Changes/dhclient deprecation

WIP: Deprecate dhclient .

Summary

This is the next step in the deprecation of ISC DHCP in Fedora due to deprecation by the vendor (ISC).

Currently, dhclient (dhcp-client) is the main implementation and while some projects switched to dhcp library provided by NetworkManager (TBD links) and some work was done in Fedora to switch to dhcp library ( BZ#1204226) dhclient binary is pulled into ISO by anaconda and dracut still.

Owner

• Name: Martin Osvald
• Email: mosvald at redhat dot com
• Release notes owner:

Current status

• Targeted release: Fedora 40
• Last updated: 2023-11-14
• Tracker bug: <will be assigned by the Wrangler>

Detailed Description

dhclient (dhcp-client) no longer receives any development by the vendor (ISC) and it is deprecated. While dhcp-server is deprecated by ISC Kea, dhcp-client doesn't have an alternative developed by ISC and the proposal is to use DHCP implementation provided by NetworkManager (preferable) and if not possible use a client provided by dhcpcd package.

Benefit to Fedora

Modern implementation fixes few bugs which are difficult to fix in dhclient like monotonic time support (bz#876791) and brings support for mixed ipv4 + ipv6 environment. Besides of that it fits more accurately into modern stack of networking management stack in Fedora (ip addresses lifetime etc)

Scope

• Proposal owners:

• Other developers: Anaconda and Dracut maintainers to drop rhard requirement of dhcp-client,

RCM to drop dhcp-client RPM from ISO

• Release engineering: #Releng issue number (a check of an impact with Release Engineering is needed)
  • List of deliverables: N/A (not a System Wide Change)

• Policies and guidelines: N/A (not a System Wide Change)

• Trademark approval: N/A (not needed for this Change)

Upgrade/compatibility impact

NetworkManager's dhcp implementation is NOT drop-in replacement of dhclient. While it supports (almost) all RFCs it can behave in different way in some cases ((IB support, client identifier, direct calls of dhclient binary etc links: TBD ). The goal is to find this cases and fix them.

How To Test

Check if dhcp-client rpm doesn't exists on installation ISO and absence of the RPM doesn't have impact on installation including network installation.

User Experience

Regular users should not be noticed by the change. Advanced users and third-party application may call dhclient binary directly thus they will be affected and should install dhclient from the repo and/or adjust dependencies list accordingly

Dependencies

anaconda-core-0:31.7-1.fc31.x86_64 dracut-network-0:049-26.git20181204.fc30.x86_64 synce-connector-0:0.15.2-20.fc29.x86_64 wicd-common-0:1.7.4-9.fc29.noarch wifi-radar-0:2.0.s10-7.fc29.noarch wlassistant-0:0.5.7-32.fc30.x86_64

Contingency Plan

• Contingency mechanism: Pull dhclient into iso and allow anaconda/dracut use it as before
• Contingency deadline: Beta freeze (not a System Wide Change)
• Blocks release? Yes
• Blocks product? product

Documentation

N/A (not a System Wide Change)