Category Archives: Uncategorized

netstat with group by (ip adress)

– netstat -ntu | awk ‘ $5 ~ /^[0-9]/ {print $5}’ | cut -d: -f1 | sort | uniq -c | sort -n  netstat with group by (ip adress) netstat has two lines of headers: Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State Added a filter in the awk command… Read More »

How to use yum history to roll back an update in Red Hat Enterprise Linux/Centos 6 , 7

Environment Red Hat Enterprise Linux 6 , 7 yum Issue How to roll back an update using yum in Red Hat Enterprise Linux-6, 7? How to use yum history? Information on best practice to enable easy backout of yum patching Resolution Note: Rollback of selinux, selinux-policy-*, kernel, glibc (dependencies of glibc such as gcc) packages to older version is not supported. Thus, downgrading a system to… Read More »

Let’s Træfɪk and Let’s Encrypt

What is Træfɪk ? Træfɪk is a reverse proxy and load-balancer designed for micro services (e.g. Containers). It is very simple, written in Go, and supports a lot backend types : Consul, Etcd, Docker, Kubernetes, Mesos, etc. It can also be backed by a classic static configuration file and a mix of the above to act as… Read More »

Automatic DNS for Kubernetes Ingresses with ExternalDNS

ExternalDNS is a relatively new Kubernetes Incubator project that makes Ingresses and Services available via DNS. It currently supports AWS Route 53 and Google Cloud DNS. There are several similar tools available with varying features and capabilities like route53-kubernetes, Mate, and the DNS controller from Kops. While it is not there yet, the goal is for ExternalDNS to include all of the functionality of the other options by 1.0. In… Read More »

Introducing AWS Keymaster

AWS Keymaster is a simple utility that allows you to import your own personal key pair into all AWS regions with a single command. Distributed as a single binary with no dependencies, AWS Keymaster is easy to deploy and run. It is also available as a Docker image. For example, to import your personal key as a… Read More »

Deploy Kubernetes in an Existing AWS VPC with Kops and Terraform

Kops is a relatively new tool that can be used to deploy production-ready Kubernetesclusters on AWS. It has the ability to create a highly-available cluster spanning multiple availability zones and supports a private networking topology. By default, Kops will create all of the required resources on AWS for you — the EC2 instances, the VPC and subnets, the required DNS entries… Read More »

Kubernetes : Ingress Controller with Træfɪk and Let’s Encrypt

Still with the alpha/beta features but not that much (it’s been here since v1.1), this week we’ll focus on the Ingress resource that makes publishing services a lot easier. First we’ll see what Ingress and Ingress Controller are then we’ll demo with an awesome cloud native reverse proxy that implements the Ingress feature. To stay swag, we’ll throw in automatic and… Read More »

Kubernetes Ingress

A lot of people seem confused about how Ingress works in Kubernetes and questions come up almost daily in Slack. It’s not their fault, either — unfortunately the Kubernetes documentation is pretty weak in this area. Updating the documentation itself is probably a better use of time than writing this, I just prefer this …medium. I’ll try to… Read More »

How can I retrieve a snapshot if I don’t know the exact filename?

A. Nexus Provides a separate REST API to retrieve files when interpreting the maven-metadata.xml is required. The syntax looks like this: wget “http://repository.sonatype.org/service/local/artifact/maven/content?r=snapshots&g=org.sonatype.nexus&a=nexus-utils&v=LATEST” –content-disposition Where: r = the id of the repository or group to search (Required) g = the groupId of the file (Required) a = the artifactId of the file (Required) v = the version of the file,… Read More »