Elastic Compute Service:Add or fix Alibaba Cloud software repositories for Linux instances

Symptom

When you use the yum command to install MySQL on an ECS instance running CentOS 7.0, the following error occurs:

File contains no section headers.

Cause

The software repository does not contain the required software package.

Resolution

Follow these steps to switch to the official CentOS software repository.

1. Connect to the Linux instance.

   For more information, see Connect to a Linux instance by using a password or key.

2. Modify the /etc/yum.repos.d/epel.repo configuration file.

   1. Run the following command to edit the /etc/yum.repos.d/epel.repo configuration file:

      vim /etc/yum.repos.d/epel.repo

   2. Press the i key to enter insert mode and replace the content of the configuration file with the following:

      [epel-source]
      name=Extra Packages for Enterprise Linux 7 - $basearch - Source
      #baseurl=http://download.fedoraproject.org/pub/epel/7/SRPMS
      mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-source-7&arch=$basearch
      failovermethod=priority
      enabled=0
      gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
      gpgcheck=1
      
      [epel]
      name=Extra Packages for Enterprise Linux 7 - $basearch
      #baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch
      mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch
      failovermethod=priority
      enabled=1
      gpgcheck=0
      gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
      
      [epel-debuginfo]
      name=Extra Packages for Enterprise Linux 7 - $basearch - Debug
      #baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch/debug
      mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-debug-7&arch=$basearch
      failovermethod=priority
      enabled=0
      gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
      gpgcheck=1

   3. After editing the file, press the Esc key to exit insert mode. Then, enter :wq and press the Enter key to save and close the file.

3. Run the following commands in sequence to apply the new software repository configuration:

   yum makecache
   yum repolist

4. Reinstall MySQL. If the error message no longer appears, the issue is resolved.

Symptom

When you use apt-get to install software on an ECS instance running Ubuntu, an "error processing package install-info (--configure)" error occurs.

Cause

This issue can be caused by a corrupted Ubuntu software package, resulting in a failed installation.

Resolution

Follow these steps to update the APT software repository and reinstall the software.

1. Connect to the Ubuntu instance.

   For more information, see Connect to a Linux instance by using a password or key.

2. Rename the info directory.

   mv /var/lib/dpkg/info/ /var/lib/dpkg/info.bak.old/

3. Create a new info directory.

   mkdir /var/lib/dpkg/info/

4. Run the following command to update the APT software repository:

   apt-get update

5. Run the following command to reinstall the software. Replace xxxxx with the name of the software package that you want to reinstall. If the error message no longer appears, the issue is resolved.

   apt-get install  xxxxx

Symptom

When you use apt-get to install or update software on an ECS instance running Ubuntu, a "Segmentation fault" error occurs.

Cause

This issue can be caused by an APT cache conflict, resulting in a failed installation or update.

Resolution

Follow these steps to update the APT software repository.

1. Connect to the Ubuntu instance.

   For more information, see Connect to a Linux instance by using a password or key.

2. Back up the /var/cache/apt/ directory.

3. After the backup, run the following command to delete all .bin files from the /var/cache/apt/ directory:

   rm /var/cache/apt/*.bin

4. Run the following command to update the APT software repository:

   apt-get update

5. Check whether you can use apt-get without errors.

   Note

   If a "Segmentation fault" error occurs on an instance with low memory, such as 512 MB, run the top command to check the memory usage. Stop non-essential processes, and then retry the apt-get command.

Symptom

When you use apt-get to install software on an ECS instance running Ubuntu, an error message similar to the following appears:

Reading package lists... Error! E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/AZ.archive.ubuntu.com_ubuntu_dists_natty_main_i18n _Translation-en E: The package lists or status file could not be parsed or opened.

Cause

The software package list is corrupted, causing the software installation to fail.

Resolution

Follow these steps to clear the corrupted list and regenerate the update list.

1. Run the following command to clear the corrupted list from the directory:

   rm -rf /var/lib/apt/lists/*

2. Run the following command to regenerate the update list:

   apt-get update

   

3. Install the software again. If the error message no longer appears, the issue is resolved.

Symptom

When you run the apt-get install unzip or aptitude install unzip command on an ECS instance running Ubuntu, the following error message appears:

Error http://mirrors.aliyun.com/ubuntu/ trusty-updates/main unzip amd64 6.0-9ubuntu1.1 404 Not Found [IP: 112.124.XXX.XXX 80]
Error http://mirrors.aliyun.com/ubuntu/ trusty-updates/main unzip amd64 6.0-9ubuntu1.1 404 Not Found [IP: 112.124.XXX.XXX 80]
Error http://mirrors.aliyun.com/ubuntu/ trusty-updates/main unzip amd64 6.0-9ubuntu1.1 404 Not Found [IP: 112.124.XXX.XXX 80]

Cause

This error typically occurs when the software package version expected by the operating system is inconsistent with the version available in the APT software repository. As a result, apt-get requests a resource that does not exist.

Resolution

Follow these steps to update the APT software repository.

1. Connect to the Ubuntu instance.

   For more information, see Connect to a Linux instance by using a password or key.

2. Run the following command to update the APT software repository:

   apt-get update

3. After updating the software repository, use the apt-get install command to install the required software.

Symptom

When you run the apt-get update command on an ECS instance running Ubuntu, the following message appears:

The following signatures were invalid: KEYEXPIRED 1544811256

Cause

The update fails because the signature for the software repository has expired.

Resolution

Follow these steps to update the expired key.

1. Connect to the Ubuntu instance.

   For more information, see Connect to a Linux instance by using a password or key.

2. Run the following command to obtain the expired key:

   sudo apt-key list | grep -A 1 expired

   

3. Run the following command to update the expired key:

   apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys [$Key]

   Note

   Replace [$Key] with the expired key from the previous step.

4. Run the following command again to update the APT software repository:

   apt-get update

Symptom

On an ECS instance that runs Alibaba Cloud Linux 2 and meets the following conditions, the installation of the Docker package fails and the following error is reported when you run the yum install docker-ce command by using the third-party docker-ce and epel YUM repositories for CentOS 7.

• Image: Alibaba Cloud Linux 2.1903 LTS 64-bit.

• Image ID: aliyun_2_1903_x64_20G_alibase_20210325.vhd or an earlier version.

Loaded plugins: fastestmirror, langpacks, update-motd
Loading mirror speeds from cached hostfile
  * epel: mirror.sjtu.edu.cn 
https://mirrors.aliyun.com/docker-ce/linux/centos/2.1903/x86_64/stable/repodata/repomd.xml: [Errno 14] HTTPS Error 404 - Not Found 
Trying other mirror.
Downloading packages:
docker-ce-20.10.6-3.el7.x86_64 FAILED
https://mirrors.aliyun.com/docker-ce/linux/centos/2.1903/x86_64/stable/Packages/docker-ce-20.10.6-3.el7.x86_64.rpm: [Errno 14] HTTPS Error 404 - Not Found 
Trying other mirror.
docker-ce-rootless-extras-20.1 FAILED
https://mirrors.aliyun.com/docker-ce/linux/centos/2.1903/x86_64/stable/Packages/docker-ce-rootless-extras-20.10.6-3.el7.x86_64.rpm: [Errno 14] HTTPS Error 404 - Not Found
 Trying other mirror. 


Error downloading packages:
  3:docker-ce-20.10.6-3.el7.x86_64: [Errno 256] No more mirrors to try.
  docker-ce-rootless-extras-20.10.6-3.el7.x86_64: [Errno 256] No more mirrors to try.

Cause

Third-party YUM repositories are designed only for the CentOS 7 distribution. The $releasever value of the Alibaba Cloud Linux 2 operating system differs from that of the CentOS 7 operating system. This discrepancy causes YUM to resolve to an invalid address, preventing the software package from being downloaded.

Resolution

Choose one of the following solutions based on your requirements.

• Resolve the issue by manually modifying the value of the $releasever variable.

