Version requirements

  1. Verify that the minor version of the Solo distribution of Istio that you want to upgrade to is tested and supported for your Gloo Mesh version. To find the available patch versions, you can get the minor version repo URL from the Istio images built by Solo.io support article, and check the patch version builds in that repo.

  2. Check the Istio release notes for the upgrade version to prepare for any breaking changes.

  3. Be sure to review the following known Istio version restrictions.

Before you begin

Set up the following tools and environment variables.

  1. Set environment variables for the Solo distribution of Istio that you want to upgrade to.

      # Solo distrubution of Istio patch version
    # in the format 1.x.x, with no tags
    export ISTIO_VERSION=1.24.2
    # Repo key for the minor version of the Solo distribution of Istio
    # This is the 12-character hash at the end of the repo URL: 'us-docker.pkg.dev/gloo-mesh/istio-<repo-key>'
    export REPO_KEY=<repo_key>
    
    # Solo distrubution of Istio patch version and Solo tag
    # Optionally append other Solo tags as needed
    export ISTIO_IMAGE=${ISTIO_VERSION}-solo
    # Solo distribution of Istio image repo
    export REPO=us-docker.pkg.dev/gloo-mesh/istio-${REPO_KEY}
      

    Be sure to review the following known Istio version restrictions.

  2. Upgrade your istioctl CLI client to the new version.

      curl -L https://istio.io/downloadIstio | ISTIO_VERSION=${ISTIO_VERSION} sh -
    cd istio-${ISTIO_VERSION}
    export PATH=$PWD/bin:$PATH
      
  3. Add and update the Helm repository for Istio.

      helm repo add istio https://istio-release.storage.googleapis.com/charts
    helm repo update
      

Upgrade service meshes

  1. Save the name and kubeconfig context of a workload cluster in the following environment variables. Each time you repeat the steps in this guide, you change these variables to the next workload cluster’s name and context.

      export CLUSTER_NAME=<cluster-name>
    export CLUSTER_CONTEXT=<cluster-context>
      
  2. Upgrade the Istio CRDs to the new version.

      helm get values istio-base -n istio-system --kube-context ${CLUSTER_CONTEXT} -o yaml > istio-base.yaml
    helm upgrade istio-base istio/base \
    --namespace istio-system \
    --kube-context ${CLUSTER_CONTEXT} \
    --version ${ISTIO_VERSION} \
    -f istio-base.yaml
      
  3. Get the current values for the istiod Helm release in your cluster. Your release might have a different name.

      helm get values istiod -n istio-system --kube-context ${CLUSTER_CONTEXT} -o yaml > istiod.yaml
    open istiod.yaml
      
  4. Make edits to the istiod Helm values, and save the file. If you update the Istio minor version, such as in the global.tag field, be sure to also update the value of the hub field to the repo for the correct version of the Solo distribution of Istio.

  5. Upgrade your Helm release with the updated values.

      helm upgrade istiod istio/istiod \
    -n istio-system \
    --kube-context ${CLUSTER_CONTEXT} \
    --version ${ISTIO_VERSION} \
    -f istiod.yaml
      
  6. Verify that the istiod pods are successfully restarted. Note that it might take a few seconds for the pods to become available.

      kubectl --kube-context ${CLUSTER_CONTEXT} get pods -n istio-system | grep istiod
      

    Example output:

      istiod-main-bb86b959f-msrg7   1/1     Running   0          2m45s
    istiod-main-bb86b959f-w29cm   1/1     Running   0          3m
      
  7. Optional: If you installed the Istio CNI, upgrade its Helm release.

    1. Get the current values for the CNI Helm release in your cluster.

    2. Make edits to the Helm values, and save the file. If you update the Istio minor version, such as in tag fields, be sure to also update the value of the hub field to the repo for the correct version of the Solo distribution of Istio.

    3. Upgrade your Helm release with the updated values.

    4. Verify that the Istio CNI pods are successfully restarted. Note that it might take a few seconds for the pods to become available.

      Example output:

        ...
      istio-cni-node-pr5rl               1/1     Running   0             42s
      istio-cni-node-pvmx2               1/1     Running   0             42s
      istio-cni-node-lcrcd               1/1     Running   0             42s
        
  8. Multicluster setups: Repeat steps 1 - 7 for each cluster where you want to upgrade Istio. Be sure to change the values of the $CLUSTER_NAME and $CLUSTER_CONTEXT environment variables for each cluster.