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Best Practices for Harvester Security

· 5 min read
Jian Wang

User-Provided Credentials on Harvester

When installing a Harvester cluster, you are asked to provide the following credential related information:

  • Cluster token of the first node that is added to the cluster. Other nodes must use this token to join the cluster.

  • Password for the default Linux user rancher on each node.

  • SSH keys on each node (optional).

  • HTTP proxy on each node (optional).

You may plan to change them from time to time, the following paragraphs describe the detailed steps.

Cluster Token

Cluster Token on Nodes Joining an Existing Cluster

When a node is unable to join a cluster because of a cluster token error, perform the recommended troubleshooting steps.

Cluster Token (RKE2 Token Rotation)

Harvester does not allow you to change the cluster token even if RKE2 is a core component of Harvester.

The RKE2 documentation states that the November 2023 releases of RKE2 (v1.28.3+rke2r2, v1.27.7+rke2r2, v1.26.10+rke2r2, and v1.25.15+rke2r2) allow you to rotate the cluster token using the command rke2 token rotate --token original --new-token new.

During testing, the command was run on the first node of a cluster running Harvester v1.3.0 with RKE2 v1.27.10+rke2r1.

  1. Rotate the token on initial node.
/opt/rke2/bin $ ./rke2 token rotate --token rancher --new-token rancher1

WARNING: Recommended to keep a record of the old token. If restoring from a snapshot, you must use the token associated with that snapshot.
WARN[0000] Cluster CA certificate is not trusted by the host CA bundle, but the token does not include a CA hash. Use the full token from the server's node-token file to enable Cluster CA validation.
Token rotated, restart rke2 nodes with new token
  1. When the first cluster node was rebooted, RKE2 service was unable to start.
RKE2 log:

May 29 15:45:11 harv41 rke2[3293]: time="2024-05-29T15:45:11Z" level=info msg="etcd temporary data store connection OK"
May 29 15:45:11 harv41 rke2[3293]: time="2024-05-29T15:45:11Z" level=info msg="Reconciling bootstrap data between datastore and disk"
May 29 15:45:11 harv41 rke2[3293]: time="2024-05-29T15:45:11Z" level=fatal msg="Failed to reconcile with temporary etcd: bootstrap data already found and encrypted with different token"
May 29 15:45:11 harv41 systemd[1]: rke2-server.service: Main process exited, code=exited, status=1/FAILURE

This known issue was logged on Github issue rke2 token rotate does not work as expected (v1.27.10+rke2r1).


Do not attempt to rotate the RKE2 token on your cluster before Harvester announces official support for this feature (even if the embedded RKE2 binary has the token rotate option).


Password of the Default User rancher

This process is node-specific. You must change the password of the default user on each node even if the same password is used on all Harvester nodes.

SSH keys

You must log into a Harvester node using the default user account rancher to change the SSH keys.

HTTP Proxy

After a Harvester cluster is installed, you can use the Harvester UI to change the HTTP proxy.

Alternatively, you can use kubectl or the rest API against the URI /

$ kubectl get http-proxy -oyaml

default: '{}'
kind: Setting
creationTimestamp: "2024-05-13T20:44:20Z"
generation: 1
name: http-proxy
resourceVersion: "5914"
uid: 282506bb-f1dd-4247-bf0e-93640698c1f5
status: {}

Harvester has a webhook that checks this setting to ensure it meets all conditions, e.g. the internal IPs and CIDRs are specified in the noProxy field.


Avoid changing the HTTP proxy from files in the host /oem path for the following reasons:

  • You must manually change the HTTP proxy on each node.

  • Contents of local files are not automatically populated to new nodes.

  • Without help from the webhook, some erroneous configurations may not be promptly detected (see Node IP should be in noProxy).

  • Harvester may change the file naming or content structure in the future.

Other Credentials and Settings


Harvester is built on top of Kubernetes, RKE2, and Rancher. RKE2 generates a list of *.crt and *.key files that allow Kubernetes components to function. The *.crt file expires after one year by default.

$ ls /var/lib/rancher/rke2/server/tls/ -alth

-rw-r--r-- 1 root root 570 May 27 08:45 server-ca.nochain.crt
-rw------- 1 root root 1.7K May 27 08:45 service.current.key
-rw-r--r-- 1 root root 574 May 27 08:45 client-ca.nochain.crt
drwxr-xr-x 2 root root 4.0K May 13 20:45 kube-controller-manager
drwxr-xr-x 2 root root 4.0K May 13 20:45 kube-scheduler
drwx------ 6 root root 4.0K May 13 20:45 .
drwx------ 8 root root 4.0K May 13 20:45 ..
-rw-r--r-- 1 root root 3.9K May 13 20:40 dynamic-cert.json
drwx------ 2 root root 4.0K May 13 20:39 temporary-certs
-rw------- 1 root root 1.7K May 13 20:39 service.key
-rw-r--r-- 1 root root 1.2K May 13 20:39 client-auth-proxy.crt
-rw------- 1 root root 227 May 13 20:39 client-auth-proxy.key
-rw-r--r-- 1 root root 1.2K May 13 20:39 client-rke2-cloud-controller.crt
-rw-r--r-- 1 root root 1.2K May 13 20:39 client-admin.crt
-rw------- 1 root root 227 May 13 20:39 client-admin.key

$ openssl x509 -enddate -noout -in /var/lib/rancher/rke2/server/tls/client-admin.crt

notAfter=May 13 20:39:42 2025 GMT

When a cluster has been running for over one year, Kubernetes components may fail to start after upgrades or node rebooting. The workaround is to delete the related files and restart the pod.

Harvester v1.3.0 added the setting auto-rotate-rke2-certs, which allows you to set the Harvester cluster to automatically rotate certificates for RKE2 services. When you enable the setting and specify a certificate validity period, Harvester automatically replaces the certificate before the specified period ends.


Enabling this setting on your cluster is highly recommended.

Harvester Cloud Credentials

See the article Renew Harvester Cloud Credentials.


See the documentation for this setting.


See the documentation for this setting.


See the documentation for this setting.


See the documentation for this setting.