vert-x-client.java

README.md

Create a new function:

faas-cli new --lang  java11-vert-x \
  github-release-finder

Replace handler.java

Now run faas-cli up -f github-release-finder.yml

Invoke the function to find the latest release URL for a project on GitHub, without incurring API token rate limiting.

curl -i -d "" http://127.0.0.1:8080/function/github-release-finder; echo
HTTP/1.1 200 OK
Content-Length: 79
Content-Type: application/x-www-form-urlencoded
Date: Wed, 29 Jan 2020 16:15:46 GMT
X-Call-Id: fcf571d2-5b3f-481b-973a-fa19fbf27142
X-Duration-Seconds: 1.075316
X-Start-Time: 1580314545314634425

{
  "releaseUrl" : "https://github.com/openfaas/faas-cli/releases/tag/0.11.7"
}

stack.yml

version: 1.0
provider:
  name: openfaas
  gateway: http://127.0.0.1:8080

functions:
  vtest:
    lang: java11-vert-x
    handler: ./github-release-finder
    image: alexellis2/github-release-finder:0.5.3
    environment:
      owner: openfaas
      repo: faas-cli

vert-x-client.java

package com.openfaas.function;

import io.vertx.core.http.HttpServerResponse;
import io.vertx.ext.web.RoutingContext;
import io.vertx.ext.web.handler.BodyHandler;
import io.vertx.core.json.JsonObject;

import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.http.HttpClientOptions;
import io.vertx.ext.web.client.HttpResponse;
import io.vertx.ext.web.client.HttpRequest;
import io.vertx.ext.web.client.WebClient;
import io.vertx.ext.web.client.WebClientOptions;


public class Handler implements BodyHandler {

  @Override
  public void handle(RoutingContext routingContext) {

    WebClientOptions options = new WebClientOptions();
    options.setFollowRedirects(false);

    WebClient client = WebClient.create(routingContext.vertx(), options);

    String repo = System.getenv("repo");
    String owner = System.getenv("owner");

    client
      .head(443, "github.com", "/"+owner+"/"+repo+"/releases/latest")
      .ssl(true)
      .send(ar -> {
        if (ar.succeeded()) {
          HttpResponse<Buffer> response = ar.result();

          System.out.println("Received response with status code " + response.statusCode());
          String location = response.getHeader("Location");

          routingContext.response()
          .putHeader("content-type", "application/json;charset=UTF-8")
          .end(
            new JsonObject()
              .put("releaseUrl", location)
              .encodePrettily()
          );

        } else {
          System.out.println("Something went wrong " + ar.cause().getMessage());

          routingContext.response()
          .putHeader("content-type", "application/json;charset=UTF-8")
          .end(
            new JsonObject()
              .put("releaseUrl", "")
              .encodePrettily()
          );

        }
      });
  }

  @Override
  public BodyHandler setBodyLimit(long bodyLimit) {
    return null;
  }

  @Override
  public BodyHandler setUploadsDirectory(String uploadsDirectory) {
    return null;
  }

  @Override
  public BodyHandler setMergeFormAttributes(boolean mergeFormAttributes) {
    return null;
  }

  @Override
  public BodyHandler setDeleteUploadedFilesOnEnd(boolean deleteUploadedFilesOnEnd) {
    return null;
  }
}