Installing Edge on Kubernetes

Prerequisites

Special instructions for K3s

To enable the proper functioning of the Edge Operator on K3s, you must install K3s with the following configuration options.

Run the command below to install Kubernetes version 1.25.13:

sudo bash -c 'echo -e "vm.panic_on_oom=0\nvm.overcommit_memory=1\nkernel.panic=10\nkernel.panic_on_oops=1" >> /etc/sysctl.d/90-kubelet.conf' \
&& sudo sysctl -p /etc/sysctl.d/90-kubelet.conf \
&& curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION=v1.25.13+k3s1 sh -s - --disable=traefik --write-kubeconfig-mode 644 --protect-kernel-defaults true  --kube-apiserver-arg=admission-control=ValidatingAdmissionWebhook,MutatingAdmissionWebhook \
&& mkdir -p ~/.kube \
&& sudo cp /etc/rancher/k3s/k3s.yaml ~/.kube/config \
&& sudo chown $USER:$USER ~/.kube/config \
&& sudo chmod 600 ~/.kube/config \
&&echo -e '\e[32mSuccessfully installed k3s!\e[0m'

For configuration options, see K3s configuration options.

• Added --disable=traefik in the install command to disable Traefik to avoid port conflicts between Traefik and cumulocity-core service, as both are LoadBalancer type services which expose port 443.
• Added --kube-apiserver-arg=admission-control=ValidatingAdmissionWebhook,MutatingAdmissionWebhook to enable admission controllers. The flag is set to enable the ValidatingAdmissionWebhook and MutatingAdmissionWebhook admission controllers, as Edge requires them. See https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/.
• Added --protect-kernel-defaults true to protect the default kernel settings on the host system. It prevents modifications to critical kernel parameters by container workloads running in Kubernetes. For more information, see https://docs.k3s.io/security/hardening-guide#host-level-requirements.

Configuring proxy

When Cumulocity IoT Edge is deployed behind a proxy, it must be configured to communicate with external endpoints over the internet through the proxy server. To configure Edge to use a proxy, you must create or update a ConfigMap named custom-environment-variables in the c8yedge namespace (or the one you deployed Edge into) with the required proxy settings. The keys http_proxy, https_proxy and socks_proxy must be set to the URLs of the HTTP, HTTPS and Socks proxies, respectively. The key no_proxy must be set to specify a comma-separated list of domain suffixes, IP addresses, or CIDR ranges that Edge should bypass the proxy server for.

Here is an example of a ConfigMap with proxy settings: apiVersion: v1 kind: ConfigMap metadata: name: custom-environment-variables data: http_proxy: http://proxy-server-ip:port https_proxy: http://proxy-server-ip:port socks_proxy: socks5://proxy-server-ip:port no_proxy: 127.0.0.1,::1,localhost,.svc,.cluster.local,cumulocity,<edge domain name, for example, myown.iot.com>,<Kubernetes cluster IP range, for example, 10.43.0.0/16>

By configuring Edge with the appropriate proxy settings, you ensure that it can seamlessly communicate with external endpoints through the proxy server, allowing it to function effectively in environments where proxy usage is mandated.

The table below provides more information:

Configuring storage

Kubernetes makes physical storage devices available to your cluster in the form of two API resources, PersistentVolume and PersistentVolumeClaim.

A Persistent Volume (PV) is a storage resource in Kubernetes that is provisioned and managed independently from the Pods that use it. It provides a way to store data in a durable and persistent manner, even if the Pod that uses it is deleted or restarted.

PVs are typically used to store data that must be preserved across Pod restarts or rescheduling, such as databases or file systems. They can be backed by various storage technologies, such as local disks, network-attached storage (NAS), or cloud-based storage services.

To use a PV in Kubernetes, you need to define a PersistentVolume object that describes the characteristics of the storage, such as capacity, access modes, and the storage-provider-specific details. Once the PV is created, you can create a PersistentVolumeClaim object that requests a specific amount of storage with specific access requirements. The Persistent Volume Claim (PVC) binds to a matching PV, and the Pod can then use the PVC to mount the storage and access the data.

By using PVs and PVCs, you can decouple the storage management from the application deployment, making it easier to manage and scale your applications in Kubernetes.

