Continental Innovates with Rancher and Kubernetes
Important: RKE add-on install is only supported up to Rancher v2.0.8 Please use the Rancher Helm chart to install Rancher on a Kubernetes cluster. For details, see the Kubernetes Install . If you are currently using the RKE add-on install method, see Migrating from a Kubernetes Install with an RKE Add-on for details on how to move to using the helm chart.
Please use the Rancher Helm chart to install Rancher on a Kubernetes cluster. For details, see the Kubernetes Install .
If you are currently using the RKE add-on install method, see Migrating from a Kubernetes Install with an RKE Add-on for details on how to move to using the helm chart.
This procedure walks you through setting up a 3-node cluster using the Rancher Kubernetes Engine (RKE). The cluster’s sole purpose is running pods for Rancher. The setup is based on:
In an Kubernetes setup that uses a layer 7 load balancer, the load balancer accepts Rancher client connections over the HTTP protocol (i.e., the application level). This application-level access allows the load balancer to read client requests and then redirect to them to cluster nodes using logic that optimally distributes load.
Kubernetes Rancher install with layer 7 load balancer, depicting SSL termination at load balancer
Installation of Rancher in a high-availability configuration involves multiple procedures. Review this outline to learn about each procedure you need to complete.
Provision three Linux hosts according to our Requirements.
When using a load balancer in front of Rancher, there’s no need for the container to redirect port communication from port 80 or port 443. By passing the header X-Forwarded-Proto: https, this redirect is disabled. This is the expected configuration when terminating SSL externally.
X-Forwarded-Proto: https
The load balancer has to be configured to support the following:
Host
X-Forwarded-Proto
https
rancher/rancher
X-Forwarded-Port
X-Forwarded-For
Health checks can be executed on the /healthz endpoint of the node, this will return HTTP 200.
/healthz
We have example configurations for the following load balancers:
Choose a fully qualified domain name (FQDN) that you want to use to access Rancher (e.g., rancher.yourdomain.com).
rancher.yourdomain.com
Log into your DNS server a create a DNS A record that points to the IP address of your load balancer.
DNS A
Validate that the DNS A is working correctly. Run the following command from any terminal, replacing HOSTNAME.DOMAIN.COM with your chosen FQDN:
HOSTNAME.DOMAIN.COM
nslookup HOSTNAME.DOMAIN.COM
Step Result: Terminal displays output similar to the following:
$ nslookup rancher.yourdomain.com Server: YOUR_HOSTNAME_IP_ADDRESS Address: YOUR_HOSTNAME_IP_ADDRESS#53 Non-authoritative answer: Name: rancher.yourdomain.com Address: HOSTNAME.DOMAIN.COM
RKE (Rancher Kubernetes Engine) is a fast, versatile Kubernetes installer that you can use to install Kubernetes on your Linux hosts. We will use RKE to setup our cluster and run Rancher.
Follow the RKE Install instructions.
Confirm that RKE is now executable by running the following command:
rke --version
RKE uses a YAML config file to install and configure your Kubernetes cluster. There are 2 templates to choose from, depending on the SSL certificate you want to use.
Download one of following templates, depending on the SSL certificate you’re using.
3-node-externalssl-certificate.yml
3-node-externalssl-recognizedca.yml
Advanced Config Options: Want records of all transactions with the Rancher API? Enable the API Auditing feature by editing your RKE config file. For more information, see how to enable it in your RKE config file. Want to know the other config options available for your RKE template? See the RKE Documentation: Config Options.
Advanced Config Options:
Rename the file to rancher-cluster.yml.
rancher-cluster.yml
Once you have the rancher-cluster.yml config file template, edit the nodes section to point toward your Linux hosts.
Open rancher-cluster.yml in your favorite text editor.
Update the nodes section with the information of your Linux hosts.
nodes
For each node in your cluster, update the following placeholders: IP_ADDRESS_X and USER. The specified user should be able to access the Docker socket, you can test this by logging in with the specified user and run docker ps.
IP_ADDRESS_X
USER
docker ps
Note: When using RHEL/CentOS, the SSH user can’t be root due to https://bugzilla.redhat.com/show_bug.cgi?id=1527565. See Operating System Requirements for RHEL/CentOS specific requirements.
Note:
When using RHEL/CentOS, the SSH user can’t be root due to https://bugzilla.redhat.com/show_bug.cgi?id=1527565. See Operating System Requirements for RHEL/CentOS specific requirements.
nodes: # The IP address or hostname of the node - address: IP_ADDRESS_1 # User that can login to the node and has access to the Docker socket (i.e. can execute `docker ps` on the node) # When using RHEL/CentOS, this can't be root due to https://bugzilla.redhat.com/show_bug.cgi?id=1527565 user: USER role: [controlplane,etcd,worker] # Path the SSH key that can be used to access to node with the specified user ssh_key_path: ~/.ssh/id_rsa - address: IP_ADDRESS_2 user: USER role: [controlplane,etcd,worker] ssh_key_path: ~/.ssh/id_rsa - address: IP_ADDRESS_3 user: USER role: [controlplane,etcd,worker] ssh_key_path: ~/.ssh/id_rsa
Optional: By default, rancher-cluster.yml is configured to take backup snapshots of your data. To disable these snapshots, change the backup directive setting to false, as depicted below.
backup
false
services: etcd: backup: false
For security purposes, SSL (Secure Sockets Layer) is required when using Rancher. SSL secures all Rancher network communication, like when you login or interact with a cluster.
