Tag Archives: Kubernetes

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

Istio: a cause and solution of the “SQLSTATE Connection refused”
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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: Istio: a cause and solution of the “SQLSTATE Connection refused”0… »

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

Istio: external AWS Application LoadBalancer and Istio Ingress Gateway
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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: Istio: external AWS Application LoadBalancer and Istio Ingress Gateway5 (1) »

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

Istio: an overview and running Service Mesh in Kubernetes
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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: Istio: an overview and running Service Mesh in Kubernetes0 (0) »

Kubernetes: ExternalDNS – records retrieval failed: failed to list hosted zones: Throttling: status code: 400
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9 April 2021

We have an ExternalDNS service running, see the Kubernetes: update AWS Route53 DNS from an Ingress post, which started sending a lot of messages like: msg=”failed to list resource records sets for zone /hostedzone/Z2VM3W5SRY4I9J: Throttling: \n\tstatus code: 400 And even AWS Console in the Route53 says “Throttling error that was caused because API rate was… Read More: Kubernetes: ExternalDNS – records retrieval failed: failed to list hosted… »

Kubernetes: Cluster Autoscaler – failed to renew lease
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7 April 2021

We have a Kubernetes Cluster Autoscaler for AWS EC2 WorkerNode groups scaling. On our Dev cluster sometimes it stop working with the following message in its logs: [simterm] … E0331 08:57:52.264549 1 leaderelection.go:320] error retrieving resource lock kube-system/cluster-autoscaler: Get https://172.20.0.1:443/apis/coordination.k8s.io/v1/namespaces/kube-system/leases/cluster-autoscaler: context deadline exceeded I0331 08:58:14.468096 1 leaderelection.go:277] failed to renew lease kube-system/cluster-autoscaler: timed out waiting… Read More: Kubernetes: Cluster Autoscaler – failed to renew lease0 (0) »

Kubernetes: namespace hangs in Terminating and metrics-server non-obviousness
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1 April 2021

Faced with a very interesting thing during removal of a Kubernetes Namespace. After a kubectl delete namespace NAMESPACE is executed, the namespace hangs in the Terminating state, and any attempt to forcibly remove it didn’t help. First, let’s see how such a force-removal can be done, and then will check the real cause and a… Read More: Kubernetes: namespace hangs in Terminating and metrics-server non-obviousness0 (0) »

Kubernetes: what is Endpoints
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13 March 2021

Usually, we don’t see Endpoints objects when using Kubernetes Services, as they are working under the hood, similarly to ReplicaSets which are “hidden” behind Kubernetes Deployments. Kubernetes Service So, Service is a Kubernetes abstraction that uses labels to chose pods to route traffic to, see the Kubernetes: ClusterIP vs NodePort vs LoadBalancer, Services, and Ingress… Read More: Kubernetes: what is Endpoints0 (0) »