Featured Load Balancer 16 November 2019 Azure load balancer SNAT behavior explained - Annotations to tcp port numbers reused, ACK with wrong sequence number plus RST from 3-way handshake and SNAT port exhaustion This article will address azure external load balancer and focus on SNAT, explains a few of behaviors seen from network trace, provides a few of suggestions for application when it is behind of load balancer and requires SNAT.
Linux 13 October 2019 Ubuntu Generate Core Dump On Fly systemctl disable apport.service /etc/security/limits.conf * soft core unlimited * hard core unlimited /etc/sysctl.conf kernel.core_pattern=/cores/core.%e.%p.%h.
Featured Nginx 23 September 2019 Nginx Ingress Controller Debugging - Print Http Raw Header kubectl exec YOUR_NGINX_INGRESS_CONTROLLER_POD -it -- cat /etc/nginx/template/nginx.tmpl > nginx.tmpl Open nginx.tmpl, add below code block
Featured Kubernetes 23 September 2019 Useful Kubernetes Tricks Find which RoleBinding/ClusterRoleBinding is related to a ServiceAccount kubectl get clusterrolebindings -o json | jq -r ' .items[] | select( .subjects // [] | .[] | [.kind,.namespace,.name] == ["ServiceAccount&
Featured Kubernetes 25 December 2018 Yet another way to troubleshoot K8S applications There are plenty of articles explains how to debug K8S applications, for example Troubleshoot Applications Connect with SSH to Azure Kubernetes Service (AKS) cluster nodes
Featured Flannel 1 June 2018 Flannel Networking Demystify In my previous article Deploy a Ubuntu Based Flannel K8S Cluster in Azure with ARM Template and Kubeadm, I provided an Azure ARM template to
Tunneling 25 May 2018 Persistent SSH Tunneling Imaging the sitaution that we need to access services behind NAT/firewall, how to achieve it? The answer is reverse SSH tunneling. Reverse SSH is
Featured Macvlan 25 May 2018 Docker Macvlan Demystify In this article, we are going to disucss a little bit about Macvlan and setup a Macvlan lab environment under Hyper-V host with 3 Ubuntu
Azure 24 May 2018 Using Lets Encrypt to Sign a Certificate First of all, a private key is needed before genreate a signing request. Either use openssl openssl genrsa -out ~/domain.com.ssl/domain.com.key
Featured Azure 23 May 2018 Deploy a Ubuntu Based Flannel K8S Cluster in Azure with ARM Template and Kubeadm The infomation migth be outdated here as acs-engine adds support for Flannel recently with PR 2967 However, if you want to gain more control on
Azure 22 May 2018 Configure Ubuntu to Support Multiple NICs in Azure By default, in Linux, if multiple NICs are in same subnet, all traffics will route through the default NIC that usually will be eth0, if
Azure 20 May 2018 How to Enable Accelerated Networking for Existing Linux VM How to enable accelerated networking for existing Linux VM