OpenShift Container Platform 4.2 (DO180): Introduction to Containers, Kubernetes, and Red Hat OpenShift

348 Pages·2019·8.922 MB·English

by  Zach Gutterman et al.

Student Workbook (ROLE)
OCP 4.2 DO180
Introduction to Containers, Kubernetes,
and Red Hat OpenShift
Edition 1
DO180-OCP4.2-en-1-20191105 Copyright ©2019 Red Hat, Inc.

Introduction
to Containers,
Kubernetes, and
Red Hat OpenShift
DO180-OCP4.2-en-1-20191105 Copyright ©2019 Red Hat, Inc.
OCP 4.2 DO180
Introduction to Containers, Kubernetes, and Red Hat
OpenShift
Edition 1 20191105
Publication date 20191105
Authors: Zach Gutterman, Dan Kolepp, Eduardo Ramirez Ronco,
Jordi Sola Alaball, Richard Allred
Editor: Seth Kenlon, Dave Sacco, Connie Petlitzer
Copyright © 2019 Red Hat, Inc.
The contents of this course and all its modules and related materials, including handouts to
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No part of this publication may be stored in a retrieval system, transmitted or reproduced in
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All other trademarks are the property of their respective owners.
Contributors: Michael Jarrett, Forrest Taylor and Manuel Aude Morales
Document Conventions                                                                                                   vii
Introduction                                                                                                                     ix
DO180: Introduction to Containers, Kubernetes, and Red Hat OpenShift ......................... ix
Orientation to the Classroom Environment .................................................................. x
Internationalization ................................................................................................. xiii
1. Introducing Container Technology                                                                                   1
Overview of Container Technology ............................................................................. 2
Quiz: Overview of Container Technology ..................................................................... 5
Overview of Container Architecture ............................................................................ 9
Quiz: Overview of Container Architecture ................................................................... 12
Overview of Kubernetes and OpenShift ..................................................................... 14
Quiz: Describing Kubernetes and OpenShift ............................................................... 17
Guided Exercise: Configuring the Classroom Environment ............................................ 19
Summary ............................................................................................................... 25
2. Creating Containerized Services                                                                                  27
Provisioning Containerized Services .......................................................................... 28
Guided Exercise: Creating a MySQL Database Instance .............................................. 35
Lab: Creating Containerized Services ....................................................................... 38
Summary ............................................................................................................... 43
3. Managing Containers                                                                                                   45
Managing the Life Cycle of Containers ..................................................................... 46
Guided Exercise: Managing a MySQL Container ......................................................... 54
Attaching Persistent Storage to Containers ............................................................... 59
Guided Exercise: Persisting a MySQL Database ......................................................... 62
Accessing Containers .............................................................................................. 65
Guided Exercise: Loading the Database .................................................................... 69
Lab: Managing Containers ....................................................................................... 73
Summary ............................................................................................................... 82
4. Managing Container Images                                                                                        83
Accessing Registries ............................................................................................... 84
Quiz: Working With Registries .................................................................................. 90
Manipulating Container Images ................................................................................ 94
Guided Exercise: Creating a Custom Apache Container Image .................................... 100
Lab: Managing Images ........................................................................................... 105
Summary ............................................................................................................... 113
5. Creating Custom Container Images                                                                              115
Designing Custom Container Images ........................................................................ 116
Quiz: Approaches to Container Image Design ........................................................... 120
Building Custom Container Images with Dockerfiles ................................................... 122
Guided Exercise: Creating a Basic Apache Container Image ........................................ 127
Lab: Creating Custom Container Images ................................................................... 131
Summary .............................................................................................................. 138
6. Deploying Containerized Applications on OpenShift                                                    139
Describing Kubernetes and OpenShift Architecture ................................................... 140
Quiz: Describing Kubernetes and OpenShift ............................................................. 146
Creating Kubernetes Resources .............................................................................. 150
Guided Exercise: Deploying a Database Server on OpenShift ..................................... 160
Creating Routes .................................................................................................... 165
Guided Exercise: Exposing a Service as a Route ........................................................ 169
Creating Applications with Source-to-Image ............................................................. 174
Guided Exercise: Creating a Containerized Application with Source-to-Image ............... 184
DO180-OCP4.2-en-1-20191105 v
Creating Applications with the OpenShift Web Console .............................................. 191
Guided Exercise: Creating an Application with the Web Console .................................. 196
