If you need to validate your AlertManager routing configuration by sending a test alert through AlertManager, you can port-forward the AlertManager pod and send it from curl on your development host. Real alerts typically have scrape delays and then durations that must be met, so this is a way of getting almost immediate feedback on … Prometheus: sending a test alert through AlertManager
While working on your Spring Boot web application locally, gradle provides the ‘bootRun’ for a quick development lifecycle and ‘bootJar’ for packaging all the dependencies as a single jar deliverable. But for most applications these days, you will need this packaged into an OCI compatible (i.e. Docker) image for its ultimate deployment to an orchestrator … Java: build OCI compatible image for Spring Boot web app using jib
The kube-prometheus-stack bundles AlertManager for taking action on Prometheus alerts. And if you are customizing the Heml custom values file to configure email alerting, there are multiple options available. The simplest is to allow the system to fallback to using the default subject and html templates. But if you need to tailor the email content … Prometheus: external template for AlertManager html email with kube-prometheus-stack
The kube-prometheus-stack bundles Prometheus, Grafana, and AlertManager for monitoring a Kubernetes cluster. By default, the Ingress of these services is disabled. In this article I will show you how to expose these services with NGINX Ingress either via subdomain (e.g. prometheus.my.domain) or web context (e.g. my.domain/prometheus). You would not want to expose these monitoring applications … Prometheus: exposing Prometheus/Grafana as Ingress for kube-prometheus-stack
The kube-prometheus-stack bundles the Prometheus Operator, monitors/rules, Grafana dashboards, and AlertManager needed to monitor a Kubernetes cluster. But there are customizations necessary to tailor the Helm installation for K3s, a lightweight Kubernetes installation. In this article, I will detail the necessary modifications to deploy a healthy monitoring stack on a K3s cluster.
If you have a Kubernetes yaml manifest that contains multiple documents, targeting a single document for modification while still outputting the other documents untouched can be a challenge. As an example, consider the simple example below were you have a single yaml file that contains: a Namespace, Deployment, and DaemonSet. And we want to add … Kubernetes: targeting the addition of array items to a multi-document yaml manifest
A Kubernetes liveness and readiness probe is how the kubelet determines health of a pod. This is often times as simple as checking the ability to reach the main service port over TCP or HTTP. But if you are using Spring Boot and have enabled the Actuator dependency, you have the ability to create even … Kubernetes: liveness probe for Spring Boot with custom Actuator health check
Although kubectl has the native ability to query on labels, it does not provide the same support for annotations. This is unfortunate, because the need to target deployments and services by annotation is commonplace. You can, however, use the power of jsonpath to find these objects. Below is an example of finding all Services that … Kubernetes: query by annotation with kubectl
It is easy to export the full manifest of an object from a Kubernetes cluster, but it will have extraneous accounting fields that not only make it hard to visually assess and compare to its original form, but can also cause a re-apply to fail. Using a combination of the jq and yq utilities, we … Kubernetes: export a clean yaml manifest that can be re-imported
If you are configuring Istio/ASM ingress gateways with a BackendConfig for specifying health checks, timeouts, or Cloud Armor policies, then you need to ensure that your GKE cluster has the HttpLoadBalancing feature enabled. If this feature is not enabled, you will see an error message like below when attempting to apply the BackendConfig manifest: unable … GCP: Enable HttpLoadBalancing feature on Cluster to avoid errors when applying BackEndConfig
Update Sep 2023: tested on Kubeadm 1.28, MetalLB v0.13.9, ingress-nginx v1.8.1 Kubeadm is a tool for quickly bootstrapping a minimal Kubernetes cluster. In this article, I will show you how to deploy a three-node Kubeadm cluster on Ubuntu 22 nodes that are created using Terraform and a local KVM libvirt provider. Ansible is used for … KVM: kubeadm cluster on KVM using Ansible
A Kubernetes Service Account (KSA) can be used to provide least-privileged access to a pod for a cluster that has Role-based access control (RBAC) enabled. This is done by making the KSA the subject in an RBAC role. But it can be challenging to discover and test whether the KSA has the correct set of … Kubernetes: testing RBAC authorization of a Kubernetes Service Account
When configuring networks and loadbalancers, sometimes you need the network CIDR block used by Services of a Kubernetes cluster. There are various ways to pull this information from different Kubernetes implementations, but one trick that works across implementations is looking at the error message from kubectl if you attempt to create a service at an … Kubernetes: retrieving services and pods network CIDR block from cluster
GKE cluster upgrades do not need to be a manual process. GKE clusters can be auto upgraded by subscribing the cluster to an appropriate release channel and assigning a sensible maintenance window. As long as adequate pod disruption budgets, replicas, and ingress are configured, these upgrades can happen without interrupting availability. To check the current … GCP: Enabling autoUpgrade for node-pools to reduce manual maintenance
Anthos GKE on-prem is a managed platform that brings GKE clusters to on-premise datacenters. This product offering brings best practice security measures, tested paths for upgrades, basic monitoring, platform logging, and full enterprise support. Setting up a platform this extensive requires many steps as officially documented here. However, if you want to practice in a … Kubernetes: Anthos GKE on-prem 1.11 on nested VMware environment
Anthos GKE on-prem is a managed platform that brings GKE clusters to on-premise datacenters. In this article, I will be following the steps required to upgrade from Anthos 1.10 to 1.11 on VMware. The instructions provided here are assuming you have used the Ansible scripts and Seed VM described in my previous Anthos 1.10 installation … Kubernetes: major version upgrade of Anthos GKE on-prem from 1.10 to 1.11
Gunicorn is a WSGI HTTP server commonly used to run Flask applications in production. If you are running these types of workloads on a production Kubernetes cluster, you should consider an observability platform such a New Relic to ensure availability, service levels, and visibility into transactions and logging. In a series of previous articles, we … Python: New Relic Agent for Gunicorn app deployed on Kubernetes
Anthos Config Management (ACM) brings the power of GitOps to your GKE clusters. Instead of needing to manually keep deployments current on a cluster or group of clusters, you can push changes to a git repository and the Config Sync component will periodically poll and attempt to reach the new state described by your git … GCP: Enable Anthos Config Management (ACM) on a GKE cluster
kustomize is typically used to overlay a base set of yaml, but it also has the ability to leverage existing Helm charts, and overlay a set of custom values with HelmChartInflationGenerator. In this article, I will use kustomize to deploy the Bitnami NGINX Helm chart with overridden values that provide a customized nginx.conf and custom … Kubernetes: kustomize with Helm charts
The power of kustomize lies in its ability to transform yaml, and one of the methods for this is patchesStrategicMerge. Where the strategic merge patch excels is in inserting elements and replacing values, allowing you to specify the desired patch using the same indentation level as the target, which makes the intended result very intuitive. … Kubernetes: kustomize transformations with patchesStrategicMerge
The power of kustomize lies in its ability to transform yaml, and to that end it has built-in support for the JSON 6902 RFC specification. This RFC specifies the syntax for adding, removing, replacing, and moving elements and values in a yaml file. And since Kubernetes manifests are yaml files, it makes perfect sense to … Kubernetes: kustomize transformations with patchesJson6902
Kubernetes has a rich way of expressing volumes/ volumeMounts for mounting files, emptyDir for ephemeral directories, and env/envFrom for adding environment variables to your container definition running on a Kubernetes cluster. However, if you are actively iterating on the development of an image, it may slow you down to require a deployment to a remote … Kubernetes: volumeMount, emptyDir, and env equivalents during local Docker development
With kustomize built into the kubectl CLI since version 1.14, there is little reason not to take advantage of this overlay system to deploy components to your Kubernetes cluster. Kustomize has the advantage that it is purpose built to understand and validate yaml and Kubernetes CRD, as opposed to bespoke templating solutions using sed/envsubst, Ansible, … Kubernetes: kustomize overlay to enrich a base resource
If your intent is to delete all the objects in a namespace, but the command is not completing, emptying the namespace finalizer will often allow the deletion to finish. For example, if you have tried deleting the “my-namespace” like below and it will not complete. kubectl delete ns my-namespace –force –grace-period=0 Then as written by … Kubernetes: emptying the finalizers for a namespace that will not delete
Anthos GKE on-prem is a managed platform that brings GKE clusters to on-premise datacenters. In this article, I will be following the steps required to upgrade from 1.9 to 1.10 on VMware. The instructions provided here are assuming you have used the Ansible scripts and Seed VM described in my previous Anthos 1.9 installation article.
Anthos GKE on-prem is a managed platform that brings GKE clusters to on-premise datacenters. In this article, I will be following the steps required to upgrade from 1.8 to 1.9 on VMware. The instructions provided here are assuming you have used the Ansible scripts and Seed VM described in my previous Anthos 1.8 installation article.
Updated Aug 2023: using the latest K3s 1.27, MetalLB 0.13.9, and NGINX v1.8.1 K3s is a lightweight Kubernetes deployment by Rancher that is fully compliant, yet also compact enough to run on development boxes and edge devices. In this article, I will show you how to deploy a three-node K3s cluster on Ubuntu nodes that … Kubernetes: K3s cluster on Ubuntu using Ansible
Updated Aug 2023: tested on Ubuntu 22 with QEMU 6.2.0/libvirt 8.0.0 and with Minikube v1.31.2 Minikube is a tool that runs a full Kubernetes stack on a host, making it ideal for local development and experimentation. We are taking it one step further by placing Minikube into a virtual machine run by the KVM virtualization … Kubernetes: running Minikube locally on Ubuntu using KVM