Deploying Apica Ascent PaaS on MicroK8s

MicroK8s is a lightweight, pure-upstream Kubernetes aiming to reduce entry barriers for K8s and cloud-native application development. It comes in a single package that installs a single-node (standalone) K8s cluster in under 60 seconds. The lightweight nature of Apica Ascent PaaS enables you to deploy Apica Ascent on lightweight, single-node clusters like MicroK8s. The following guide takes you through deploying Apica Ascent PaaS on MicroK8s.

Prerequisites

  • Ubuntu OS x64 - 20.04.6 LTS

  • 32 vCPU

  • 64GB RAM

  • 500GB disk space on the root partition

Installing MicroK8s

The first step in this deployment is to install MicroK8s on your machine. The following instructions pertain to Debian-based Linux systems. To install MicroK8s on such systems, do the following.

  1. Update package lists by running the following command.

    sudo apt-get -y update

  2. Install core using Snap by running the following command.

    sudo snap install core

  3. Install MicroK8s using Snap by running the following command.

    sudo snap install microk8s --classic --channel=1.21/stable

  4. Join the group created by MicroK8s that enables uninterrupted usage of commands that require admin access by running the following command.

    sudo usermod -a -G microk8s $USER

  5. Create the .kube directory.

    mkdir ~/.kube

  6. Add your current user to the group to gain access to the .kube caching directory by running the following command.

    sudo chown -f -R $USER ~/.kube

  7. Generate your MicroK8s configuration and merge it with your Kubernetes configuration by running the following command.

    sudo microk8s config > ~/.kube/config

  8. Check whether MicroK8s is up and running with the following command.

    sudo microk8s status

MicroK8s is now installed on your machine.

Enabling add-ons

Now that we have MicroK8s up and running, let’s set up your cluster and enable the add-ons necessary such as Helm, CoreDNS, ingress, storage, and private registry. MicroK8s readily provides these addons and can be enabled and disabled at any time. Most of these add-ons are pre-configured to work without any additional setup.

To enable add-ons on your MicroK8s cluster, run the following commands in succession.

  1. Enable Helm 3.

microk8s enable helm3

If you get a message telling you have insufficient permissions, a few of the commands above which tried to interpolate your current user into the command with the $USER variable did not work. You can easily fix it by adding your user to the microk8s group by specifying the name of the user explicitly:

sudo usermod -a -G microk8s ubuntu
sudo chown -R ubuntu ~/.kube

  1. Enable a default storage class that allocates storage from a host directory.

microk8s enable storage

  1. Enable CoreDNS.

microk8s enable dns

  1. Enable ingress.

To enable the Ingress controller in MicroK8s, run the following command:

microk8s enable ingress

  1. Enable HTTPS (optional)

This step is optional; you can still access the site using HTTP if you don't install an SSL certificate on the host.

How to Create a Self-Signed Certificate using OpenSSL:

  • Create server private key

    openssl genrsa -out cert.key 2048

  • Create certificate signing request (CSR)

    openssl req -new -key cert.key -out cert.csr

  • Sign the certificate using the private key and CSR

    openssl x509 -req -days 3650 -in cert.csr -signkey cert.key -out cert.crt

To create a TLS secret in MicroK8s using kubectl, use the following command:

microk8s kubectl create secret tls https --cert=cert.crt --key=cert.key

This command creates a secret named "https" containing the TLS keys for use in your Kubernetes cluster. Ensure you have the cert.crt and cert.key files in your current directory or specify full paths.

To enable Ingress on microk8s with a default SSL certificate, issue the following command:

microk8s enable ingress:default-ssl-certificate=secret/https

  1. Enable private registry.

microk8s enable registry

  1. Copy over your MicroK8s configuration to your Kubernetes configuration with the following command.

microk8s.kubectl config view --raw > $HOME/.kube/config

Provisioning an IP address (optional)

Note: This step is optional and will depend on your individual access needs - for instance, if you need to access the PaaS instance from a certain IP. You can skip this step if you are installing the app locally - in that case, you can access the UI after installation via the machine's public IP address.

In this step, we'll provision an endpoint or an IP address where we access Apica Ascent PaaS after deploying it on MicroK8s. For this, we'll leverage MetalLB which is a load-balancer implementation that uses standard routing protocols for bare metal Kubernetes clusters.

Note: Since MetalLB is available as an add-on for MicroK8s, you can also run these steps while enabling add-ons for your MicroK8s cluster.

To provision an IP address, do the following:

  1. Check your local machine's IP address by running the ifconfig command, as shown below.

     ifconfig:
 wlp60s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
 inet 192.168.1.27 netmask 255.255.255.0 broadcast 192.168.1.255

  2. Enable MetalLB by running the following command.

     microk8s enable metallb
 Enabling MetalLB
 Enter each IP address range delimited by comma (e.g.     '10.64.140.43-10.64.140.49,192.168.0.105-192.168.0.111'): 192.168.1.27-192.168.1.27

Note: MetalLB will not work on macOS due to network filtering that macOS applies. MetalLB might not work if you're provisioning an EC2 instance on AWS due to your private/public IP configuration.

Installing Apica Ascent PaaS

Now that your MicroK8s environment is configured and ready, we can proceed with installing Apica Ascent PaaS on it. To install Apica Ascent PaaS using Helm, do the following:

  1. Add the Apica Ascent PaaS Helm chart to your Helm repository by running the following command.

    microk8s helm3 repo add apica-repo https://logiqai.github.io/helm-charts

  2. Update your Helm repository by running the following command.

    microk8s helm3 repo update

  3. Create a namespace on MicroK8s on which to install Apica Ascent PaaS.

    microk8s kubectl create namespace apica-ascent

  4. Prepare your values.microk8s.yaml file. You can use the starter values.microk8s.yaml file we've created to configure your Apica Ascent PaaS deployment. If you need to download the file to your own machine, edit, and then transfer to a remote linux server, use this command:

scp -i /path/to/private_key.pem /path/to/local/file username@remote_host:/path/to/remote/directory

  1. Create a namespace on MicroK8s on which to install Apica Ascent PaaS.

    microk8s kubectl create namespace apica-ascent

Make sure you have the necessary permissions to copy a file to the specified folder on the Linux machine.

Optionally, if you are provisioning public IP using Metallb, use the values.yaml instead. run the following command.

microk8s enable metallb
Enabling MetalLB
Enter each IP address range delimited by comma (e.g.  '10.64.140.43-10.64.140.49,192.168.0.105-192.168.0.111'): 192.168.1.27-192.168.1.27

In the values file, add the below fields global-> environment section with your own values.

s3_bucket: <your-s3-bucket>
AWS_ACCESS_KEY_ID: <your-aws-access-key-id>
AWS_SECRET_ACCESS_KEY: <your-aws-secret-access-key-id>

In the global -> chart section, change S3gateway to false.

s3gateway: false

In the global -> persistence section, change storageClass as below.

storageClass: microk8s-hostpath

  1. Install Apica Ascent PaaS using Helm with the storage class set to microk8s-hostpath with the following command.

microk8s helm3 install apica-ascent -n apica-ascent --set global.persistence.storageClass=microk8s-hostpath apica-repo/apica-ascent -f  values.microk8s.yaml  --debug --timeout 10m

If you see a large wall of text listing configuration values, the installation was successful - Ascent PaaS is now installed in your MicroK8s environment!

Accessing Apica Ascent PaaS

Now that Apica Ascent PaaS is installed on your MicroK8s cluster, you can visit the Apica Ascent PaaS UI by either accessing the MetalLB endpoint we defined in the pre-install steps (if you installed/configured MetalLB), or by accessing the public IP address of the instance over HTTP(S) (if you aren't utilizing MetalLB).

If you are load balancing the hosting across multiple IPs using MetalLB, do the following to access the Apica Ascent PaaS UI:

  1. Inspect the pods in your MicroK8s cluster in the apica-ascent namespace by running the following command.

    microk8s kubectl get pod -n apica-ascent

  2. Find the exact MetalLB endpoint that's serving the Apica Ascent PaaS UI by running the following command.

    microk8s kubectl get service -n apica-ascent |grep -i loadbalancer

    The above command should give you an output similar to the following.

    logiq-kubernetes-ingress  LoadBalancer   10.152.183.45  192.168.1.27

80:30537/TCP,20514:30222/TCP,24224:30909/TCP,24225:31991/TCP,2514:30800/TCP,3000:32680/TCP,514:32450/    TCP,7514:30267/TCP,8081:30984/TCP,9998:31425/TCP     18m

  3. Using a web browser of your choice, access the IP address shown by the load balancer service above. For example, http://192.168.1.27:80.

If you aren't utilizing MetalLB, you can access the Ascent UI simply by accessing the public IP or hostname of your machine over HTTP(S); you can utilize HTTPS by following the "enabling HTTPS" step in the "Enabling Add-Ons" section above.

You can log into Apica Ascent PaaS using the following default credentials.

  • Username: flash-admin@foo.com

  • Password: flash-password

Note: You can change the default login credentials after you've logged into the UI.

Troubleshooting

Kubernetes cluster is unreachable

If you see an error message indicating the Kubernetes cluser is unreachable, the Microk8s service has stopped - simply restart it. Error text:

Error: INSTALLATION FAILED: Kubernetes cluster unreachable: Get "https://127.0.0.1:16443/version": dial tcp 127.0.0.1:16443: connect: connection refused
helm.go:84: [debug] Get "https://127.0.0.1:16443/version": dial tcp 127.0.0.1:16443: connect: connection refused
...

Solution:

ubuntu@ip-172-31-31-72:~$ microk8s status
microk8s is not running. Use microk8s inspect for a deeper inspection.
ubuntu@ip-172-31-31-72:~$ microk8s start

Restarting the Ascent installation after a failed installation

If the Ascent installation using the supplied .yaml file fails, you must first remove the name in use. Error text:

Error: INSTALLATION FAILED: cannot re-use a name that is still in use
helm.go:84: [debug] cannot re-use a name that is still in use
helm.sh/helm/v3/pkg/action.(*Install).availableName
...

Solution:

ubuntu@ip-172-31-31-72:~$ microk8s helm3 uninstall apica-ascent -n apica-ascent
release "apica-asent" uninstalled
ubuntu@ip-172-31-31-72:~$ microk8s helm3 install apica-ascent -n apica-ascent --set global.persistence.storageClass=microk8s-hostpath apica-repo/apica-ascent -f values.microk8s.yaml --debug --timeout 10m
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