Author: buildbot
Date: Thu Nov 7 15:03:46 2013
New Revision: 885755
Log:
Staging update by buildbot for ace
Added:
websites/staging/ace/trunk/content/user-doc/ace_dnd_artifacts.png (with
props)
websites/staging/ace/trunk/content/user-doc/ace_dnd_artifacts_fail.png
(with props)
websites/staging/ace/trunk/content/user-doc/ace_dnd_artifacts_ok.png
(with props)
websites/staging/ace/trunk/content/user-doc/ace_dynamic_association.png
(with props)
websites/staging/ace/trunk/content/user-doc/ace_static_association.png
(with props)
websites/staging/ace/trunk/content/user-doc/ace_target_tag_editor.png
(with props)
Modified:
websites/staging/ace/trunk/content/ (props changed)
websites/staging/ace/trunk/content/user-doc/ace_server_ui.png
websites/staging/ace/trunk/content/user-doc/user-guide.html
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Modified: websites/staging/ace/trunk/content/user-doc/user-guide.html
==============================================================================
--- websites/staging/ace/trunk/content/user-doc/user-guide.html (original)
+++ websites/staging/ace/trunk/content/user-doc/user-guide.html Thu Nov 7
15:03:46 2013
@@ -1,7 +1,7 @@
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html lang="en">
<head>
- <title>ACE Users guide</title>
+ <title>ACE User guide</title>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<meta property="og:image"
content="http://www.apache.org/images/asf_logo.gif"; />
<link href="/css/bootstrap.min.css" rel="stylesheet" media="screen">
@@ -160,7 +160,7 @@
</div>
<div class="container">
<p><a href="/"><i class='icon-home'></i> Home</a> » <a
href="/user-doc/">User-doc</a></p>
- <h1>ACE Users guide</h1>
+ <h1>ACE User guide</h1>
<div class="clear"></div>
<div id="content"><p>This article describes how to use ACE and is a good
starting point for new users of Apache ACE. The remainder of this article
assumes you've read and followed the "<a
href="/user-doc/getting-started.html">Getting Started</a>" guide, meaning that
you have an ACE server successfully up and running.</p>
<div class="toc">
@@ -181,8 +181,9 @@
</div>
<h2 id="introduction">Introduction</h2>
<p>Apache ACE is a framework that enables you to provision OSGi
software(components) in a controlled manner. What this means is that you have a
central server to which clients, or "targets" in ACE terminology, connect and
fetch their software from. This allows one to control which target gets which
software. </p>
-<p>The software that is deployed to a target, is composed of one or more
distributions. A distribution is roughly similar to a piece of self-contained
software. For example, it could be a plugin or even a full application. On
their own, distributions consist of one or more features, that provide pieces
of functionality to your software. The difference between a feature and
distribution is that the former is not necessarily fully self-contained: it
might need other features in order to work. Each feature groups one or more
artifacts. An artifact is anything from an OSGi bundle to a configuration file
or any other kind of artifact that is needed for the software to work.</p>
-<p>The artifacts themselves reside in an <abbr title="OSGi Bundle
Repository">OBR</abbr>, which can be either the default one supplied by ACE, or
an external one. Think of an <abbr title="OSGi Bundle Repository">OBR</abbr> as
a repository, like the Maven repository or a content repository, storing
immutable versions of artifacts<sup id="fnref:1"><a class="footnote-ref"
href="#fn:1" rel="footnote">1</a></sup>. As the <abbr title="OSGi Bundle
Repository">OBR</abbr> is the single source for all artifacts, and therefore
the software that is deployed on a target, ACE is able to calculate how to
upgrade a target from one version to another version. This is possible because
all changes made to (the metadata of) ACE are stored in an internal versioned
database. In other words, we always keep a full history and audit trail.</p>
+<p>The software that is deployed to a target, is composed of one or more
distributions. A distribution is roughly similar to a piece of self-contained
software. For example, it could be a plugin or even a full application. On
their own, distributions consist of one or more features, that provide pieces
of functionality to your software. The difference between a feature and
distribution is that the former is not necessarily fully self-contained: it
might need other features in order to
+operate properly. Each feature groups one or more artifacts. An artifact is
anything from an OSGi bundle to a configuration file or any other kind of
artifact that is needed for the software to work.</p>
+<p>The artifacts themselves reside in an <abbr title="OSGi Bundle
Repository">OBR</abbr>, which can be either the default one supplied by ACE, or
an external one. Think of an <abbr title="OSGi Bundle Repository">OBR</abbr> as
a repository, like the Maven repository or a content repository, storing
<em>immutable</em> versions of artifacts<sup id="fnref:1"><a
class="footnote-ref" href="#fn:1" rel="footnote">1</a></sup>. As the <abbr
title="OSGi Bundle Repository">OBR</abbr> is the single source for all
artifacts, and therefore the software that is deployed on a target, ACE is able
to calculate how to upgrade a target from one version to another version. This
is possible because all changes made to (the metadata of) ACE are stored in an
internal versioned database. In other words, ACE always keeps a full history
and audit trail for all changes.</p>
<h2 id="workflow">Workflow</h2>
<p>The typical use case for using ACE is where you want to control and manage
which software runs on what target. So, how does one use ACE in practice? To
explain the typical workflow of ACE, let's take the following example.</p>
<p>Assume you are working on a large OSGi-based system that provides some kind
of service to your users (the exact details on what it does isn't relevant for
this example).</p>
@@ -202,16 +203,24 @@ Even though they are smart guys that kno
<li>The resource area, consisting of (up to) four columns showing the current
artifacts, features, distributions and targets that are known to ACE. When you
select an entity here, the associated entities in other columns will
automatically be highlighted, giving you an instant overview of the links
within the system.</li>
</ol>
<h3 id="uploading-artifacts">Uploading artifacts</h3>
-<p>To upload one or more artifacts, you click on the "Add artifactâ¦" button.
An "Add artifact" dialog opens, showing both the artifacts currently in the
<abbr title="OSGi Bundle Repository">OBR</abbr> but not in the artifact list
and a list of uploaded artifacts. There are two possibilities to upload a
file:</p>
+<p>The easiest way to add one or more <em>new</em> artifacts is by simply
dragging and dropping them on the artifact column. <em>Note that a drop is
accepted only when a blue line or border is shown around the artifacts column
(see figure 2)</em>. The artifacts are uploaded automatically in the
background, and when they are complete, a summary of the upload results is
shown as notification (see figure 3).</p>
+<p><a href="ace_dnd_artifacts.png" target="_blank"><img
src="ace_dnd_artifacts.png" width="640px" title="Figure 2: Adding new artifacts
by dragging them onto the artifacts column. Note the blue line surrounding the
artifacts column denoting the drop can be accepted." /></a><br />
+<strong>Figure 2</strong>: Adding new artifacts by dragging them onto the
artifacts column. Note the blue line surrounding the artifacts column denoting
the drop can be accepted (click on image to see full size).</p>
+<p><a href="ace_dnd_artifacts_ok.png" target="_blank"><img
src="ace_dnd_artifacts_ok.png" width="640px" title="Figure 3: A notification is
shown when all artifacts are successfully uploaded." /></a><br />
+<strong>Figure 3</strong>: A notification is shown when all artifacts are
successfully uploaded (click on image to see full size).</p>
+<p>To add artifacts that are already in the <abbr title="OSGi Bundle
Repository">OBR</abbr>, you click the "Add artifactâ¦" button. An "Add
artifact" dialog opens, showing the artifacts currently in the <abbr
title="OSGi Bundle Repository">OBR</abbr> (but not yet in the list of selected
artifacts) and a list of to-be-uploaded artifacts. This window also allows you
to upload artifacts, and offers two options to do so:</p>
<ol>
-<li>Upload the individual artifacts by pressing the "Upload" button and
selecting the artifact from the file chooser dialog, or;</li>
+<li>by uploading the individual artifacts by pressing the "Upload" button and
selecting the artifact from the file chooser dialog, or;</li>
<li>by using drag-and-drop: select all artifacts in an Explorer or Finder and
drag them onto the "Upload artifact" area. This way, you can upload multiple
artifacts in one go.</li>
</ol>
-<p>Once artifacts are uploaded, they appear in the Artifacts column. For each
artifact, you can edit its properties by double clicking on it. In addition,
you can unlink an artifact from a feature, which will be discussed later on,
and remove an artifact. <strong>Note</strong>: removing an artifact will only
remove it from the server's metadata, <em>not</em> from the <abbr title="OSGi
Bundle Repository">OBR</abbr>. </p>
-<p>If you try to upload an artifact that is not recognized by ACE, an error is
displayed noting that that particular artifact is not uploaded. Adding support
for new types of artifacts in ACE is discussed in <a
href="/dev-doc/adding-custom-artifact-types.html">this article</a>.</p>
-<p><strong>NOTE</strong>: All changes made through the Web UI need to be
stored explicitly by pressing the "Store" button, otherwise they will not be
visible to the ACE server. In case you want to revert all changes, you can use
the "Revert" button. This will ignore all changes and retrieve the latest state
from the server. In case there are no local changes, you can still retrieve the
latest state from the server using the "Retrieve" button.</p>
+<p>If you try to upload an artifact that is not recognized by ACE, a failure
notification is displayed noting that that particular artifact is not uploaded,
see also figure 4. Adding support for new types of artifacts in ACE is
discussed in <a href="/dev-doc/adding-custom-artifact-types.html">this
article</a>.</p>
+<p><img src="ace_dnd_artifacts_fail.png" width="369px" title="Figure 4: A
failure notification is shown when one or more artifacts could not be
recognized by ACE." /><br />
+<strong>Figure 4</strong>: A failure notification is shown when one or more
artifacts could not be recognized by ACE.</p>
+<p>Once all artifacts are uploaded, they appear as selected rows in the
artifacts column. You can immediately drag them onto the feature column to link
them to a particular feature. By double clicking on an artifact, you can edit
some of its properties, for example, its description.<br />
+To remove an artifact from the artifacts column, you simply press its
trash-can icon. Note that removing an artifact will only remove it from the
artifacts column, <em>not</em> from the <abbr title="OSGi Bundle
Repository">OBR</abbr>.</p>
+<p><strong>NOTE</strong>: All changes made through the Web UI need to be
stored explicitly by pressing the "Store" button or by hitting CTRL+S (or CMD+S
if you happen to use OSX), otherwise they will not be visible to the ACE
server. In case you want to revert all changes, you can use the "Revert" button
or CTRL/CMD+U. This will ignore all local changes but does <em>not</em>
retrieve the latest state from the server. To retrieve the latest state from
the server, use the "Retrieve" button or CTRL/CMD+G.</p>
<h3 id="creating-a-new-feature-distribution-andor-target">Creating a new
feature, distribution and/or target</h3>
-<p>Adding features and distributions are very similar. You either click the
"Add Featureâ¦" or "Add Distributionâ¦" buttons. In both cases, you are
presented with a dialog that allows you to enter the (mandatory) name of the
feature or distribution and an optional description.</p>
+<p>Adding features and distributions are very similar. You either click the
"Add Featureâ¦" or "Add Distributionâ¦" buttons (or use the shortcut keys
CTRL/CMD+F and CTRL/CMD+D). In both cases, you are presented with a dialog that
allows you to enter the (mandatory) name of the feature or distribution and an
optional description.</p>
<p>There are two ways of adding a target to ACE:</p>
<ol>
<li>You can pre-register a target by clicking the "Add Targetâ¦" button and
entering the name of the new target. This allows you to associate software to
this target even before it has ever been started or seen by the server.</li>
@@ -226,52 +235,79 @@ Even though they are smart guys that kno
</ul>
<h3 id="creating-associations">Creating associations</h3>
<p>To link artifacts to features, you simply select the artifact and drag it
on top of the feature to which it should be associated. The same principle also
applies if you want to associate features to distributions and distributions to
targets.
