Swagger with strip_prefixes

[paulorangeljr]

Hi there.

I have a lambda function with I have enabled swagger for the Api

app = APIGatewayHttpResolver(strip_prefixes=["/api/v1"],enable_validation=True)
app.enable_swagger(path="/swagger")

and I have a endpoint like this

@router.get("/databases")

The problem is that on the swagger page it does not add the prefix /api/v1 to the endpoint addresses. Is there something that I'm missing?

[leandrodamascena]

Olá @paulorangeljr, tudo bem?!

The problem is that on the swagger page it does not add the prefix /api/v1 to the endpoint addresses. Is there something that I'm missing?

Can you explain to me a little bit what you're doing here? Are you using custom domains with this prefix as path or are you expecting us to add this prefix? Sorry, but I got a little confused here.

[paulorangeljr]

@leandrodamascena

In reality, I'm not using Custom Domain, but instead I'm adding to every endpoint this prefix. Code

app = APIGatewayHttpResolver(strip_prefixes=["/api/v1"],enable_validation=True)
app.enable_swagger(path="/swagger')
app.include_router(catalog_route.router, prefix="/catalog")
app.include_router(contract_route.router, prefix="/contract")
app.include_router(dataquality_route.router, prefix="/dataquality")
app.include_router(lineage_route.router, prefix="/lineage")
app.include_router(jobstats_route.router, prefix="/jobstats")

With this my endpoint is something like this

catalog_route.py
@router.get("/databases",
summary='Databases In Lake',
description='Get all databases in the data lake',
response_description='Database List',
},
tags=['CATALOG'],
)
def handle_catalog_routes():
logger.info("Getting all databases in the data lake")
try:
databases = wrap_glue_databases()
return DatabaseOutputResponse(**databases.model_dump())
except Exception as e:
logger.error(f"Error in getting databases in the data lake. Stacktrace: {e}")
return {"error": str(e)}, 501

with this my endpoint is like this

https://api-id.execute-api.region.amazonaws.com/stage/api/v1/catalog/databases

The problem is that on swagger it considers that my endpoint is
https://api-id.execute-api.region.amazonaws.com/stage/catalog/databases

It does not add the prefix

[leandrodamascena]

Thanks for adding more details @paulorangeljr.

I will break down your code and explain what Powertools is doing and the result.

app = APIGatewayHttpResolver(strip_prefixes=["/api/v1"],enable_validation=True)
app.enable_swagger(path="/swagger')
app.include_router(catalog_route.router, prefix="/catalog")
app.include_router(contract_route.router, prefix="/contract")
app.include_router(dataquality_route.router, prefix="/dataquality")
app.include_router(lineage_route.router, prefix="/lineage")
app.include_router(jobstats_route.router, prefix="/jobstats")

In this code block, Powertools is stripping the /api/v1 prefix from the path (a key from the event) that APIGW is sending to Lambda. This is used when you have a custom domain and you need to map the domain with a path, so, APIGW will inject this prefix in the path. Powertools will not add the strip_prefixes value to all routes, but will only strip it when trying to resolve the route against the APIGW event.

@router.get("/databases",
        summary='Databases In Lake',
        description='Get all databases in the data lake',
        response_description='Database List',
        tags=['CATALOG'],
)
app.include_router(router=router,prefix="/catalog")

Here you are defining a GET /databases, but since you are injecting a prefix (/catalog) into this route, Powertools will resolve this route when it receives a request for /catalog/databases and not for /api/v1/catalog/databases because strip_prefixes does not inject a prefix, but stripes instead.

Based on the code you sent, you are getting the expected result. But considering that I may not have fully understood the problem here, I see that you can make two modifications to have the endpoints:

1 - Add the prefix "/api/v1" when including the route
2 - Modify the enable_swagger to consider that the server will start with the url "/api/v1"

from aws_lambda_powertools.event_handler.openapi.models import Server

app = APIGatewayRestResolver(strip_prefixes=["/api/v1"], enable_validation=True)
app.enable_swagger(path="/swagger", servers=[Server(url="/api/v1")])

Please let me know if I missed something and if I can help further to solve your case.

[paulorangeljr]

Thanks @leandrodamascena

you got it. The strip prefix was used as a default route prefix. So on every endpoint on apigw I’ve added that.

And what you sent about swagger it worked

[leandrodamascena]

I'm glad to hear that @paulorangeljr! please let me know if you need any additional help.