Prerequisites Management

The backend microservice uses most of the same resources as the FlowX Engine.

Database - Postgres / Oracle

The backend microservice connects to the same Postgres / Oracle database as FlowX Engine.

Kafka cluster

If you intend to use the audit functionality, ensure that the backend microservice can connect to the Kafka cluster. When connected to Kafka, it sends details about all database transactions to a configured Kafka topic.

NGINX

For optimal operation the FlowX Designer should use a separate NGINX load balancer from the FlowX Engine. This routing mechanism handles API calls from the SPA (single page application) to the backend service, to the engine and to various plugins.

Here’s an example/suggestion of an NGINX setup:

For routing calls to plugins:

metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/enable-cors: "true"
    nginx.ingress.kubernetes.io/cors-allow-methods: GET, PUT, POST, DELETE, PATCH
    nginx.ingress.kubernetes.io/cors-allow-origin: "http://localhost:4200,http://localhost:80,http://localhost:8080"
    nginx.ingress.kubernetes.io/rewrite-target: /$2
  name: flowx-admin-plugins-subpaths
spec:
  rules:
  - host: {{host}}
    http:
      paths:
      - path: /notification(/|$)(.*)
        backend:
          serviceName: notification
          servicePort: 80
      - path: /document(/|$)(.*)
        backend:
          serviceName: document
          servicePort: 80
  tls:
  - hosts:
    - {{host}}
    secretName: {{tls secret}}

For routing calls to the engine

Three different configurations are needed:

  1. For viewing the current instances of processes running in the Engine:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /api/instances/$2
    nginx.ingress.kubernetes.io/enable-cors: "true"
    nginx.ingress.kubernetes.io/cors-allow-methods: GET, PUT, POST, DELETE, PATCH
    nginx.ingress.kubernetes.io/cors-allow-origin: "http://localhost:4200,http://localhost:80,http://localhost:8080"
  name: flowx-admin-engine-instances
spec:
  rules:
  - host: {{host}}
    http:
      paths:
      - path: /api/instances(/|$)(.*)
        backend:
          serviceName: {{engine-service-name}}
          servicePort: 80
  1. For testing process definitions from the FLOWX Designer, route API calls and SSE communication to the Engine backend.

Setup for routing REST calls:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /api/$2
    nginx.ingress.kubernetes.io/enable-cors: "true"
    nginx.ingress.kubernetes.io/cors-allow-methods: GET, PUT, POST, DELETE, PATCH
    nginx.ingress.kubernetes.io/cors-allow-origin: "http://localhost:4200,http://localhost:80,http://localhost:8080"
  name: flowx-admin-engine-rest-api
spec:
  rules:
  - host: {{host}}
    http:
      paths:
      - path: /{{PROCESS_API_PATH}}/api(/|$)(.*)
        backend:
          serviceName: {{engine-service-name}}
          servicePort: 80

Setup for routing SSE communication:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/cors-allow-headers: "<your_defaultCorsAllowHeaders_value>"
  name: flowx-public-subpath-events-rewrite
spec:
  rules:
  - host: {{host}}
    http:
      paths:
      - backend:
          service:
            name: events-gateway
            port:
              name: http
        path: /api/events(/|$)(.*)
  1. For accessing the REST API of the backend microservice
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/proxy-body-size: "4m"
    nginx.ingress.kubernetes.io/enable-cors: "true"
    nginx.ingress.kubernetes.io/cors-allow-methods: GET, PUT, POST, DELETE, PATCH
    nginx.ingress.kubernetes.io/cors-allow-origin: "http://localhost:4200,http://localhost:80,http://localhost:8080"
  name: flowx-admin-api
spec:
  rules:
  - host: {{host}}
    http:
      paths:
        - path: /
          backend:
            serviceName: {{flowx-admin-service-name}}
            servicePort: 80
  tls:
  - hosts:
    - {{host}}
    secretName: {{tls secret}}

For configuring the SPA:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    certmanager.k8s.io/issuer: letsencrypt-prod
    kubernetes.io/ingress.class: nginx
    ingress.kubernetes.io/affinity: cookie
  name: flowx-designer-spa
spec:
  rules:
  - host: {{host of web app}}
    http:
      paths:
      - backend:
          serviceName: {{flowx-designer-service-name}}
          servicePort: 80
  tls:
  - hosts:
    - {{host of web app}}
    secretName: {{tls secret}}

Steps to deploy Frontend app

The FLOWX Designer is an SPA application that is packaged in a docker image with nginx:1.19.10. The web application allows an authenticated user to administrate the FLOWX platform.

In order to configure the docker image you need to configure the next parameters:

flowx-process-renderer:
  env:
    BASE_API_URL: {{the one configured as host in the nginx}}
    PROCESS_API_PATH: {{something like /engine}}
    KEYCLOAK_ISSUER: {{openid provider - ex: https://something/auth/realms/realmName}}
    KEYCLOAK_REDIRECT_URI: {{url of the SPA}}
    KEYCLOAK_CLIENT_ID: {{client ID}}
    STATIC_ASSETS_PATH: {{mediaLibrary.s3.publicUrl }}/{{env}}