DNF plugin for detecting local mirrors

This is a plugin for letting DNF work together with package repositories that are not always available or accessible.

For example, you have set up a package mirror in your home network to serve all the Fedora boxes you run at home. However, your laptop is sometimes used outside of your home network, which won't allow DNF to access your home mirror server. This DNF plugin will detect that your home mirror is not accessible and it will instruct DNF to use public mirrors again.

Installation

1. Install lazy-package-mirror, or set up another local mirror of dnf repositories as desired, for example under http://mirror.local/fedora/ and http://mirror.local/fedora/, mirroring the 'fedora' and 'fedora-updates' repositories

2. Clone this git repository

3. Copy the file src/local-mirror-detection.py into the appropriate directory, e.g. /usr/lib/python3.7/site-packages/dnf-plugins/local-mirror-detection.py for Fedora 31

4. If you are not using lazy-package-mirror, create a file 'repos.json' containing a description of your locally mirrored repositories:

   {"fedora": {"url": "http://mirror.local/fedora/$releasever/Everything/$basearch/os/"},
    "updates": {"url": "http://mirror.local/updates/$releasever/Everything/$basearch/"}}
   

5. Serve the file 'repos.json' under 'http://mirror.local/repos.json'

6. Create a configuration file /etc/dnf/plugins/local-mirror-detection.conf with the following content:

   [main]
   local_mirror_url=http://mirror.local/repos.json
   

   If you are running the lazy-package-mirror on mirror.local, you can use the following settings:

   [main]
   local_mirror_url=http://mirror.local/repo-data/fedora/
   

   In the lazy-package-mirror you have to set up caching for Fedora repositories.

7. Run dnf and you should see that your local mirror is detected and used when it is available:

   Local mirror url: http://mirror.local/repos.json
   Local mirror available
   Last metadata expiration check: 0:02:34 ago on Fr 01. Mee 2020 16:59:13.
   Dependencies resolved.
   ===================================================================================================================================================================================================================================================
   Package                                                            Architecture                                     Version                                                               Repository                                         Size
   ===================================================================================================================================================================================================================================================
   Upgrading:
    cldr-emoji-annotation                                              noarch                                           36.12.120200305_0-1.fc31                                              updates                                           4.7 M
    cups                                                               x86_64                                           1:2.2.12-8.fc31                                                       updates                                           1.4 M
   
   Transaction Summary
   ===================================================================================================================================================================================================================================================
   Upgrade  2 Packages
   
   Total size: 6.1 M
   Total download size: 6.1 M
   Is this ok [y/N]: