<p>I'm trying to deploy the BookInfo application described here: <a href="https://istio.io/docs/examples/bookinfo/" rel="nofollow noreferrer">https://istio.io/docs/examples/bookinfo/</a></p>

<p>And, I'm working on Routing the Request based on header "end-user: jason" per this tutorial. <a href="https://istio.io/docs/tasks/traffic-management/request-routing/" rel="nofollow noreferrer">https://istio.io/docs/tasks/traffic-management/request-routing/</a></p>

<p>According to this tutorial, <em>product</em> Microservices adds a request header "end-user: jason" <strong>once you log in</strong>. </p>

<p>I want it to send out this header in all circumstances. In other words, for all requests which go out of <strong>product</strong> microservice, I want this header to to attached, irrespective of where the request lands on.</p>

<p>How can I achieve this?</p>

<p><a href="https://i.stack.imgur.com/fI2vh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fI2vh.png" alt="I want to achieve this"></a></p>

<p><strong>EDIT</strong></p>

<p>I created the following based on advice given below. For some reason, the traffic is going to both versions of product all the time. This are all the configurations I have.</p>

<pre><code>##################################################################################################
# Details service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: details
  labels:
    app: details
    service: details
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: details
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: details-v1
  labels:
    app: details
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: details
        version: v1
    spec:
      containers:
      - name: details
        image: istio/examples-bookinfo-details-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Ratings service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: ratings
  labels:
    app: ratings
    service: ratings
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: ratings
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: ratings-v1
  labels:
    app: ratings
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: ratings
        version: v1
    spec:
      containers:
      - name: ratings
        image: istio/examples-bookinfo-ratings-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Reviews service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: reviews
  labels:
    app: reviews
    service: reviews
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: reviews
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: reviews-v1
  labels:
    app: reviews
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: reviews
        version: v1
    spec:
      containers:
      - name: reviews
        image: istio/examples-bookinfo-reviews-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: reviews-v2
  labels:
    app: reviews
    version: v2
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: reviews
        version: v2
    spec:
      containers:
      - name: reviews
        image: istio/examples-bookinfo-reviews-v2:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: reviews-v3
  labels:
    app: reviews
    version: v3
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: reviews
        version: v3
    spec:
      containers:
      - name: reviews
        image: istio/examples-bookinfo-reviews-v3:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Productpage services
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: productpage
  labels:
    app: productpage
    service: productpage
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: productpage
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: productpage-v1
  labels:
    app: productpage
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: productpage
        version: v1
    spec:
      containers:
      - name: productpage
        image: istio/examples-bookinfo-productpage-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: productpage-v2
  labels:
    app: productpage
    version: v2
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: productpage
        version: v2
    spec:
      containers:
      - name: productpage
        image: istio/examples-bookinfo-productpage-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: bookinfo-gateway
spec:
  selector:
    istio: ingressgateway # use istio default controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: bookinfo
spec:
  hosts:
  - "*"
  gateways:
  - bookinfo-gateway
  http:
  - match:
    - uri:
        exact: /productpage
    - uri:
        exact: /login
    - uri:
        exact: /logout
    - uri:
        prefix: /api/v1/products
    route:
    - destination:
        host: productpage
        port:
          number: 9080
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: productpage
spec:
  host: productpage
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v3
    labels:
      version: v3
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: ratings
spec:
  host: ratings
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v2-mysql
    labels:
      version: v2-mysql
  - name: v2-mysql-vm
    labels:
      version: v2-mysql-vm
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: details
spec:
  host: details
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: productpage
spec:
  hosts:
  - productpage
  http:
  - match:
    - headers:
        end-user:
          exact: jason
    route:
    - destination:
        host: productpage
        subset: v2
  - route:
    - destination:
        host: productpage
        subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
  - reviews
  http:
  - match:
    - headers:
        end-user:
          exact: jason
    route:
    - destination:
        host: reviews
        subset: v2
  - route:
    - destination:
        host: reviews
        subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: ratings
spec:
  hosts:
  - ratings
  http:
  - route:
    - destination:
        host: ratings
        subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: details
spec:
  hosts:
  - details
  http:
  - route:
    - destination:
        host: details
        subset: v1
---
</code></pre>

<p><a href="https://i.stack.imgur.com/wrn1q.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wrn1q.png" alt="enter image description here"></a></p>

