Allow config to reverse library precedence

src/main/groovy/org/boozallen/plugins/jte/binding/injectors/LibraryLoader.groovy

@@ -17,6 +17,7 @@
 package org.boozallen.plugins.jte.binding.injectors
 
 import org.boozallen.plugins.jte.binding.*
+import org.boozallen.plugins.jte.config.TemplateGlobalConfig
 import org.boozallen.plugins.jte.utils.RunUtils
 import org.boozallen.plugins.jte.utils.TemplateScriptEngine
 import org.boozallen.plugins.jte.config.TemplateConfigObject
@@ -38,6 +39,9 @@ import com.cloudbees.groovy.cps.NonCPS
         List<GovernanceTier> tiers = GovernanceTier.getHierarchy() 
         List<LibraryConfiguration> libs = tiers.collect{ it.getLibraries() }.flatten().minus(null)
         List<LibraryProvider> providers = libs.collect{ it.getLibraryProvider() }.flatten().minus(null)
+        if(!TemplateGlobalConfig.get().getAllowLibraryOverride()) {
+            providers = providers.reverse();
+        }
 
         ArrayList libConfigErrors = []
         config.getConfig().libraries.each{ libName, libConfig ->
@@ -50,7 +54,7 @@ import com.cloudbees.groovy.cps.NonCPS
         }
         libConfigErrors = libConfigErrors.flatten().minus(null)
 
-        // if library errors were found: 
+        // if library errors were found:
         if(libConfigErrors){
             TemplateLogger.printError("----------------------------------")
             TemplateLogger.printError("   Library Configuration Errors   ")

src/main/groovy/org/boozallen/plugins/jte/config/TemplateGlobalConfig.groovy

@@ -26,6 +26,7 @@ import jenkins.model.GlobalConfiguration
 public class TemplateGlobalConfig extends GlobalConfiguration {
 
     private GovernanceTier tier
+    private Boolean allowLibraryOverride = true;
 
     public static TemplateGlobalConfig get() {
         return GlobalConfiguration.all().get(TemplateGlobalConfig)
@@ -44,4 +45,11 @@ public class TemplateGlobalConfig extends GlobalConfiguration {
         return tier
     }
 
+    Boolean getAllowLibraryOverride() {
+        return allowLibraryOverride
+    }
+
+    void setAllowLibraryOverride(Boolean allowLibraryOverride) {
+        this.allowLibraryOverride = allowLibraryOverride
+    }
 }

src/main/resources/org/boozallen/plugins/jte/config/TemplateGlobalConfig/config.jelly

@@ -17,6 +17,9 @@
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form">
     <f:section title="${%Jenkins Templating Engine}">
+        <f:entry title="Allow library override">
+            <f:checkbox field="allowLibraryOverride" checked="${descriptor.libraryOverride}"/>
+        </f:entry>
         <f:entry field="tier" title="">
             <f:property/>
         </f:entry>

src/test/groovy/org/boozallen/plugins/jte/binding/injectors/LibraryLoaderSpec.groovy

@@ -1,6 +1,7 @@
 package org.boozallen.plugins.jte.binding
 
 import org.boozallen.plugins.jte.binding.injectors.LibraryLoader
+import org.boozallen.plugins.jte.config.TemplateGlobalConfig
 import org.boozallen.plugins.jte.utils.TemplateScriptEngine
 import spock.lang.*
 import org.boozallen.plugins.jte.binding.injectors.StepWrapper
@@ -196,6 +197,49 @@ class LibraryLoaderSpec extends Specification {
             0 * s2.loadLibrary(script, "libA", [:])        
     }
 
+    @WithoutJenkins
+    def "library on higher governance tier gets loaded if library override set to false"(){
+        setup:
+        TemplateGlobalConfig.get().setAllowLibraryOverride(false)
+        MockLibraryProvider s1 = Mock{
+            hasLibrary("libA") >> true
+        }
+        MockLibraryProvider s2 = Mock{
+            hasLibrary("libA") >> true
+        }
+
+        LibraryConfiguration c1 = Mock{
+            getLibraryProvider() >> s1
+        }
+        LibraryConfiguration c2 = Mock{
+            getLibraryProvider() >> s2
+        }
+
+        GovernanceTier tier1 = Mock{
+            getLibraries() >> [ c1 ]
+        }
+        GovernanceTier tier2 = GroovyMock(global:true){
+            getLibraries() >> [ c2 ]
+        }
+        GovernanceTier.getHierarchy() >> [ tier1, tier2 ]
+
+        // mock libraries to load
+        TemplateConfigObject config = new TemplateConfigObject(config: [
+                libraries: [
+                        libA: [:]
+                ]
+        ])
+
+        when:
+        LibraryLoader.doInject(config, script)
+        then:
+        0 * s1.loadLibrary(script, "libA", [:])
+        1 * s2.loadLibrary(script, "libA", [:])
+
+        cleanup:
+        TemplateGlobalConfig.get().setAllowLibraryOverride(true)
+    }
+
     @WithoutJenkins
     def "library loader correctly passes step config"(){
         setup: