Tonight I just stumbled on a command line tool or utility called ipcacl. This tool is used to perform operations on IP addresses and networks. On Fedora, ipcalc is provided by ipcacl package. If you on a different distro, search for ipcaclc, there should be a similar package name. ➜ rpm -q ipcalc ipcalc-1.0.3-9.fc40.x86_64 Here are some examples of what we can use this utility for, though I encourage you to run man ipcalc to learn more what you can do with it. ...

This is a short note on how to install metrics-server using Helm on my k8s cluster. $ kubectl version Client Version: v1.29.3 Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3 Server Version: v1.29.3 $ helm version --short v3.14.4+g81c902a Before we can install the chart, we will need to add the metrics-server repo to Helm. $ helm repo add metrics-server https://kubernetes-sigs.github.io/metrics-server/ Update the repo: $ helm repo update Hang tight while we grab the latest from your chart repositories... ...Successfully got an update from the "metrics-server" chart repository Update Complete. ⎈Happy Helming!⎈ I also need to make a small customization to the chart’s default value since my k8s cluster uses self-signed certificates. ...

To connect to a Redis server with Python, one can use python3-redis module. First verify that python3-redis module is installed. I’m showing the package name in Fedora 39, if you use a different distro, then check for the relevant package name. $ rpm -q python3-redis python3-redis-4.3.3-1.el9.noarch Here is the sample code to connect to a non-cluster Redis server: import redis # Connect to Redis r = redis.Redis(host='10.97.147.175', port=6379) # Set a key-value pair r.set('my_key', 'Hello, Redis!') # Get the value of the key value = r.get('my_key') print(value.decode('utf-8')) If you want to connect to a Redis cluster (that has both master and replicas), use this version instead: ...

Assuming that you use brew on your macOS, converting a ppk file to pem file is relatively easy. Install putty on your mac ➜ brew install putty Generate the key ➜ puttygen existing_key.ppk -O private-openssh -o new_key.pem Here are the options used in above command: -O private-openssh : save the output as a SSH-2 private key -o new_key.pem : save the output to new_key.pem Full credit go to this blog post [1], where I had learned to convert a PPK to PEM file. ...

I’ve been running Uptime Kuma on a podman-container for a long time with no problem. Recently, though, I’ve been running a mini Kubernetes cluster at home, and decided to move this conatainer to the same cluster. The following is to document how I deploy Uptime Kuma on a Kubernetes cluster. As I’m new to Kubernetes world, I broke down the tasks I need to do in 6 pieces: $ ls -1 1.namespace.yaml 2.service.yaml 3.pvc.yaml 4.deployment.yaml 5.tls-secret.yaml 6.ingress.yaml The first step is to create a new namespace for this application or deployment. It’ll be called ‘uptime-kuma’. $ cat 1.namespace.yaml kind: Namespace apiVersion: v1 metadata: name: uptime-kuma $ kubectl apply -f ./1.namespace.yaml Create a new service, which will listen on port 3001. $ cat 2.service.yaml apiVersion: v1 kind: Service metadata: name: uptime-kuma-svc namespace: uptime-kuma spec: selector: app: uptime-kuma ports: - name: uptime-kuma port: 3001 targetPort: 3001 protocol: TCP Next is to create a persistent volume claim for Uptime Kuma’s app data. Based on the current usage on my existing podman-container, 512 MiB is plenty. In my cluster, I use Longhorn as the persistent block storage. $ cat 3.pvc.yaml apiVersion: v1 kind: PersistentVolumeClaim metadata: name: uptime-kuma-pvc namespace: uptime-kuma spec: accessModes: - ReadWriteOnce storageClassName: longhorn resources: requests: storage: 512Mi Here is the deployment file. $ cat 4.deployment.yaml apiVersion: apps/v1 kind: Deployment metadata: name: uptime-kuma namespace: uptime-kuma spec: selector: matchLabels: app: uptime-kuma replicas: 1 strategy: type: RollingUpdate rollingUpdate: maxSurge: 1 maxUnavailable: 1 template: metadata: labels: app: uptime-kuma spec: containers: - name: uptime-kuma image: louislam/uptime-kuma:1.23.11 imagePullPolicy: IfNotPresent ports: - containerPort: 3001 name: web-ui resources: limits: cpu: 200m memory: 512Mi requests: cpu: 50m memory: 128Mi livenessProbe: tcpSocket: port: web-ui initialDelaySeconds: 60 periodSeconds: 10 readinessProbe: httpGet: scheme: HTTP path: / port: web-ui initialDelaySeconds: 30 periodSeconds: 10 volumeMounts: - name: data mountPath: /app/data volumes: - name: data persistentVolumeClaim: claimName: uptime-kuma-pvc (Optional) I want to use SSL when accessing the web UI of Uptime Kuma, therefore I need to create a new TLS secret. $ cat 5.tls-secret.yaml apiVersion: v1 data: tls.crt: VERY-LONG-BASE-64-ENCODED-STRING tls.key: ANOTHER-LONG-BASE-64-ENCODED-STRING kind: Secret metadata: name: wildcard-tls-secret namespace: uptime-kuma type: kubernetes.io/tls The last file 6.ingress.yaml contains the manifest for ingress-nginx which allows me to access the Uptime Kuma at https://uptime.home-lab-internal-domain.com: $ cat 6.ingress.yaml apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: uptime-kuma-ingress namespace: uptime-kuma spec: ingressClassName: nginx tls: - hosts: - uptime.home-lab-internal-domain.com secretName: wildcard-tls-secret rules: - host: uptime.home-lab-internal-domain.com http: paths: - path: / pathType: Prefix backend: service: name: uptime-kuma-svc port: number: 3001 References: ...