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19.3. Patching a Standalone Container

Abstract

You apply patches to a standalone container using the command console's patch shell. You cam apply and roll back patches as needed.

Overview

Patching a standalone container directs the container to load the patch versions of artifacts instead of the non-patch versions. The patch shell provides commands to patch the container's environment, see which bundles are effected by applying the patch, apply the patch to the container, and back the patch out if needed (see chapter "Patch Console Commands" in "Console Reference").
To make sure that a patch can be rolled back Red Hat JBoss Fuse applies the patch in a non-destructive manner. The patching process does not overwrite the artifacts included in the original installation. The patched artifacts are placed in the container's system folder. When the patch is applied, the container's configuration is changed so that it points to the patched artifacts instead of the artifacts from the original installation. This makes it easy for the system to be restored to its original state or to selectively back out patches.
Important
Patches do not persist across installations. If you delete and reinstall a JBoss Fuse instance you will need to download the patches and reapply them.

Applying a patch

To apply a patch to a standalone container:
  1. Before you proceed to install the patch, make sure to read the text of the README file that comes with the patch, as there might be additional manual steps required to install a particular patch.
  2. Make sure you install all the Apache Karaf features you need before you start to install the patch. If you install any features after installing the patch, the features will install the original unpatched versions of the dependencies—see the section called “Adding features to a patched container”.
  3. Add the patch to the container's environment using the patch:add command.
    Example 19.1, “Adding a Patch to a Broker's Environment” shows the command for adding the patch contained in the patch file patch.zip from the local file system.

    Example 19.1. Adding a Patch to a Broker's Environment

    JBoss Fuse> patch:add file://patch.zip
    This command copies the specified patch file to the container's system folder and unpacks it.
  4. Simulate installing the patch using the patch:simulate command.
    This will generate a log of the changes that will be made to the container when the patch is installed, but will not make any actual changes to the container.
    Note
    The patch:list command displays a list of all patches added to the container's system folder.
  5. Review the simulation log to understand the changes that will be made to the container.
  6. Apply the patch to the container using the patch:install command.
    Warning
    Running patch:install before the container is fully started and all of the bundles are active will cause the container to hang.
    Note
    The patch:list command displays a list of all patches added to the container's system folder.
    The container will need to restart to apply the patch. If you are using a remote console, you will lose the connection to the container. If you are using the container's local console, it will automatically reconnect when the container restarts.
  7. Validate the patch, by searching for one of the patched artifacts. For example, if you had just upgraded JBoss Fuse 6.1 to the patch with build number 611423, you could search for bundles with this build number, as follows: 
    JBoss Fuse:karaf@root> osgi:list -s -t 0 | grep -i 611423
[   6] [Active     ] [            ] [       ] [   10] org.apache.felix.configadmin    (1.4.0.redhat-611423)

Rolling back a patch

Occasionally a patch will not work or introduce new issues to a container. In these cases you can easily back the patch out of the system and restore it pre-patch behavior using the patch:rollback command. As shown in Example 19.2, “Rolling Back a Patch”, the command takes the name of patch to be backed out.

Example 19.2. Rolling Back a Patch

JBoss Fuse> patch:rollback patch1
Note
The patch:list command displays a list of all patches added to the container's system folder.
The container will need to restart to roll back the patch. If you are using a remote console, you will lose the connection to the container. If you are using the container's local console, it will automatically reconnect when the container restarts.

Adding features to a patched container

If you need to add some Apache Karaf features to an already patched standalone container, you should proceed as follows:
  1. Roll back the patch, as follows: 
    JBoss Fuse> patch:rollback patch1
  2. Install the additional features you require, using the features:install command.
  3. Apply the patch to the container using the patch:install command.
  4. The container automatically restarts to apply the patch. If you are using a remote console, you will lose the connection to the container. If you are using the container's local console, it will automatically reconnect when the container restarts.