From Fedora Project Wiki

(Drop versioning. It's unnecessary and confusing. Change to foo-config-standard)
(Finish the writeup of https://fedorahosted.org/fpc/ticket/675)
 
(23 intermediate revisions by 4 users not shown)
Line 1: Line 1:
= Fedora.next Per-Product Configuration Packaging =
+
{{DISPLAYTITLE:Per-Product Configuration Packaging Guidelines}}
{{admon/warning|This document is a DRAFT. It has not been approved for use yet.}}
+
<div style="float: right; margin-left: 0.5em" class="toclimit-2">__TOC__</div>
  
This is an interim solution for Fedora 21 only. Work is in progress for Fedora 22 to simplify this using the new advanced dependencies available in RPM 4.11 and later
+
In the Fedora.next world, we have a set of curated Fedora Products as well as the availability of classic Fedora. Historically, we have maintained a single set of configuration defaults for all Fedora installs, but different target use-cases have different needs. The goal of this document is to set out the guidelines for creating per-Product configuration defaults.
  
 +
We want to ensure that all packages have sensible defaults for whichever Product on which they are installed, while also avoiding situations where users would have some packages installed with one Product's defaults and some packages with another.
  
== Definitions ==
+
== Per-product Configuration Packaging ==
 
+
{{admon/warning|These guidelines are not needed for all packages|Only packages whose defaults differ between Fedora Products are required to follow these instructions. Packages whose configuration is the same for all products can simply install the config files as they normally would.}}
<b>Fedora.next</b>: Umbrella term for planning Fedora's future. Currently covering the creation of the Fedora Products, Fedora Base Design and Fedora Environments and Stacks.<br>
 
<b>$PRODUCT</b>: One of the Fedora.next Product deliverables, currently "cloud", "server" and "workstation".<br>
 
<b>yum/dnf</b>: Package managers for Fedora used for installing and updating software.<br>
 
 
 
== Sub-package definition ==
 
{{admon/warning|Only packages whose defaults differ between Fedora Products are required to follow these instructions}}
 
  
 
=== Requirements ===
 
=== Requirements ===
* All packages must have a global default configuration. This configuration will be used whenever a Product-specific default configuration is not required. (For example, if a non-Product install is in use or only Fedora Cloud has a custom configuration and Fedora Workstation was installed).
+
* All packages MUST have a global default configuration. This configuration will be used whenever a Product-specific default configuration is not required. (For example, if a non-Product install is in use or only Fedora Cloud has a custom configuration and Fedora Workstation was installed).
* Any package that requires a per-product default configuration must provide a sub-package containing that configuration.
+
* Any package that requires a per-product default configuration MUST provide all alternate configuration files in the same package.
 +
* Any package that requires a configuration that differs between Products MUST obtain permission from that Product's Working Group before packaging it.
  
 
=== Global Default Configuration ===
 
=== Global Default Configuration ===
* The global default configuration <b>must</b> be specified by a sub-package named "foo-config-standard", where foo is the base package name.
+
* The global default configuration MUST be provided by the package that requires it.
* The global default configuration sub-package <b>must</b> "Requires: foo = %{version}-%{release}" (or appropriate variant including epoch)
+
* The global default configuration MUST be named based on the package's normal naming scheme, with the main part of the name being suffixed by -default. For example, if the package normally uses foo.conf, then the global default configuration MUST be named foo-default.conf
* The global default configuration sub-package <b>must</b> explicitly "Conflicts: fedora-release-$PRODUCT" for all Products for which there exists a separate configuration.
 
* The global default configuration sub-package <b>must</b> explicitly "Conflicts: foo-config-$PRODUCT" for all Products for which there exists a separate configuration.
 
