support RPM 'Prefix'.

src/main/scala/com/typesafe/sbt/packager/rpm/Keys.scala

@@ -11,6 +11,7 @@ trait RpmKeys {
   val rpmVendor = SettingKey[String]("rpm-vendor", "Name of the vendor for this RPM.")
   val rpmOs = SettingKey[String]("rpm-os", "Name of the os for this RPM.")
   val rpmRelease = SettingKey[String]("rpm-release", "Special release number for this rpm (vs. the software).")
+  val rpmPrefix = SettingKey[Option[String]]("rpm-prefix", "File system prefix for relocatable package.")
   val rpmMetadata = SettingKey[RpmMetadata]("rpm-metadata", "Metadata associated with the generated RPM.")
 
   // DESCRIPTION KEYS

src/main/scala/com/typesafe/sbt/packager/rpm/RpmMetadata.scala

@@ -10,6 +10,7 @@ case class RpmMetadata(
   name: String,
   version: String,
   release: String,
+  prefix: Option[String] = None,
   arch: String,
   vendor: String,
   os: String,
@@ -168,6 +169,7 @@ case class RpmSpec(meta: RpmMetadata,
     sb append ("Version: %s\n" format meta.version)
     sb append ("Release: %s\n" format meta.release)
     sb append ("Summary: %s\n" format meta.summary)
+    meta.prefix foreach { v => sb append ("prefix: %s\n" format v) }
 
     desc.license foreach { v => sb append ("License: %s\n" format v) }
     desc.distribution foreach { v => sb append ("Distribution: %s\n" format v) }

src/main/scala/com/typesafe/sbt/packager/rpm/RpmPlugin.scala

@@ -17,6 +17,7 @@ trait RpmPlugin extends Plugin with LinuxPlugin {
   def rpmSettings: Seq[Setting[_]] = Seq(
     rpmOs := "Linux", // TODO - default to something else?
     rpmRelease := "0",
+    rpmPrefix := None,
     rpmVendor := "", // TODO - Maybe pull in organization?
     rpmLicense := None,
     rpmDistribution := None,
@@ -46,7 +47,7 @@ trait RpmPlugin extends Plugin with LinuxPlugin {
   ) ++ inConfig(Rpm)(Seq(
       packageArchitecture := "noarch",
       rpmMetadata <<=
-        (name, version, rpmRelease, packageArchitecture, rpmVendor, rpmOs, packageSummary, packageDescription, rpmAutoprov, rpmAutoreq) apply (RpmMetadata.apply),
+        (name, version, rpmRelease, rpmPrefix, packageArchitecture, rpmVendor, rpmOs, packageSummary, packageDescription, rpmAutoprov, rpmAutoreq) apply RpmMetadata,
       rpmDescription <<=
         (rpmLicense, rpmDistribution, rpmUrl, rpmGroup, rpmPackager, rpmIcon) apply RpmDescription,
       rpmDependencies <<=

src/sphinx/DetailedTopics/redhat.rst

@@ -57,6 +57,12 @@ Dependency Settings
     ``rpmConflcits``
     The packages this RPM conflicts with and cannot be installed with.
 
+Meta Settings
+~~~~~~~~~~~~~
+
+    ``rpmPrefix``
+    The path passed set as the base for the revocable package
+
 
 Scriptlet Settings
 ~~~~~~~~~~~~~~~~~~
@@ -96,6 +102,62 @@ The Rpm support grants the following commands:
 
   ``rpm:rpmlint``
     Generates the ``.rpm`` file and runs the ``rpmlint`` command to look for issues in the package.  Useful for debugging.
+
+
+Rpm Prefix
+----------
+The rpm prefix allows you to create a relocatable package as defined by http://www.rpm.org/max-rpm/s1-rpm-reloc-prefix-tag.html.  This optional setting with a handful of overrides to scriptlets and templates will allow you to create a working java_server archetype that can be relocated in the file system.  
+
+Example Settings
+~~~~~~~~~~~~~~~~~~
+
+.. code-block:: scala
+
+    defaultLinuxInstallLocation := "/opt/package_root",
+    rpmPrefix := Some(defaultLinuxInstallLocation),
+    linuxPackageSymlinks := Seq.empty,
+    defaultLinuxLogsLocation := defaultLinuxInstallLocation + "/" + name
+
+
+Template Changes
+~~~~~~~~~~~~~~~~~~
+Apply the following changes to the default init start script.  You can find this in the sbt-native-packager source.
+
+
+``src/templates/start``
+
+.. code-block:: bash
+
+    ...
+    [ -e /etc/sysconfig/$prog ] && . /etc/sysconfig/$prog
+
+    # smb could define some additional options in $RUN_OPTS
+    RUN_CMD="${PACKAGE_PREFIX}/${{app_name}}/bin/${{app_name}}"
+    ...
+
+
+
+Scriptlet Changes
+~~~~~~~~~~~~~~~~~~
+Apply the following changes to the scriptlets that can be found in the sbt-native-packager source.
+
+``src/rpm/scriptlets/post-rpm``
+
+.. code-block:: bash
+
+    ...
+    echo "PACKAGE_PREFIX=${RPM_INSTALL_PREFIX}" > /etc/sysconfig/${{app_name}}
+    ...
+
+``src/rpm/scriptlets/preun-rpm``
+
+.. code-block:: bash
+
+    ...
+    rm /etc/sysconfig/${{app_name}}
+    ...
+
+
 
 Jar Repackaging
 ---------------