JarCastingkqr-pay
Sample serverless QR payment system using Knative and Camel-K.
Application Architecture
QR (quick response) codes are increasing in popularity for a variety of use cases, from loyaty programs to complete cashless payment systems, which is what we will simulate on this tutorial as a sample serverless application.
There are 4 services as part of this architecture:
- An in-store Kiosk: The in-store service that generates a QR code when a customer hit a Payment button after scanning all products. It can be scanned to process the payment.
- A Web/Mobile Store App: A web application that can be used from a mobile device or web broswer. A customer would have her credit card on file and after scanning the QR code the system process the payment using that information. Once payment is processed another backend service would notify the in-store Kiosk of the event.
- The Camel-Rourter: This component will receive a request from the Store application and decide which items to be backfilled in SalesForce or directly processed by the Payment Service.
- Payment Service: A web service that process credit card payments using a third-party company. In this example we are using Stripe.
The serverless aspects of the application allow for the system to auto-scale based on store demand like during peak hours or scale down during hours of less store traffic.
Requirements
- An OpenShift 4 cluster with:
- Knative v0.7+
- Tekton v0.6+
- Istio and Kiali
kn,s2ianddockeron the development environment.
Setup
Let's start by creating one of the services using kn - Which is the official Knative CLI, still in early stages and under development. At the time I'm writing this there are no released builds for kn yet, so you will have to build one manually following these instructions.
Once you have a kn binary in your $PATH proceed to the next steps.
Building the applications
Skip this step if you just want to recreate/run the demo.
Quick build
Run ./build.sh
Build Kiosk QR encoder
We are going to use s2i tool to build the application and produce a container without creating a Dockerfile.
s2i build qr-encode centos/python-36-centos7 markito/qr-encode:v1
Push the image to a container registry. For example: docker push markito/qr-encode:v1 or use the internal container registry in OpenShift. For details on that check this blog post.
Build Kiosk QR reader
Build the application using docker build, assuming a user would then need to create a specific Dockerfile describing some dependencies for the application.
docker build qr-decode/ -t markito/qr-decode:v1
Push the image to a container registry. For example: docker push markito/qr-decode:v1
Deploy the aplications as serverless services in Knative
Create the kiosk-encoder service:
kn service create kiosk-encoder --image markito/qr-encode:v1 -n markito
Hit the endpoint ("kiosk-encoder/encode") to test using curl or a browser. To obtain the URL for the service use kn service get and use the value from the domain column.
Create the kiosk-decoder service:
kn service create kiosk-decoder --image markito/qr-decode:v1 -n markito
Bonus: Add some load to the system
In order to show how auto-scale works, you can add some load to the cluster using a tool like wrk. There is a shell script under the qr-encode project that can be used to cause some load for 30s.
wrk -t10 -c10 -d30s http://kiosk-encoder.markito.apps.openshift.codeready.cloud/encode
Use the Openshift console to visualize pods coming up and down or monitor the live traffic using Kiali.
Bonus: Create the Quarkus version of the kiosk-decoder
Create a new Knative service and deploy a Quarkus based application. If you cloned this repository the source code for this app is under the quarkus folder.
Build a container for the Quarkus application
To build the Quarkus version of the kiosk application, use the plugin integrated with Maven that allows for a streamlined experience to produce containers. From the quarkus-kiosk directory you can execute:
-
Build the application
./mvnw package -Dnative-image.docker-build=true -
Build the container image using the JVM profile
docker build -f src/main/docker/Dockerfile.jvm -t markito/quarkus-decoder:v1 .
Create the quarkus-decoder service
kn service create quarkus-qrdecoder --image markito/quarkus-decoder:v1 -n markito
This will create a new Knative service and since we have a single revision available it will receive 100% of the traffic.
Now let's modify something in our application, like the background color of the landing page, then build and deploy a new version of the service.
docker build -f src/main/docker/Dockerfile.jvm -t markito/quarkus-decoder:v2 .
PS: Note the use of v2 as part of the tag.
Then create a new revision of the service:
kn service update quarkus-qrdecoder --image markito/quarkus-decoder:v2 -n markito
List the revisions available for a given service with kn revision list:
kn revision list -s quarkus-qrdecoder
NAME SERVICE GENERATION AGE CONDITIONS READY REASON
quarkus-qrdecoder-dnhlx-3 quarkus-qrdecoder 2 46m 3 OK / 4 True
quarkus-qrdecoder-gwbgs-1 quarkus-qrdecoder 1 6h41m 3 OK / 4 True
Now using the name of these revisions let's peform some A/B testing and give them 50% of traffic each.
kn service update quarkus-qrdecoder --traffic quarkus-qrdecoder-gwbgs-1=50,quarkus-qrdecoder-dnhlx-3=50
Please note that the revision names might differ on your environment.
Observe the traffic going to the different versions of the service using Kiali or by accessing the service URL. -->
Running the demo
Quick run
Run ./deploy.sh
Container images
For reference, here are all the container images being used:
- markito/kiosk:v1
- markito/payment-service:v1
- markito/store-app:v1
Create Kiosk Service (Generate QR Codes)
kn service create kiosk --image=markito/kiosk:v1 --requests-memory=100Mi --concurrency-limit=1
Test by accessing: http://kiosk.<namespace>.apps.<ocp-host>/?productIds=[1,2,3,4]&amount=5000
Payment Service (Process payment using Stripe)
kn service create payment-service --image=markito/payment-service:v1 --requests-memory=100Mi --concurrency-limit=1
Create Store App (Web or Mobile app that process QR codes)
kn service create store-app --force --image=markito/store-app:v1 --requests-memory=300Mi --concurrency-limit=10 --env PAYMENT_SERVICE="http://payment-service.rhte-live.apps.rhte19.markito.org/"
Autoscaling
wrk -t10 -c10 -d30s http://kiosk.rhte-live.apps.rhte19.markito.org/\?productIds\=\[1,2,3,4\]\&amount\=5000
Adding Camel-K
Requirements:
- Download kamel CLI from https://github.com/apache/camel-k/releases
- OpenShift 4.x
- Knative 0.7+
Installation
Perform the installation on the namespace you want the Knative services running. . From camel-k/camel-k-router folder.
kamel install --wait
oc replace --force -f src/main/resources/camel-k-builder.yaml
oc create secret generic salesforce --from-file= src/main/resources/application.properties
⚠️ Warning:src/main/resources/application.propertiesis a skeleton, you need to add your own salesforce credentials and ... don't push it to github ;)
⚠️ Notice: The output when you replce resources should be like:oc replace --force -f src/main/resources/>camel-k-builder.yaml role.rbac.authorization.k8s.io >"camel-k-builder" deleted role.rbac.authorization.k8s.io/>camel-k-builder replaced
To check that the patch is applied successfully, check the camel-k-builder role that should contains something like:
- apiGroups:
- ""
resources:
- events
- configmaps
verbs:
- get
- list
- watch
The role installed by default does not list configmaps among the resources.
Running the Camel Route & Knative Services
kamel run -t gc.enabled=false --dev src/main/groovy/payment-service.groovy
kamel run -t gc.enabled=false --dev src/main/groovy/request-router.groovy --dependency=mvn:com.github.lburgazzoli/camel-k-kqr-pay-support/1.0.0 --secret=salesforce
Automating the build and deployment steps with a Tekton pipeline
TBD.
Useful alias commands used in live demos
alias kn-kiosk='echo "kn service create kiosk --image=markito/kiosk:v1 --requests-memory=100Mi --concurrency-limit=1"; kn service create kiosk --image=markito/kiosk:v1 --requests-memory=100Mi --concurrency-limit=1'
alias kn-payment='echo "kn service create payment-service --image=markito/payment-service:v1 --requests-memory=100Mi --concurrency-limit=1"; kn service create payment-service --image=markito/payment-service:v1 --requests-memory=100Mi --concurrency-limit=1'
alias kn-store='echo "kn service create store-app --force --image=markito/store-app:v1 --requests-memory=300Mi --concurrency-limit=10 --env PAYMENT_SERVICE=http://request-router.namespace.cluster-url"; kn service create store-app --force --image=markito/store-app:v1 --requests-memory=300Mi --concurrency-limit=10 --env PAYMENT_SERVICE="http://request-router.namespace.cluster-url"'
alias kamel-router='echo "kamel run -t gc.enabled=false --dev src/main/groovy/request-router.groovy --dependency=mvn:com.github.lburgazzoli/camel-k-kqr-pay-support/1.0.0 --secret=salesforce"; kamel run -t gc.enabled=false --dev src/main/groovy/request-router.groovy --dependency=mvn:com.github.lburgazzoli/camel-k-kqr-pay-support/1.0.0 --secret=salesforce'
alias kn-load='echo "wrk -t10 -c10 -d30s http://kiosk.namespace.cluster-url/\?productIds\=\[1,2,3,4\]\&amount\=5000"; wrk -t10 -c10 -d30s http://kiosk.namespace.cluster-url/\?productIds\=\[1,2,3,4\]\&amount\=5000'