,Foreword
Containers, their various runtimes, and Kubernetes are seeing fierce momentum in the technology
and computing worlds. They are no longer just the darling of system administrators and Kubernetes
distributed workloads. Containers are now endemic in Continuous Integration (CI) tasks, cloud
workloads, and microservices. Starting with programmers, containers have even broken into the
desktop space, where Integrated Development Environments (IDEs) can be the backend into
containers for things such as testing language versions or compiling code. We can attribute the
latest invigoration to the simplification of container images and the ability to distribute them in
container registries. Not bad for a decades-old technology that used to simply focus on the isolation
of a computing process.
Podman for DevOps begins with a detailed exploration of container history, from its inception to
now. It then transitions into the various container technologies and arrives at the two most common
ones: Docker and Podman (short for Pod Manager). The early chapters provide a comprehensive
examination of Docker and Podman and describe the pros and cons of both. These comparisons
demonstrate Podman's novelty and strengths.
Gianni and Alessandro then settle on Podman, beginning with an exploration of its architecture.
They then follow the architecture by illustrating the various applications in the Podman stack, such
as conmon and network tooling. After laying the groundwork for how Podman works, they
meticulously review each Podman command in an example-oriented approach. Finally, Gianni and
Alessandro provide a thorough review of Buildah, Podman's best friend and a best-of-breed
application for building container images.
When I write about containers and Podman, one of my challenges when explaining concepts can
be providing too many details or oversimplifying things. Gianni and Alessandro have found a
perfect medium between both ends by supplying ample amounts of detail. I appreciated the
carefully crafted explanations when the topic required them. Not only was the level of detail
appropriate, but they also used a very wide scope when writing about Podman and containers. As
I read the book, I was able to relate to their superb use of examples and they did not add layers of
abstraction that can make learning difficult. Podman for DevOps was a pleasure to read. As a
subject matter expert, I am certain it will be a perfect resource for those both new to and
experienced with Podman and containers.
Brent J. Baude, Senior Principal Software Engineer
Podman Architect
Contributors
About the authors
,Alessandro Arrichiello is a solution architect for Red Hat Inc. with a special focus on telco
technologies. He has a passion for GNU/Linux systems, which began at age 14 and continues
today. He has worked with tools for automating enterprise IT: configuration management and
continuous integration through virtual platforms. Alessandro is also a writer for the Red Hat
Developer Blog, on which he has authored several articles about container architecture and
technology. He now helps telecommunication customers with adopting container orchestration
environments such as Red Hat OpenShift and Kubernetes, infrastructure as a service such as
OpenStack, edge computing, and data center automation.
Gianni Salinetti is a solution architect from Rome working for Red Hat Inc. with a special focus
on cloud-native computing and hybrid cloud strategies. He started working with GNU/Linux back
in 2001 and developed a passion for open source software. His main fields of interest are
application orchestration, automation, and systems performance tuning. He is also an advocate of
DevSecOps and GitOps practices. He is a former Red Hat instructor, having taught many classes
about GNU/Linux, OpenStack, JBoss middleware, Ansible, Kubernetes, and Red Hat OpenShift.
He won Red Hat EMEA awards as the best DevOps, cloud, and middleware instructor. He is also
an author for the Red Hat Developer Blog and actively contributes to webinars and events.
About the reviewers
Nicolò Amato has over 20 years of experience working in the field of IT, 16 of which were at
Hewlett Packard Enterprise, Accenture, DXC, and Red Hat Inc. Working in both technical and
development roles has given him a broad base of skills and the ability to work with a diverse range
of clients. His time was spent designing and implementing complex infrastructures for clients with
the aim to migrate traditional services to hybrid, multi-cloud, and edge environments, evolving
them into cloud-native services. He is enthusiastic about new technologies and he likes to be up to
date – in particular with open source, which he considers one of the essences of technology that
regulates the evolution of information technology.
Pierluigi Rossi is a solution architect for Red Hat Inc. His passion for GNU/Linux systems began
20 years ago and continues today. He has built a strong business and technical know-how on
enterprise and cutting-edge technologies, working for many companies on different verticals and
roles in the last 20 years. He has worked with virtualization and containerization tools (open source
and not). He has also participated in several projects for corporate IT automation. He is now
working on distributed on-premises and cloud environments involving IaaS, PaaS (OpenShift and
Kubernetes), and automation. He loves open source in all its shades, and he enjoys sharing ideas
and solutions with customers, colleagues, and community members.
Marco Alessandro Fagotto has been in the IT industry for 13 years, ranging across frontend and
backend support, administration, system configuration, and security roles. Working in both
technical and development roles has given him a broad base of skills and the ability to work with
a diverse range of clients. He is a Red Hat Certified Professional, always looking for new
technology and solutions to explore due to his interest in the fast evolution of the open source
world.
, Table of content
Section 1: From Theory to Practice: Running Containers with Podman
Chapter 1: Introduction to Container Technology
Technical requirements
Book conventions
What are containers?
Resource usage with cgroups
Running isolated processes
Isolating mounts
Container images to the rescue
Security considerations
Container engines and runtimes
Containers versus virtual machines
Why do I need a container?
Open source
Portability
DevOps facilitators
Cloud readiness
Infrastructure optimization
Microservices
Chroot and Unix v7
FreeBSD jails
Solaris Containers (also known as Solaris Zones)
Containers, their various runtimes, and Kubernetes are seeing fierce momentum in the technology
and computing worlds. They are no longer just the darling of system administrators and Kubernetes
distributed workloads. Containers are now endemic in Continuous Integration (CI) tasks, cloud
workloads, and microservices. Starting with programmers, containers have even broken into the
desktop space, where Integrated Development Environments (IDEs) can be the backend into
containers for things such as testing language versions or compiling code. We can attribute the
latest invigoration to the simplification of container images and the ability to distribute them in
container registries. Not bad for a decades-old technology that used to simply focus on the isolation
of a computing process.
Podman for DevOps begins with a detailed exploration of container history, from its inception to
now. It then transitions into the various container technologies and arrives at the two most common
ones: Docker and Podman (short for Pod Manager). The early chapters provide a comprehensive
examination of Docker and Podman and describe the pros and cons of both. These comparisons
demonstrate Podman's novelty and strengths.
Gianni and Alessandro then settle on Podman, beginning with an exploration of its architecture.
They then follow the architecture by illustrating the various applications in the Podman stack, such
as conmon and network tooling. After laying the groundwork for how Podman works, they
meticulously review each Podman command in an example-oriented approach. Finally, Gianni and
Alessandro provide a thorough review of Buildah, Podman's best friend and a best-of-breed
application for building container images.
When I write about containers and Podman, one of my challenges when explaining concepts can
be providing too many details or oversimplifying things. Gianni and Alessandro have found a
perfect medium between both ends by supplying ample amounts of detail. I appreciated the
carefully crafted explanations when the topic required them. Not only was the level of detail
appropriate, but they also used a very wide scope when writing about Podman and containers. As
I read the book, I was able to relate to their superb use of examples and they did not add layers of
abstraction that can make learning difficult. Podman for DevOps was a pleasure to read. As a
subject matter expert, I am certain it will be a perfect resource for those both new to and
experienced with Podman and containers.
Brent J. Baude, Senior Principal Software Engineer
Podman Architect
Contributors
About the authors
,Alessandro Arrichiello is a solution architect for Red Hat Inc. with a special focus on telco
technologies. He has a passion for GNU/Linux systems, which began at age 14 and continues
today. He has worked with tools for automating enterprise IT: configuration management and
continuous integration through virtual platforms. Alessandro is also a writer for the Red Hat
Developer Blog, on which he has authored several articles about container architecture and
technology. He now helps telecommunication customers with adopting container orchestration
environments such as Red Hat OpenShift and Kubernetes, infrastructure as a service such as
OpenStack, edge computing, and data center automation.
Gianni Salinetti is a solution architect from Rome working for Red Hat Inc. with a special focus
on cloud-native computing and hybrid cloud strategies. He started working with GNU/Linux back
in 2001 and developed a passion for open source software. His main fields of interest are
application orchestration, automation, and systems performance tuning. He is also an advocate of
DevSecOps and GitOps practices. He is a former Red Hat instructor, having taught many classes
about GNU/Linux, OpenStack, JBoss middleware, Ansible, Kubernetes, and Red Hat OpenShift.
He won Red Hat EMEA awards as the best DevOps, cloud, and middleware instructor. He is also
an author for the Red Hat Developer Blog and actively contributes to webinars and events.
About the reviewers
Nicolò Amato has over 20 years of experience working in the field of IT, 16 of which were at
Hewlett Packard Enterprise, Accenture, DXC, and Red Hat Inc. Working in both technical and
development roles has given him a broad base of skills and the ability to work with a diverse range
of clients. His time was spent designing and implementing complex infrastructures for clients with
the aim to migrate traditional services to hybrid, multi-cloud, and edge environments, evolving
them into cloud-native services. He is enthusiastic about new technologies and he likes to be up to
date – in particular with open source, which he considers one of the essences of technology that
regulates the evolution of information technology.
Pierluigi Rossi is a solution architect for Red Hat Inc. His passion for GNU/Linux systems began
20 years ago and continues today. He has built a strong business and technical know-how on
enterprise and cutting-edge technologies, working for many companies on different verticals and
roles in the last 20 years. He has worked with virtualization and containerization tools (open source
and not). He has also participated in several projects for corporate IT automation. He is now
working on distributed on-premises and cloud environments involving IaaS, PaaS (OpenShift and
Kubernetes), and automation. He loves open source in all its shades, and he enjoys sharing ideas
and solutions with customers, colleagues, and community members.
Marco Alessandro Fagotto has been in the IT industry for 13 years, ranging across frontend and
backend support, administration, system configuration, and security roles. Working in both
technical and development roles has given him a broad base of skills and the ability to work with
a diverse range of clients. He is a Red Hat Certified Professional, always looking for new
technology and solutions to explore due to his interest in the fast evolution of the open source
world.
, Table of content
Section 1: From Theory to Practice: Running Containers with Podman
Chapter 1: Introduction to Container Technology
Technical requirements
Book conventions
What are containers?
Resource usage with cgroups
Running isolated processes
Isolating mounts
Container images to the rescue
Security considerations
Container engines and runtimes
Containers versus virtual machines
Why do I need a container?
Open source
Portability
DevOps facilitators
Cloud readiness
Infrastructure optimization
Microservices
Chroot and Unix v7
FreeBSD jails
Solaris Containers (also known as Solaris Zones)
