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Switch from unmanaged to managed Istio installations

Use the Istio lifecycle manager to switch from your existing, unmanaged Istio installations to Gloo-managed Istio installations. The takeover process follows these general steps:

  1. Create IstioLifecycleManager and GatewayLifecycleManager resources in the management cluster that use a different revision than the existing Istio installations in your workload clusters. The istiod control planes and Istio gateways for the new installation are deployed to each workload cluster, but the new, managed control planes are not active at deployment time.
  2. Test the new control plane and gateways by deploying workloads with a label for the new revision and generating traffic to those workloads.
  3. Change the new control planes to be active, and rollout a restart to data plane workloads so that they are managed by the new control planes.
  4. Update service selectors or update internal/external DNS entries to point to the new gateways.
  5. Uninstall the old Istio installations.

Considerations

Before you follow this takeover process, review the following important considerations.

Before you begin

  1. Set the names of your clusters from your infrastructure provider. If your clusters have different names, specify those names instead.

    export REMOTE_CLUSTER1=<cluster1>
export REMOTE_CLUSTER2=<cluster2>
...
  2. Save the kubeconfig contexts for your clusters. Run kubectl config get-contexts, look for your cluster in the CLUSTER column, and get the context name in the NAME column. Note: Do not use context names with underscores. The context name is used as a SAN specification in the generated certificate that connects workload clusters to the management cluster, and underscores in SAN are not FQDN compliant. You can rename a context by running kubectl config rename-context "<oldcontext>" <newcontext>. 
    export MGMT_CONTEXT=<management-cluster-context>
export REMOTE_CONTEXT1=<remote-cluster1-context>
export REMOTE_CONTEXT2=<remote-cluster2-context>
...

  3. To use a Gloo Mesh hardened image of Istio, you must have a Solo account. Make sure that you can log in to the Support Center. If not, contact your account administrator to get the repo key for the Istio version that you want to install from the Istio images built by Solo.io support article.

Deploy the managed Istio installations

Create IstioLifecycleManager and GatewayLifecycleManager resources in the management cluster that use a different revision than the existing Istio installations in your workload clusters. The istiod control planes and Istio gateways for the new installation are deployed to each workload cluster, but the new, managed control planes are not active at deployment time.

  1. Save the Istio version information as environment variables.

    • For REPO, use a Gloo Istio repo key that you can get by logging in to the Support Center and reviewing the Istio images built by Solo.io support article. For more information, see Get the Gloo Istio version that you want to use.
    • For ISTIO_IMAGE, save the version that you downloaded, such as 1.17.2, and append the solo tag, which is required to use many enterprise features. You can optionally append other Gloo Istio tags, as described in About Gloo Istio. If you downloaded a different version than the following, make sure to specify that version instead.
    • For REVISION, specify any name or integer. For example, you can specify the version, such as 1-17-2. If you currently use a revision for your existing Istio installations, be sure to use a different revision than the existing one.
    export REPO=<repo-key>
export ISTIO_IMAGE=1.17.2-solo
export REVISION=1-17-2

  2. Prepare an IstioLifecycleManager resource to manage istiod control planes.

    1. Download the gm-istiod.yaml example file. 
      curl -0L https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/gloo-mesh/istio-install/gm-managed/takeover/gm-istiod.yaml > gm-istiod.yaml

      curl -0L https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/gloo-mesh/istio-install/gm-managed/takeover/gm-istiod-openshift.yaml > gm-istiod.yaml
    2. Update the example file with the environment variables that you previously set for $REPO, $ISTIO_IMAGE, $REVISION, $REMOTE_CLUSTER1, and $REMOTE_CLUSTER2. Save the updated file as gm-istiod-values.yaml.
      • Tip: Instead of updating the file manually, try running a terminal command to substitute values, such as the following command. 
        envsubst < gm-istiod.yaml > gm-istiod-values.yaml
open gm-istiod-values.yaml
    3. Check the settings in the IstioLifecycleManager resource. You can further edit the file to provide your own details.
      • Clusters: Specify the registered cluster names in the clusters section. For single-cluster setups, you must edit the file to specify only the name of your cluster (value of $CLUSTER_NAME). For each cluster, defaultRevision: false ensures that the Istio operator spec for the control plane installation is NOT active in the cluster.
      • Root namespace: If you do not specify a namespace, the root namespace for the installed Istio resources in workload clusters is set to istio-system. If the istio-system namespace does not already exist, it is created for you.
      • Trust domain: By default, the trustDomain value is automatically set by the installer to the name of each workload cluster. To override the trustDomain for each cluster, you can instead specify the override value in the trustDomain field, and include the value in the list of cluster names. For example, if you specify trustDomain: cluster1-trust-override in the operator spec, you then specify the cluster name (cluster1) and the trust domain (cluster1-trust-override) in the list of cluster names. Additionally, because Gloo requires multiple trust domains for east-west routing, the PILOT_SKIP_VALIDATE_TRUST_DOMAIN field is set to "true" by default.
    4. Apply the IstioLifecycleManager resource to your management cluster. 
      kubectl apply -f gm-istiod-values.yaml --context $MGMT_CONTEXT

  3. Optional: If you have a multicluster setup, prepare a GatewayLifecycleManager custom resource to manage the east-west gateways.

    1. Download the gm-ew-gateway.yaml example file. 
      curl -0L https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/gloo-mesh/istio-install/gm-managed/gm-ew-gateway.yaml > gm-ew-gateway.yaml
    2. Update the example file with the environment variables that you previously set for $REPO, $ISTIO_IMAGE, $REVISION, $REMOTE_CLUSTER1, and $REMOTE_CLUSTER2. Save the updated file as gm-ew-gateway-values.yaml.
      • Tip: Instead of updating the file manually, try running a terminal command to substitute values, such as the following command. 
        envsubst < gm-ew-gateway.yaml > gm-ew-gateway-values.yaml
open gm-ew-gateway-values.yaml
    3. Check the settings in the GatewayLifecycleManager resource. You can further edit the file to provide your own details.
      • Clusters: Specify the registered cluster names in the clusters section. For each cluster, activeGateway: true ensures that the Istio operator spec for the gateway is deployed and actively used by the istiod control plane.
      • Gateway name and namespace: The default name for the gateway is set to istio-eastwestgateway, and the default namespace for the gateway is set to gloo-mesh-gateways. If the gloo-mesh-gateways namespace does not already exist, it is created in each workload cluster for you. Note: To prevent conflicts, be sure to choose a different name or namespace than your existing gateway. For example, if your existing gateway is named istio-eastwestgateway and deployed in a namespace such as istio-gateways, you can still name the new gateway istio-eastwestgateway, but you must deploy it in a different namespace, such as gloo-mesh-gateways.
    4. Apply the GatewayLifecycleManager resource to your management cluster. 
      kubectl apply -f gm-ew-gateway-values.yaml --context $MGMT_CONTEXT

  4. Optional: If you also have a Gloo Gateway license, prepare a GatewayLifecycleManager custom resource to manage the ingress gateways.

    1. Download the gm-ingress-gateway.yaml example file. 
      curl -0L https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/gloo-mesh/istio-install/gm-managed/gm-ingress-gateway.yaml > gm-ingress-gateway.yaml
    2. Update the example file with the environment variables that you previously set for $REPO, $ISTIO_IMAGE, $REVISION, $REMOTE_CLUSTER1, and $REMOTE_CLUSTER2. Save the updated file as gm-ingress-gateway-values.yaml.
      • Tip: Instead of updating the file manually, try running a terminal command to substitute values, such as the following command. 
        envsubst < gm-ingress-gateway.yaml > gm-ingress-gateway-values.yaml
open gm-ingress-gateway-values.yaml
    3. Check the settings in the GatewayLifecycleManager resource. You can further edit the file to provide your own details.
      • Clusters: Specify the registered cluster names in the clusters section. For single-cluster setups, you must edit the file to specify only the name of your cluster (value of $CLUSTER_NAME). For each cluster, activeGateway: true ensures that the Istio operator spec for the gateway is deployed and actively used by the istiod control plane.
      • Gateway name and namespace: The default name for the gateway is set to istio-ingressgateway, and the default namespace for the gateway is set to gloo-mesh-gateways. If the gloo-mesh-gateways namespace does not already exist, it is created in each workload cluster for you. Note: To prevent conflicts, be sure to choose a different name or namespace than your existing gateway. For example, if your existing gateway is named istio-ingressgateway and deployed in a namespace such as istio-gateways, you can still name the new gateway istio-ingressgateway, but you must deploy it in a different namespace, such as gloo-mesh-gateways.
    4. Apply the GatewayLifecycleManager resource to your management cluster. 
      kubectl apply -f gm-ingress-gateway-values.yaml --context $MGMT_CONTEXT

Verify and test the new managed installations

Verify that the new control plane and gateways are deployed to your workload clusters. Then test them by deploying workloads with a label for the new revision and generating traffic to those workloads.

  1. In each workload cluster, verify that the namespaces for your managed Istio installations are created.

    kubectl get ns --context $REMOTE_CONTEXT1

    For example, the gm-iop-1-17-2 and gloo-mesh-gateways namespaces are created alongside the namespaces you might already use for your existing Istio installations (such as istio-system and istio-gateways):

    NAME               STATUS   AGE
default            Active   56m
gloo-mesh          Active   36m
gm-iop-1-17-2        Active   91s
gloo-mesh-gateways Active   90s
istio-gateways     Active   50m
istio-system       Active   50m
kube-node-lease    Active   57m
kube-public        Active   57m
kube-system        Active   57m

  2. In each namespace, verify that the Istio resources for the new revision are successfully installed. 

    kubectl get all -n gm-iop-1-17-2 --context $REMOTE_CONTEXT1

    Example output:

    NAME                                       READY   STATUS    RESTARTS   AGE
pod/istio-operator-1-17-2-678fd95cc6-ltbvl   1/1     Running   0          4m12s

NAME                          TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/istio-operator-1-17-2   ClusterIP   10.204.15.247   <none>        8383/TCP   4m12s

NAME                                  READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/istio-operator-1-17-2   1/1     1            1           4m12s

NAME                                             DESIRED   CURRENT   READY   AGE
replicaset.apps/istio-operator-1-17-2-678fd95cc6   1         1         1       4m12s

    kubectl get all -n istio-system --context $REMOTE_CONTEXT1

    Example output: Note that your existing Istio control plane pods might be deployed to this namespace too.

    NAME                              READY   STATUS    RESTARTS   AGE
pod/istiod-1-17-2-b65676555-g2vmr   1/1     Running   0          8m57s

NAME                  TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)                                 AGE
service/istiod-1-17-2   ClusterIP   10.204.6.56   <none>        15010/TCP,15012/TCP,443/TCP,15014/TCP   8m56s

NAME                          READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/istiod-1-17-2   1/1     1            1           8m57s

NAME                                    DESIRED   CURRENT   READY   AGE
replicaset.apps/istiod-1-17-2-b65676555   1         1         1       8m57s

NAME                                              REFERENCE                     TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
horizontalpodautoscaler.autoscaling/istiod-1-17-2   Deployment/istiod-1-17-2   1%/80%    1         5         1          8m58s

    kubectl get all -n gloo-mesh-gateways --context $REMOTE_CONTEXT1

    Example output: Your output might vary depending on which gateways you installed. Note that the gateways might take a few minutes to be created.

    NAME                                              READY   STATUS    RESTARTS   AGE
pod/istio-eastwestgateway-1-17-2-66f464ff44-qlhfk   1/1     Running   0          2m6s
pod/istio-ingressgateway-1-17-2-77d5f76bc8-j6qkp    1/1     Running   0          2m18s

NAME                                      TYPE           CLUSTER-IP     EXTERNAL-IP      PORT(S)                                      AGE
service/istio-eastwestgateway             LoadBalancer   10.204.4.172   34.86.225.164    15021:30889/TCP,15443:32489/TCP              2m5s
service/istio-ingressgateway              LoadBalancer   10.44.4.140    34.150.235.221   15021:31321/TCP,80:32525/TCP,443:31826/TCP   2m16s

NAME                                         READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/istio-eastwestgateway-1-17-2   1/1     1            1           2m6s
deployment.apps/istio-ingressgateway-1-17-2    1/1     1            1           2m18s

NAME                                                    DESIRED   CURRENT   READY   AGE
replicaset.apps/istio-eastwestgateway-1-17-2-66f464ff44   1         1         1       2m6s
replicaset.apps/istio-ingressgateway-1-17-2-77d5f76bc8    1         1         1       2m18s

NAME                                                             REFERENCE                                    TARGETS         MINPODS   MAXPODS   REPLICAS   AGE
horizontalpodautoscaler.autoscaling/istio-eastwestgateway-1-17-2   Deployment/istio-eastwestgateway-1-17-2   <unknown>/80%   1         5         0          2m7s
horizontalpodautoscaler.autoscaling/istio-ingressgateway-1-17-2    Deployment/istio-ingressgateway-1-17-2    4%/80%          1         5         1          2m19s

  3. Verify that your workloads and existing gateways still point to the old revision, and only the new gateway points to the new revision.

    istioctl proxy-status --context $REMOTE_CONTEXT1

    In this example output, the Bookinfo apps and existing east-west gateway in cluster1 still point to the existing Istio installation that uses version 1.16.4. Only the new east-west gateway points to the managed Istio installation that uses version 1.17.2-solo and revision 1-17-2.

    NAME                                                              CLUSTER   ...  ISTIOD                           VERSION
details-v1-6758dd9d8d-rh4db.bookinfo                              cluster1  ...  istiod-66d54b865-6b6zt           1.16.4
istio-eastwestgateway-575b697f9-49v4c.istio-gateways              cluster1  ...  istiod-66d54b865-6b6zt           1.16.4
istio-eastwestgateway-1-17-2-575b697f9-49v4c.gloo-mesh-gateways     cluster1  ...  istiod-1-17-2-5b7b9df586-95sq6     1.17.2-solo
productpage-v1-b4cf67f67-s5lsh.bookinfo                           cluster1  ...  istiod-66d54b865-6b6zt           1.16.4
ratings-v1-f849dc6d-wqdc8.bookinfo                                cluster1  ...  istiod-66d54b865-6b6zt           1.16.4
reviews-v1-74fb8fdbd8-z8bzc.bookinfo                              cluster1  ...  istiod-66d54b865-6b6zt           1.16.4
reviews-v2-58d564d4db-g8jzr.bookinfo                              cluster1  ...  istiod-66d54b865-6b6zt           1.16.4

  4. Deploy test workloads with a label for the new revision, such as istio.io/rev=1-17-2.

    1. In both workload clusters, create the petstore namespace, and label it with the new revision so that apps in the namespace are injected with sidecars for the managed control plane. 

      kubectl --context $REMOTE_CONTEXT1 create ns petstore
kubectl --context $REMOTE_CONTEXT1 label ns petstore istio.io/rev=$REVISION
kubectl --context $REMOTE_CONTEXT1 label ns istio.io/injection=enabled

      kubectl --context $REMOTE_CONTEXT2 create ns petstore
kubectl --context $REMOTE_CONTEXT2 label ns petstore istio.io/rev=$REVISION
kubectl --context $REMOTE_CONTEXT2 label ns istio.io/injection=enabled

