Workflow Demo using Temporal.io (Spring Boot Example) for Onboarding use case

1. What does the Application do?
2. What is Temporal.io ?
3. Pre-requisites
4. Run the application
5. Invoke the API
6. View the workflow instance
7. Running on GKE

The workflow application invokes 4 activities in the following sequence 1) Create CustReg Record --> 2) Create Mailer Record --> 3) Create Payment Account --> 4) Set Payment Account Type (ACH, Credit)

Activities 1 & 2 are invoked in sequence as soon as the workflow instance begins. The workflow instance is now awaiting a user click on the application UI, on this signal Activity 3 is invoked. After Activity 3 is completed, the workflow instance is awaiting a user click on the application UI to set the Payment type, on this signal Activity 4 is invoked.

Each Activity or step calls a Rest API and gets a response. The response payload could be used in subsequent activities. If the API call fails (when the REST API is not running for example), the temporal worflow engine persists the state of the activity to retry with a backoff coefficient up to a given number of attempts.

Temporal https://github.com/temporalio is an orchestration engine (MIT License) that can be used to orchestrate services at scale.

You must make sure a temporal server is running https://github.com/temporalio/docker-compose#readme

Clone the repo https://github.com/vikramspringml/ppc-onboarding-demo.git

Use mvn install clean package spring-boot:run to run the application.

Invoke the REST API to start the workflow instance using POST http://localhost:8080/start ,Use the POST payload body

{
    "username": "brian",
    "password": "test",
    "secqtn1": "test",
    "secqtn2": "test",
    "contactTitle": "test",
    "contactFName":"fname",
    "contactLName":"lname",
    "contactEmail":"[email protected]"
}

Invoke the REST API to view the latest status of the workflow instance using GET http://localhost:8080/getwfstatus?id=brian

Invoke the REST API to CONTINUE the workflow instance using POST http://localhost:8080/step2 ,Use the POST payload body

{
    "username": "brian",
    "crid": "5678765"
}

Invoke the REST API to view the LATEST status of the workflow instance using GET http://localhost:8080/getwfstatus?id=brian

Invoke the REST API to CONTINUE the workflow instance using POST http://localhost:8080/step3 ,Use the POST payload body

{
    "username": "brian",
    "password": "test",
    "secqtn1": "test",
    "secqtn2": "test",
    "contactTitle": "test",
    "contactFName":"fname",
    "contactLName":"lname",
    "contactEmail":"[email protected]"
}

Invoke the REST API to view the LATEST status of the workflow instance using GET http://localhost:8080/getwfstatus?id=brian

Once the API is invoked you can view the workflow instances using the Temporal Web UI

On a web browser, navigate to http://localhost:8088/ to access the Temporal UI to observe the workflow instances.

The application can be run as a Workflow client and worker using env variable configuration. The workflow client is a REST API invoked application that creates the workflow instance on the Temporal server. The workflow worker is an application that listens to Temporal task queues and performs the activities defined in the workflow.

mvn -DskipTests=true clean install spring-boot:repackage

gcloud auth login

gcloud builds submit .
--tag us.gcr.io/{gcp-projectid}/{container-name}

gcloud builds submit .

Run the following commands on cloud shell to authenticate gcloud, authenticate w GKE cluster and add master authorized network

gcloud auth login

gcloud config set project {PROJECT_ID}

gcloud container clusters get-credentials 
${GKE_CLUSTER} --region {GKE_CLUSTER_REGION} 
--project {PROJECT_ID}

gcloud container clusters update {GKE_CLUSTER} 
--region {GKE_CLUSTER_REGION} 
--enable-master-authorized-networks 
--master-authorized-networks $(dig +short myip.opendns.com @resolver1.opendns.com)/32

• Apply workflow API service deployment

kubectl apply -f k8s/service.yaml

Verify your deployment using the deployment name temporal-demo-api

• Apply workflow worker (Poller) deployment

kubectl apply -f k8s/deployment.yaml

Verify your deployment using the deployment name temporal-demo-worker

kubectl port-forward services/temporaltest-web 8088:8088

Navigate to http://localhost:8888 on your browser

kubectl port-forward services/temporal-demo-api-svc 8080:80

Invoke the API on curl using Invoke the API

See instructions here