The plugin feature is available only in V4.1 and later of the software.
V4.1 introduces a new mechanism to install functionality into the IdP called Plugins.
- Are distinguished from each other by a unique identifier in the style of a Java package name.
- Are revised on a different schedule to the IdP itself, so upgrading the IdP does not upgrade a plugin and equally upgrading a plugin does not affect the IdP.
- Must be GPG signed.
- May be installed and updated directly from a web-hosted file or from a local file (with associated signature).
- Generally has no configuration that it directly installs, leaving this to the Module layer
- May require one or more Modules to be enabled before they can be installed, this being controlled by the plugin developer.
- May automatically enable a Module on install and/or disable a Module on uninstall, this being controlled by the plugin developer.
It is usual that a plugin contains one or more Modules, so the usual way to add functionality via a plugin is to install the plugin, then enable the module (if not already done for you) and then complete any per-module configuration.
Plugin Versioning and IdP Versioning
The developer of the plugin defines the minimum (inclusive) and maximum (exclusive) IdP versions that the plugin can operate with. This information is not distributed with the plugin; instead, the plugin package points to a URL (or redundant URLs) where the information is contained. This allows the plugin developer to change the supported status or the compatibility bounds of a particular plugin version after it has been released and installed based on testing and unexpected changes to the IdP.
The goal is not a bulletproof, perfectly-working-at-all times system because that's impossible, but it will allow for clear command-line driven determinations of the likely compatibility situation at any given time and a means to update a non-working system to a more-working system despite independent code streams.
Example of Versioning
Version 1.0 of a plugin is released and the minimum IdP version is specified as 4.1.0 and the maximum as 5.0.0 This means that the plugin will only work when the IdP is at version V4.1.0 or later and will fail to work if the IdP is updated to V5.0.0. During the development of IdP V5 the plugin developer establishes that the plugin will continue work with version 5.x and so they dynamically change the maximum to 6.0.0. No changes are required by the deployer and the plugin continues to work even after an upgrade to IdP V5.0.0
The IdP plugin developer then develops version 1.2 of the Plugin which requires at least version 4.2.0 This is released and the versions specified for this version are 4.2,0 and 6.0.0.
At any time the Plugin developer can change the status of any released plugin from Supported (current) to
- OutOfDate meaning: Still working but a new version is available
- Unsupported: Out of Support
- Secadv: Security alerts exist against this plugin
There are no semantics associated with these beyond that only Current versions are candidates for automatically selected update. The other states are there as (dynamic) guidance from the developer to the deployer of the state of the plugin.
In order for a plugin to be installed, the distribution must be accompanied by a GPG signature. The installation process checks the correctness of this signature before it does any installation or other potentially dangerous operations. Before it can do this check, the public key needs to be available to the plugin command in a trust store. By default each plugin has its own trust store. This means that the trust surrounding one plugin cannot be subverted to allow another plugin to be installed. Alternatively the
--truststore qualifier to the plugin command can be used to point to a central store (which you are expected to maintain).
The default location for a plugin is derived from the "pluginId" as:
This is a user-editable file you may delete or add to as you wish.
A plugin author may chose to ship signing key(s) with the plugin. If the key is not found in the trust store during the signature check, then you will be prompted to optionally install it:
Note that the default operation it to refuse to install the key.
The 'plugin' Command
All plugin manipulation (except trust store maintenance) is done via the
plugin command. Operations fall into 2 broad categories.
Install, Update, and Uninstall
Installation (specified by the -i or --input qualifier, immediately followed by the file name or URL) either installs a plugin or updates/downgrades it to a provided version.
Update (specified by the
--update qualifier, followed by the plugin id) consults the remote location to find the best version to update the plugin to. If it finds one, it automatically downloads it, checks the signature and installs it (think
Uninstall (specified by the
--remove qualifier, followed by the plugin id) removes the plugin from the IdP, generally including disabling Module(s) at the same time. It does not touch the truststore.
Qualifiers exist to:
- List which plugins are installed
- Provide details about available versions of existing plugins
- Output the license information for the plugin
- Detail the content that the plugin installed
These define which operation to perform.
|File Or URL||Install the provided qualifier|
|List installed plugins|
|PluginId||Remove the installed plugin|
|Enumerate all installed plugins|
|Give full version details for all installed plugins|
|PluginId||List all files installed by the specified plugin|
|Do not check for compatibility with the current IdP Version|
|PluginId||Output the license information for the specified plugin|
These provide extra/advanced options for the command:
|a logback file||Specify a file to use to control the logging of the plugin command|
|Output the version of the plugin command|
|file list||Any property files that are to be included when parsing a Spring file input (see below)|
|Use for unattended installs.|
If specified the install will fail rather than require input.
Path to the (non default) trust store file used during installs and updates.
|Version||Used with the -u qualifier to force the update (or downgrade) to a specific version|
Allows specification of the client used to download updates (or perform any related Module operation.
For details refer to the HttpClientConfiguration topic.
|bean name||This is only used if the plugin installer need to invoke the module operation|
Finally the plugin command can take one additional bare parameter - the path to a file which contains native Spring bean definitions that may be needed. This is typically only required for the
-hs qualifiers to perform advanced customization of HTTP operations, and should be very rare.