Install Custom Drivers in NodeRed

NodeRed is running on Alpine Linux as non-root user. This means that you can’t install packages with apk. This tutorial shows you how to install packages with proper security measures.

Before you begin

You need to have a UMH cluster. If you do not already have a cluster, you can create one by following the Getting Started guide.

You also need to access the system where the cluster is running, either by logging into it or by using a remote shell.

Change the security context

From the instance’s shell, execute this command:

sudo $(which kubectl) patch statefulset united-manufacturing-hub-nodered -n united-manufacturing-hub -p '{"spec":{"template":{"spec":{"securityContext":{"runAsUser":0,"runAsNonRoot":false,"fsGroup":0}}}}}' --kubeconfig /etc/rancher/k3s/k3s.yaml

Install the packages

1. Open a shell in the united-manufacturing-hub-nodered-0 pod with:

   sudo $(which kubectl) exec -it united-manufacturing-hub-nodered-0 -n united-manufacturing-hub --kubeconfig /etc/rancher/k3s/k3s.yaml -- /bin/sh
   

2. Install the packages with apk:

   apk add <package>
   

   For example, to install unixodbc:

   apk add unixodbc
   

   You can find the list of available packages here.

3. Exit the shell by typing exit.

Revert the security context

For security reasons, you should revert the security context after you install the packages.

From the instance’s shell, execute this command:

sudo $(which kubectl) patch statefulset united-manufacturing-hub-nodered -n united-manufacturing-hub -p '{"spec":{"template":{"spec":{"securityContext":{"runAsUser":1000,"runAsNonRoot":true,"fsGroup":1000}}}}}' --kubeconfig /etc/rancher/k3s/k3s.yaml

What’s next