💝 Event receiver & stream via Server-Sent Events (#11)

* Events endpoint PoC

* Workaround for quarkusio/quarkus#31587 and cloudevents/sdk-java#533

* Better workaround, thx @pierDipi

for quarkusio/quarkus#31587 and cloudevents/sdk-java#533

* Development data

* Proper streaming of events SSE

* Frontend in React PoC

* Event stream using u-cloudevents

* Quarkus backend uses the React frontend

* Express app uses the React frontend

* Tests for Express's event receiver

* GH Actions Testing

* Container build fix

* Remove pre-build Containerfiles

* Self-review fixes

* Tests for Quarkus event receiver

* README format and npm install instructions

.containerignore

@@ -0,0 +1,9 @@
+**/node_modules
+**/deployment
+**/target/**
+!**/target/*-runner
+!**/target/quarkus-app/**
+**/.idea/**
+**/*.iml
+**/.mvn/wrapper/maven-wrapper.jar
+**/.git-versioned-pom.xml

.editorconfig

@@ -10,3 +10,6 @@ insert_final_newline = true
 charset = utf-8
 indent_style = space
 indent_size = 2
+
+[{*.go,Makefile}]
+indent_style = tab

.github/workflows/container-build.yaml

@@ -1,5 +1,5 @@
 ---
-name: Container build
+name: Container
 
 on:
   schedule:
@@ -19,6 +19,7 @@ env:
 
 jobs:
   build-image:
+    name: Build Image
     runs-on: ubuntu-22.04
     strategy:
       matrix:
@@ -41,38 +42,23 @@ jobs:
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v2
 
-      - uses: actions/setup-node@v3
-        with:
-          node-version: ${{ env.NODE_VERSION }}
-
       - name: Prepare
         id: prep
         run: .github/workflows/prepare.sh
         env:
           KIND: ${{ matrix.kind }}
           APP: ${{ matrix.app }}
 
-      - name: Pre-build artifacts using Containerfile
+      - name: Build frontend
         uses: redhat-actions/buildah-build@v2
-        if: ${{ steps.prep.outputs.pre_build == 'containerfile' }}
         with:
-          image: builder
+          image: localhost/openshift-knative/frontend
           tags: ${{ github.sha }}
-          containerfiles: ${{ steps.prep.outputs.containerfile_prebuild }}
-          platforms: linux/amd64
-          context: ${{ matrix.app }}
+          containerfiles: frontend/deployment/Containerfile
+          platforms: ${{ steps.prep.outputs.platforms }}
+          build-args: CONTEXT_DIR=./frontend/
           extra-args: --ulimit nofile=51200:51200
 
-      - name: Extract build artifacts from OCI image
-        if: ${{ steps.prep.outputs.pre_build == 'containerfile' }}
-        run: ../.github/workflows/extract.sh localhost/builder:${{ github.sha }}
-        working-directory: ${{ matrix.app }}
-
-      - name: Pre-build with language tools
-        if: ${{ steps.prep.outputs.pre_build == 'native' }}
-        run: ../.github/workflows/pre-build/${{ matrix.app }}.sh
-        working-directory: ${{ matrix.app }}
-
       - name: Build the multi-arch image
         id: build-image
         uses: redhat-actions/buildah-build@v2
@@ -81,7 +67,10 @@ jobs:
           containerfiles: ${{ steps.prep.outputs.containerfile }}
           tags: ${{ steps.prep.outputs.tags }}
           platforms: ${{ steps.prep.outputs.platforms }}
-          context: ${{ matrix.app }}
+          build-args: |
+            CONTEXT_DIR=./${{ matrix.app }}/
+            APP_VERSION=${{ github.sha }}
+          extra-args: --ulimit nofile=51200:51200
           labels: |
             org.opencontainers.image.title=${{ github.event.repository.name }}
             org.opencontainers.image.description=${{ github.event.repository.description }}

.github/workflows/prepare.sh

@@ -4,12 +4,11 @@ set -Eeuo pipefail
 
 GITHUB_EVENT_NAME="${GITHUB_EVENT_NAME:?Missing event name}"
 
-PRE_BUILD=containerfile
 PLATFORMS=linux/amd64,linux/ppc64le,linux/s390x
 VERSION=noop
 PUSH=true
-CONTAINERFILE="${APP}/src/main/container/${KIND}/Containerfile"
-CONTAINERFILE_PREBUILD="${APP}/src/main/container/${KIND}/build.Containerfile"
+CONTAINERFILE="${APP}/deployment/${KIND}/Containerfile"
+
 if [ "${GITHUB_EVENT_NAME}" = "schedule" ]; then
   VERSION=nightly
 elif [[ "$GITHUB_REF" == refs/tags/* ]]; then
@@ -29,15 +28,11 @@ if [[ "${KIND}" == *"native"* ]]; then
   VERSION="${VERSION}-native"
   PLATFORMS=linux/amd64
 fi
-if [[ "${KIND}" == *"standalone"* ]]; then
-  PRE_BUILD=false
-fi
 if [[ "${APP}" == 'expressjs' ]]; then
   VERSION="js-${VERSION}"
   if [[ "${VERSION}" == 'js-latest' ]]; then
     VERSION="${VERSION} js"
   fi
-  PRE_BUILD=native
   CONTAINERFILE="${APP}/deployment/Containerfile"
 fi
 TAGS="${VERSION}"
@@ -47,8 +42,6 @@ TAGS="${VERSION}"
   echo "tags=${TAGS}"
   echo "created=$(date -u +'%Y-%m-%dT%H:%M:%SZ')"
   echo "platforms=${PLATFORMS}"
-  echo "pre_build=${PRE_BUILD}"
   echo "push=${PUSH}"
   echo "containerfile=${CONTAINERFILE}"
-  echo "containerfile_prebuild=${CONTAINERFILE_PREBUILD}"
 } >> "$GITHUB_OUTPUT"

.github/workflows/test.yaml

@@ -1,6 +1,6 @@
 ---
 
-name: Validate & Test
+name: Tests
 
 on:
   push:
@@ -18,8 +18,8 @@ env:
   JDK_DISTRO: adopt
 
 jobs:
-  lint-expressjs:
-    name: Lint Express app
+  expressjs:
+    name: Express backend
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
@@ -29,56 +29,29 @@ jobs:
         with:
           node-version: ${{ env.NODE_VERSION }}
 
-      - name: Install dependencies
-        working-directory: expressjs
-        run: npm install
-
-      - name: Run Lints
-        working-directory: expressjs
-        run: npm run lint
+      - name: Test
+        run: make expressjs
         env:
           FORCE_COLOR: 1
 
-  test-expressjs:
-    name: Tests Express app
-    needs:
-     - lint-expressjs
+  quarkus:
+    name: Quarkus backend
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0 # fetch all branches and tags
+
       - uses: actions/setup-node@v3
         with:
-          node-version: ${{ env.NODE_VERSION }}
-
-      - name: Install dependencies
-        working-directory: expressjs
-        run: npm install
-
-      - name: Run Tests
-        working-directory: expressjs
-        run: npm test
-        env:
-          FORCE_COLOR: 1
+          node-version: ${{ env.NODE_VERSION }}          
 
-  test-quarkus:
-    name: Tests Quarkus app
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0 # fetch all branches and tags
       - uses: actions/setup-java@v3
         with:
           distribution: ${{ env.JDK_DISTRO }}
           java-version: ${{ env.JDK_VERSION }}
 
       - name: Run Tests
-        working-directory: quarkus
-        run: |
-          ./mvnw -V --no-transfer-progress -Dmaven.artifact.threads=50 \
-            clean dependency:go-offline
-          ./mvnw -V --no-transfer-progress verify -Pnative
+        run: make quarkus
         env:
           FORCE_COLOR: 1

