Upgrading from kube-up to kops

    This is a slightly risky procedure, so we recommend backing up important data before proceeding.Take a snapshot of your EBS volumes; export all your data from kubectl etc.

    Limitations:

    • kops splits etcd onto two volumes now: and events. We will keep the main data, butyou will lose your events history.

    There are a few steps to upgrade a kubernetes cluster:

    • First you import the existing cluster state, so you can see and edit the configuration
    • You verify the cluster configuration
    • You move existing AWS resources to your new cluster
    • You bring up the new cluster
    • You can then delete the old cluster

    Importing the existing cluster

    The import cluster command reverse engineers an existing cluster, and creates a clusterconfiguration.

    Make sure you have set export KOPS_STATE_STORE=s3://<mybucket>

    Then import the cluster; setting --name and --region to match the old cluster. If you’re not sureof the old cluster name, you can find it by looking at the KubernetesCluster tag on your AWS resources.

    Verify the cluster configuration

    Now have a look at the cluster configuration, to make sure it looks right. If it doesn’t, pleaseopen an issue.

    1. kops get cluster ${OLD_NAME} -oyaml
    2. `

    The upgrade moves some resources so they will be adopted by the new cluster. There are a number of thingsthis step does:

    • It will stop the existing master
    • It detaches the master EBS volume from the master
    • It re-tags resources to associate them with the new cluster: volumes, ELBs
    • It re-tags the VPC to associate it with the new cluster

    The upgrade procedure forces you to choose a new cluster name (e.g. k8s.mydomain.com)

    1. export NEW_NAME=k8s.mydomain.com
    2. kops toolbox convert-imported --newname ${NEW_NAME} --name ${OLD_NAME}

    If you now list the clusters, you should see both the old cluster & the new cluster

    1. kops get clusters

    Import the SSH public key

    The SSH public key is not easily retrieved from the old cluster, so you must add it:

    Bring up the new cluster

    Use the update command to bring up the new cluster:

    1. kops update cluster ${NEW_NAME}

    Things to check are that it is reusing the existing volume for the main etcd cluster (but not the events clusters).

    And then when you are happy:

    1. kops update cluster ${NEW_NAME} --yes

    You can export a kubecfg (although update cluster did this automatically):

    Workaround for secret import failure

    The import procedure tries to preserve the CA certificates, but unfortunately this isn’t supportedin kubernetes until ships (should bein 1.5).

    So you will need to delete the service-accounts, so they can be recreated with the correct keys.

    Unfortunately, until you do this, some services (most notably internal & external DNS) will not work.Because of that you must SSH to the master to do this repair.

    You can get the public IP address of the master from the AWS console, or by doing this:

    1. aws ec2 --region $REGION describe-instances \
    2.     --filter Name=tag:KubernetesCluster,Values=${NEW_NAME} \
    3.              Name=tag-key,Values=k8s.io/role/master \
    4.              Name=instance-state-name,Values=running \
    5.     --query Reservations[].Instances[].PublicIpAddress \
    6.     --output text

    Then ssh admin@<ip> (the SSH key will be the one you added above, i.e. ~/.ssh/id_rsa.pub), and run:

    You should see only one node (the master). Then run

    1. NS=`kubectl get namespaces -o 'jsonpath={.items[*].metadata.name}'`
    2. for i in ${NS}; do kubectl get secrets --namespace=${i} --no-headers | grep "kubernetes.io/service-account-token" | awk '{print $1}' | xargs -I {} kubectl delete secret --namespace=$i {}; done
    3. sleep 60 # Allow for new secrets to be created
    4. kubectl delete pods -lk8s-app=kube-dns --namespace=kube-system

    You probably also want to delete the imported DNS services from prior versions:

    1. kubectl delete rc -lk8s-app=kube-dns --namespace=kube-system # Will work for k8s <= 1.4
    2. kubectl delete deployment --namespace=kube-system  kube-dns # Will work for k8s >= 1.5

    Within a few minutes the new cluster should be running.

    Try kubectl get nodes --show-labels, etc until you are sure that all is well.

    This should work even without being SSH-ed into the master, although it can take a few minutesfor DNS to propagate. If it doesn’t work, double-check that you have specified a validdomain name for your cluster, that records have been created in Route53, and that youcan resolve those records from your machine (using nslookup or dig).

    Other fixes

    • If you’re using a manually created ELB, the auto-scaling groups change, so you will need to reconfigureyour ELBs to include the new auto-scaling group(s).

    • It is recommended to delete old kubernetes system services that we imported (and replace them with newer versions):

    1. kubectl delete rc -lk8s-app=kube-dns --namespace=kube-system       # <= 1.4
    2. kubectl delete deployment --namespace=kube-system  kube-dns        # 1.5
    4. kubectl delete rc -lk8s-app=elasticsearch-logging --namespace=kube-system
    6. kubectl delete rc -lk8s-app=kibana-logging --namespace=kube-system                   # <= 1.4
    7. kubectl delete deployment -lk8s-app=kibana-logging --namespace=kube-system           # 1.5
    9. kubectl delete rc -lk8s-app=kubernetes-dashboard --namespace=kube-system             # <= 1.4
    10. kubectl delete deployment -lk8s-app=kubernetes-dashboard --namespace=kube-system     # 1.5
    12. kubectl delete rc -lk8s-app=influxGrafana --namespace=kube-system

    And once you’ve confirmed it looks right, run with --yes

    You will also need to release the old ElasticIP manually.