    2. In the first workload cluster, deploy the petstore app. 

      kubectl apply --context $REMOTE_CONTEXT1 -n petstore -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: petstore
  name: petstore
  namespace: petstore
spec:
  selector:
    matchLabels:
      app: petstore
  replicas: 1
  template:
    metadata:
      labels:
        app: petstore
    spec:
      containers:
      - image: openapitools/openapi-petstore
        name: petstore
        env:
          - name: DISABLE_OAUTH
            value: "1"
          - name: DISABLE_API_KEY
            value: "1"
        ports:
        - containerPort: 8080
          name: http
---
apiVersion: v1
kind: Service
metadata:
  name: petstore
  namespace: petstore
  labels:
    service: petstore
spec:
  ports:
  - port: 8080
    protocol: TCP
  selector:
    app: petstore
EOF

  5. Generate traffic through the new gateways to the test workloads.

    • East-west (cross-cluster) routing:

      1. Create a Gloo root trust policy to ensure that services in each workload cluster can communicate securely. The root trust policy sets up the domain and certificates to establish a shared trust model across multiple clusters in your service mesh.

        kubectl apply --context $MGMT_CONTEXT -f - <<EOF
apiVersion: admin.gloo.solo.io/v2
kind: RootTrustPolicy
metadata:
  name: root-trust
  namespace: gloo-mesh
spec:
  config:
    autoRestartPods: true
    mgmtServerCa:
      generated: {}
EOF

      2. Create a Gloo virtual destination for the petstore app.

        kubectl apply --context $REMOTE_CONTEXT1 -n petstore -f- <<EOF
apiVersion: networking.gloo.solo.io/v2
kind: VirtualDestination
metadata:
  name: petstore-vd
  namespace: petstore
spec:
  hosts:
  # Arbitrary, internal-only hostname assigned to the endpoint
  - petstore.mesh.internal.com
  ports:
  - number: 8080
    protocol: HTTP
    targetPort:
      number: 8080
  services:
    - labels:
        app: petstore
EOF

      3. Create a curl pod in the second cluster.

        kubectl run -it -n petstore --context $REMOTE_CONTEXT2 curl \ 
--image=curlimages/curl:7.73.0 --rm  -- sh

      4. Send a request to the petstore app's virtual destination hostname.

        curl http://petstore.mesh.internal.com/ -v

        Example output:

        *   Trying 45.33.2.79:80...
* Connected to petstore.mesh.internal.com (45.33.2.79) port 80 (#0)
> GET / HTTP/1.1
> Host: petstore.mesh.internal.com
> User-Agent: curl/7.73.0-DEV
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< server: envoy
< date: Fri, 28 Oct 2022 20:11:00 GMT
< content-type: application/octet-stream,text/html
< content-length: 134
< x-envoy-upstream-service-time: 68
< 
* Connection #0 to host petstore.mesh.internal.com left intact
<html><head><title>petstore.mesh.internal.com</title></head><body><h1>petstore.mesh.internal.com</h1><p>Coming soon.</p></body></html>

      5. Exit the temporary pod. The pod deletes itself.

        exit
    • North-south (ingress) routing: If you also have a Gloo Gateway license and deployed an ingress gateway for the new revision, you can test traffic to your workloads by using the ingress gateway.
      1. Save the external address of the ingress gateway for the new revision. 
        export INGRESS_GW_IP=$(kubectl get svc --context $REMOTE_CONTEXT1 -n gloo-mesh-gateways istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
echo $INGRESS_GW_IP