-To delete an association once is created, you can click either the left- or
the right hand side of the association (viz. either the artifact or the
feature), and click the "-" on the opposite side of the association. For
example, to delete an association between an feature and distribution, you can
select the feature first, and hit the "-" on the distribution. Alternatively,
you can select the distribution first and hit the "-" on the feature to delete
the association.</p>
-<p>Associations can be parameterized, allowing them to be dynamic in what they
match on the left hand side and/or the right hand side of the association. For
example, by default an association between a bundle artifact and a feature will
be made to match the <em>latest</em> version of the bundle. This way, if you
upload a new version of a bundle, the feature will automatically link to that
version. While this is certainly handy in many situations, there are also
situations in which you do not always want to link to the latest greatest
version of a bundle. An example might be the bundles that should run on your
production environment, which should only get an update in controlled upgrades,
not when you upload a new artifact to ACE. To disable the "dynamic"
associations between, uncheck the "Dynamic Links" option in the UI
<em>before</em> you create the association. This will create an association
that is explicitly bound to the symbolic name and version of a bundle.</p>
+To delete an association once is created, you can click either the left- or
the right hand side of the association (viz. either the artifact or the
feature), and click the "broken chain" button on the opposite side of the
association. For example, to delete an association between an feature and
distribution, you can select the feature first, and hit the "broken chain"
button on the distribution. Alternatively, you can select the distribution
first and hit the "broken chain" button on the feature to delete the
association.</p>
+<p>There is a subtle, but very important, difference when you associate a
bundle-artifact to a feature by dragging its symbolic name (without a version)
onto a feature, or when you drag a bundle-artifact with a version onto a
feature. In the first case, you make a "dynamic" association (see figure 5),
which states that you always want the <em>latest</em> version of that bundle to
be associated to the feature, including any newer version that might be
uploaded in the future. In the latter case, you make a "static" association
(see figure 6), which states that you always want that particular version of
that bundle to be associated to the feature.</p>
+<p><img src="ace_dynamic_association.png" width="516px" title="Figure 5:
Creating a dynamic association by dragging the BSN of a bundle onto a feature."
/><br />
+<strong>Figure 5</strong>: Creating a dynamic association by dragging the BSN
of a bundle onto a feature.</p>
+<p><img src="ace_static_association.png" width="522px" title="Figure 6:
Creating a static association by dragging a particular version of a bundle onto
a feature." /><br />
+<strong>Figure 6</strong>: Creating a static association by dragging a
particular version of a bundle onto a feature.</p>
+<p>Creating dynamic associations is currently only supported for bundle
artifacts. For other types of artifacts, such as configuration files, only
static associations can be created<sup id="fnref:2"><a class="footnote-ref"
href="#fn:2" rel="footnote">2</a></sup>. </p>
<h2 id="running-a-target">Running a target</h2>
-<p>As mentioned, a target represents a client on which software can be
deployed by ACE. Actually, a target consists of an OSGi runtime that runs a
management agent that periodically checks with the ACE server whether or not it
has new software for it. In case new software is available for a target, it can
automatically download and install it.</p>
-<p>ACE provides a fully self-contained target that includes a management agent
and can be run as plain Java JAR, named <tt>org.apache.ace.launcher.jar</tt>.
This target accepts the following command line arguments:</p>
+<p>As mentioned, a target represents a client on which software can be
deployed by ACE. Actually, a target consists of an OSGi runtime that runs at
least the ACE management agent. This management agent periodically checks with
the ACE server whether or not new software is available. In case new software
is available for a target, it can automatically download and install it.</p>
+<p>ACE provides a runnable eclipse project, <tt>run-target</tt> that starts an
OSGi runtime, the ACE management agent, and a Gogo shell for easy debugging and
demo purposes. The management agent, or agent for short, itself can be found in
the <tt>org.apache.ace.agent</tt> project. This agent simply does the
following:</p>
+<ol>
+<li>it uploads the audit log of the target to the ACE server. The audit log
contains all changes in bundle and framework state, such as the starting and
stopping of the framework and (de)installation of bundles;</li>
+<li>it check whether or not software updates are available. If so, it will
download it and install this update automatically.</li>
+</ol>
+<p>The agent can be configured by supplying it options through the command
line (e.g. <tt>-Dname=value</tt>):</p>
<dl>
-<dt><code>agents</code></dt>
-<dd>Configures the target to have multiple management agents:
<code>agent-id,identification,discovery[;agent-id,identification,discovery]*</code>.
