Feature/filter environment variables

src/main/java/com/cloudbees/jenkins/plugins/docker_build_env/Docker.java

@@ -26,6 +26,7 @@
 import java.net.InterfaceAddress;
 import java.net.NetworkInterface;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -47,8 +48,9 @@ public class Docker implements Closeable {
     private final boolean privileged;
     private final AbstractBuild build;
     private EnvVars envVars;
+    private List<String> environmentFilters;
 
-    public Docker(DockerServerEndpoint dockerHost, String dockerInstallation, String credentialsId, AbstractBuild build, Launcher launcher, TaskListener listener, boolean verbose, boolean privileged) throws IOException, InterruptedException {
+    public Docker(DockerServerEndpoint dockerHost, String dockerInstallation, String credentialsId, AbstractBuild build, Launcher launcher, TaskListener listener, boolean verbose, boolean privileged, String filterEnvVariables) throws IOException, InterruptedException {
         this.dockerHost = dockerHost;
         this.dockerExecutable = DockerTool.getExecutable(dockerInstallation, Computer.currentComputer().getNode(), listener, build.getEnvironment(listener));
         this.registryEndpoint = new DockerRegistryEndpoint(null, credentialsId);
@@ -57,6 +59,7 @@ public Docker(DockerServerEndpoint dockerHost, String dockerInstallation, String
         this.build = build;
         this.verbose = verbose | debug;
         this.privileged = privileged;
+        this.environmentFilters = getEnvFilters(filterEnvVariables);
     }
 
 
@@ -95,6 +98,13 @@ private EnvVars getEnvVars() throws IOException, InterruptedException {
         return envVars;
     }
 
+    private List<String> getEnvFilters(String envFilters){
+        if(envFilters != null && !envFilters.equals("")) {
+            return Arrays.asList(envFilters.split(","));
+        }
+        return Arrays.asList();
+    }
+
     public boolean pullImage(String image) throws IOException, InterruptedException {
         ArgumentListBuilder args = dockerCommand()
             .add("pull", image);
@@ -332,7 +342,17 @@ public EnvVars getEnv(String container, Launcher launcher) throws IOException, I
         EnvVars env = new EnvVars();
         LineIterator it = new LineIterator(new StringReader(out.toString()));
         while (it.hasNext()) {
-            env.addLine(it.nextLine());
+            boolean found = false;
+            String envV = it.nextLine();
+            for(String filter: environmentFilters) {
+                if(!filter.equals("") && envV.contains(filter + "=")) {
+                    found = true;
+                    break;
+                }
+            }
+            if(!found) {
+                env.addLine(envV);
+            }
         }
         return env;
     }

src/main/java/com/cloudbees/jenkins/plugins/docker_build_env/DockerBuildWrapper.java

@@ -73,13 +73,15 @@ public class DockerBuildWrapper extends BuildWrapper {
 
     private String cpu;
 
+    private String filterEnvVariables;
+
     private final boolean noCache;
 
     @DataBoundConstructor
     public DockerBuildWrapper(DockerImageSelector selector, String dockerInstallation, DockerServerEndpoint dockerHost, String dockerRegistryCredentials, boolean verbose, boolean privileged,
                               List<Volume> volumes, String group, String command,
                               boolean forcePull,
-                              String net, String memory, String cpu, boolean noCache) {
+                              String net, String memory, String cpu, String filterEnvVariables, boolean noCache) {
         this.selector = selector;
         this.dockerInstallation = dockerInstallation;
         this.dockerHost = dockerHost;
@@ -94,6 +96,7 @@ public DockerBuildWrapper(DockerImageSelector selector, String dockerInstallatio
         this.memory = memory;
         this.cpu = cpu;
         this.noCache = noCache;
+        this.filterEnvVariables = filterEnvVariables;
     }
 
     public DockerImageSelector getSelector() {
@@ -142,13 +145,17 @@ public boolean isForcePull() {
 
     public String getCpu() { return cpu;}
 
+    public String getFilterEnvVariables() {
+        return filterEnvVariables;
+    }
+
     public boolean isNoCache() {
         return noCache;
     }
 
     @Override
     public Launcher decorateLauncher(final AbstractBuild build, final Launcher launcher, final BuildListener listener) throws IOException, InterruptedException, Run.RunnerAbortedException {
-        final Docker docker = new Docker(dockerHost, dockerInstallation, dockerRegistryCredentials, build, launcher, listener, verbose, privileged);
+        final Docker docker = new Docker(dockerHost, dockerInstallation, dockerRegistryCredentials, build, launcher, listener, verbose, privileged, filterEnvVariables);
 
         final BuiltInContainer runInContainer = new BuiltInContainer(docker);
         build.addAction(runInContainer);

src/main/resources/com/cloudbees/jenkins/plugins/docker_build_env/DockerBuildWrapper/config.jelly

@@ -70,6 +70,9 @@ THE SOFTWARE.
           <f:entry field="cpu" title="CPU shares">
             <f:textbox/>
           </f:entry>
+          <f:entry field="filterEnvVariables" title="Filter Environment Variables">
+            <f:textbox/>
+          </f:entry>
         </f:advanced>
 
     </f:nested>

src/main/resources/com/cloudbees/jenkins/plugins/docker_build_env/DockerBuildWrapper/help-filterEnvVariables.html

@@ -0,0 +1,2 @@
+Please provide the environment variables you want not to be overridden in the docker container. Please list the variables
+comma separated. Example: PATH,BUILD_URL

src/test/java/com/cloudbees/jenkins/plugins/docker_build_env/FunctionalTests.java

@@ -33,7 +33,7 @@ public void run_inside_pulled_container() throws Exception {
         project.getBuildWrappersList().add(
             new DockerBuildWrapper(
                 new PullDockerImageSelector("ubuntu:14.04"),
-                "", new DockerServerEndpoint("", ""), "", true, false, Collections.<Volume>emptyList(), null, "cat", false, "bridge", null, null, false)
+                "", new DockerServerEndpoint("", ""), "", true, false, Collections.<Volume>emptyList(), null, "cat", false, "bridge", null, null, "PATH", false)
         );
         project.getBuildersList().add(new Shell("lsb_release  -a"));
 
@@ -51,8 +51,8 @@ public void run_inside_built_container() throws Exception {
 
         project.getBuildWrappersList().add(
                 new DockerBuildWrapper(
-                        new DockerfileImageSelector(".", "Dockerfile"),
-                        "", new DockerServerEndpoint("", ""), "", true, false, Collections.<Volume>emptyList(), null, "cat", false, "bridge", null, null, true)
+                        new DockerfileImageSelector(".", "$WORKSPACE/Dockerfile"),
+                        "", new DockerServerEndpoint("", ""), "", true, false, Collections.<Volume>emptyList(), null, "cat", false, "bridge", null, null, "PATH", true)
         );
         project.getBuildersList().add(new Shell("lsb_release  -a"));
 
@@ -77,7 +77,7 @@ public void run_inside_built_python_pip_container() throws Exception {
         project.getBuildWrappersList().add(
                 new DockerBuildWrapper(
                         new DockerfileImageSelector(".", "Dockerfile"),
-                        "", new DockerServerEndpoint("", ""), "", true, false, Collections.<Volume>emptyList(), null, "cat", false, "bridge", null, null, true)
+                        "", new DockerServerEndpoint("", ""), "", true, false, Collections.<Volume>emptyList(), null, "cat", false, "bridge", null, null, "PATH", true)
         );
         project.getBuildersList().add(new Shell("python -V"));