Applies to SUSE Linux Enterprise Server 15 SP3, K3s 1.20.14, SUSE Rancher 2.5.12

5 Deployment #

This section describes the process steps for the deployment of the SUSE Rancher solution. It describes the process steps to deploy each of the component layers starting as a base functional proof-of-concept, having considerations on migration toward production, providing scaling guidance that is needed to create the solution.

5.1 Deployment overview #

The deployment stack is represented in the following figure:

Figure 5.1: Deployment Stack - SUSE Rancher #

and details are covered for each layer in the following sections.

Note

The following section’s content is ordered and described from the bottom layer up to the top.

5.2 Compute Platform #

The base, starting configuration can reside all within a single server. Based upon the relatively small resource requirements for a SUSE Rancher deployment, a viable approach is to deploy directly on baremetal or as a virtual machine (VM) on the target nodes, on top of an existing hypervisor, like KVM. For physical host, there are tools that can be used during the setup of the server, see below:

The Supermicro Baseboad Management Controller (BMC) provides remote access to multiple users at different locations for networking. It also allows a system administrator to monitor system health and manage computer events remotely, including media redirection of software image files used for installing operating systems and and HTML5 web console interaction.

5.3 SUSE Linux Enterprise Server #

As the base software layer, use an enterprise-grade Linux operating system. For example, SUSE Linux Enterprise Server.

Preparation(s)

To meet the solution stack prerequisites and requirements, SUSE operating system offerings, like SUSE Linux Enterprise Server can be used.

Ensure these services are in place and configured for this node to use:
- Domain Name Service (DNS) - an external network-accessible service to map IP Addresses to host names
- Network Time Protocol (NTP) - an external network-accessible service to obtain and synchronize system times to aid in time stamp consistency
- Software Update Service - access to a network-based repository for software update packages. This can be accessed directly from each node via registration to
  - the general, internet-based SUSE Customer Center (SCC) or
  - an organization’s SUSE Manager infrastructure or
  - a local server running an instance of Repository Mirroring Tool (RMT)
    Note
    During the node’s installation, it can be pointed to the respective update service. This can also be accomplished post-installation with the command line tool named SUSEConnect.

Deployment Process

On the compute platform node, install the noted SUSE operating system, by following these steps:

Download the SUSE Linux Enterprise Server product (either for the ISO or Virtual Machine image)
- Identify the appropriate, supported version of SUSE Linux Enterprise Server by reviewing the support matrix for SUSE Rancher versions Web page.
The installation process is described and can be performed with default values by following steps from the product documentation, see Installation Quick Start
Tip
Adjust both the password and the local network addressing setup to comply with local environment guidelines and requirements.

Deployment Consideration(s)

To further optimize deployment factors, leverage the following practices:

Automation
- To reduce user intervention, unattended deployments of SUSE Linux Enterprise Server can be automated
  - for ISO-based installations, by referring to the AutoYaST Guide

5.4 K3s #

Preparation(s)

Identify the appropriate, desired version of the K3s binary (for example vX.YY.ZZ+k3s1) by reviewing
- the "Installing SUSE Rancher on K3s" associated with the respective SUSE Rancher version, or
- the "Releases" on the Download Web page.
For the underlying operating system firewall service, either
- enable and configure the necessary inbound ports or
- stop and completely disable the firewall service.

Deployment Process

Perform the following steps to install the first K3s server on one of the nodes to be used for the Kubernetes control plane

Set the following variable with the noted version of K3s, as found during the preparation steps.
```
K3s_VERSION=""
```
Install the version of K3s with embedded etcd enabled:
```
curl -sfL https://get.k3s.io | \
        INSTALL_K3S_VERSION=${K3s_VERSION} \
        INSTALL_K3S_EXEC='server --cluster-init --write-kubeconfig-mode=644' \
        sh -s -
```
Tip
To address Availability and possible scaling to a multiple node cluster, etcd is enabled instead of using the default SQLite datastore.
- Monitor the progress of the installation: watch -c "kubectl get deployments -A"
  - The K3s deployment is complete when elements of all the deployments (coredns, local-path-provisioner, metrics-server, and traefik) show at least "1" as "AVAILABLE"
  - Use Ctrl+c to exit the watch loop after all deployment pods are running

