Fixes issue #255: Can't access HTTP request body in java11-vert-x template.

[p-fortier]

Signed-off-by: Patrik Fortier patrik.fortier@insa-lyon.fr

Description

Added a io.vertx.ext.web.handler.BodyHandler instance to the handlers to populate routingContext with the HTTP request body.

Motivation and Context

• I have raised an issue to propose this change (required)

Which issue(s) this PR fixes

Fixes #255

How Has This Been Tested?

I deployed a function reading the http request body using the modified

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Version change (see: Impact to existing users)

Impact to existing users

Adds one handler to the router. According to vertx documentation, the overhead is negligible.

Checklist:

• My code follows the code style of this project.
  • Maybe a separation is required between my modification and the static handler bloc.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.
  • I did not run the verify.sh script

[alexellis]

How Has This Been Tested?
I deployed a function reading the http request body using the modified

Could you share testing instructions please? I'd like to try it.

Before:

faas-cli template pull ...
faas-cli new --...
faas-cli up ...
faas-cli invoke

After:

faas-cli template pull ...
faas-cli new --...
faas-cli up ...
faas-cli invoke

[akshatdev0]

Tried this change. And it works.

[alexellis]

Sorry I wasn't clear.

How Has This Been Tested? <- I'd like the output from the above.

Thanks

[p-fortier]

Hi, sorry I didn't follow this right away. I took time to make a small example.
Source code is available at https://github.com/p-fortier/try-fix but the idea is described below:

Before:

faas-cli template pull 
faas-cli new --lang java11-vert-x tryout

The handler for the project should look something like this. This simply returns the request body sent:

  public void handle(RoutingContext routingContext) {
    routingContext.response()
      .putHeader("content-type", "application/json;charset=UTF-8")
      .end(
              routingContext.getBodyAsString()
      );
  }

Calling the function

faas-cli up -f tryout.yml -g $OPENFAAS_URL
echo "hello" | faas-cli invoke tryout -g $OPENFAAS_URL
->  Server returned unexpected status code: 500 - Internal Server Error

Logs show something like this:

tryout-5f76f98558-5hkhn:2021/05/02 14:51:53 stderr: SEVERE: Unexpected exception in route                                                                  
tryout-5f76f98558-5hkhn:2021/05/02 14:51:53 stderr: java.lang.NullPointerException
...
tryout-5f76f98558-5hkhn:2021/05/02 14:51:53 POST / - 500 Internal Server Error - ContentLength: 21

Applying fix

rm -r template/java11-vert-x
faas template pull https://github.com/p-fortier/templates#f255 #This should take the fixed template 
faas-cli up -f tryout.yml -g $OPENFAAS_URL
echo "hello" | faas-cli invoke tryout -g $OPENFAAS_URL
--> hello

[alexellis]

Hi @p-fortier this dropped off my radar.

It seems important to be able to access the request body and I wasn't aware that this was not possible with the template!

@pmlopes pinged me about this, so I think we should consider revisiting this.

Thanks for adding context.

[alexellis]

Please see also #282 - let me know your thoughts on that one.

[alexellis]

@pmlopes can this be merged in your opinion?

[pmlopes]

Yes, this will always parse the request body. For security or latency reasons not everyone might want/need it, but is a quick solution. In the refered issue about upgrading the template we shall address this in a user defined way.

[alexellis]

What do you mean "parse"?

Is there a way to get the RAW body without this change?

[pmlopes]

Yes you can get the raw body, by replicating what the BodyHandler is doing, on the request object, add a handler that will receive the chunks of the HTTP body and either assemble a full buffer or process it as a stream.

The body handler does a bit more, it handles, http body, form uploads, ensures that files are discarded, limits the size to avoid DoS, etc...