  
 
=== Per-Product Default Configuration ===
 
=== Per-Product Default Configuration ===
* For each Product requiring a unique default configuration, the packager <b>must</b> provide a sub-package named "foo-config-$PRODUCT", where foo is the base package name and $PRODUCT is the Fedora Product in question. If the global default is sufficient, the packager <b>must not</b> create a Product-specific sub-package.
+
* For each Product requiring a unique default configuration, the packager MUST provide a copy of the default configuration file, modified as appropriate for the specific product.
* Each Product sub-package <b>must</b> include a virtual "Provides: foo-config".
+
* The product-specific configuration file MUST be named based on the package's normal naming scheme, with the main part of the name being suffixed by a dash followed by the name of the product. For example, if the package normally uses <code>foo.conf</code>, then the Server version MUST be named <code>foo-server.conf</code>.
* Each Product sub-package <b>must</b> "Requires: foo = %{version}-%{release}" (or appropriate variant including epoch)
+
* If the configuration will be symlinked in place, the product-specific configuration file MUST be located in an appropriate part of the /etc hierarchy. The divergent config file MUST be specified as `%config(noreplace)` in %files as per the usual /etc packaging guidelines.
* Each Product sub-package <b>must</b> "Requires: fedora-release-$PRODUCT", for the matching Product.
+
* If the configuration will be copied in place, the product-specific configuration file MUST be located in an appropriate part of the /usr/share hierarchy. The divergent config file MUST be specified as a normal file in the %files section.  
* Each Product sub-package <b>must</b> explicitly "Conflicts: foo-config-standard"
 
* Each Product sub-package <b>must</b> explicitly "Conflicts: foo-config-$PRODUCT" for all other Products for which there exists a separate configuration.
 
  
  
 +
=== Applying Configuration ===
 +
In order to apply the configuration, the packager MUST implement a mechanism in the <code>%posttrans</code> section of the specfile that behaves as follows:
 +
* It MUST first check whether the final config file already exists. If so, the script MUST make no changes.
 +
<pre>
 +
%posttrans
 +
if [ ! -e %{_sysconfdir}/foo/foo.conf ]; then
 +
    ...
 +
fi
 +
</pre>
 +
 +
* Then it MUST use the value of the Fedora <code>VARIANT_ID</code> to symlink or copy one of the divergent config files (or the default) to the final config file location. It will get this value by importing the contents of /etc/os-release as shell values.  Known values of this field at the time of this writing are "atomichost", "cloud", "server" and "workstation". For more detail, see [http://www.freedesktop.org/software/systemd/man/os-release.html#VARIANT_ID= the os-release(5) man page].
 +
<pre>
 +
    . /etc/os-release || :
 +
    case "$VARIANT_ID" in
 +
        server)
 +
            ln -sf foo-server.conf %{_sysconfdir}/foo/foo.conf || :
 +
            ;;
 +
        *)
 +
            ln -sf foo-default.conf %{_sysconfdir}/foo/foo.conf || :
 +
            ;;
 +
        esac
 +
</pre>
 +
 +
* Lastly, the final config file location MUST be listed in the %files section with %ghost:
 +
<pre>
 +
%ghost %config(noreplace) %{_sysconfdir}/foo/foo.conf
 +
</pre>
 +
 +
* For tracking purposes, the package providing the various configuration files MUST also contain a virtual Provides: for each variant configuration that may be applied:
 +
<pre>
 +
Provides: variant_config(Atomic.host)
 +
Provides: variant_config(Cloud)
 +
Provides: variant_config(Server)
 +
Provides: variant_config(Workstation)
 +
</pre>
  
 
=== Example (firewalld) ===
 
=== Example (firewalld) ===
Line 38: Line 65:
  
 
<pre>
 
<pre>
 +
...
 +
Provides: variant_config(Server)
 +
Provides: variant_config(Workstation)
 +
...
  
Name: firewalld
+
%posttrans
Version: 0.3.10
+
# If we don't yet have a symlink or existing file for firewalld.conf,
Release: 1{?dist}
+
# create it. Note: this will intentionally reset the policykit policy
Requires: firewalld-config
+
# at the same time, so they are in sync.
 
