Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Create a new role named packtpub-os-compute-worker.json."

A block of code is set as follows:

heat_template_version: 
description: 
parameters:
  param1
    type: 
    label: 
    description:
    default: 
  param2:
     ....

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

input  {
. . . 
   }
filter{
  if [type] == "openstack" {
    grok {
      patterns_dir => "/opt/logstash/patterns/"
      match=>[ "message","%{TIMESTAMP_ISO8601:timestamp} %{NUMBER:response} %{AUDITLOGLEVEL:level} %{NOTSPACE:module} \[%{GREEDYDATA:program}\] %{GREEDYDATA:content}"]
    }

Any command-line input or output is written as follows:

# yum clean all
# yum update –y
# yum install nginx redis –y

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "To install Ruby, you need to go from the Eclipse menu bar and navigate to Help | Install New Software."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.