Lab: Deploying Containerized Applications on OpenShift .......................................... 208
Summary .............................................................................................................. 213
7. Deploying Multi-Container Applications                                                                       215
Considerations for Multi-Container Applications ........................................................ 216
Guided Exercise: Deploying the Web Application and MySQL Containers ...................... 221
Deploying a Multi-Container Application on OpenShift .............................................. 228
Guided Exercise: Creating an Application with a Template ......................................... 238
Lab: Deploying Multi-Container Applications ........................................................... 244
Summary .............................................................................................................. 251
8. Troubleshooting Containerized Applications                                                               253
Troubleshooting S2I Builds and Deployments ........................................................... 254
Guided Exercise: Troubleshooting an OpenShift Build ............................................... 259
Troubleshooting Containerized Applications ............................................................. 267
Guided Exercise: Configuring Apache Container Logs for Debugging .......................... 273
Lab: Troubleshooting Containerized Applications ...................................................... 276
Summary ............................................................................................................. 287
9. Comprehensive Review                                                                                              289
Comprehensive Review ......................................................................................... 290
Lab: Containerizing and Deploying a Software Application ......................................... 293
A. Implementing Microservices Architecture                                                                  303
Implementing Microservices Architectures ............................................................... 304
Guided Exercise: Refactoring the To Do List Application ........................................... 308
Summary .............................................................................................................. 313
B. Creating a GitHub Account                                                                                         315
Creating a GitHub Account .................................................................................... 316
C. Creating a Quay Account                                                                                            319
Creating a Quay Account ...................................................................................... 320
Repositories Visibility ............................................................................................ 323
D. Useful Git Commands                                                                                                327
Git Commands ..................................................................................................... 328
vi DO180-OCP4.2-en-1-20191105
Document Conventions
References
"References" describe where to find external documentation relevant to a subject.
Note
"Notes" are tips, shortcuts or alternative approaches to the task at hand. Ignoring a
note should have no negative consequences, but you might miss out on a trick that
makes your life easier.
Important
"Important" boxes detail things that are easily missed: configuration changes that
only apply to the current session, or services that need restarting before an update
will apply. Ignoring a box labeled "Important" will not cause data loss, but may cause
irritation and frustration.
Warning
"Warnings" should not be ignored. Ignoring warnings will most likely cause data loss.
DO180-OCP4.2-en-1-20191105 vii
viii DO180-OCP4.2-en-1-20191105
Introduction
DO180: Introduction to Containers, Kubernetes, and
Red Hat OpenShift
DO180: Introduction to Containers, Kubernetes, and Red Hat OpenShift is a
hands-on course that teaches students how to create, deploy, and manage
containers using Podman, Kubernetes, and the Red Hat OpenShift Container
Platform.
One of the key tenants of the DevOps movement is continuous integration
and continuous deployment. Containers have become a key technology
for the configuration and deployment of applications and microservices.
Red Hat OpenShift Container Platform is an implementation of Kubernetes, a
container orchestration system.
Course • Demonstrate knowledge of the container
ecosystem.
Objectives
• Manage Linux containers using Podman.
• Deploy containers on a Kubernetes cluster
using the OpenShift Container Platform.
• Demonstrate basic container design and the
ability to build container images.
• Implement a container-based architecture
using knowledge of containers, Kubernetes, and
OpenShift.
Audience • System Administrators
• Developers
• IT Leaders and Infrastructure Architects
Prerequisites Students should meet one or more of the
following prerequisites:
• Be able to use a Linux terminal session and
issue operating system commands. An RHCSA
certification is recommended but not required.
• Have experience with web application
architectures and their corresponding
technologies.
DO180-OCP4.2-en-1-20191105 ix
Introduction
Orientation to the Classroom
Environment
Figure 0.1: Classroom environment
In this course, the main computer system used for hands-on learning activities is workstation.
This is a virtual machine (VM) named workstation.lab.example.com.
All student computer systems have a standard user account, student, which has the password
student. The root password on all student systems is redhat.
Classroom Machines
Machine name IP addresses Role
content.example.com, 172.25.252.254, Classroom utility server
materials.example.com, 172.25.253.254,
classroom.example.com 172.25.254.254
workstation.lab.example.com 172.25.250.254, Student graphical workstation
172.25.252.1
Several systems in the classroom provide supporting services. Two servers,
content.example.com and materials.example.com, are sources for software and lab
materials used in hands-on activities. Information on how to use these servers is provided in the
instructions for those activities.
Students use the workstatoin machine to access a shared OpenShift cluster hosted externally
in AWS. Students do not have cluster administrator privileges on the cluster, but that is not
necessary to complete the DO180 content.
Students are provisioned an account on a shared OpenShift 4 cluster when they provision their
environments in the Red Hat Online Learning interface. Cluster information such as the API
endpoint, and cluster-ID, as well as their username and password are presented to them when they
provision their environment.
x DO180-OCP4.2-en-1-20191105