How to add header to each request from source Pod to destination Pod?

Question

I'm trying to deploy the BookInfo application described here: https://istio.io/docs/examples/bookinfo/

And, I'm working on Routing the Request based on header "end-user: jason" per this tutorial. https://istio.io/docs/tasks/traffic-management/request-routing/

According to this tutorial, product Microservices adds a request header "end-user: jason" once you log in.

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

How can I achieve this?

EDIT

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.

##################################################################################################
# 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
---

I'm not sure I understand correctly, but I think simple `headers: response: add:` in virtual service is enough in your case. Check this [example](https://stackoverflow.com/a/60826906/11977760) and let me know if that's what we're you looking for, or you need something else. — Jakub, Apr 06 '20 at 10:20
I want to solve this problem: I want to deploy sets of 2 product and review services v1 and v2. v1 product should reach v1 review and similar for v2. Can you help me achieve this? — Anoop Hallimala, Apr 06 '20 at 10:25
So based on the istio example, it has 1 product page which can route to 3 reviews, you want to create 2 product pages, first product page will route only to review v1 and second product page will route only to review v2? Or you want to add header and based on the header control if it should go to review v1/v2? — Jakub, Apr 06 '20 at 10:37
"first product page will route only to review v1 and second product page will route only to review v2" Ultimately, this one. If I'm able to add the header to all outbound HTTP requests, the example already talks of header-based routing. — Anoop Hallimala, Apr 06 '20 at 12:50
@jt97 I've updated the question with the diagram I want it to look like. — Anoop Hallimala, Apr 07 '20 at 06:46

score 1 · Answer 1 · edited Jun 20 '20 at 09:12

As Anoop mentioned in comments he want to deploy 2 productpage apps

first will route only to review v1
second route only to review v2

So I made quick test with the productpage from istio docs, and u have to configure virtual services and destination rules to make it happen.

Install istio bookinfo

deployments and services

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/platform/kube/bookinfo.yaml

gateway and virtual service

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/networking/bookinfo-gateway.yaml

As mentioned here

Before you can use Istio to control the Bookinfo version routing, you need to define the available versions, called subsets, in destination rules.

If you did not enable mutual TLS, execute this command:

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/networking/destination-rule-all.yaml

If you did enable mutual TLS, execute this command:

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/networking/destination-rule-all-mtls.yaml

Then simply add your virtual service

You can either use v1 of each microservice as in this example or just reviews v1.

So for each microservice to use v1 it would be

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/networking/virtual-service-all-v1.yaml

Just for reviews v1

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
  - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v1

And that's everything what you need to do for the first productpage app.

Second productpage app

You have to do exactly the same with second one, the only change here would be virtual service to match subset v2, of course if you want to deploy both of them I suggest using 2 namespaces and seperate them, change the namespaces in virtual services,deployments, gateways etc.

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
  - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v2

Headers

As mentioned in istio documentation you can use

request Header -> manipulation rules to apply before forwarding a request to the destination service

OR

response Header -> manipulation rules to apply before returning a response to the caller

I'm not totally sure what you need, this example shows how to add response header to every request, you can either add it in virtual service. More about it in below example link.

EDIT

I made this virtual services based on the picture you add, so every time if you login as jason you it will redirect you to product v2 and review v2, I left ratings and details v1 by default.

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
---

Thanks for the quick response. I've a requirement to deploy both sets of versions on the same namespace. I tried to follow the steps you mentioned but on the same namespace. The end result is either Review V1 or V2 is serving the requests. I want all the version sets to be deployed on the same namespace, is that possible? — Anoop Hallimala, Apr 07 '20 at 06:33
As far as I unserstand istio it's might be not possible to do in the same namespace, as gateways, virtualservices, destinationes rules will bother each other. As far as i'm concerned namespace will give you some sort of "isolation". I'm worried because it's the same app with same prefixes and everything and i'm not sure how it's going to work. Why won't you go with just 1 version od productpage and use the header in virtual service to route it to specific versions of reviews? — Jakub, Apr 07 '20 at 07:29
Yes, that was my initial thought. When Product V2 calls Review, is there a way to intercept the http request and add a header "x-end-user: jason" to the request? This will solve my problem, I'm thinking. — Anoop Hallimala, Apr 07 '20 at 07:33
Thank you for your edit. I've done the needful and still the traffic is going to both versions. I've attached all the configs I've. Can you point out where I'm going wrong? — Anoop Hallimala, Apr 08 '20 at 14:36

Anoop Hallimala · Accepted Answer · 2020-04-08T17:02:27.190

I figured it out!

Thanks to @jt97 for helping me.

Follow all the steps here: https://istio.io/docs/examples/bookinfo/
Set up virtual services as provided here:

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.5/samples/bookinfo/networking/virtual-service-all-v1.yaml

Add product v2 deployment configuration to create the pod product v2.
Modify the product's destinationrule and virtualservices to accommodate v1 and v2.
Now, modify the virtualservices for review and use sourceLabels to specify how it should route.

The entire configuration looks like this:

##################################################################################################
# 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
---

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.

So every time you hit http://localhost/productpage, it'll route 50% of the traffic to product v1 and product v2 respectively.

Traffic from product v1 is routed to review v1 and traffic from product v2 is routed to review v2.

This is how it looks now: