hard link is the same file, using the same inode. soft link is a shortcut to another file, using a different inode. soft links can be created between different file systems while hard link can be created only within the same file system. 

You can achieve that by specifying & at end of the command. As to Why? since some commands/processes can take a lot of time to finish execution or run forever 

The default signal is SIGTERM (15). This signal kills process gracefully which means it allows it to save current state configuration. 

SIGTERM - default signal for terminating a process SIGHUP - common usage is for reloading configuration SIGKILL - a signal which cannot caught or ignored To view all available signals run `kill -l` 

Task – a call to a specific Ansible module Module – the actual unit of code executed by Ansible on your own host or a remote host. Modules are indexed by category (database, file, network, …) and also referred as task plugins. Play – One or more tasks executed on a given host(s) Playbook – One or more plays. Each play can be executed on the same or different hosts Role – Ansible roles allows you to group resources based on certain functionality/service such that they can be easily reused. In a role, you have directories for variables, defaults, files, templates, handlers, tasks, and metadata. You can then use the role by simply specifying it in your playbook. 

- name: Create a new directory file: path: "/tmp/new_directory" state: directory 

--- - name: Print information about my host hosts: localhost gather_facts: 'no' tasks: - name: Print hostname debug: msg: "It's me, {{ ansible_hostname }}" 

When given a written code, always inspect it thoroughly. If your answer is “this will fail” then you are right. We are using a fact (ansible_hostname), which is a gathered piece of information from the host we are running on. But in this case, we disabled facts gathering (gather_facts: no) so the variable would be undefined which will result in failure. 

--- - hosts: all vars: mario_file: /tmp/mario package_list: - 'zlib' - 'vim' tasks: - name: Check for mario file stat: path: "{{ mario_file }}" register: mario_f - name: Install zlib and vim if mario file exists become: "yes" package: name: "{{ item }}" state: present with_items: "{{ package_list }}" when: mario_f.stat.exists 

--- - name: Deploy /tmp/system_info file hosts: all:!controllers tasks: - name: Deploy /tmp/system_info template: src: system_info.j2 dest: /tmp/system_info 

# {{ ansible_managed }} I'm {{ ansible_hostname }} and my operating system is {{ ansible_distribution } 

Docker CLI passes your request to Docker daemon. Docker daemon downloads the image from Docker Hub Docker daemon creates a new container by using the image it downloaded Docker daemon redirects output from container to Docker CLI which redirects it to the standard output 

FROM registry.access.redhat.com/rhel7/rhel RUN yum -y install httpd && yum -y update; yum clean all EXPOSE 80 ENTRYPOINT [ "/usr/sbin/httpd" ] CMD [ "-D", "FOREGROUND" ] 

Use the image 'rhel7/rhel' from the registry 'registry.access.redhat.com` to run httpd. Befor running it, install the httpd package, update all packages and expose port 80. 

The mutable data types are: List Dictionary Set The immutable data types are: Numbers (int, float, ...) String Bool Tuple The id function can be used to check if a given variable is mutable or not. 

PEP8 is a list of coding conventions and style guidelines for Python 5 style guidelines: 1. Limit all lines to a maximum of 79 characters. 2. Surround top-level function and class definitions with two blank lines. 3. Use commas when making a tuple of one element 4. Use spaces (and not tabs) for indentation 5. Use 4 spaces per indentation level 

1. Translation lookup in i18n 2. Hold the result of the last executed expression or statement 3. As a general purpose "throwaway" variable name. For example: x, y, _ = get_data() (x and y are used but since we don't care about third variable, we "threw it away"). 

li = [[1, 4], [2, 1], [3, 9], [4, 2], [4, 5]] sorted(x, key=lambda l: l[1]) 

set([food for bro in x for food in bro['food']]) 

Prometheus server responsible for scraping the storing the data Push gateway is used for short-lived jobs Alert manager is responsible for alerts ;)