(Initial Draft) |
(Updates based on collaboration with Cloud, IoT, Server, Workstation representatives.) |
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{{admon/tip | Guidance | For details on how to fill out this form, see the [https://docs.fedoraproject.org/en-US/program_management/changes_guide/ documentation].}} | {{admon/tip | Guidance | For details on how to fill out this form, see the [https://docs.fedoraproject.org/en-US/program_management/changes_guide/ documentation].}} | ||
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* Email: dustymabe@redhat.com | * Email: dustymabe@redhat.com | ||
* Name: [[User:davdunc| David Duncan]] (Fedora Cloud) | * Name: [[User:davdunc| David Duncan]] (Fedora Cloud) | ||
* Email: | * Email: davdunc@gmail.com | ||
* Name: [[User:pwhalen| Paul Whalen]] (Fedora IoT) | * Name: [[User:pwhalen| Paul Whalen]] (Fedora IoT) | ||
* Email: | * Email: pwhalen@redhat.com | ||
* Name: [[User:salimma| Michel Alexandre Salim]] (Fedora Server) | * Name: [[User:salimma| Michel Alexandre Salim]] (Fedora Server) | ||
* Email: | * Email: michel@michel-slm.name | ||
* Name: [[User:ngompa| Neal Gompa]] (Fedora | * Name: [[User:ngompa| Neal Gompa]] (Fedora Workstation/KDE) | ||
* Email: | * Email: ngompa13@gmail.com | ||
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== Detailed Description == | == Detailed Description == | ||
In Fedora 33 the default fallback hostname was changed from `localhost` to `fedora` for Fedora Linux instances that didn't get the hostname set in any other way (i.e. it's the fallback if it's not set anywhere else). This change came in a systemd update and was never proposed as a change in Fedora itself. | |||
The | The enablement upstream was in https://github.com/systemd/systemd/pull/5175 and the BZ requesting the change in Fedora was https://bugzilla.redhat.com/show_bug.cgi?id=1392925. The original reasoning being that `localhost` is a bad hostname for auto-discovery protocols (think `avahi`) that are useful for more desktop applications. | ||
Unfortunately, this caused | Unfortunately, this caused issues because setting the hostname via reverse DNS lookups (via NetworkManager) stopped working along with breaking 3rd party tools that set the hostname. The NetworkManager problem was subsequently fixed, but it still remains that a lot of third party software will check to see if an instance's hostname is "unset" by checking the current hostname against the string "localhost". Additionally it appears this change will never be picked up by Fedora's primary downstream in CentOS/RHEL (see https://src.fedoraproject.org/rpms/systemd/c/13d1341b108a24d13f5922054307b5c2efc6836a?branch=rawhide). | ||
The proposal here is to enable variants of Fedora Linux to configure their default/fallback hostname | The proposal here is to enable variants of Fedora Linux to configure their default/fallback hostname and to set the default for variants targetting servers (Cloud, CoreOS, IoT, Server) to `localhost`. | ||
== Feedback == | == Feedback == | ||
| Line 92: | Line 90: | ||
https://fedoraproject.org/wiki/Changes/perl5.26 (major upgrade to a popular software stack, visible to users of that stack) | https://fedoraproject.org/wiki/Changes/perl5.26 (major upgrade to a popular software stack, visible to users of that stack) | ||
--> | --> | ||
With this change Fedora's server-like variants will become more compatible with 3rd party tools that expect a hostname of `localhost` means the system is unconfigured. It also will mean system administrator's will see `localhost` and assume the hostname is unconfigured. | |||
== Scope == | == Scope == | ||
* Proposal owners: | * Proposal owners: | ||
<!-- What work do the feature owners have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | <!-- What work do the feature owners have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | ||
The feature owners will update the systemd compile time switch for fallback hostname back to `localhost`. The `fedora-release` package will be updated such that the Fedora Server, IoT, Cloud, and CoreOS editions will use `localhost` as the fallback hostname. All other variants of Fedora (the ones that target desktop/laptop uses) will default to `fedora` as the fallback hostname. | |||
The proposed changes are a relatively small amount of a work. | |||
* Other developers: <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | * Other developers: | ||
<!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | |||
<!-- What work do other developers have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | <!-- What work do other developers have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | ||
For any variants other than Cloud, CoreOS, IoT, and Server they will see no change. Work with QA to verify other editions continue to have a fallback hostname of `fedora`. | |||
For Cloud, CoreOS, IoT, and Server the default fallback hostname would be `localhost`. | |||
* Release engineering: [https://pagure.io/releng/issues #Releng issue number] <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | * Release engineering: [https://pagure.io/releng/issues #Releng issue number] <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | ||
<!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)? Is a mass rebuild required? include a link to the releng issue. | <!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)? Is a mass rebuild required? include a link to the releng issue. | ||