Choose from the following options:
Prerequisites: Create a self-signed certificate. The certificate files must be in PEM format. The certificate files must be encoded in base64. In your certificate file, include all intermediate certificates in the chain. Order your certificates with your certificate first, followed by the intermediates. For an example, see Certificate Troubleshooting.
Prerequisites: Create a self-signed certificate.
In kind: Secret with name: cattle-keys-ingress, replace <BASE64_CA> with the base64 encoded string of the CA Certificate file (usually called ca.pem or ca.crt)
kind: Secret
name: cattle-keys-ingress
<BASE64_CA>
ca.pem
ca.crt
Note: The base64 encoded string should be on the same line as cacerts.pem, without any newline at the beginning, in between or at the end.
cacerts.pem
After replacing the values, the file should look like the example below (the base64 encoded strings should be different):
--- apiVersion: v1 kind: Secret metadata: name: cattle-keys-server namespace: cattle-system type: Opaque data: cacerts.pem: 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
If you are using a Certificate Signed By A Recognized Certificate Authority, you don’t need to perform any step in this part.
There is one reference to <FQDN> in the RKE config file. Replace this reference with the FQDN you chose in 3. Configure DNS.
<FQDN>
Open rancher-cluster.yml.
In the kind: Ingress with name: cattle-ingress-http:
kind: Ingress
name: cattle-ingress-http:
Replace <FQDN> with the FQDN chosen in 3. Configure DNS.
Step Result: After replacing the values, the file should look like the example below (the base64 encoded strings should be different):
apiVersion: extensions/v1beta1 kind: Ingress metadata: namespace: cattle-system name: cattle-ingress-http annotations: nginx.ingress.kubernetes.io/proxy-connect-timeout: "30" nginx.ingress.kubernetes.io/proxy-read-timeout: "1800" # Max time in seconds for ws to remain shell window open nginx.ingress.kubernetes.io/proxy-send-timeout: "1800" # Max time in seconds for ws to remain shell window open spec: rules: - host: rancher.yourdomain.com http: paths: - backend: serviceName: cattle-service servicePort: 80
Save the file and close it.
The last reference that needs to be replaced is <RANCHER_VERSION>. This needs to be replaced with a Rancher version which is marked as stable. The latest stable release of Rancher can be found in the GitHub README. Make sure the version is an actual version number, and not a named tag like stable or latest. The example below shows the version configured to v2.0.6.
<RANCHER_VERSION>
stable
latest
v2.0.6
spec: serviceAccountName: cattle-admin containers: - image: rancher/rancher:v2.0.6 imagePullPolicy: Always
After you close your RKE config file, rancher-cluster.yml, back it up to a secure location. You can use this file again when it’s time to upgrade Rancher.
With all configuration in place, use RKE to launch Rancher. You can complete this action by running the rke up command and using the --config parameter to point toward your config file.
rke up
--config
From your workstation, make sure rancher-cluster.yml and the downloaded rke binary are in the same directory.
rke
Open a Terminal instance. Change to the directory that contains your config file and rke.
Enter one of the rke up commands listen below.
rke up --config rancher-cluster.yml
Step Result: The output should be similar to the snippet below:
INFO[0000] Building Kubernetes cluster INFO[0000] [dialer] Setup tunnel for host [1.1.1.1] INFO[0000] [network] Deploying port listener containers INFO[0000] [network] Pulling image [alpine:latest] on host [1.1.1.1] ... INFO[0101] Finished building Kubernetes cluster successfully
During installation, RKE automatically generates a config file named kube_config_rancher-cluster.yml in the same directory as the rancher-cluster.yml file. Copy this file and back it up to a safe location. You’ll use this file later when upgrading Rancher Server.
kube_config_rancher-cluster.yml
You can recognize the PEM format by the following traits:
-----BEGIN CERTIFICATE-----
-----END CERTIFICATE-----
PEM Certificate Example:
----BEGIN CERTIFICATE----- MIIGVDCCBDygAwIBAgIJAMiIrEm29kRLMA0GCSqGSIb3DQEBCwUAMHkxCzAJBgNV ... more lines VWQqljhfacYPgp8KJUJENQ9h5hZ2nSCrI+W00Jcw4QcEdCI8HL5wmg== -----END CERTIFICATE-----
To encode your certificates in base64:
FILENAME
# MacOS cat FILENAME | base64 # Linux cat FILENAME | base64 -w0 # Windows certutil -encode FILENAME FILENAME.base64
To decode your certificates in base64:
YOUR_BASE64_STRING
# MacOS echo YOUR_BASE64_STRING | base64 -D # Linux echo YOUR_BASE64_STRING | base64 -d # Windows certutil -decode FILENAME.base64 FILENAME.verify
The order of adding certificates is as follows:
-----BEGIN CERTIFICATE----- %YOUR_CERTIFICATE% -----END CERTIFICATE----- -----BEGIN CERTIFICATE----- %YOUR_INTERMEDIATE_CERTIFICATE% -----END CERTIFICATE-----
You can validate the certificate chain by using the openssl binary. If the output of the command (see the command example below) ends with Verify return code: 0 (ok), your certificate chain is valid. The ca.pem file must be the same as you added to the rancher/rancher container. When using a certificate signed by a recognized Certificate Authority, you can omit the -CAfile parameter.
openssl
Verify return code: 0 (ok)
-CAfile
Command:
openssl s_client -CAfile ca.pem -connect rancher.yourdomain.com:443 -servername rancher.yourdomain.com ... Verify return code: 0 (ok)