How To Install Podman 3.x on CentOS 7 / RHEL 7

How To Install Podman 3.x on CentOS 7

For close to a decade now, the Linux containers adoption as a key open source application packaging and delivery technology is immense. The container technology combines a lightweight application isolation with the flexibility of image-based deployment methods. Podman was created around the Docker container engine technology. Linux containers are implemented on RHEL based systems using core technologies such as:

• Control groups (cgroups) for resource management
• SELinux for security
• Namespaces for process isolation
• Secure multi-tenancy

The use of these technologies aims at reducing the risks for potential security exploits. Podman is a tool created as a Docker alternative to running Linux containers. The main advantages of Podman are as listed:

• Running containers in rootless mode – You can run rootless containers which are more secure, as they run without any added privileges
• Native systemd integration – With Podman you can create systemd unit files and run containers as system services
• No daemon required – Podman have much lower resource requirements at idle since Podman is daemonless.

Install Podman 3.x on CentOS 7 / RHEL 7

When Podman installation on CentOS/RHEL 7 system is performed from upstream OS repositories, an older version is installed.

$ podman version
Version:            1.6.4
RemoteAPI Version:  1
Go Version:         go1.12.12
OS/Arch:            linux/amd64

In this article we install the latest Podman 3.x on CentOS 7 / RHEL 7. We’re building the application from source code to get the latest release of software.

Step 1 – Install dependencies for building Podman

When performing an installation of Podman 3.x on CentOS 7 / RHEL 7, we’ve to build the application from source. Some dependencies are required for this operation.

Enable EPEL repository:

sudo yum -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

Install standard build tools on your CentOS 7 / RHEL 7:

sudo yum -y install "@Development Tools"

Install all required deps by running the command below:

sudo yum install -y \
  gcc \
  make \
  device-mapper-devel \
  git \
  btrfs-progs-devel \
  conmon \
  containernetworking-plugins \
  containers-common \
  git \
  glib2-devel \
  glibc-devel \
  glibc-static \
  golang-github-cpuguy83-md2man \
  gpgme-devel \
  iptables \
  libassuan-devel \
  libgpg-error-devel \
  libseccomp-devel \
  libselinux-devel \
  pkgconfig \
  systemd-devel \
  autoconf \
  python3 \
  python3-devel \
  python3-pip \
  yajl-devel \
  libcap-devel

Wait for the installation of these dependencies to complete then proceed to step 2.

Step 2 – Install Golang on CentOS 7 / RHEL 7

You can refer to our guide below on the installation of Go on CentOS 7 / RHEL 7:

• Install Go (Golang) on CentOS 7 / RHEL 7

 Alternatively, build go from source:

cd ~
export GOPATH=~/go
git clone https://go.googlesource.com/go $GOPATH
cd $GOPATH
cd src
./all.bash
export PATH=$GOPATH/bin:$PATH

Checking version of Go installed

$ go version
go version go1.17.6 linux/amd64

Step 3 – Install conmon and runc

Conmon is used to monitor OCI Runtimes and the package is expected installed on the system. This can be done by executing the following commands in the terminal

cd ~
git clone https://github.com/containers/conmon
cd conmon
export GOCACHE="$(mktemp -d)"
make
sudo make podman

If installation was successful the command below should return software version:

$ conmon --version
conmon version 2.0.8
commit: f85c8b1ce77b73bcd48b2d802396321217008762

We also need the latest version of runc installed on the system.

git clone https://github.com/opencontainers/runc.git $GOPATH/src/github.com/opencontainers/runc
cd $GOPATH/src/github.com/opencontainers/runc
make BUILDTAGS="selinux seccomp"
sudo cp runc /usr/bin/runc

Checking version of runc installed:

$ runc --version 
runc version 1.1.0+dev
commit: v1.1.0-32-geddf35e
spec: 1.0.2-dev
go: go1.17.6
libseccomp: 2.3.1

Step 4 – Setup CNI networking for Podman

A basic setup for CNI networking is required to use Podman. Begin with the creation of required directories:

sudo mkdir -p /etc/containers

Download configuration samples and place in relevant directories.

sudo curl -L -o /etc/containers/registries.conf https://src.fedoraproject.org/rpms/containers-common/raw/main/f/registries.conf
sudo curl -L -o /etc/containers/policy.json https://src.fedoraproject.org/rpms/containers-common/raw/main/f/default-policy.json

Step 5 – Build Podman 3.x on CentOS 7 / RHEL 7

Clone the podman project source code from Github.

cd ~
git clone https://github.com/containers/podman/

Change to podman directory and begin the build process.

cd podman
make BUILDTAGS="selinux seccomp"
sudo make install PREFIX=/usr

List of available build tags, feature and dependency:

Build TagFeatureDependencyapparmorapparmor supportlibapparmorexclude_graphdriver_btrfsexclude btrfslibbtrfsexclude_graphdriver_devicemapperexclude device-mapperlibdmlibdm_no_deferred_removeexclude deferred removal in libdmlibdmseccompsyscall filteringlibseccompselinuxselinux process and mount labeling systemdjournald logginglibsystemd

Optional flags for gpgme:

CGO_CFLAGS="-Dgpgme_off_t=off_t"

You can check the version of Podman 3 installed on CentOS 7 / RHEL 7 after the build.

$ podman  version
Version:      3.3.1
API Version:  3.3.1
Go Version:   go1.16.7
Built:        Wed Nov 10 01:48:06 2021
OS/Arch:      linux/amd64

The next article to read is on the usage of Podman:

• Run Docker Containers using Podman and Libpod

More articles on containerization: