods on that resource.
In your case, you need to create an api resource /api and under that, create a new proxy resource {proxy+}. If you are creating it through the AWS console, you just have to check the check box for the option Configure as proxy resource while creating the resource. When you get to the integration setup, select Lambda Function Proxy as your integration type, choose the region and select the lambda function you want to invoke.
This is described in detail in the API gateway docs here.
I have been putting together and deploying Lambda functions using Apex and the functions, where I have been using GET method through AWS API Gateway are working fine.
I now need to create an API to call into a Lambda function using POST and pass in a JSON object. To get the basics of POST working I created a simple Lambda function that just does the following
console.log("!!!!!!! Received request");
callback(null, {data: "Success"});
return;
When I call this Lambda function using a GET method from API Gateway and test the API, it works fine - the API Gateway Test mechanism gives the "success" message while "Received Request" is logged in a successful call in CloudWatch.
However when I use the POST request to call the same Lambda function from API Gateway I get the following
"message": "Internal server error"
And I also see "Execution failed due to configuration error: Invalid permissions on Lambda function"
So what I am wondering is whether the role by which Lambda functions are called require any additional privileges when that function is invoked through a POST method. If so what is that privilege that I need to assign to the role being used?
Thanks,
Sanjay.
If you want to call POST method through API gateway level, that post method you have to deploy. Go to AWS API Gateway console. then select your POST API name and on the top of the grid (screen) you will find a drop down called Actions, there one option called deploy. That you have to select then only your POST API will work.
API Gateway needs permissions to invoke your Lambda function. It prompts you to add the permission automatically if you configure your API via the web console, and the Lambda function is not specified with a stage variable.
So if you're using a tool like CloudFormation or Swagger import to create or update your APIs, or the Lambda function is specified with a stage variable, you'll need issue a aws lambda add-permission command manually to set the permission.
See these posts for more details:
Lambda function -> Api Gateway stage variable permission manually
AWS API Gatewat with proxy Lambda: Invalid permissions on Lambda function
I have a lambda function that I'd like to trigger via HTTP request.
When I click add trigger to a lambda function, I get an API Gateway API set up with:
method: ANY
Great. Now, when viewing this lambda function, I see a trigger has been configured.
However, I would like to restrict the trigger to only allow POST requests.
So I deleted the API Gateway method ANY, and created a new method POST, under the same resource, using an integration type of Lambda Function. I select my region, and sure enough, my existing lambda function is autocompleted.
However, when I view the triggers tab on the lambda function itself, it shows that there are no triggers.
What am I missing?
If you need flexible control of the API, I would suggest to use the API Gateway console to mange your API. Lambda triggers should only be used for simple use-cases - API methods configured through API Gateway will not show up in the Lambda triggers list.