+
if [ ! -e %{_sysconfdir}/firewalld/firewalld.conf ]; then
%package config-standard
+
    # Import /etc/os-release to get the variant definition
Requires: firewalld = %{version}-%{release}
+
    . /etc/os-release || :
Conflicts: fedora-release-server
 
Conflicts: firewalld-config-server
 
Conflicts: fedora-release-workstation
 
Conflicts: firewalld-config-workstation
 
  
%package config-server
+
    case "$VARIANT_ID" in
Provides: firewalld-config
+
        server)
Requires: firewalld = %{version}-%{release}
+
            ln -sf firewalld-server.conf %{_sysconfdir}/firewalld/firewalld.conf || :
Requires: fedora-release-server
+
            ln -sf org.fedoraproject.FirewallD1.server.policy %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy || :
Conflicts: firewalld-config-workstation
+
            ;;
Conflicts: firewalld-config-standard
+
        workstation)
 +
            ln -sf firewalld-workstation.conf %{_sysconfdir}/firewalld/firewalld.conf || :
 +
            ln -sf org.fedoraproject.FirewallD1.desktop.policy %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy || :
 +
            ;;
 +
        *)
 +
            ln -sf firewalld-default.conf %{_sysconfdir}/firewalld/firewalld.conf || :
 +
            # The default firewall policy will be the same as Server
 +
            ln -sf org.fedoraproject.FirewallD1.server.policy %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy || :
 +
            ;;
 +
        esac
 +
fi
  
%package config-workstation
+
...
Provides: firewalld-config = 1.0
 
Requires: firewalld = %{version}-%{release}
 
Requires: fedora-release-workstation
 
Conflicts: firewalld-config-server
 
Conflicts: firewalld-config-standard
 
  
 +
%files -f %{name}.lang
 +
...
 +
%attr(0750,root,root) %dir %{_sysconfdir}/firewalld
 +
%ghost %config(noreplace) %{_sysconfdir}/firewalld/firewalld.conf
 +
%config(noreplace) %{_sysconfdir}/firewalld/firewalld-default.conf
 +
%config(noreplace) %{_sysconfdir}/firewalld/firewalld-server.conf
 +
%config(noreplace) %{_sysconfdir}/firewalld/firewalld-workstation.conf
 +
...
 +
%ghost %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy
 +
%{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.desktop.policy
 +
%{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.server.policy
 
</pre>
 
</pre>
  
== Reasoning ==
+
[[Category:Packaging guidelines]]
The reason for the virtual versioning of the config packages (2.0 for the global default and 1.0 for the per-Product default) is to help ensure that the yum dependency solver will prefer to choose the global default foo-config rather than cascading the installation of one of the fedora-release-$PRODUCT packages.
 
 
 
Similarly, we are using foo-config for the global default rather than foo-config-global so that the dnf dependency solver will select the shorter name instead of picking the lexicographically first config option (which would usually be foo-config-cloud if it exists).
 
 
 
The configuration sub-packages Requires: the main package in order to guarantee that they always update together (since the reverse dependency is not versioned).
 
 
 
== References ==
 
* http://yum.baseurl.org/wiki/CompareProviders
 

Latest revision as of 03:50, 16 February 2017

In the Fedora.next world, we have a set of curated Fedora Products as well as the availability of classic Fedora. Historically, we have maintained a single set of configuration defaults for all Fedora installs, but different target use-cases have different needs. The goal of this document is to set out the guidelines for creating per-Product configuration defaults.

We want to ensure that all packages have sensible defaults for whichever Product on which they are installed, while also avoiding situations where users would have some packages installed with one Product's defaults and some packages with another.

Per-product Configuration Packaging

Warning.png
These guidelines are not needed for all packages
Only packages whose defaults differ between Fedora Products are required to follow these instructions. Packages whose configuration is the same for all products can simply install the config files as they normally would.

Requirements

  • All packages MUST have a global default configuration. This configuration will be used whenever a Product-specific default configuration is not required. (For example, if a non-Product install is in use or only Fedora Cloud has a custom configuration and Fedora Workstation was installed).
  • Any package that requires a per-product default configuration MUST provide all alternate configuration files in the same package.
  • Any package that requires a configuration that differs between Products MUST obtain permission from that Product's Working Group before packaging it.

Global Default Configuration

  • The global default configuration MUST be provided by the package that requires it.
  • The global default configuration MUST be named based on the package's normal naming scheme, with the main part of the name being suffixed by -default. For example, if the package normally uses foo.conf, then the global default configuration MUST be named foo-default.conf

Per-Product Default Configuration

  • For each Product requiring a unique default configuration, the packager MUST provide a copy of the default configuration file, modified as appropriate for the specific product.
  • The product-specific configuration file MUST be named based on the package's normal naming scheme, with the main part of the name being suffixed by a dash followed by the name of the product. For example, if the package normally uses foo.conf, then the Server version MUST be named foo-server.conf.
  • If the configuration will be symlinked in place, the product-specific configuration file MUST be located in an appropriate part of the /etc hierarchy. The divergent config file MUST be specified as %config(noreplace) in %files as per the usual /etc packaging guidelines.
  • If the configuration will be copied in place, the product-specific configuration file MUST be located in an appropriate part of the /usr/share hierarchy. The divergent config file MUST be specified as a normal file in the %files section.


Applying Configuration

In order to apply the configuration, the packager MUST implement a mechanism in the %posttrans section of the specfile that behaves as follows:

  • It MUST first check whether the final config file already exists. If so, the script MUST make no changes.
%posttrans
if [ ! -e %{_sysconfdir}/foo/foo.conf ]; then
    ...
fi
  • Then it MUST use the value of the Fedora VARIANT_ID to symlink or copy one of the divergent config files (or the default) to the final config file location. It will get this value by importing the contents of /etc/os-release as shell values. Known values of this field at the time of this writing are "atomichost", "cloud", "server" and "workstation". For more detail, see the os-release(5) man page.
    . /etc/os-release || :
    case "$VARIANT_ID" in
        server)
            ln -sf foo-server.conf %{_sysconfdir}/foo/foo.conf || :
            ;;
        *)
            ln -sf foo-default.conf %{_sysconfdir}/foo/foo.conf || :
            ;;
        esac
  • Lastly, the final config file location MUST be listed in the %files section with %ghost:
%ghost %config(noreplace) %{_sysconfdir}/foo/foo.conf
  • For tracking purposes, the package providing the various configuration files MUST also contain a virtual Provides: for each variant configuration that may be applied:
Provides: variant_config(Atomic.host)
Provides: variant_config(Cloud)
Provides: variant_config(Server)
Provides: variant_config(Workstation)

Example (firewalld)

We will assume for the sake of demonstration that firewalld will need a custom configuration for Fedora Server and Fedora Workstation, but that Fedora Cloud will not require any changes from the global default.

...
Provides: variant_config(Server)
Provides: variant_config(Workstation)
...

%posttrans
# If we don't yet have a symlink or existing file for firewalld.conf,
# create it. Note: this will intentionally reset the policykit policy
# at the same time, so they are in sync.
if [ ! -e %{_sysconfdir}/firewalld/firewalld.conf ]; then
    # Import /etc/os-release to get the variant definition
    . /etc/os-release || :

    case "$VARIANT_ID" in
        server)
            ln -sf firewalld-server.conf %{_sysconfdir}/firewalld/firewalld.conf || :
            ln -sf org.fedoraproject.FirewallD1.server.policy %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy || :
            ;;
        workstation)
            ln -sf firewalld-workstation.conf %{_sysconfdir}/firewalld/firewalld.conf || :
            ln -sf org.fedoraproject.FirewallD1.desktop.policy %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy || :
            ;;
        *)
            ln -sf firewalld-default.conf %{_sysconfdir}/firewalld/firewalld.conf || :
            # The default firewall policy will be the same as Server
            ln -sf org.fedoraproject.FirewallD1.server.policy %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy || :
            ;;
        esac
fi

...

%files -f %{name}.lang
...
%attr(0750,root,root) %dir %{_sysconfdir}/firewalld
%ghost %config(noreplace) %{_sysconfdir}/firewalld/firewalld.conf
%config(noreplace) %{_sysconfdir}/firewalld/firewalld-default.conf
%config(noreplace) %{_sysconfdir}/firewalld/firewalld-server.conf
%config(noreplace) %{_sysconfdir}/firewalld/firewalld-workstation.conf
...
%ghost %{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.policy
%{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.desktop.policy
%{_datadir}/polkit-1/actions/org.fedoraproject.FirewallD1.server.policy