Docker Machine is a tool that lets you install Docker Engine on virtual hosts, and manage the hosts with docker-machine commands. You can use Machine to create Docker hosts on your local Mac or Windows box, on your company network, in your data center, or on cloud providers like Azure, AWS, or Digital Ocean. Using … Continue reading Docker Machine

Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a Compose file to configure your application's services. Then, using a single command, you create and start all the services from your configuration. Install Docker Compose https://github.com/docker/compose/releases [root@jenkins ~]# curl -o /usr/local/bin/docker-compose -L "https://github.com/docker/compose/releases/download/1.15.0/docker-compose-$(uname -s)-$(uname -m)" % Total % Received % Xferd Average Speed Time Time … Continue reading Docker Compose

[root@jenkins ~]# docker Usage: docker COMMAND A self-sufficient runtime for containers Options: --config string Location of client config files (default "/root/.docker") -D, --debug Enable debug mode --help Print usage -H, --host list Daemon socket(s) to connect to -l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info") --tls Use TLS; implied by --tlsverify --tlscacert string … Continue reading Docker Deep Dive

A namespace wraps a global system resource in an abstraction that makes it appear to the processes within the namespace that they have their own isolated instance of the global resource. Changes to the global resource are visible to other processes that are members of the namespace, but are invisible to other processes. One use … Continue reading Linux namespaces

[root@server ~]# puppet module list /etc/puppetlabs/code/environments/production/modules ├── bashtoni-timezone (v1.0.0) ├── fschaer-omd (v1.0.3) ├── puppetlabs-apache (v1.8.1) ├── puppetlabs-apt (v2.4.0) ├── puppetlabs-concat (v2.2.1) ├── puppetlabs-firewall (v1.9.0) ├── puppetlabs-inifile (v1.6.0) ├── puppetlabs-ntp (v6.2.0) ├── puppetlabs-postgresql (v4.9.0) ├── puppetlabs-puppetdb (v5.1.2) ├── puppetlabs-stdlib (v4.17.1) ├── puppetlabs-xinetd (v2.0.0) ├── saz-ssh (v3.0.1) ├── saz-sudo (v4.2.0) └── users (???) /etc/puppetlabs/code/modules (no modules installed) … Continue reading Environments usage in puppet

[root@localhost ~]# locate nagios/plugins |head -n1 /usr/lib64/nagios/plugins check_swap  [root@localhost ~]# /usr/lib64/nagios/plugins/check_swap --help check_swap v2.2.1 (nagios-plugins 2.2.1) Copyright (c) 2000-2014 Nagios Plugin Development Team <devel@nagios-plugins.org> Check swap space on local machine. Usage: check_swap [-av] -w % -c % -w -c Options: -h, --help Print detailed help screen -V, --version Print version information --extra-opts=[section][@file] Read options from … Continue reading nagios plugins functionality

What is a Linux container? LXC (Linux Containers) is an operating-system-level virtualization method for running multiple isolated Linux systems (containers) on a control host using a single Linux kernel. ... LXC combines the kernel's cgroups and support for isolated namespaces to provide an isolated environment for applications. What is a chroot? Chroot is an operation … Continue reading How Containers Work’s

[mshaik@server ~]$ sudo yum install gem [mshaik@server ~]$ sudo gem install yaml-lint [mshaik@server ~]$ yaml-lint /etc/puppetlabs/code/environments/production/hieradata/common.yaml Checking the content of ["/etc/puppetlabs/code/environments/production/hieradata/common.yaml"] File : /etc/puppetlabs/code/environments/production/hieradata/common.yaml, Syntax OK Done.  

The stages involved in Linux Booting Process are: BIOS/uefi boot Boot Loader - MBR - GRUB Kernel Init Runlevel scripts BIOS This is the first thing which loads once you power on your machine. When you press the power button of the machine, CPU looks out into ROM for further instruction. The ROM contains JUMP … Continue reading Boot procedure