Makefile

@@ -0,0 +1,23 @@
+default: expressjs quarkus
+
+frontend:
+	+$(MAKE) -C frontend
+
+frontend.clean:
+	+$(MAKE) -C frontend clean
+
+expressjs:
+	+$(MAKE) -C expressjs
+
+expressjs.clean:
+	+$(MAKE) -C expressjs clean
+
+quarkus:
+	+$(MAKE) -C quarkus
+
+quarkus.clean:
+	+$(MAKE) -C quarkus clean
+
+clean: frontend.clean expressjs.clean quarkus.clean
+
+.PHONY: default frontend expressjs quarkus clean frontend.clean expressjs.clean quarkus.clean

README.md

@@ -6,6 +6,15 @@ Express.JS frameworks.
 
 ## Features
 
+The features below are there for two basic reasons. First reason is to showcase
+some of the features of the Knative (like scaling, traffic shaping, or event
+sending and receiving). The other group is to showcase some basic features
+almost every production ready application deployed on Kubernetes should have.
+The non-functional features were added, so the apps be close to the real world 
+apps, and could serve as a reference for developers.
+
+### Knative related features
+
 * [x] Supports the `PORT` env
 
   ```bash
@@ -14,19 +23,6 @@ Express.JS frameworks.
   http :$PORT
   ```
 
-* [x] `/`
-
-  ```bash
-  http :8080 user-agent:Mozilla/5.0
-  # returns a nice hello page when called from Browser
-
-  http :8080
-  # returns a JSON with app's coordinates when called from command line
-
-  http options :8080
-  # returns a JSON with app's coordinates
-  ```  
-
 * [x] `/hello`
 
   ```bash
@@ -37,6 +33,36 @@ Express.JS frameworks.
   operational delay can be enforced by using `DELAY` (in msec) environmental
   variable.
 
+* [x] `/events`
+
+  ```bash
+  http :8080/events
+  ```
+  Returns a stream of Server-Sent Events, where each event is a CloudEvent 
+  represented in structured JSON format. This stream will continue to send next
+  events if they come.
+
+  ```bash
+  kn event send --field a.b=true --to-url http://localhost:8080/events
+  ```
+  You can send events to the app, by `POST /events` endpoint. Those events will
+  be stored in ephemeral im-memory storage and send to the listening clients.
+
+### Openshift Serverless related features
+
+* [x] `/` home page ready for Web, and CLI
+
+  ```bash
+  http :8080 user-agent:Mozilla/5.0
+  # returns a React app when called from Browser,
+  # together with browser for captured CloudEvents
+
+  http :8080
+  # returns a JSON with app's coordinates when called from command line
+  ```  
+
+### Supporting features
+
 * [x] K8s readyness and liveness probes
 
   ```bash
@@ -58,3 +84,24 @@ Express.JS frameworks.
   ```
 * [x] Input validation (validation by OpenAPI schema)
 * [ ] Distributed Tracing
+
+## Architecture
+
+We've prepared two backend implementations of the above feature. First one is 
+implemented in Red Hat build of Quarkus framework and live in the `quarkus`
+directory. The second backend has been implemented in Express.JS, runs on Node,
+and lives in `expressjs` directory. Both of those backend are using single 
+frontend, written in React framework, in Typescript.
+
+```
+├── quarkus/     # Quarkus backend
+├── expressjs/   # Express.JS backend
+├── frontend/    # React frontend
+└── Makefile     # Main make file
+```
+
+The frontend application builds static Web files. They are packaged as
+[Webjar](https://www.webjars.org/documentation) in the user's Maven repository
+(`~/.m2/repository`). Thanks to that the Quarkus application is able to use
+those static files directly. The express backend needs to extract those webjar
+files.

expressjs/.dockerignore → expressjs/.containerignore

@@ -1,4 +1,2 @@
 node_modules/
-.git
 deployment/
-test/

expressjs/.eslintignore

@@ -0,0 +1,2 @@
+build/
+public/

expressjs/.gitignore

@@ -1,3 +1,4 @@
 node_modules/
 build/
+public/
 npm-debug.log