If you specify this option, the identification and discovery arguments below
are ignored. Configuring multiple management agents is a very specific use case
that should be avoided unless you know exactly what you're doing. It was added
so a target can fetch different, non-overlapping parts of the software from
different servers. In general though, it is preferable and more convenient to
channel all software updates through a single server.</dd>
-<dt><code>auth</code></dt>
-<dd>point to the properties file containing the authentication credentials for
a certain subsystem. Can be either a directory, file or URL;</dd>
-<dt><code>discovery</code></dt>
-<dd>Sets the ACE server to connect to, should be an URL. Defaults to
<code>http://localhost:8080</code>.</dd>
-<dt><code>id</code> or <code>identification</code></dt>
-<dd>Defines the name to identify the target on in the ACE server. Defaults to
<code>defaultTargetID</code>.</dd>
-<dt><code>bundle</code></dt>
-<dd>Adds an additional bundle to be started with this management agent. The
bundle itself has to be on the Java classpath.
<code>bundle=my.fully.qualified.BundleActivator</code>;</dd>
-<dt><code>fwOption</code></dt>
-<dd>Sets framework options for the OSGi framework to be created. This argument
may be repeated. For example:
<code>fwOption=org.osgi.framework.system.packages.extra=sun.misc,com.sun.management</code>.</dd>
+<dt><tt>agent.identification.agentid</tt></dt>
+<dd>defines the name to uniquely identify a target on the ACE server. In case
this option is not supplied, a default value of <code>defaultTargetID</code> is
used;</dd>
+<dt><tt>agent.discovery.serverurls</tt></dt>
+<dd>defines the ACE server URLs to connect to. Multiple URLs can be given to
get a form of fail-over: in case a connection to the first URL cannot be
established, the second URL will be used, and so on. If this option is given,
at least one URL should be supplied, and multiple URLs can be supplied by
separating them with a comma. If this option is omitted, a default value of
<tt>http://localhost:8080</tt> is used;</dd>
+<dt><tt>agent.logging.level</tt></dt>
+<dd>defines the log level of the agent, and should be one of the following
values: <tt>DEBUG</tt>, <tt>INFO</tt>, <tt>WARNING</tt> or <tt>ERROR</tt>. The
default log level is <tt>INFO</tt>;</dd>
+<dt><tt>agent.controller.syncinterval</tt></dt>
+<dd>defines the interval (in seconds) in which the agent should synchronize
with the ACE server. A default of 60 seconds is used in case this option is not
supplied;</dd>
+<dt><tt>agent.controller.syncdelay</tt></dt>
+<dd>defines how long the agent should wait (in seconds) after startup before
it will synchronize with the ACE server for the first time. A default of 5
seconds is used in case this option is not supplied;</dd>
+<dt><tt>agent.controller.streaming</tt></dt>
+<dd>if given a value of <tt>false</tt>, all software updates will be
downloaded completely first after which it will be installed. Use this value in
case you suffer from unreliable network connections. A value of <tt>true</tt>
(the default) causes the agent to download and install any software update
directly.</dd>
+<dt><tt>agent.controller.fixpackages</tt></dt>
+<dd>if given a value of <tt>true</tt> (the default), software updates will
only contain the deltas or changed artifacts. For large deployment packages,
this can dramatically reduce the size of an update. Use a value of
<tt>false</tt> to get all artifacts for each software update;</dd>
+<dt><tt>agent.controller.retries</tt></dt>
+<dd>defines the number of times the agent should retry to install a software
update in case its installation fails. If omitted, an installation is retried 3
times;</dd>
+<dt><tt>agent.connection.authtype</tt></dt>
+<dd>defines how to connections to the server are to be authenticated. Valid
values are <tt>NONE</tt> for no authentication, <tt>BASIC</tt> for using
HTTP-BASIC authentication or <tt>CLIENTCERT</tt> for using client certificates.
