CentOS 7 fix Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=container error was 14: curl#6 -

yum update Loaded plugins: fastestmirror, ovl Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=container error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo= ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable or subscription-manager repos --disable= 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=.skip_if_unavailable=true Cannot find a valid baseurl for repo: base/7/x86_64

The issue is that CentOS 7 went EOL in June 2024, but you can still access the packages in the CentOS vault for the last 7.9.2009 release for testing purposes or to create an environment to update to AlmaLinux or another newer distro.

Solution - Replace the contents of the Base Repo file "/etc/yum.repos.d/CentOS-Base.repo" as below:

[base] name=CentOS-$releasever - Base baseurl=http://vault.centos.org/7.9.2009/os/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 [updates] name=CentOS-$releasever - Updates baseurl=http://vault.centos.org/7.9.2009/updates/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 [extras] name=CentOS-$releasever - Extras baseurl=http://vault.centos.org/7.9.2009/extras/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 [centosplus] name=CentOS-$releasever - Plus baseurl=http://vault.centos.org/7.9.2009/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

Solution for the SCLo repo

yum install centos-release-scl

/etc/yum.repos.d/CentOS-SCLo-scl.repo

[centos-sclo-sclo] name=CentOS-7 - SCLo sclo baseurl=http://vault.centos.org/7.9.2009/sclo/$basearch/sclo/ gpgcheck=1 enabled=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 [centos-sclo-sclo-source] name=CentOS-7 - SCLo sclo Source baseurl=http://vault.centos.org/7.9.2009/sclo/Source/sclo/ gpgcheck=1 enabled=0 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

/etc/yum.repos.d/CentOS-SCLo-scl

[centos-sclo-rh] name=CentOS-7 - SCLo rh baseurl=http://vault.centos.org/7.9.2009/sclo/$basearch/rh/ gpgcheck=1 enabled=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 [centos-sclo-rh-source] name=CentOS-7 - SCLo rh Source baseurl=http://vault.centos.org/7.9.2009/sclo/Source/rh/ gpgcheck=1 enabled=0 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7