Support raw XML injection in multibranch build strategies

build-strategies:
     - raw:
         xml: |
           <c.i.j.p.m.b.IncludeRegionBranchBuildStrategy plugin="...">
             <includedRegions>my/cool/project/*.cpp</includedRegions>
           </c.i.j.p.m.b.IncludeRegionBranchBuildStrategy>

Change-Id: I3679c81a4a4b28204460b1563bb7585a3e67a449
Signed-off-by: Anna Tikhonova <anna.m.tikhonova@gmail.com>

jenkins_jobs/modules/project_multibranch.py

@@ -86,6 +86,7 @@ import six
 from jenkins_jobs.modules.scm import git_extensions
 from jenkins_jobs.errors import InvalidAttributeError
 from jenkins_jobs.errors import JenkinsJobsException
+from jenkins_jobs.xml_config import remove_ignorable_whitespace
 
 logger = logging.getLogger(str(__name__))
 
@@ -1102,6 +1103,8 @@ def build_strategies(xml_parent, data):
     Requires the :jenkins-plugins:`Basic Branch Build Strategies Plugin
     <basic-branch-build-strategies>`.
 
+    Other build strategies can be configured via raw XML injection.
+
     :arg list build-strategies: Definition of build strategies.
 
         * **tags** (dict): Builds tags
@@ -1142,6 +1145,8 @@ def build_strategies(xml_parent, data):
                     for example: `master release*` (default `*`)
                 * **excludes** (str) Name patterns to ignore even if matched
                     by the includes list. For example: release (optional)
+        * **raw** (dict): Injects raw BuildStrategy XML to use other build
+            strategy plugins.
 
     """
 
@@ -1268,6 +1273,11 @@ def build_strategies(xml_parent, data):
                         fail_required=False,
                     )
 
+        if "raw" in bbs_list:
+            raw_xml = XML.fromstring(bbs_list["raw"].get("xml"))
+            remove_ignorable_whitespace(raw_xml)
+            XML.SubElement(bbs, None).append(raw_xml)
+
 
 def property_strategies(xml_parent, data):
     """Configure Basic Branch Property Strategies.

tests/multibranch/fixtures/scm_git_full.xml

@@ -140,6 +140,9 @@
               </jenkins.branch.buildstrategies.basic.NamedBranchBuildStrategyImpl_-WildcardsNameFilter>
             </filters>
           </jenkins.branch.buildstrategies.basic.NamedBranchBuildStrategyImpl>
+          <com.igalg.jenkins.plugins.multibranch.buildstrategy.IncludeRegionBranchBuildStrategy plugin="multibranch-build-strategy-extension">
+            <includedRegions>my/cool/project/*.cpp</includedRegions>
+          </com.igalg.jenkins.plugins.multibranch.buildstrategy.IncludeRegionBranchBuildStrategy>
         </buildStrategies>
       </jenkins.branch.BranchSource>
     </data>

tests/multibranch/fixtures/scm_git_full.yaml

@@ -37,6 +37,11 @@ scm:
                 - exact-name: {}
                 - regex-name: {}
                 - wildcards-name: {}
+            - raw:
+                xml: |
+                  <com.igalg.jenkins.plugins.multibranch.buildstrategy.IncludeRegionBranchBuildStrategy plugin="multibranch-build-strategy-extension">
+                    <includedRegions>my/cool/project/*.cpp</includedRegions>
+                  </com.igalg.jenkins.plugins.multibranch.buildstrategy.IncludeRegionBranchBuildStrategy>
         clean:
             after: true
             before: true