In case this option is omitted, a value of <tt>NONE</tt> is assumed and no
authentication is used. In case of the values <tt>BASIC</tt> or
<tt>CLIENTCERT</tt>, additional options should be supplied (see below);</dd>
+<dt><tt>agent.connection.username</tt> and
<tt>agent.connection.password</tt></dt>
+<dd>provide the username and password used for HTTP-BASIC authentication;</dd>
+<dt><tt>agent.connection.sslProtocol</tt></dt>
+<dd>defines what SSL protocol is to be used for creating secure connections to
the ACE server, defaults to <tt>TLS</tt>;</dd>
+<dt><tt>agent.connection.keyfile</tt> and
<tt>agent.connection.keypass</tt></dt>
+<dd>provide the keystore file and password that contain the certificate
information for establishing a secure conncetion between agent and server;</dd>
+<dt><tt>agent.connection.trustfile</tt> and
<tt>agent.connection.trustpass</tt></dt>
+<dd>provide the truststore file and password that contain the trusted (server)
certificate(s) for establishing a secure connection between agent and
server.</dd>
</dl>
-<p>An example on how to run the launcher is:</p>
-<div class="codehilite"><pre><span class="nv">$ </span>java -jar
org.apache.ace.launcher.jar <span class="nv">id</span><span
class="o">=</span>MyTarget <span class="nv">discovery</span><span
class="o">=</span>http://192.168.1.1:8080
-Adding additional bundle activator: org.apache.ace.managementagent.Activator
-Started management agent.
- Target ID : MyTarget
- Server : http://192.168.1.1:8080
- Sync interval: 2000 ms
- Unaffected bundles will not be stopped during deployment.
-</pre></div>
-
-
-<p>After the management agent is started, a new target should appear in the
ACE server after you "Retrieve" the latest changes or "Revert" the current
changes. If a target is added this way to the ACE server (instead of adding it
through the "Add targetâ¦" button), it initially will be
<em>unregistered</em>. This means that no metadata is present in the ACE server
yet and will not be created. To register a target, you can double click the
target to edit its properties. On the "Management" tab, you can select the
"Registered?" (and optionally the "Auto approve?" option as well) and close the
dialog by pressing "Ok"<sup id="fnref:2"><a class="footnote-ref" href="#fn:2"
rel="footnote">2</a></sup>. </p>
+<p>When the agent is started, a new target should appear in the ACE server
after you "Retrieve" the latest changes. If a target is added this way to the
ACE server (instead of adding it through the "Add targetâ¦" button), it
initially will be <em>unregistered</em>. This means that no metadata is present
in the ACE server yet and will not be created. To register a target, you can
double click the target to edit its properties. On the "Management" tab, you
can check the "Registered?" option (and optionally the "Auto approve?" option
as well) and close the dialog by pressing "Ok"<sup id="fnref:3"><a
class="footnote-ref" href="#fn:3" rel="footnote">3</a></sup>. Once a target is
registered, it cannot be unregistered unless it is deleted (using the
trash-icon).</p>
<h3 id="using-the-template-engine-for-targets">Using the template engine for
targets</h3>
<p>If you want to provision software to multiple targets, those targets
probably need to have their own specific configuration. For example, the IP
address on which it should listen for web requests, or the credentials to
access a database. One could create specific configuration files for each
target, however, this can become quite tedious if you have lots of targets.
Besides that, ACE requires that each artifact has a unique name, so you need to
create unique file names for your configuration files for each change you make.
Fortunately, ACE provides an easier way to solve this problem: a template
engine.</p>
-<p>All configuration files<sup id="fnref:3"><a class="footnote-ref"
href="#fn:3" rel="footnote">3</a></sup> can be regarded as templates, in which
variables are replaced with values supplied by ACE. In fact, the values are
definable per target, distribution, feature or artifact and ACE will collect
all tags of entities that are associated with a specific target. To define
variables and their replacement values (or "tags") for, for example, a
distribution, open up its properties dialog by double clicking on it, and
selecting the "Tag Editor" tab. Each line in this editor represents a tag. The
key of a tag defines that (part of) the variable name to be replaced in
configuration files, and the value of a tag the actual replacement value. </p>
-<p>For example, consider the following configuration file:</p>
-<div class="codehilite"><pre><span class="nt"><properties></span>