Deployment Consideration(s)

To further optimize deployment factors, leverage the following practices:

Availability
- A full high-availability K3s cluster is recommended for production workloads. The etcd key/value store (aka database) requires an odd number of servers (aka master nodes) be allocated to the K3s cluster. In this case, two additional control-plane servers should be added; for a total of three.
  1. Deploy the same operating system on the new compute platform nodes, then log in to the new nodes as root or as a user with sudo privileges.
  2. Execute the following sets of commands on each of the remaining control-plane nodes:
    Set the following additional variables, as appropriate for this cluster
    # Private IP preferred, if available FIRST_SERVER_IP="" # From /var/lib/rancher/k3s/server/node-token file on the first server NODE_TOKEN="" # Match the first of the first server K3s_VERSION=""
    Install K3s
    curl -sfL https://get.k3s.io | \ INSTALL_K3S_VERSION=${K3s_VERSION} \ K3S_URL=https://${FIRST_SERVER_IP}:6443 \ K3S_TOKEN=${NODE_TOKEN} \ K3S_KUBECONFIG_MODE="644" INSTALL_K3S_EXEC='server' \ sh -
    Monitor the progress of the installation: watch -c "kubectl get deployments -A"
    The K3s deployment is complete when elements of all the deployments (coredns, local-path-provisioner, metrics-server, and traefik) show at least "1" as "AVAILABLE"
    Use Ctrl+c to exit the watch loop after all deployment pods are running
    By default, the K3s server nodes are available to run non-control-plane workloads. In this case, the K3s default behavior is perfect for the SUSE Rancher server cluster as it does not require additional agent (aka worker) nodes to maintain a highly available SUSE Rancher server application.
    Note
    This can be changed to the normal Kubernetes default by adding a taint to each server node. See the official Kubernetes documentation for more information on how to do that.
    (Optional) In cases where agent nodes are desired, execute the following sets of commands, using the same "K3s_VERSION", "FIRST_SERVER_IP", and "NODE_TOKEN" variable settings as above, on each of the agent nodes to add it to the K3s cluster:
    curl -sfL https://get.k3s.io | \ INSTALL_K3S_VERSION=${K3s_VERSION} \ K3S_URL=https://${FIRST_SERVER_IP}:6443 \ K3S_TOKEN=${NODE_TOKEN} \ K3S_KUBECONFIG_MODE="644" \ sh -

5.5 SUSE Rancher #

Preparation(s)

For the respective node’s firewall service, either
- enable and configure the necessary inbound ports or
- stop and completely disable the firewall service.
Determine the desired SSL configuration for TLS termination
- Rancher-generated TLS certificate NOTE: This is the easiest way of installing SUSE Rancher with self-signed certificates.
- Let’s Encrypt
- Bring your own certificate
Obtain a Helm binary matching the respective Kubernetes version for this SUSE Rancher implementation.
Note
Enable the respective kubeconfig setting for kubectl , K3s - /etc/rancher/k3s/k3s.yml, to be leveraged by helm command.

