Server/Technical Specification

Fedora Server Technical Specification

This document aims to describe the technical characteristics Fedora Server product in detail. This includes provided services and APIs, installed software, etc. Some of the desired characteristics may not be entirely achievable in the first version of the Server product, and will be approximated.

The content of the spec unavoidably overlaps with the work of the Base Working Group, and needs to be aligned with their deliverables.

Core Services and Features

This section should describe the core services of the platform and their intended use. The items here should refer back to the PRD for a functional justification.

Supported Architectures

Fedora Server will run on and provide install media for i686, x86_64 and armv7hl servers. In the future, Fedora Server will also support armv8 (64-bit) when the hardware becomes available.

File system

The default file system type for Fedora Server installs will be XFS running atop LVM for all partitions except /boot. The /boot partition will remain a non-LVM partition due to technological limitations of the bootloader.

File-system layout will be discussed with the Anaconda team and reasonable defaults will be selected based on a combination of the number of available, selected disks and the available memory on the system (for determining SWAP space).

Service management

Systemd provides ways to control and monitor the activity and status of system services, resources they require, etc. System services must provide systemd units to be included in the Fedora Server standard installation. See the systemd documentation.

Logging

The systemd journal will be used as the local storage backend for system logs. For 'managed' scenarios (e.g the 'developer in a large organization' use case of the PRD), it must be possible to collect the logs in a centralized location, off the local machine.

Applications and services can either use the syslog API or the journal APIs for their logging. See the journal API documentation.

Networking

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

Network devices and connections will be controlled by NetworkManager by default. Server Roles that may need to interact with the network configuration must do so through the public NetworkManager D-BUS API.

Firewall

A firewall in its default configuration may not interfere with the normal operation of programs installed by default.

Server Roles that need to interact with the firewall must do so through the public firewalld D-BUS API. Server Roles that modify the firewall must also provide a public configuration API describing what interfaces are permitted through the firewall.

A public, external API will be provided by the OpenLMI project to manage firewalld centrally. (This is not yet scheduled for a Fedora release, but is a medium-term plan)

SELinux

SELinux will be enabled in enforcing mode, using the targeted policy. The Fedora Server standard install and all promoted Server Roles must operate in enforcing mode.

Problem reporting

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

Problems and error conditions (e.g. kernel oopses, Selinux AVCs, application crashes, OOM, disk errors) should all be reported in the systemd journal.

Support for sending this information to a central place (like abrt does for crashes today) is mandatory.

Session tracking

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

Logind will be used as the session tracking facility.

Applications that need to interact with sessions can use the logind library API, the D-Bus API, or a higher-level API

Account handling

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

SSSD is providing the backing storage for identity management. The Fedora Server is expected to nearly always be configured for 'centrally-managed' user information; it must be possible to configure it to rely on a directory service for this information. Fedora Server will provide and support the realmd project for joining FreeIPA and Active Directory domains automatically. Interacting with other identity sources will remain a manual configuration effort.

The accountsservice is providing a D-Bus interface for user account information; this may be integrated into SSSD at some point.

Depending on their needs, application and services can either use the POSIX APIs (getpwent(), etc) or the accountsservice D-Bus interface to obtain user information.

Software updates

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

Software updates on the Fedora Server must be possible to perform either locally using command-line tools (e.g. yum/dnf) or centrally by common management systems (e.g. Puppet, Chef, Satellite, Spacewalk, OpenLMI).

Miscellaneous system information

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

System locale, timezone, hostname, etc. will be managed through the services provided by systemd for this purpose. See developer documentation for localed, timedated and hostnamed

Virtualization

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

libvirt-daemon will be used to manage virtualization capabilities. systemd-nspawn will be used to manage containerization capabilities.

Display manager

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

<Wording?>

Accessibility

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

Accessibility support on the Fedora Server will be limited to devices supporting the vision-impaired on the console.

Accessibility support in the optional graphical environment will be aligned with the Fedora Workstation offering.

Input Methods

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

The input method support for the Fedora Server console access will be limited to LOCALE support in the command shell.

Input method support in the optional graphical console will be aligned with the Fedora Workstation offering.

Graphics

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

The optional graphical console will be aligned with the Fedora Workstation offering.

Appearance

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

<Simo: do you want to talk about how the shell is configured, defaults, bash-completion, vim-enhanced/emacs/other plugins?>

Appearance of the optional graphical console will be aligned with the Fedora Workstation offering.

Application Integration

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

Application integration into the graphical console will be aligned with the Fedora Workstation offering.

System Installer

This is not yet approved!
This statement is a work-in-progress draft and has not been agreed upon yet.

The desired installation experience for the Fedora Server product is to limit the pre-installation user interaction to the minimum. The storage configuration UI should provide a single sensible default and an alternative, fully customizable configuration UI.

Package selection will be supplementary. There will be no option in the installer to install less than the Fedora Server standard installation. Options to install Fedora Server Roles will be provided, as well as a UI to install other software from the Fedora Project repositories.

Fedora Server will expect to be the sole citizen on the system. Support for coexisting with other operating systems is not a goal.

Server Roles

The following Server Roles are approved to be worked on in the Fedora 21 timeframe.

The public D-BUS API to support Server Roles will be provided from the Cockpit Project.

Domain Controller

The Fedora Server Domain Controller Role will be provided by the FreeIPA project.

This Server Role is a blocker for the release of Fedora Server in Fedora 21.

Database Server

The Fedora Server Database Server will be provided by the PostgreSQL project.

This Server Role is a nice-to-have for the release of Fedora Server in Fedora 21.

Core Package list

List the core packages of the product. This list includes all packages that will be shipping on the core media. This is the mandatory minimal list of packages that needs to be installed on a system at all times for it to qualify as a Fedora Server install. This package list will be the priority focus for QA and bug fixing.

Package list

<TBD>