- <span class="nt"><key></span>ipAddress<span
class="nt"></key></span>
- <span class="nt"><value></span>${context.address}<span
class="nt"></value></span>
+<p>All configuration files<sup id="fnref:4"><a class="footnote-ref"
href="#fn:4" rel="footnote">4</a></sup> can be regarded as templates, in which
variables are replaced with values supplied by ACE. In fact, the values are
definable per target, distribution, feature or artifact and ACE will collect
all tags of entities that are associated with a specific target. To define
variables and their replacement values (or "tags") for, for example, a
distribution, open up its properties dialog by double clicking on it, and
selecting the "Tag Editor" tab. Each line in this editor represents a tag. The
key of a tag defines that (part of) the variable name to be replaced in
configuration files, and the value of a tag the actual replacement value.<br />
+In order to let ACE provision your (templated) configuration files to your
target, you need a <strong>resource processor</strong> that is capable of
handling the configuration files. Without such a resource processor, the
configuration files cannot be deployed to your target. See <a
href="/dev-doc/adding-custom-artifact-types.html">this article</a> for more
information about writing resource processor for your configuration files, or
use an existing one, such as <a
href="http://felix.apache.org/documentation/subprojects/apache-felix-autoconf.html";>Felix
Autoconf resource processor</a>. </p>
+<p>Suppose a valid resource processor is available that recognizes <a
href="http://docs.oracle.com/javase/7/docs/api/java/util/Properties.html";>Java
Properties XML</a>, consider the following configuration file:</p>
+<div class="codehilite"><pre><span class="nt"><properties</span> <span
class="na">version=</span><span class="s">"1.0"</span><span
class="nt">></span>
+ <span class="nt"><entry</span> <span class="na">key=</span><span
class="s">"ipAddress"</span><span
class="nt">></span>${context.address}<span class="nt"></entry></span>
+ <span class="nt"><entry</span> <span class="na">key=</span><span
class="s">"port"</span><span
class="nt">></span>${context.port}<span class="nt"></entry></span>
+ <span class="nt"><entry</span> <span class="na">key=</span><span
class="s">"logLevel"</span><span class="nt">></span>INFO<span
class="nt"></entry></span>
<span class="nt"></properties></span>
</pre></div>
-<p>The <tt>${context.address}</tt> represent the variable that will be
replaced. The "context." part is mandatory, and everything after that is user
definable. Suppose we want to deploy this configuration file to two targets,
"Target1", which is supposed to listen on address 192.168.2.1 and "Target2",
which is supposed to listen on address 192.168.2.2. To make the configuration
file specific for both targets, we simply need to define a tag on "Target1",
like: <code>address</code> -> <code>192.168.2.1</code>, and a similar tag on
"Target2", like <code>address</code> -> <code>192.168.2.2</code>.</p>
-<p>Under the covers, ACE uses Velocity<sup id="fnref:4"><a
class="footnote-ref" href="#fn:4" rel="footnote">4</a></sup> to parse the
template. This means that, apart from variable substitution, you can also use
other Velocity macros and create more complex configurations that might contain
conditional sections, loops and other features Velocity provides.</p>
-<p><strong>NOTE</strong>: In case a configuration file consists of a variable
that cannot be resolved, it will simply not be replaced, but left as-is.</p>
-<p>ACE will scan all configuration files and replace all known variables as
soon as a new deployment is created. This means that for our example, both
"Target1" and "Target2" will get their own copy of the configuration file with
their specific content. ACE also automatically versions these generated files,
to aid downgrading software.</p>
+<p>The <tt>${context.address}</tt> and <tt>${context.port}</tt> represent
variables that can be replaced. The <tt>context.</tt> (including the dot)
prefix is mandatory, and everything after this prefix is user-definable and
considered as variable name. In this example, two variables are expected:
<tt>address</tt> and <tt>port</tt>. The values for these variables can be added
to entities by using the "Tag Editor", available when you double click on an
artifact, feature, distribution or target in the web UI<sup id="fnref:5"><a
class="footnote-ref" href="#fn:5" rel="footnote">5</a></sup>. It does not
really matter on what entity the variables are actually defined, but in most
cases they are either defined on a distribution and/or target.</p>