<p>I figured it out!</p>

<p>Thanks to @jt97 for helping me.</p>

<ol>
<li>Follow all the steps here:
<a href="https://istio.io/docs/examples/bookinfo/" rel="nofollow noreferrer">https://istio.io/docs/examples/bookinfo/</a></li>
<li>Set up virtual services as provided here:</li>
</ol>

<blockquote>
  <p>kubectl apply -f
  <a href="https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/networking/virtual-service-all-v1.yaml" rel="nofollow noreferrer">https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/networking/virtual-service-all-v1.yaml</a></p>
</blockquote>

<ol start="3">
<li><p>Add product v2 deployment configuration to create the pod product v2.</p></li>
<li><p>Modify the product's destinationrule and virtualservices to accommodate v1 and v2.</p></li>
<li><p>Now, modify the virtualservices for review and use sourceLabels to specify how it should route. </p></li>
</ol>

<p>The entire configuration looks like this:</p>

<pre><code>##################################################################################################
# Details service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: details
  labels:
    app: details
    service: details
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: details
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: details-v1
  labels:
    app: details
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: details
        version: v1
    spec:
      containers:
      - name: details
        image: istio/examples-bookinfo-details-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Ratings service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: ratings
  labels:
    app: ratings
    service: ratings
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: ratings
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: ratings-v1
  labels:
    app: ratings
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: ratings
        version: v1
    spec:
      containers:
      - name: ratings
        image: istio/examples-bookinfo-ratings-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Reviews service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: reviews
  labels:
    app: reviews
    service: reviews
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: reviews
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: reviews-v1
  labels:
    app: reviews
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: reviews
        version: v1
    spec:
      containers:
      - name: reviews
        image: istio/examples-bookinfo-reviews-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: reviews-v2
  labels:
    app: reviews
    version: v2
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: reviews
        version: v2
    spec:
      containers:
      - name: reviews
        image: istio/examples-bookinfo-reviews-v2:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: reviews-v3
  labels:
    app: reviews
    version: v3
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: reviews
        version: v3
    spec:
      containers:
      - name: reviews
        image: istio/examples-bookinfo-reviews-v3:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Productpage services
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: productpage
  labels:
    app: productpage
    service: productpage
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: productpage
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: productpage-v1
  labels:
    app: productpage
    version: v1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: productpage
        version: v1
    spec:
      containers:
      - name: productpage
        image: istio/examples-bookinfo-productpage-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: productpage-v2
  labels:
    app: productpage
    version: v2
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: productpage
        version: v2
    spec:
      containers:
      - name: productpage
        image: istio/examples-bookinfo-productpage-v1:1.13.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: bookinfo-gateway
spec:
  selector:
    istio: ingressgateway # use istio default controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: bookinfo
spec:
  hosts:
  - "*"
  gateways:
  - bookinfo-gateway
  http:
  - match:
    - uri:
        exact: /productpage
    - uri:
        exact: /login
    - uri:
        exact: /logout
    - uri:
        prefix: /api/v1/products
    route:
    - destination:
        host: productpage
        port:
          number: 9080
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: productpage
spec:
  host: productpage
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v3
    labels:
      version: v3
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: ratings
spec:
  host: ratings
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v2-mysql
    labels:
      version: v2-mysql
  - name: v2-mysql-vm
    labels:
      version: v2-mysql-vm
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: details
spec:
  host: details
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: productpage
spec:
  hosts:
  - productpage
  http:
  - route:
    - destination:
        host: productpage
        subset: v2
  - route:
    - destination:
        host: productpage
        subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
  - reviews
  http:
  - match:
    - sourceLabels:
        version: v2
    route:
    - destination:
        host: reviews
        subset: v2
  - route:
    - destination:
        host: reviews
        subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: ratings
spec:
  hosts:
  - ratings
  http:
  - route:
    - destination:
        host: ratings
        subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: details
spec:
  hosts:
  - details
  http:
  - route:
    - destination:
        host: details
        subset: v1
---
</code></pre>

<p>Here, sourceLabels is the key. We are basically saying all the traffic from any source with label "version: v2" should be routed to reviews v2. </p>

<p>So every time you hit <a href="http://localhost/productpage" rel="nofollow noreferrer">http://localhost/productpage</a>, it'll route 50% of the traffic to product v1 and product v2 respectively. </p>

<p>Traffic from product v1 is routed to review v1 and traffic from product v2 is routed to review v2. </p>

<p>This is how it looks now:</p>

<p><a href="https://i.stack.imgur.com/EFApq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EFApq.png" alt="enter image description here"></a></p>
