Installing and configuring Docker
by Uday R. Sawant, William Leemans, Jonathan Hobson, Oliver Pelz
Linux: Powerful Server Administration
- Linux: Powerful Server Administration
- Table of Contents
- Linux: Powerful Server Administration
- Linux: Powerful Server Administration
- Credits
- Preface
- 1. Module 1
- 1. Managing Users and Groups
- 2. Networking
- Introduction
- Connecting to a network with a static IP
- Installing the DHCP server
- Installing the DNS server
- Hiding behind the proxy with squid
- Being on time with NTP
- Discussing load balancing with HAProxy
- Tuning the TCP stack
- Troubleshooting network connectivity
- Securing remote access with OpenVPN
- Securing a network with uncomplicated firewall
- Securing against brute force attacks
- Discussing Ubuntu security best practices
- 3. Working with Web Servers
- Introduction
- Installing and configuring the Apache web server
- Serving dynamic contents with PHP
- Hosting multiple websites with a virtual domain
- Securing web traffic with HTTPS
- Installing Nginx with PHP_FPM
- Setting Nginx as a reverse proxy
- Load balancing with Nginx
- Setting HTTPs on Nginx
- Benchmarking and performance tuning of Apache
- Securing the web server
- Troubleshooting the web server
- 4. Working with Mail Servers
- 5. Handling Databases
- Introduction
- Installing relational databases with MySQL
- Storing and retrieving data with MySQL
- Importing and exporting bulk data
- Adding users and assigning access rights
- Installing web access for MySQL
- Setting backups
- Optimizing MySQL performance – queries
- Optimizing MySQL performance – configuration
- Creating MySQL replicas for scaling and high availability
- Troubleshooting MySQL
- Installing MongoDB
- Storing and retrieving data with MongoDB
- 6. Network Storage
- 7. Cloud Computing
- 8. Working with Containers
- Introduction
- Installing LXD, the Linux container daemon
- Deploying your first container with LXD
- Managing LXD containers
- Managing LXD containers – advanced options
- Setting resource limits on LXD containers
- Networking with LXD
- Installing Docker
- Starting and managing Docker containers
- Creating images with a Dockerfile
- Understanding Docker volumes
- Deploying WordPress using a Docker network
- Monitoring Docker containers
- Securing Docker containers
- 9. Streaming with Ampache
- 10. Communication Server with XMPP
- 11. Git Hosting
- Introduction
- Installing Git
- Creating a local repository with Git CLI
- Storing file revisions with Git commit
- Synchronizing the repository with a remote server
- Receiving updates with Git pull
- Creating repository clones
- Installing GitLab, your own Git hosting
- Adding users to the GitLab server
- Creating a repository with GitLab
- Automating common tasks with Git hooks
- 12. Collaboration Tools
- 13. Performance Monitoring
- 14. Centralized Authentication Service
- 2. Module 2
- 1. Installing CentOS
- Introduction
- Downloading CentOS and confirming the checksum on Windows or OS X
- Creating USB installation media on Windows or OS X
- Performing an installation of CentOS using the graphical installer
- Running a netinstall over HTTP
- Installing CentOS 7 using a kickstart file
- Getting started and customising the boot loader
- Troubleshooting the system in rescue mode
- Updating the installation and enhancing the minimal install with additional administration and development tools
- 2. Configuring the System
- Introduction
- Navigating text files with less
- Introduction to Vim
- Speaking the right language
- Synchronizing the system clock with NTP and the chrony suite
- Setting your hostname and resolving the network
- Building a static network connection
- Becoming a superuser
- Customizing your system banners and messages
- Priming the kernel
- 3. Managing the System
- Introduction
- Knowing and managing your background services
- Troubleshooting background services
- Tracking system resources with journald
- Configuring journald to make it persistent
- Managing users and their groups
- Scheduling tasks with cron
- Synchronizing files and doing more with rsync
- Maintaining backups and taking snapshots
- Monitoring important server infrastructure
- Taking control with GIT and Subversion
- 4. Managing Packages with YUM
- 5. Administering the Filesystem
- 6. Providing Security
- 7. Building a Network
- 8. Working with FTP
- 9. Working with Domains
- 10. Working with Databases
- 11. Providing Mail Services
- 12. Providing Web Services
- 13. Operating System-Level Virtualization
- 14. Working with SELinux
- 15. Monitoring IT Infrastructure
- 1. Installing CentOS
- 3. Module 3
- 1. Working with KVM Guests
- 2. Deploying RHEL "En Masse"
- 3. Configuring Your Network
- 4. Configuring Your New System
- 5. Using SELinux
- 6. Orchestrating with Ansible
- 7. Puppet Configuration Management
- 8. Yum and Repositories
- 9. Securing RHEL 7
- 10. Monitoring and Performance Tuning
- Bibliography
- Index
Traditional virtualization technologies provide hardware virtualization, which means they create a complete hardware environment so each virtual machine (VM) needs a complete operating system to run it. Therefore they have some major drawbacks because they are heavyweight and produce a lot of overhead while running. This is where the open-source Docker containerization engine offers an attractive alternative. It can help you build applications in Linux containers, thus providing application virtualization.
This means that you can bundle any Linux program of choice with all its dependencies and its own environment and then share it or run multiple instances of it, each as a completely isolated and separated process on any modern Linux kernel, thus providing native runtime performance, easy portability, and high scalability. Here, in this recipe, we will show you how to install and configure Docker on your CentOS 7 server.
To complete this recipe, you will require a working installation of the CentOS 7 operating system with root privileges, a console-based text editor of your choice, and a connection to the Internet in order to download additional rpm packages and a test Docker image.
While Docker is available as a package in the official CentOS 7 repository, we will use the official Docker repository to install it on our system instead.
- To begin, log in as root and update your YUM packages before downloading and executing the official Docker Linux installation script using the following command:
yum update && curl -sSL https://get.docker.com/ | sh - Next, enable Docker at boot time before starting the Docker daemon (the first time you start, it will take a while):
systemctl enable docker && systemctl start docker - Finally, after starting Docker you can verify that it's working by typing:
docker run hello-world
When installing any software on CentOS 7, most of the time it is a very good advice to use the packages available in your official CentOS repository instead of downloading and installing from third-party locations. Here by installing Docker using the official Docker repository instead we made an exception. We did this because Docker is a very young project and is evolving fast, and it keeps changing a lot. While you can use Docker for running every Linux application, including critical web servers or programs dealing with confidential data, bugs found or introduced into the Docker program can have severe security consequences. By using the official Docker repository, we make sure we always get the latest updates and patches available as fast as possible right from the developers of this fast-moving project. So anytime you type yum update in the future, your package manager will automatically query and check the Docker repos to see if there is a new version of Docker available for you.
So what did we learn from this experience?
We started this recipe by logging into our server as root and updated the YUM package's database. Then we used a command to download and execute the official Docker installation script from https://get.docker.com/ in one step. What this script does is add the official Docker repository to the YUM package manager as a new package source and then automatically install Docker in the background. Afterwards, we enabled the Docker service at boot-time and started it by using systemd. Finally, to test our installation, we issued the command docker run hello-world, which downloads a special image from the official Docker registry to test our installation. If everything went fine, you should see the following success message (output truncated):
Hello from Docker
This message shows that your installation appears to be working correctly.
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