Why
Redhat recently changed how they release source code which prompted me to try out CentOS Stream again. There is nothing wrong with Alma Linux, but I have heard that the rebuilds are not the same as CentOS Stream. I decided to try and spot the differences. There were some workloads like AdGuardHome that I can easily re-deploy to a new VM since there is an Ansible role to deploy it, the config is a single file, and all the logs are shipped to Shift-mon. Other workloads like Nextcloud and MeshCentral can be deployed using the same Ansible collection, but can require data and database migrations to move to a new server. So after testing on a few of my own machines, I have created a process to upgrade an Enterprise Linux 9 server from a rebuild like AlmaLinux or Rocky Linux to CentOS Stream to avoid those difficult data migrations. I have only tested this on Rocky Linux and AlmaLinux. I have not tested this on Oracle Linux, RHEL, or any other Enterprise Linux distribution, but it should be mostly the same.
How
There is no way of migrating back, so please make sure you have a recent backup before you start. To confirm we are not running CentOS Stream already, run cat /etc/os-release
1. Copy CentOS Stream Key
You need to create a file called /etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial that has the following contents:
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v2.0.22 (GNU/Linux)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=kkH7
-----END PGP PUBLIC KEY BLOCK-----
If the key is updated, you can copy it off of an existing CentOS Stream install. This file is the signing key used for verifying content from the CentOS Stream repos.
2. Add CentOS Stream Repos Copy
Create a file called /etc/yum.repos.d/centos.repo and add the following text:
[baseos-stream]
name=CentOS Stream $releasever - BaseOS
metalink=https://mirrors.centos.org/metalink?repo=centos-baseos-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=1
[baseos-debuginfo-stream]
name=CentOS Stream $releasever - BaseOS - Debug
metalink=https://mirrors.centos.org/metalink?repo=centos-baseos-debug-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[baseos-source-stream]
name=CentOS Stream $releasever - BaseOS - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-baseos-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[appstream-stream]
name=CentOS Stream $releasever - AppStream
metalink=https://mirrors.centos.org/metalink?repo=centos-appstream-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=1
[appstream-debuginfo-stream]
name=CentOS Stream $releasever - AppStream - Debug
metalink=https://mirrors.centos.org/metalink?repo=centos-appstream-debug-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[appstream-source-stream]
name=CentOS Stream $releasever - AppStream - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-appstream-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[crb-stream]
name=CentOS Stream $releasever - CRB
metalink=https://mirrors.centos.org/metalink?repo=centos-crb-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=0
[crb-debuginfo-stream]
name=CentOS Stream $releasever - CRB - Debug
metalink=https://mirrors.centos.org/metalink?repo=centos-crb-debug-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[crb-source-stream]
name=CentOS Stream $releasever - CRB - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-crb-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
Create a file called /etc/yum.repos.d/centos-addons.repo and add the following text:
[highavailability-stream]
name=CentOS Stream $releasever - HighAvailability
metalink=https://mirrors.centos.org/metalink?repo=centos-highavailability-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=0
[highavailability-debuginfo-stream]
name=CentOS Stream $releasever - HighAvailability - Debug
metalink=https://mirrors.centos.org/metalink?repo=centos-highavailability-debug-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[highavailability-source-stream]
name=CentOS Stream $releasever - HighAvailability - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-highavailability-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[nfv-stream]
name=CentOS Stream $releasever - NFV
metalink=https://mirrors.centos.org/metalink?repo=centos-nfv-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=0
[nfv-debuginfo-stream]
name=CentOS Stream $releasever - NFV - Debug
metalink=https://mirrors.centos.org/metalink?repo=centos-nfv-debug-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[nfv-source-stream]
name=CentOS Stream $releasever - NFV - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-nfv-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[rt-stream]
name=CentOS Stream $releasever - RT
metalink=https://mirrors.centos.org/metalink?repo=centos-rt-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=0
[rt-debuginfo-stream]
name=CentOS Stream $releasever - RT - Debug
metalink=https://mirrors.centos.org/metalink?repo=centos-rt-debug-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[rt-source-stream]
name=CentOS Stream $releasever - RT - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-rt-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[resilientstorage-stream]
name=CentOS Stream $releasever - ResilientStorage
metalink=https://mirrors.centos.org/metalink?repo=centos-resilientstorage-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=0
[resilientstorage-debuginfo-stream]
name=CentOS Stream $releasever - ResilientStorage - Debug
metalink=https://mirrors.centos.org/metalink?repo=centos-resilientstorage-debug-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[resilientstorage-source-stream]
name=CentOS Stream $releasever - ResilientStorage - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-resilientstorage-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
[extras-common-stream]
name=CentOS Stream $releasever - Extras packages
metalink=https://mirrors.centos.org/metalink?repo=centos-extras-sig-extras-common-$stream&arch=$basearch&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-Extras-SHA512
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=1
[extras-common-source-stream]
name=CentOS Stream $releasever - Extras packages - Source
metalink=https://mirrors.centos.org/metalink?repo=centos-extras-sig-extras-common-source-$stream&arch=source&protocol=https,http
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-Extras-SHA512
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0
These files are defining the CentOS Stream repositories for your system, but are named differently to avoid multiple sources sharing the same name.
If you need a more up to date version you can copy them from a CentOS Stream box in the paths mentioned above.
You will want to append -stream to any line containing brackets. For example: [extras-common-source] should be changed to [extras-common-source-stream]
3. Update Repos
Run sudo dnf update to refresh the repos.
4. Swap Release and Logo Packages
If you are running AlmaLinux, run sudo dnf swap almalinux-logos centos-logos && sudo dnf swap almalinux-release centos-stream-release. This will swap the release info and logos over to CentOS Stream.
If you are running Rocky Linux, run sudo dnf swap rocky-logos centos-logos && sudo dnf swap rocky-release centos-stream-release.
If you are using another rebuild, you can find the release and logos packages for your EL9 distro by running sudo rpm -qa | grep -E "logo|release" and replace almalinux-release and almalinux-logos with packages for your distro in the command above.
5. Run Distro Sync to Refresh All Your Packages
Run sudo dnf distro-sync to swap all the packages over from the existing vendor to CentOS Stream
6. Install EPEL Next (If you are Using EPEL)
If you are using EPEL, you should install the epel-next-release package by running sudo dnf install epel-next-release && sudo dnf update. This package will add updates to any EPEL packages that require changes to work on CentOS Stream.
7. Reboot
Since we have re-installed every package on the system including the kernel, we will need to reboot the host to apply the changes we just made.
Conclusion
You should now have a fully functional CentOS Stream box where your EL9 box was with minimal downtime.
Thanks for reading and happy hacking.
Shift Systems 