• Install the yum-plugin-releasever-adapter plug-in.

Symptom

On an ECS instance that runs Alibaba Cloud Linux 3 and meets the following conditions, the dnf install docker-ce command fails to install the container software package, and the following error is reported.

• A third-party DNF repository designed for the CentOS 8 system is used.

• The image is aliyun_3_x64_20G_alibase_20210425.vhd or an earlier version.

The system displays an error message similar to the following:

Docker CE Stable - x86_64
Failed to download metadata for repo 'docker-ce-stable'
Error: Failed to download metadata for repo 'docker-ce-stable'

Cause

Third-party DNF repositories are compatible only with the CentOS 8 distribution, and because the system's $releasever variable has a different value in Alibaba Cloud Linux 3, DNF resolves to an invalid address and fails to download RPM packages.

Resolution

Choose one of the following solutions based on your requirements.

• You can fix this by manually modifying the $releasever variable value.

• Install the dnf-plugin-releasever-adapter plug-in.

Symptom

When you run the yum command on an ECS instance that runs CentOS 7, the following error message is reported.

-bash: /usr/bin/yum: /usr/bin/python: bad interpreter: No such file or directory

Cause

The yum command may fail due to issues with the Python installation, such as Python being uninstalled, renamed, or moved to a different path.

Resolution

Follow these steps to diagnose and fix the Python issue.

1. Connect to the Linux instance.

   For more information, see Connect to a Linux instance by using a password or key.

2. Run the following command to check the yum path:

   which yum

   The following output indicates that the yum path is /usr/bin/yum.

   /usr/bin/yum

3. Run the following command to view the content of the yum file:

   cat /usr/bin/yum

   The following output indicates the path of the Python version being used.

   #!/usr/bin/python

   Note

   This topic uses the /usr/bin/python path as an example. Use the actual path based on your environment.

4. Run the following command to check the path that you viewed:

   ls -al /usr/bin/python

   If an output similar to the following is displayed, Python may have been uninstalled, renamed, or moved.

   ls: cannot access /usr/bin/python: No such file or directory

5. Run the following command to check whether Python-related files exist:

   rpm -qa | grep python

   Under normal circumstances, an output similar to the following is returned.

   python-decorator-3.4.0-3.el7.noarch
   libselinux-python-2.5-14.1.el7.x86_64
   python-backports-1.0-8.el7.x86_64
   python-pyudev-0.15-9.el7.noarch
   rpm-python-4.11.3-35.el7.x86_64
   python-2.7.5-76.el7.x86_64
   .....

   • If Python-related files exist, they may have been renamed or moved.

     1. Run the following command to view the Python-related files:

        ls -al /usr/bin/python*

        An output similar to the following, which includes "/usr/bin/python.bak -> python2", indicates that the Python executable was renamed.

        lrwxrwxrwx  1 root root   14 Feb 15  2019 /usr/bin/python-config -> python2-config
        lrwxrwxrwx. 1 root root    7 Feb 15  2019 /usr/bin/python.bak -> python2
        lrwxrwxrwx. 1 root root    9 Feb 15  2019 /usr/bin/python2 -> python2.7
        lrwxrwxrwx  1 root root   16 Feb 15  2019 /usr/bin/python2-config -> python2.7-config
        -rwxr-xr-x. 1 root root 7216 Oct 31  2018 /usr/bin/python2.7
        -rwxr-xr-x  1 root root 1835 Oct 31  2018 /usr/bin/python2.7-config

     2. Run the following command to change the name of /usr/bin/python.bak back to /usr/bin/python:

        mv python.bak python

     3. Run the yum command again. If the error message no longer appears, the issue is resolved.

   • If no Python-related packages are listed, Python may have been uninstalled.

     1. You cannot use a broken yum command to fix itself. Manually download the required Python RPM package from a CentOS vault mirror by using a tool such as curl, and then install the package by using the rpm command:

        rpm -ivh --replacepkgs python-2.7.5-*.rpm

     2. Rerun the yum command. If the preceding error message no longer appears, the problem is fixed.