PVs represent cluster resources, while PVCs serve as requests for these resources and also serve as validation checks for the resource they request. Provisioning PVs can be done in two ways: statically or dynamically.

• Static provisioning: In this method, a cluster administrator manually creates PVs, specifying details about the actual storage available for cluster users. These PVs are registered in the Kubernetes API and are ready for consumption.

• Dynamic provisioning: When none of the statically created PVs match a PVC’s requirements, the cluster can automatically provision storage on-demand, specifically tailored for the PVC. This dynamic provisioning relies on StorageClasses. To trigger dynamic provisioning, the PVC must request a StorageClass, and the administrator must have set up and configured that class accordingly. Claims that request an empty string (“”) for the class effectively disable dynamic provisioning for themselves. If no StorageClass is specified in a claim, it falls back to using a default StorageClass if one is configured in the cluster. To enable a default StorageClass, the cluster administrator must activate the DefaultStorageClass admission controller on the API server. This can be achieved, for instance, by ensuring that DefaultStorageClass is included in the comma-delimited, ordered list of values for the –enable-admission-plugins flag of the API server component. For more details on API server command-line flags, refer to the kube-apiserver documentation.

Persistent Volume Claims made by the Edge Operator

The Edge Operator requests three PVCs, as outlined in the table below. Each of these PVCs utilizes the StorageClass if specified within the spec.storageClassName field of the Edge CR.

• In case you omit the spec.storageClassName, the Edge Operator requests PVCs without a StorageClass, thereby instructing Kubernetes to utilize the default StorageClass configured in the cluster.

• If you explicitly specify an empty StorageClass as "", the Edge Operator requests PVCs with an empty StorageClass, thereby instructing Kubernetes to carry out static provisioning.

• Finally, if you specify the name of an existing StorageClass for which dynamic provisioning is enabled, the Operator requests PVCs with that same class name, thereby instructing Kubernetes to utilize dynamic provisioning according to the specified class.

To guarantee the retention of physical storage even after the PVC is deleted (for example, when Edge is deleted) and to enable future storage expansion if needed, it’s crucial to configure the StorageClass and/or the PVs with the following settings:

1. Reclaim Policy: Ensure that the reclaim policy is set to Retain. This setting preserves the storage even after the PVC deletion.
2. Volume Expansion: Set the volume expansion option to true. This setting enables the storage to be expanded when necessary.

If these recommended settings are not configured in the StorageClass, in the Edge CR status you receive the warnings below:

• persistent volume reclaim policy of StorageClass [storage-class] is currently set to [Delete] instead of the recommended value [Retain]

• allow volume to expand setting of the StorageClass [storage-class] is currently set to [false] instead of the recommended value [true]

These warnings serve as reminders to adjust these settings for optimal storage management.

Kubernetes provides a variety of persistent volume types, but two specific types enable Pod containers to access either a Network File System (NFS) or the cluster node’s local filesystem (often set up as a NFS drive mapped to a local folder). This configuration is especially prevalent in on-premises deployments.

Static provisioning of PVs

This section outlines the steps for configuring the Kubernetes cluster to enable Edge to utilize NFS as a source for the PVs. For additional storage options, refer to the Kubernetes documentation.

• Storage provisioning by connecting directly to the NFS server via PV configuration

  • Download the c8yedge-pv-nfs.yaml file.

  • Create and export the folders required for the 3 PVs defined in the c8yedge-pv-nfs.yaml file. Ensure that the user running Kubernetes server has read/write access to these folders.

  • Run the command below:

    kubectl apply -f c8yedge-pv-nfs.yaml
    

• Storage provisioning by mapping NFS drive to a local folder into the cluster node

  • Download the c8yedge-pv-local-path.yaml file.

  • Create the folders in the local file system or mount NFS folders required for the 3 PVs defined in the c8yedge-pv-local-path.yaml file. Ensure that the user running Kubernetes server has read/write access to these folders.

  • Run the command below:

    kubectl apply -f c8yedge-pv-local-path.yaml
    

Installing the Edge Operator

A Helm chart is available for installing the Edge Operator. To begin, create a new single-node Kubernetes cluster with the Kubernetes distribution of your choice, and configure kubectl to use that cluster. See Prerequisites for the supported Kubernetes distributions and versions.