        export INGRESS_GW_IP=$(kubectl get svc --context $REMOTE_CONTEXT1 -n gloo-mesh-gateways istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')
echo $INGRESS_GW_IP
      2. Apply a virtual gateway to the ingress gateway for the new revision. 
        kubectl apply --context $REMOTE_CONTEXT1 -f- <<EOF
apiVersion: networking.gloo.solo.io/v2
kind: VirtualGateway
metadata:
  name: istio-ingressgateway-$REVISION
  namespace: petstore
spec:
  listeners:
  - http: {}
    port:
      number: 80
  workloads:
  - selector:
      labels:
        istio: ingressgateway
      cluster: ${REMOTE_CLUSTER1}
      namespace: gloo-mesh-gateways
EOF
      3. Apply a route table to allow requests to the /api/pets path of the petstore app. 
        kubectl apply --context $REMOTE_CONTEXT1 -f- <<EOF
apiVersion: networking.gloo.solo.io/v2
kind: RouteTable
metadata:
  name: petstore-routes
  namespace: petstore
spec:
  hosts:
    - '*'
  virtualGateways:
    - name: istio-ingressgateway-$REVISION
      cluster: ${REMOTE_CLUSTER1}
      namespace: petstore
  http:
    - name: petstore
      matchers:
      - uri:
          prefix: /api/pets
      forwardTo:
        destinations:
          - ref:
              name: petstore
              namespace: petstore
              cluster: ${REMOTE_CLUSTER1}
            port:
              number: 8080
EOF
      4. Test the ingress gateway by sending a request to the petstore service. 
        curl http://$INGRESS_GW_IP:80/api/pets

Activate the managed installations

After you finish testing, change the new control planes to be active, and rollout a restart to data plane workloads so that they are managed by the new control planes. Then, you can update service selectors or update internal/external DNS entries to point to the new gateways. You can also optionally uninstall the old Istio installations.

  1. Switch to the new istiod control plane revision by changing defaultRevision to true.

    kubectl edit IstioLifecycleManager -n gloo-mesh --context $MGMT_CONTEXT istiod-control-plane

    Example:

    apiVersion: admin.gloo.solo.io/v2
kind: IstioLifecycleManager
metadata:
  name: istiod-control-plane
  namespace: gloo-mesh
spec:
  installations:
    - revision: 1-17-2
      clusters:
      - name: cluster1
        # Set this field to TRUE
        defaultRevision: true
      - name: cluster2
        # Set this field to TRUE
        defaultRevision: true
      istioOperatorSpec:
        profile: minimal
        ...

  2. In each workload cluster, roll out a restart to your workload apps so that they are managed by the new control planes.

    1. Update any Istio-managed apps by rolling out restarts. The Istio sidecars for each microservice are updated to use the new Istio version. Make sure that you only restart one microservice at a time. For example, in the following commands to update the Bookinfo microservices, 20 seconds elapse between each restart to ensure that the pods have time to start running. 
      kubectl rollout restart deployment -n bookinfo details-v1 --context $REMOTE_CONTEXT1
sleep 20s
kubectl rollout restart deployment -n bookinfo ratings-v1 --context $REMOTE_CONTEXT1
sleep 20s
kubectl rollout restart deployment -n bookinfo productpage-v1 --context $REMOTE_CONTEXT1
sleep 20s
kubectl rollout restart deployment -n bookinfo reviews-v1 --context $REMOTE_CONTEXT1
sleep 20s
kubectl rollout restart deployment -n bookinfo reviews-v2 --context $REMOTE_CONTEXT1
sleep 20s
kubectl rollout restart deployment -n bookinfo reviews-v3 --context $REMOTE_CONTEXT2
sleep 20s
kubectl rollout restart deployment -n bookinfo ratings-v1 --context $REMOTE_CONTEXT2
sleep 20s
    2. Verify that your workloads and new gateways point to the new revision. 
      istioctl proxy-status --context $REMOTE_CONTEXT1

      Example output:

      NAME                                                              CLUSTER     ...     ISTIOD                           VERSION
details-v1-7b6df9d8c8-s6kg5.bookinfo                              cluster1    ...     istiod-1-17-2-7c8f6fd4c4-m9k9t     1.17.2-solo
istio-eastwestgateway-1-17-2-bdc4fd65f-ftmz9.gloo-mesh-gateways     cluster1    ...     istiod-1-17-2-6495985689-rkwwd     1.17.2-solo
productpage-v1-bb494b7d7-xbtxr.bookinfo                           cluster1    ...     istiod-1-17-2-7c8f6fd4c4-m9k9t     1.17.2-solo
ratings-v1-55b478cfb6-wv2m5.bookinfo                              cluster1    ...     istiod-1-17-2-7c8f6fd4c4-m9k9t     1.17.2-solo
reviews-v1-6dfcc9fc7d-7k6qh.bookinfo                              cluster1    ...     istiod-1-17-2-7c8f6fd4c4-m9k9t     1.17.2-solo
reviews-v2-7dddd799b5-m5n2z.bookinfo                              cluster1    ...     istiod-1-17-2-7c8f6fd4c4-m9k9t     1.17.2-solo

  3. If you use your own load balancer services for gateways, update the service selectors to point to the gateways for the new revision. Alternatively, if you use the load balancer services that are deployed by default, update any internal or external DNS entries to point to the new gateway IP addresses.

  4. Uninstall the old Istio installations from each workload cluster. The uninstallation process varies depending on your original installation method. For example, if you created Istio operators in each workload cluster, the uninstallation process might follow these general steps:

    1. Delete the IstioOperator resources for the control plane, ingress gateway, and east-west gateway. 
      kubectl delete -n istio-system --context $REMOTE_CONTEXT1 IstioOperator <istiod-control-plane>
kubectl delete -n istio-system --context $REMOTE_CONTEXT1 IstioOperator <ingress-gateway>
kubectl delete -n istio-system --context $REMOTE_CONTEXT1 IstioOperator <east-west-gateway>

      kubectl delete -n istio-system --context $REMOTE_CONTEXT2 IstioOperator <istiod-control-plane>
kubectl delete -n istio-system --context $REMOTE_CONTEXT2 IstioOperator <ingress-gateway>
kubectl delete -n istio-system --context $REMOTE_CONTEXT2 IstioOperator <east-west-gateway>
    2. Uninstall the control plane for the old revision. If you did not use revisions, specify default in the revision flag. 
      istioctl uninstall --context $REMOTE_CONTEXT1 --revision <revision_or_default>

      istioctl uninstall --context $REMOTE_CONTEXT2 --revision <revision_or_default>
    3. Delete the operator and the operator's ClusterIP service. 
      kubectl delete -n istio-operator --context $REMOTE_CONTEXT1 deploy <istio-operator>
kubectl delete -n istio-operator --context $REMOTE_CONTEXT1 svc <istio-operator>

      kubectl delete -n istio-operator --context $REMOTE_CONTEXT2 deploy <istio-operator>
kubectl delete -n istio-operator --context $REMOTE_CONTEXT2 svc <istio-operator>
    4. Delete any unused namespaces that were for the old Istio installation only. WARNING: Do not delete namespaces that the Istio lifecycle manager uses, such as istio-system, gloo-mesh-gateways, or gm-iop-1-17-2. Check the contents of each namespace before you delete it. 
      kubectl delete namespace istio-operator --context $REMOTE_CONTEXT1
kubectl delete namespace istio-ingress --context $REMOTE_CONTEXT1
kubectl delete namespace istio-eastwest --context $REMOTE_CONTEXT1

      kubectl delete namespace istio-operator --context $REMOTE_CONTEXT2
kubectl delete namespace istio-ingress --context $REMOTE_CONTEXT2
kubectl delete namespace istio-eastwest --context $REMOTE_CONTEXT2
    5. Repeat these steps for each workload cluster.

  5. Optional: Delete any workloads that you used for testing, such as the petstore apps.

    kubectl delete ns petstore --context $REMOTE_CONTEXT1
kubectl delete ns petstore --context $REMOTE_CONTEXT2

Next steps