Deployment Process

While logged in to the node, as root or with sudo privileges, install SUSE Rancher:

Install cert-manager

Set the following variable with the desired version of cert-manager
```
CERT_MANAGER_VERSION=""
```
Note
At this time, the most current, supported version of cert-manager is v1.5.1

Create the cert-manager CRDs and apply the Helm Chart resource manifest

kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/${CERT_MANAGER_VERSION}/cert-manager.crds.yaml

# Add the Jetstack Helm repository
helm repo add jetstack https://charts.jetstack.io

# Update your local Helm chart repository cache
helm repo update

# Install the cert-manager Helm chart
helm install cert-manager jetstack/cert-manager \
  --namespace cert-manager \
  --create-namespace \
  --version ${CERT_MANAGER_VERSION}

Check the progress of the installation, looking for all pods to be in running status:
```
kubectl get pods --namespace cert-manager
```

Add the SUSE Rancher helm chart repository:

helm repo add rancher-stable https://releases.rancher.com/server-charts/stable

Create a namespace for SUSE Rancher
```
kubectl create namespace cattle-system
```
Prepare to use the Helm Chart for SUSE Rancher:
- Set the following variable to the host name of the SUSE Rancher server instance
```
HOSTNAME=""
```
  Note
  This host name should be resolvable to an IP address of the K3s host, or a load balancer/proxy server that supports this installation of SUSE Rancher.
- Set the following variable to the number of deployed K3s nodes planned to host the SUSE Rancher service
```
REPLICAS=""
```
- Set the following variable to the desired version of SUSE Rancher server instance
```
RANCHER_VERSION=""
```
- Install the SUSE Rancher Helm Chart
```
helm install rancher rancher-stable/rancher \
  --namespace cattle-system \
  --set hostname=${HOSTNAME} \
  --set replicas=${REPLICAS} \
  --version=${RANCHER_VERSION}
```
  - Monitor the progress of the installation:
    kubectl -n cattle-system rollout status deploy/rancher
(Optional) Create an SSH tunnel to access SUSE Rancher:
Note
This optional step is useful in cases where NAT routers and/or firewalls prevent the client Web browser from reaching the exposed SUSE Rancher server IP address and/or port. This step requires that a Linux host is accessible through SSH from the client system and that the Linux host can reach the exposed SUSE Rancher service. The SUSE Rancher host name should be resolvable to the appropriate IP address by the local workstation.
- Create an SSH tunnel through the Linux host to the IP address of the SUSE Rancher server on the NodePort, as noted in Step 3:
```
ssh -N -D 8080 user@Linux-host
```
- On the local workstation Web browser, change the SOCKS Host settings to "127.0.0.1" and port "8080".
  Note
  This will route all traffic from this Web browser through the remote Linux host. Be sure to close the tunnel and revert the SOCKS Host settings when you are done.
Connect to the SUSE Rancher Web UI:
- On a client system, use a Web browser to connect to the SUSE Rancher service, via HTTPs.
- Provide a new Admin password.
  Important
  On the second configuration page, ensure the "Rancher Server URL" is set to the host name specified when installing the SUSE Rancher Helm Chart and the port is 443.

Deployment Consideration(s)

To further optimize deployment factors, leverage the following practices

Availability
- In instances where a load balancer is used to access a K3s cluster, deploying two additional K3s cluster nodes, for a total of three, will automatically make SUSE Rancher highly available.
Security
- The basic deployment steps described above are for deploying SUSE Rancher with automatically generated, self-signed security certificates. Other options are to have SUSE Rancher create public certificates via Let’s Encrypt associated with a publicly resolvable host name for the SUSE Rancher server, or to provide preconfigured, private certificates.
Integrity
- This deployment of SUSE Rancher uses the K3s etcd key/value store to persist its data and configuration, which offers several advantages. With a multi-node cluster and this resiliency through replication, having to provide highly-available storage is not needed. In addition, backing up the K3s etcd store protects the cluster and the installation of SUSE Rancher and permits restoration of a given state.

After this successful deployment of the SUSE Rancher solution, review the product documentation for details on how downstream Kubernetes clusters can be:

deployed (refer to sub-section "Setting up Kubernetes Clusters in Rancher") or
imported (refer to sub-section "Importing Existing Clusters"), then
managed (refer to sub-section "Cluster Administration") and
accessed (refer to sub-section "Cluster Access") to address orchestration of workload, maintaining security and many more functions are readily available.