Clusterpirate

Introduction to Kubernetes   Kubernetes is a powerful platform for managing containerized applications. It is an open-source project that was originally developed by Google, and is now maintained by the Cloud Native Computing Foundation (CNCF). One of the key benefits of Kubernetes is its ability to automate the deployment, scaling, and management of containerized applications. This makes it an ideal platform for running microservices, which are small, modular, and independently deployable units of software. Kubernetes is built on top of a number of core components, including: The API server, which exposes the Kubernetes API and handles communication between the different components of the system. The etcd datastore, which stores the configuration data for the Kubernetes cluster. The controller manager and the scheduler, which handle the orchestration of the containerized applications and the scheduling of resources, respectively. The kubelet, which runs on each node in the cluster...

    There are may ways to check for open TCP ports. Usually I prefer to use netcat or telnet, however in some cases (especially within docker containers) these tools are not installed or available. This post shows most common ways to check if a remote port is open or not. telnet Even though the telnet client tool is supposed to be used for the telnet protocol (ie. remotely logging in to a Unix computer before we had ssh), it is also a handy tool to check for an open port. For example, we can use it to check if we can access www.google.com via HTTPS: $ telnet www.google.com 443 Trying 142.250.70.196... Connected to www.google.com. If we see the " Connected " message, we can deduct from this that the port is open - even though there are protocol differences. Furthermore, if the service is unencrypted, telnet will show us status messages / protocol hints and versions etc. The following connects to a Google mail / SMTP server. $ telnet smtp.google.com 25 Trying 74.125.24.27... Co...

Why Often I need to look at multiple pod logs at the same time. For example the nginx ingress controller deployment or daemonset usually has at least a handful of pods running to share the load and for additional redundancy. To troubleshoot problems, I need to see them all. Options The trusted kubectl (I am a kube cuttle guy) command has an option to view or tail multiple containers based on a selector like this. $ kubectl logs -n nginx-ingress -l ' app.kubernetes.io/name=fluent -bit '  -f  --max-log-requests 60 --tail=1 --prefix=true However, if the pods in question come and go frequently, I am recommending stern instead:   https://github.com/wercker/stern

  The following steps will migrate your CentOS8 server to Rocky Linux 8. dnf -y install wget wget https://raw.githubusercontent. com/rocky-linux/rocky-tools/ main/migrate2rocky/ migrate2rocky.sh chmod a+x migrate2rocky.sh ./migrate2rocky.sh -r rm -rf /etc/yum.repos.d/backups /etc/yum.repos.d/CentOS-Linux- AppStream.repo.rpmsave /etc/yum.repos.d/CentOS-Linux- BaseOS.repo.rpmsave sync && init 6   That's it.

    The following steps will migrate a CentOS7 server to CentOS8. yum -y install epel-release yum -y install yum-utils rpmconf rm -f /etc/ issue.net ; mv /etc/issue.net.rpmsave /etc/ issue.net rpmconf -a # 5 times N rm -rf /etc/yum.repos.d/reece.repo yum clean all package-cleanup --orphans | egrep 'noarch|x86_64' | xargs -r -n 1 yum -y remove package-cleanup --leaves | egrep 'noarch|x86_64' | xargs -r -n 1 yum -y remove # do above until none found - leaves 4-5 times yum install -y dnf dnf remove -y yum yum-metadata-parser rm -Rf /etc/yum dnf -y upgrade dnf -y install http://vault.centos.org/8.5. 2111/BaseOS/x86_64/os/ Packages/{centos-linux-repos- 8-3.el8.noarch.rpm,centos- linux-release-8.5-1.2111.el8. noarch.rpm,centos-gpg-keys-8- 3.el8.noarch.rpm} dnf -y upgrade https://dl.fedoraproject.org/ pub/epel/epel-release-latest- 8.noarch.rpm cd /etc/yum.repos.d && mkdir backups && mv CentOS-* backups tee CentOS-Linux-BaseOS.repo<<...

    The following steps will convert a RHEL7 Linux server to CentOS7.   yum -y remove rhnlib redhat-support-tool redhat-support-lib-python rpm -e --nodeps redhat-release-server rpm -e --nodeps redhat-logos rpm -e --nodeps yum rpm -e redhat-indexhtml-7-13.el7. noarch rpm -qa | egrep -i "rhn|redhat" rm -rf /usr/share/doc/redhat-release/ /usr/share/redhat-release/   mkdir tmp && cd tmp curl -O http://mirror.centos.org/ centos/7/os/x86_64/RPM-GPG- KEY-CentOS-7 curl -O http://mirror.centos.org/ centos/7/os/x86_64/Packages/ yum-plugin-fastestmirror-1.1. 31-54.el7_8.noarch.rpm curl -O http://mirror.centos.org/ centos/7/os/x86_64/Packages/ yum-3.4.3-168.el7.centos. noarch.rpm curl -O http://mirror.centos.org/ centos/7/os/x86_64/Packages/ centos-release-7-9.2009.0.el7. centos.x86_64.rpm curl -O http://mirror.centos.org/ centos/7/os/x86_64/Packages/ centos-logos-70.0.6-3.el7. centos.noarch.rpm rpm --import RPM-GPG-KEY-CentOS-7 rpm -Uvh *.rpm yum clean...

  Intro Kubernetes deprecates API versions over time. Usually this affects alpha and beta versions and only requires changing the apiVersion: line in your resource file to make it work. However with this Ingress object version change, additional changes are necessary. Basics For this post I am quickly creating a new cluster via Kind (Kubernetes in Docker) . Once done, we can see which API versions are supported by this cluster (version v1.21.1). $ kubectl api-versions | grep networking networking.k8s.io/v1 networking.k8s.io/v1beta1 Kubernetes automatically converts existing resources internally into different supported API versions. So if we create a new Ingress object with version v1beta1 on a recent cluster version, you will receive a deprecation warning - and the same Ingress object will exist both in version v1beta1 and v1. Create $ cat ingress_beta.yaml apiVersion: networking.k8s.io/v1beta1 kind: Ingress metadata:   name: clusterpirate-ingress spec:   rules:  ...