How do I find the API endpoint of a lambda function? - aws-lambda

Question

I have a Lambda function that has an exposed API Gateway endpoint, and I can get the URL for that via the AWS console. However, I would like to get that URL via API call. Neither the Lambda API documentation nor the API Gateway documentation seem to have that information (or perhaps I've missed it), so is this even possible in the first place?

Answer 1

I don't really understand the above answer (maybe it's outdated?).
The absolute easiest way:
Choose "API Gateway" under "Services" in AWS.
Click on your API.
Click on "Stages".
Choose the stage you want to use
Now you can see the entire URL very visible inside a blue box on the top with the heading "Invoke URL"

Answer 2

Your API Gateway endpoint URL doesn't get exposed via an API call. However, since the URL of the API follows a certain structure, you could get all the necessary pieces and create the URI within your code.
https://API-ID.execute-api.REGION.amazonaws.com/STAGE
You could use apigateway:rest-apis to get your API-ID and restapi:stages to get the stage corresponding identifier.

Answer 3

I'm not seeing a direct answer to the OP's question (get endpoint URL using API). Here's a snippet of Python code that I hope will guide the way, even if you're using other language bindings or the CLI. Note the difference in approach for getting the internal endpoint vs getting any associated custom domain endpoints.
import boto3
apigw = boto3.client('apigateway')
def get_rest_api_internal_endpoint(api_id, stage_name, region=None):
if region is None:
region = apigw.meta.region_name
return f"https://{api_id}.execute-api.{region}.amazonaws.com/{stage_name}"
def get_rest_api_public_endpoints(api_id, stage_name):
endpoints = []
for item in apigw.get_domain_names().get('items',[]):
domain_name = item['domainName']
for mapping in apigw.get_base_path_mappings(domainName=domain_name).get('items', []):
if mapping['restApiId'] == api_id and mapping['stage'] == stage_name:
path = mapping['basePath']
endpoint = f"https://{domain_name}"
if path != "(none)":
endpoint += path
endpoints.append(endpoint)
return endpoints

Answer 4

Go to you lambda main page -> Click on "Application" [Function Overview section] -> Resource section -> LambdaAPIDefinition -> Stages tab -> [Select required stage] -> [Invoke URL] You can see the api endpoint visible.

Answer 5

Following up on #larschanders comment, if you create the gateway using CloudFormation, the endpoint URL is surfaced as one of the stack outputs.

Answer 6

If you use CloudFormation you can get this with Python and Boto3:
import boto3
cloudformation = boto3.resource('cloudformation')
stack = cloudformation.Stack(name=stack_name)
api_url = next(
output['OutputValue'] for output in stack.outputs
if output['OutputKey'] == 'EndpointURL')
This is from a working example of a REST service using Chalice that I put on GitHub. Here's a link to the pertinent code, in context: aws-doc-sdk-examples.

Answer 7

If you know the function name, you can get the apigw endpoint by fetching the policy:
aws lambda get-policy --function-name <name> \
| jq -r '.Policy | fromjson | .Statement[0].Condition.ArnLike."AWS:SourceArn"'
THen it's just a matter of extracting the api_id and construct the endpoint like Jurgen suggested

Answer 8

A Script is the only answer as of now
But if someone wants to do purely on CLI using commands here is the long way (though I am a very beginner in AWS and I tried this during learning Lambda basics), maybe there is a much better way...
The format of Invoke-URL of the endpoint is something like this
https://YOUR-REST-API-ID.execute-api.REGION.amazonaws.com/STAGE/RESOURCE
// get YOUR-REST-API-ID e.g., 0w12zl28di
aws apigateway get-rest-apis | jq -r '.items[] | [.id, .name] | #tsv'
// get REGION using Lambda_function_name e.g., ap-east-1
aws lambda get-function-configuration --function-name YOUR_LAMBDA_FUNCTION_NAME | jq '.FunctionArn | split(":")[3]'
// get STAGE e.g., dev
aws apigateway get-stages --rest-api-id YOUR-REST-API-ID | jq -r '.item[] | [.stageName] | #tsv'
// get RESOURCE e.g., users
aws apigateway get-resources --rest-api-id YOUR-REST-API-ID | jq '.items[] | [.id, .path]'
// finally put your pieces in this way
https://0w12zl28di.execute-api.ap-east-1.amazonaws.com/dev/users
Note you have to install jq parser (if you don't have it already)
https://stedolan.github.io/jq/download/
I was using Linux on top of Windows, so I need to do it in this way
curl -L -o /usr/bin/jq.exe https://github.com/stedolan/jq/releases/latest/download/jq-win64.exe

Answer 9

To very precise Go to AWS Console search :
Lambda under services
Search the Function name which are looking for.
In Function overview, you will find API GATEWAY (Click on this)
Under API GATEWAY, click on Details (down arrow)
Under Details, you will find all the details like
API endpoint :
API type :
Authorization :
Method :
Resource path :
Stage :