+<p>Suppose we want to deploy the aforementioned configuration file to two
targets, "target-1", which is supposed to listen on <tt>192.168.2.1:80</tt> and
"target-2", which is supposed to listen on <tt>192.168.2.2:8080</tt>. To make
the configuration file specific for both targets, we simply need to define two
tags on "target-1", like (see also figure 7):</p>
+<ul>
+<li><tt>address</tt> -> <tt>192.168.2.1</tt>;</li>
+<li><tt>port</tt> -> <tt>80</tt>.</li>
+</ul>
+<p>And similar tags on "target-2": </p>
+<ul>
+<li><tt>address</tt> -> <tt>192.168.2.2</tt>;</li>
+<li><tt>port</tt> -> <tt>8080</tt>.</li>
+</ul>
+<p><img src="ace_target_tag_editor.png" width="600px" title="Figure 7: Using
the Tag Editor of a target to supply configuration variables." /><br />
+<strong>Figure 7</strong>: Using the Tag Editor of a target to supply
configuration variables.</p>
+<p>Under the covers, ACE uses Velocity<sup id="fnref:6"><a
class="footnote-ref" href="#fn:6" rel="footnote">6</a></sup> to parse the
template. This means that, apart from variable substitution, you can also use
other Velocity macros and create more complex configurations that might contain
conditional sections, loops and other features Velocity provides. See the
Velocity documentation for more information on how to use this
functionality.</p>
+<p>In case a variable cannot be resolved, it will simply not be replaced, but
left as-is. This could lead to invalid or unparsable artifacts (configuration
files) on your target!</p>
+<p>ACE will scan all configuration files and replace all known variables as
soon as a new deployment is created. This means that for our example, both
"target-1" and "target-2" will get a processed version of the configuration
file, each with its own specific content. ACE also automatically versions these
generated files, to aid downgrading software.</p>
<div class="footnote">
<hr />
<ol>
@@ -279,13 +315,19 @@ Started management agent.
<p>Once an artifact is uploaded to the <abbr title="OSGi Bundle
Repository"><abbr title="OSGi Bundle Repository"><abbr title="OSGi Bundle
Repository">OBR</abbr></abbr></abbr>, it cannot be modified anymore. This is
necessary in order to allow both software upgrades as downgrades and to ensure
that everything you do is reproducible. One thing to note is that this is not
compatible with the way that Maven handles snapshot versions. A snapshot can
contain anything. In stead we usually use the version qualifier to append a
timestamp in such scenarios. <a class="footnote-backref" href="#fnref:1"
rev="footnote" title="Jump back to footnote 1 in the text">↩</a></p>
</li>
<li id="fn:2">
-<p>Do not forget to store your changes! <a class="footnote-backref"
href="#fnref:2" rev="footnote" title="Jump back to footnote 2 in the
text">↩</a></p>
+<p>This is a limitation of the current web UI. It is possible to create more
sophisticated associations by using the REST API or the Gogo shell
commands. <a class="footnote-backref" href="#fnref:2" rev="footnote"
title="Jump back to footnote 2 in the text">↩</a></p>
</li>
<li id="fn:3">
-<p>In fact any artifact can be considered as an template, but by default ACE
only considers configuration files.  <a class="footnote-backref"
href="#fnref:3" rev="footnote" title="Jump back to footnote 3 in the
text">↩</a></p>
+<p>Do not forget to store your changes! <a class="footnote-backref"
href="#fnref:3" rev="footnote" title="Jump back to footnote 3 in the
text">↩</a></p>
</li>
<li id="fn:4">
-<p>Apache Velocity is an engine that can generate documents by combining a
template with a context that contains variables. To learn more about it, visit
the <a href="http://velocity.apache.org/";>Velocity website</a>. <a
class="footnote-backref" href="#fnref:4" rev="footnote" title="Jump back to
footnote 4 in the text">↩</a></p>
+<p>In fact any artifact can be considered as an template, but by default ACE
only considers configuration files.  <a class="footnote-backref"
href="#fnref:4" rev="footnote" title="Jump back to footnote 4 in the
text">↩</a></p>
+</li>
+<li id="fn:5">
+<p>In other UIs, such as the Gogo shell, you need to supply these tags
manually. <a class="footnote-backref" href="#fnref:5" rev="footnote"
title="Jump back to footnote 5 in the text">↩</a></p>
+</li>
+<li id="fn:6">
+<p>Apache Velocity is an engine that can generate documents by combining a
template with a context that contains variables. To learn more about it, visit
the <a href="http://velocity.apache.org/";>Velocity website</a>. <a
class="footnote-backref" href="#fnref:6" rev="footnote" title="Jump back to
footnote 6 in the text">↩</a></p>
</li>
</ol>
</div></div>
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