Edge provides a script to install the Edge Operator. This script is located at c8yedge-operator-install.sh.

To install the Edge Operator, run and enter the version (for example, 1017.0.0) you want to install, and the repository credentials you received along with the license.

curl -sfL https://cumulocity.com/guides/10.17.0/files/edge-k8s/c8yedge-operator-install.sh -O && bash ./c8yedge-operator-install.sh

Provide the Edge Operator repository credentials in the prompt:

Enter username to access Edge Operator repository:  
Enter password to access Edge Operator repository:

By default, the Edge Operator is deployed within the c8yedge namespace. If you wish to install the Edge Operator and Edge in a different namespace, you can specify it using the -n option in the installation script.

Run the following command to follow the logs for the Edge Operator pod:

kubectl logs -f -n c8yedge deployment/c8yedge-operator-controller-manager manager

Installing Edge

Before you start the installation, ensure that you have fulfilled the prerequisites and configured the storage as described in Configuring storage.

Download and edit the Edge CR (c8yedge.yaml), before applying it to your Kubernetes cluster by running the command below:

kubectl apply -f c8yedge.yaml

For more information about the structure and configuration options available in the Edge CR, see the Edge Custom Resource section.

Verifying the Edge installation

To monitor the installation progress, run the command below:

kubectl describe edge c8yedge -n c8yedge

This command allows you to view the details about the installation of c8yedge in the c8yedge namespace.

You can also follow the events raised for the Edge CR by running the command below:

kubectl get events -n c8yedge --field-selector involvedObject.name=c8yedge --watch

The Events section in the output of the describe edge command specifies the installation progress and the Status section displays the generation of the Edge CR which is being installed and its current state. Once the installation succeeds, the Status section also displays the generation of the CR which is deployed, Edge version, last deployed time/age, validation warnings, if any and some help commands for downloading the diagnostic logs, extracting the Root CA of the Edge Operator generated TLS certificates.

A sample status output:

Name:         c8yedge
Namespace:    c8yedge
Kind:         CumulocityIoTEdge

Metadata:
  Creation Timestamp:  2023-08-11T00:00:01Z
  Generation:          1

Spec:
  Version:             1017.0.0
  License Key:         ***************
  Company:             IoT Company
  Domain:              myown.iot.com
  Email:               myown@iot.com
  ....
  ....

Status:
  Deployed Generation:  1
  Last Deployed Time:  2023-08-11T00:15:00Z
  State:               Ready
  Version:             1017.0.0-4638

  Help Commands:
    Download Logs:   
FILE_NAME="edge-diagnostic-archive-$(date +%Y%m%d%H%M%S).tar.gz" && \
kubectl exec -n edge-sample-logging logging-fluentd-0 -c fluentd -- tar -czvf /var/log/$FILE_NAME /var/log/edge && \
kubectl cp edge-sample-logging/logging-fluentd-0:/var/log/$FILE_NAME -c fluentd ./$FILE_NAME && \
kubectl exec -n edge-sample-logging logging-fluentd-0 -c fluentd -- rm /var/log/$FILE_NAME

A sample set of installation events:

Events:
  Type     Reason            Age    From               Message
  ----     ------            ----   ----               -------
  Normal   Validating        15m    cumulocityiotedge  validating
  Normal   ValidationPassed  15m    cumulocityiotedge  validation passed
  Normal   Installing        15m    cumulocityiotedge  installing
…………
…………
  Normal   Installing        12m    cumulocityiotedge  finished installing mongo server
…………
…………
  Normal   Installing        8m     cumulocityiotedge  finished installing core
…………
…………
  Normal   Installing        5m     cumulocityiotedge  finished installing and updating microservices
…………
…………
  Normal   Installing        2m     cumulocityiotedge  finished installing thin-edge
…………
  Normal   Ready             1m     cumulocityiotedge  installed successfully

Before you continue, wait for the Edge CR status to reach the Ready state.

Accessing Edge

Before you can access Edge, you must first get the external IP address. The Edge Operator creates a load balancer service named cumulocity-core, which receives an external IP. Clients outside of the cluster can access the Edge through this external IP.

Assigning an external IP

To get the external IP to access Edge, run the command below:

kubectl get service cumulocity-core -n c8yedge

Sample output of the kubectl get service command:

NAME              TYPE           CLUSTER-IP          EXTERNAL-IP         PORT(S)
cumulocity-core   LoadBalancer   X.X.X.X **REDACTED  X.X.X.X **REDACTED  443:31342/TCP,1883:32751/TCP,8883:32270/TCP

Sometimes the external IP displays as <pending> or <none>. The IP assignment process is dependent on the Kubernetes hosting environment. An external load balancer in the hosting environment handles the IP allocation and any other configurations necessary to route the external traffic to the Kubernetes service. Most on-premise Kubernetes clusters do not have external load balancers that can dynamically allocate IPs. The most common solution is to manually assign an external IP to the service. This can be done in the service’s YAML configuration. You can use the following command to manually assign an external IP to the cumulocity-core service (replace <EXTERNAL-IP> in the command below with the IP address you want to assign).

kubectl patch service cumulocity-core -n c8yedge -p '{"spec":{"type": "LoadBalancer", "externalIPs":["<EXTERNAL-IP>"]}}'

You can access Edge using a domain name in a web browser.

Accessing Edge using the domain name

Access Edge using the domain name configured as part of the installation. There are two ways of configuring the accessibility with the domain names:

• Add an entry of the domain name and IP address mapping in the DNS servers.
  For example, if your domain name is myown.iot.com, add an entry for both myown.iot.com and management.myown.iot.com.
  
• Alternatively, Add the alias to access Edge through the domain name provided during installation. This must be performed on each client host on which Edge is accessed.

The first option is always preferable so that Edge is accessible over LAN.

Adding the alias

On Linux machines, add the following entry to /etc/hosts:

<IP address> <domain_name>
<IP address> management.<domain_name>

Use the external IP address fetched by running the command kubectl get service in the previous section.

On Windows machines, add the same entry to C:\Windows\System32\drivers\etc\hosts.

Ping the <domain_name> to verify it.

ping <domain_name>
ping management.<domain_name>

If the ping is successful, the DNS resolution is working properly.

To access Edge

Enter one of the following URLs in the browser:

• To log in to the “edge” tenant, use the URL https://<domain_name>.
• To log in to the Management tenant, use the URL https://management.<domain_name>.

The login screen appears.

Change the password on first login.

If you are logging in for the first time, you will see a cookie banner at the bottom of the login screen:

• Click Agree and Proceed to accept the default cookie settings (required and functional cookies enabled).
• Click Reject all to reject all of the default cookie settings.
• Click Preferences to select your individual cookie preferences:
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• Click See also our Privacy Notice to open the Software AG privacy statement with details on the Software AG privacy policy.

Select the Remember me checkbox if you want the browser to remember your credentials, so that you do not have to enter them again when opening the application the next time. This is especially convenient if you frequently switch between Cumulocity IoT applications, as Edge requests you to authenticate each time when starting an application. You can make the browser “forget” your credentials by explicitly logging out.

Finally, click Login to enter Edge. Initially, you will be taken to the Cockpit application (if not configured differently).

To explicitly log out, click the User button at the right of the top bar, then select Logout from the context menu.

How to reset your password

To reset your password, you must first configure the “reset password” template and email server settings in Edge. For information about configuring the email server, see Configuring the email server.

For information about resetting the password, see To change your password.

How to access pages using URLs

For information about accessing pages using the URLs, see To access pages using URLs.

Accessing logs

The Edge Operator deploys and configures a Fluent Bit daemonset on the Kubernetes node to collect the container and application logs from the node file system. Fluent Bit queries the Kubernetes API, enriches the logs with metadata about the pods (in the Edge namespace), and transfers both the logs and metadata to Fluentd. Fluentd receives, filters, and persists the logs in the persistent volume claim configured for logging.

To download the diagnostic log archive, run the command below. It generates a file named c8yedge-logs-{current date}.tar.gz in the current directory.

kubectl get edge c8yedge -n c8yedge --output jsonpath='{.status.helpCommands.downloadLogs}' | sh

Download the log archives remotely from your cloud tenant. For more information, see Downloading diagnostics remotely.