Configuring an ISO File as a Local Image Source

Context

When you install software on a Linux ECS, the network may be disconnected or resources on the network may be invalid, resulting in software installation failures. In this case, you can configure an ISO file as a local image source to install the software.

Package Managers

Before configuring a local source, you need to determine the package manager to be used. Generally, there are three types of package managers: yum, apt, and zypper.

• yum is for RHEL-based OSs: RHEL, CentOS, EulerOS, and Fedora.
• apt is for Debian and Ubuntu.
• zypper is for SUSE and openSUSE.

Configure a Local Image Source

Configure a local image source by following the instructions in yum, apt, or zypper.

• yum
  1. Upload the ISO file to the ECS and mount it to the /mnt directory.

     mount XXX.iso /mnt

  2. Enter the /etc/yum.repo.d directory where the yum configuration file is stored and back up all .repo files. Then, create a new .repo configuration file, for example local.repo. Add the following information to the local.repo file:

     [rhel-local]
     name=local
     baseurl=file:///mnt
     enabled=1
     gpgcheck=0

     

     The /mnt directory specified in the configuration file must be the same as the mounting directory of the ISO file.

  3. Clear yum.

     yum clean all

  4. Generate a new cache.

     yum makecache

• apt
  1. Upload the ISO file to the ECS and mount it to the /mnt directory.

     mount XXX.iso /mnt

  2. Add the apt cdrom source.

     apt-cdrom -m -d /mnt/ add

  3. View the added source in the configuration file.

     cat /etc/apt/sources.list

  4. Update the source.

     apt-get update

• zypper
  1. Upload the ISO file to the ECS.
  2. Add the ISO file as the source.

     sudo zypper addrepo iso:/?iso=/media/SOFTWARE/openSUSE-11.4-DVD-i586.iso DVDISO

     In the preceding command:

     • /media/SOFTWARE/openSUSE-11.4-DVD-i586.iso is the location of the ISO file.
     • DVDISO is the source alias.
  3. Check whether the source is successfully added.

     zypper repos

  4. Refresh the source.

     zypper refresh

Examples

The operations in Configure a Local Image Source may be different depending on the OS version. Basically, you need to add a source and refresh it. Debian 10.1.0 and CentOS 8.0 are used as examples to describe how to add a local source.

• Debian 10.1.0

  Run cat /etc/apt/sources.list to check whether the sources.list file contains a default cdrom source.

  Figure 1 Viewing the source
  

  The source directs to the CD-ROM drive /dev/cdrom. Debian 10.1.0 provides a soft link to link the CD-ROM drive to /media/cdrom.

  Figure 2 Checking the media directory
  

  Therefore, mount the ISO file to /media/cdrom.

• CentOS 8.0
  1. Mount the ISO file to the /mnt directory.
  2. Rename all source files except CentOS-Media.repo in the /etc/yum.repo.d directory as .bak files or move them to another directory.
  3. Modify the CentOS-Media.repo file.
     Figure 3 Modifying the CentOS-Media.repo file
     

     The modifications in the red box are as follows:

     • Set baseurl to file:///mnt/BaseOS and file:///mnt/AppStream. mnt is the mounting directory of the ISO file. Delete invalid paths from the default configuration, or a checksum error will occur.
     • Change the value of gpgcheck to 0, indicating that the check is not performed.
     • Change the value of enabled to 1 for the configurations to take effect.
  4. Clear yum and generate a new cache.

     yum clean all && yum makecache