The issue is required to be filed prior to feature submission, to ensure that someone is on board to do any process development work and testing and that all changes make it into the pipeline; a bullet point in a change is not sufficient communication --> | The issue is required to be filed prior to feature submission, to ensure that someone is on board to do any process development work and testing and that all changes make it into the pipeline; a bullet point in a change is not sufficient communication --> | ||
No changes needed for release engineering. | |||
* Policies and guidelines: N/A (not needed for this Change) | * Policies and guidelines: N/A (not needed for this Change) | ||
* Trademark approval: N/A (not needed for this Change) | * Trademark approval: N/A (not needed for this Change) | ||
* Alignment with Objectives: | * Alignment with Objectives: N/A | ||
== Upgrade/compatibility impact == | == Upgrade/compatibility impact == | ||
There will be NO upgrade impact to systems where: | |||
- An admin statically set the hostname | |||
- A hostname was provided to a system via DHCP | |||
- A hostname was found for a system via reverse DNS lookup | |||
In the case where none of the above are true for a system (i.e. a fallback hostname will be used) the following upgrade impact will be observed: | |||
Fedora Cloud: No impatct. An booted Fedora Cloud 36 instance has `/etc/hostname` written by `cloud-init` on first boot. | |||
Fedora CoreOS: No impact. Already using `localhost` as fallback hostname. | |||
Fedora IoT: Some impact. The fallback hostname will change from `fedora` to `localhost` after upgrade. | |||
Fedora Server: Some impact. The fallback hostname will change from `fedora` to `localhost` after upgrade. | |||
For Fedora IoT and Fedora Server we will announce the change and encourage users to statically set a hostname for their machines if they don't want the change in behavior. | |||
== How To Test == | == How To Test == | ||
Boot an instance of the flavor of Fedora you are testing in an environment where there is no DHCP hostname provided and no anser to a reverse DNS lookup for the instance IP. Run `hostnamectl get-hostname` and verify that it matches expectation. For Fedora Cloud, CoreOS, IoT, Server it should be `localhost`. For all others it should be `fedora`. | |||
== User Experience == | == User Experience == | ||
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- Green has been scientifically proven to be the most relaxing color. The move to a default background color of green with green text will result in Fedora users being the most relaxed users of any operating system. | - Green has been scientifically proven to be the most relaxing color. The move to a default background color of green with green text will result in Fedora users being the most relaxed users of any operating system. | ||
--> | --> | ||
For Cloud, CoreOS, IoT and Server users will notice intances now default to `localhost` if a hostname is not provided to an instance by any other means. For all other variants of Fedora there will be no change. | |||
== Dependencies == | == Dependencies == | ||
| Line 153: | Line 163: | ||
<!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | ||
There will be changes to the `systemd` and `fedora-release` packages for this change. | |||
| Line 158: | Line 170: | ||
<!-- If you cannot complete your feature by the final development freeze, what is the backup plan? This might be as simple as "Revert the shipped configuration". Or it might not (e.g. rebuilding a number of dependent packages). If you feature is not completed in time we want to assure others that other parts of Fedora will not be in jeopardy. --> | <!-- If you cannot complete your feature by the final development freeze, what is the backup plan? This might be as simple as "Revert the shipped configuration". Or it might not (e.g. rebuilding a number of dependent packages). If you feature is not completed in time we want to assure others that other parts of Fedora will not be in jeopardy. --> | ||
* Contingency mechanism: | * Contingency mechanism: Revert the pull requests to the `systemd` and `fedora-release` packages. | ||
* Contingency deadline: Final Freeze | |||
* Contingency deadline: | * Blocks release? Yes | ||
* Blocks release? | |||
== Documentation == | == Documentation == | ||
The fallback hostname has now changed to `localhost` for the Cloud, CoreOS, IoT, and Server variants of Fedora. | |||
<!-- Is there upstream documentation on this change, or notes you have written yourself? Link to that material here so other interested developers can get involved. --> | <!-- Is there upstream documentation on this change, or notes you have written yourself? Link to that material here so other interested developers can get involved. --> | ||
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Release Notes are not required for initial draft of the Change Proposal but has to be completed by the Change Freeze. | Release Notes are not required for initial draft of the Change Proposal but has to be completed by the Change Freeze. | ||
--> | --> | ||
The fallback hostname has now changed for the Cloud, CoreOS, IoT, and Server editions of Fedora to `localhost`. The fallback hostname is the hostname that is set if the hostname cannot be determined by any other mechanism (statically set, DHCP, or reverse DNS). This change was done in order to conform to the common expectation that a hostname of `localhost` on a system means the hostname is "unset". | |||
Revision as of 15:10, 26 May 2022
For details on how to fill out this form, see the documentation.
Fallback Hostname
Summary
This proposal is for the fallback hostname for server like variants of Fedora to use localhost as the fallback hostname.
