Category Archives: Kubernetes

Kubernetes is an open-source container orchestration system for automating application deployment, scaling, and management.

ArgoCD: declarative Projects, Applications, and ArgoCD deploy from Jenkins

19 May 2021
 

 An application, cluster, or repository can be created In ArgoCD from its WebUI, CLI, or by writing a Kubernetes manifest that then can be passed to kubectl to create resources. For example, Applications are Kubernetes CustomResources and described in Kubernetes CRD applications.argoproj.io: [simterm] $ kubectl get crd applications.argoproj.io NAME CREATED AT applications.argoproj.io 2020-11-27T15:55:29Z [/simterm] And… Read More »

ArgoCD: Okta integration, and user groups

17 May 2021
 

 In the previous post ArgoCD: users, access, and RBAC we’ve checked how to manage users and their permissions in ArgoCD, now let’s add an SSO authentification. The idea is that we don’t add user accounts locally in the ArgoCD’s ConfigMap, but instead will use our Okta users databases and Okta will perform their authentication. And… Read More »

Kubernetes: spec.ports[0].nodePort: Forbidden: may not be used when `type` is ‘ClusterIP’

5 May 2021
 

 During applications deploy from a Helm chart described in the Istio: shared Ingress/AWS ALB, Helm chart with conditions, Istio, and ExternalDNS we are getting the “spec.ports[0].nodePort: Forbidden: may not be used when `type` is ‘ClusterIP’” error. Let’s reproduce it and find solutions with kubectl and Helm to solve it. The “spec.ports[0].nodePort: Forbidden: may not be… Read More »

Istio: shared Ingress/AWS ALB, Helm chart with conditions, Istio, and ExternalDNS

27 April 2021
 

 Let’s proceed with our journey with Istio. Previous parts: Istio: an overview and running Service Mesh in Kubernetes Istio: external AWS Application LoadBalancer and Istio Ingress Gateway Besides Istio, in this post, we will also configure ExternalDNS, see the Kubernetes: update AWS Route53 DNS from an Ingress for details. Everything described below is a kind… Read More »

Istio: a cause and solution of the “SQLSTATE Connection refused”

23 April 2021
 

 During starting a pod we got errors “SQLSTATE[HY000] [2002] Connection refused’” in two different applications – a РНР/Yii and NodeJS. In the РHР/Yii it’s coming when we are running a pre-install hook during deployment with Helm and on the MySQL Migration Job execution: Yii Migration Tool (based on Yii v2.0.38)Exception ‘yii\db\Exception’ with message ‘SQLSTATE[HY000] [2002]… Read More »

Kubernetes: metrics-server – “401 Unauthorized” amd “kubelet stopped posting node status”

23 April 2021
 

 On our AWS Elastic Kubernetes Service Dev cluster, we got a couple of namespaees hanging i nthe Termination state. “401 Unauthorized”, response: “Unauthorized” Remembering a similar issue where the root cause was the metrics-server (see the Kubernetes: namespace hangs in Terminating and metrics-server non-obviousness post for details), the first thing I did was to check… Read More »

Istio: external AWS Application LoadBalancer and Istio Ingress Gateway

22 April 2021
 

 In the previous post, Istio: an overview and running Service Mesh in Kubernetes, we started Istion io AWS Elastic Kubernetes Service and got an overview of its main components. The next task is to add an AWS Application Load Balancer (ALB) before Istio Ingress Gateway because Istio Gateway Service with its default type LoadBalancer creates… Read More »

Kubernetes: NodeLocal DNS and the “lookup istiod.istio-system.svc on lookup: no such host” error

19 April 2021
 

 In our Deployments, we are using the NodeLocal DNS as a local DNS cache to reduce requests number to the AWS VPC DNS, see the Kubernetes: load-testing and high-load tuning – problems and solutions for details. Currently, a manifest looks like the next: … dnsPolicy: “None” dnsConfig: nameservers: – 169.254.20.10 … The problem is, that… Read More »

Istio: an overview and running Service Mesh in Kubernetes

11 April 2021
 

 Istio is a Service Mesh solution that allows performing Service Discovery, Load Balancing, traffic control, canary rollouts and blue-green deployments, traffic monitoring between microservices. We will use Istio in our AWS Elastic Kubernetes Service for traffic monitoring, as an API Gateway service, for traffic policies, and for various deployment strategies. In this post, will speak… Read More »