Use CentOS 7 vault mirrors

centos7-self-contained/Dockerfile

 FROM centos:7
 
+# CentOS 7 has reached end-of-life on 2024-06-30, thus use vault mirrors
+RUN sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-* && \
+    sed -i 's%#baseurl=http://mirror.centos.org%baseurl=http://vault.centos.org%g' /etc/yum.repos.d/CentOS-*
+
 RUN yum update -y && \
     yum groupinstall -y "Development Tools" && \
     yum groupinstall -y "X Window System" && \
@@ -21,5 +25,8 @@ RUN yum update -y && \
         qt5-qtbase-devel \
         which && \
     yum install -y centos-release-scl && \
+    sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-SCLo-* && \
+    sed -i 's%#baseurl=http://mirror.centos.org%baseurl=http://vault.centos.org%g' /etc/yum.repos.d/CentOS-SCLo-* && \
+    sed -i 's%/7/%/$releasever/%g' /etc/yum.repos.d/CentOS-SCLo-* && \
     yum install -y devtoolset-8 && \
     yum clean all

centos7-system-dependencies/Dockerfile

 FROM centos:7
 
+# CentOS 7 has reached end-of-life on 2024-06-30, thus use vault mirrors
+RUN sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-* && \
+    sed -i 's%#baseurl=http://mirror.centos.org%baseurl=http://vault.centos.org%g' /etc/yum.repos.d/CentOS-*
+
 RUN yum update -y && \
     yum groupinstall -y "Development Tools" && \
     yum groupinstall -y "X Window System" && \
@@ -16,5 +20,8 @@ RUN yum update -y && \
         texlive-dvipng \
         which && \
     yum install -y centos-release-scl && \
+    sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-SCLo-* && \
+    sed -i 's%#baseurl=http://mirror.centos.org%baseurl=http://vault.centos.org%g' /etc/yum.repos.d/CentOS-SCLo-* && \
+    sed -i 's%/7/%/$releasever/%g' /etc/yum.repos.d/CentOS-SCLo-* && \
     yum install -y devtoolset-8 && \
     yum clean all