Owner
- Name: Dusty Mabe (Fedora CoreOS)
- Email: dustymabe@redhat.com
- Name: David Duncan (Fedora Cloud)
- Email: davdunc@gmail.com
- Name: Paul Whalen (Fedora IoT)
- Email: pwhalen@redhat.com
- Name: Michel Alexandre Salim (Fedora Server)
- Email: michel@michel-slm.name
- Name: Neal Gompa (Fedora Workstation/KDE)
- Email: ngompa13@gmail.com
Current status
- Targeted release: Fedora Linux 37
- Last updated: 2022-05-26
- FESCo issue: <will be assigned by the Wrangler>
- Tracker bug: <will be assigned by the Wrangler>
- Release notes tracker: <will be assigned by the Wrangler>
Detailed Description
In Fedora 33 the default fallback hostname was changed from localhost to fedora for Fedora Linux instances that didn't get the hostname set in any other way (i.e. it's the fallback if it's not set anywhere else). This change came in a systemd update and was never proposed as a change in Fedora itself.
The enablement upstream was in https://github.com/systemd/systemd/pull/5175 and the BZ requesting the change in Fedora was https://bugzilla.redhat.com/show_bug.cgi?id=1392925. The original reasoning being that localhost is a bad hostname for auto-discovery protocols (think avahi) that are useful for more desktop applications.
Unfortunately, this caused issues because setting the hostname via reverse DNS lookups (via NetworkManager) stopped working along with breaking 3rd party tools that set the hostname. The NetworkManager problem was subsequently fixed, but it still remains that a lot of third party software will check to see if an instance's hostname is "unset" by checking the current hostname against the string "localhost". Additionally it appears this change will never be picked up by Fedora's primary downstream in CentOS/RHEL (see https://src.fedoraproject.org/rpms/systemd/c/13d1341b108a24d13f5922054307b5c2efc6836a?branch=rawhide).
The proposal here is to enable variants of Fedora Linux to configure their default/fallback hostname and to set the default for variants targetting servers (Cloud, CoreOS, IoT, Server) to localhost.
Feedback
Benefit to Fedora
With this change Fedora's server-like variants will become more compatible with 3rd party tools that expect a hostname of localhost means the system is unconfigured. It also will mean system administrator's will see localhost and assume the hostname is unconfigured.
Scope
- Proposal owners:
The feature owners will update the systemd compile time switch for fallback hostname back to localhost. The fedora-release package will be updated such that the Fedora Server, IoT, Cloud, and CoreOS editions will use localhost as the fallback hostname. All other variants of Fedora (the ones that target desktop/laptop uses) will default to fedora as the fallback hostname.
The proposed changes are a relatively small amount of a work.
- Other developers:
For any variants other than Cloud, CoreOS, IoT, and Server they will see no change. Work with QA to verify other editions continue to have a fallback hostname of fedora.
For Cloud, CoreOS, IoT, and Server the default fallback hostname would be localhost.
- Release engineering: #Releng issue number
No changes needed for release engineering.
- Policies and guidelines: N/A (not needed for this Change)
- Trademark approval: N/A (not needed for this Change)
- Alignment with Objectives: N/A
Upgrade/compatibility impact
There will be NO upgrade impact to systems where:
- An admin statically set the hostname - A hostname was provided to a system via DHCP - A hostname was found for a system via reverse DNS lookup
In the case where none of the above are true for a system (i.e. a fallback hostname will be used) the following upgrade impact will be observed:
Fedora Cloud: No impatct. An booted Fedora Cloud 36 instance has /etc/hostname written by cloud-init on first boot.
Fedora CoreOS: No impact. Already using localhost as fallback hostname.
Fedora IoT: Some impact. The fallback hostname will change from fedora to localhost after upgrade.
Fedora Server: Some impact. The fallback hostname will change from fedora to localhost after upgrade.
For Fedora IoT and Fedora Server we will announce the change and encourage users to statically set a hostname for their machines if they don't want the change in behavior.
How To Test
Boot an instance of the flavor of Fedora you are testing in an environment where there is no DHCP hostname provided and no anser to a reverse DNS lookup for the instance IP. Run hostnamectl get-hostname and verify that it matches expectation. For Fedora Cloud, CoreOS, IoT, Server it should be localhost. For all others it should be fedora.
User Experience
For Cloud, CoreOS, IoT and Server users will notice intances now default to localhost if a hostname is not provided to an instance by any other means. For all other variants of Fedora there will be no change.
Dependencies
There will be changes to the systemd and fedora-release packages for this change.
Contingency Plan
- Contingency mechanism: Revert the pull requests to the
systemdandfedora-releasepackages. - Contingency deadline: Final Freeze
- Blocks release? Yes
Documentation
The fallback hostname has now changed to localhost for the Cloud, CoreOS, IoT, and Server variants of Fedora.
N/A (not a System Wide Change)
Release Notes
The fallback hostname has now changed for the Cloud, CoreOS, IoT, and Server editions of Fedora to localhost. The fallback hostname is the hostname that is set if the hostname cannot be determined by any other mechanism (statically set, DHCP, or reverse DNS). This change was done in order to conform to the common expectation that a hostname of localhost on a system means the hostname is "unset".