With the dramatically increasing demand for container orchestration specifically Kubernetes, demand to template K8S manifests(Json/Yaml) also came to light. To handle increasing manifests, new CRDs(Custom resource definition), etc… it became obvious that we need a package manager somewhat like yum, apt, etc… However, the nature of Kubernetes manifest is very different than what one used to have with Yum and Apt. These manifests required a lot of templates which is now supported by Helm, a tool written in GoLang with custom helm functions and pipelines. Neutral background on templating Templating has been a driver for configuration management for a long time. While it may seem trivial for users coming from Ansible, Chef, Puppet, Salt, etc…, it is not. Once one moves to Kubernetes, the very first realization is hard declarative approach that Kubernetes follows. It is difficult to make generic templating with declarative form since each application may have some unique feature and r...
Allowing users to have ssh access Hi Readers, It is one of the tasks we need to complete in order to allow users to log-in into your server without compromising your security. We are going to accomplish the following tasks, 1.) Allow the users for given domain only 2.) Must allow access to a given domain 3.) Block access for a specific domain. These questions are asked in RedHat certification examination RHCE6 We are going to complete the above mention task using iptables To give proper example we are taking 192.168.20.0/255.255.255.0 as our domain and 192.168.21.0/255.255.255.0 as other domain. Assuming that your system is a fresh installation we can remove all rules previously applied. # iptables -F The above mention command will flush all the previously applied rules. Insert a rule in your input chain by below mention command, # iptables -I INPUT -s <ip of your domain>/<subnet mask> -p <protocal tcp/udp> --dport <port> -...