Namespaces for Container Label Keys

src/main/java/com/nirima/jenkins/plugins/docker/DockerCloud.java

@@ -599,10 +599,10 @@ public synchronized void removeTemplate(DockerTemplate t) {
      */
     public int countContainersInDocker(final String imageName) throws Exception {
         final Map<String, String> labelFilter = new HashMap<>();
-        labelFilter.put(DockerTemplateBase.CONTAINER_LABEL_JENKINS_INSTANCE_ID,
+        labelFilter.put(DockerContainerLabelKeys.JENKINS_INSTANCE_ID,
                 DockerTemplateBase.getJenkinsInstanceIdForContainerLabel());
         if (imageName != null) {
-            labelFilter.put(DockerTemplateBase.CONTAINER_LABEL_IMAGE, imageName);
+            labelFilter.put(DockerContainerLabelKeys.CONTAINER_IMAGE, imageName);
         }
         final List<?> containers;
         try(final DockerClient client = dockerApi.getClient()) {

src/main/java/com/nirima/jenkins/plugins/docker/DockerContainerLabelKeys.java

@@ -0,0 +1,64 @@
+package com.nirima.jenkins.plugins.docker;
+
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
+
+import hudson.model.Node;
+import jenkins.model.Jenkins;
+
+/**
+ * This constant interface defines the identifiers of label keys used at containers, which
+ * are generated using this plugin.
+ * 
+ * @author eaglerainbow
+ *
+ */
+public final class DockerContainerLabelKeys {
+
+    /**
+     * As requested by https://docs.docker.com/config/labels-custom-metadata/, keys of labels used
+     * in docker shall be prefixed by a namespace using the reverse DNS notation.
+     * All label keys of this plugin shall use this namespace as a prefix. 
+     * 
+     * Label keys defined in this interface already have this namespace prefixed.
+     */
+    private static final String PLUGIN_LABEL_KEY_NAMESPACE = DockerContainerLabelKeys.class.getPackage().getName()+".";
+
+    /**
+     * Name of the Docker "label" that we'll put into every container we start,
+     * setting its value to our {@link DockerTemplateBase#getJenkinsInstanceIdForContainerLabel()}, so that we
+     * can recognize our own containers later.
+     */
+    static final String JENKINS_INSTANCE_ID = PLUGIN_LABEL_KEY_NAMESPACE + "JenkinsId";
+
+    /**
+     * Name of the Docker "label" that we'll put into every container we start,
+     * setting its value to our {@link Jenkins#getRootUrl()}, so that we
+     * can recognize our own containers later.
+     */
+    static final String JENKINS_URL = PLUGIN_LABEL_KEY_NAMESPACE + "JenkinsServerUrl";
+
+    /**
+     * Name of the Docker "label" that we'll put into every container we start,
+     * setting its value to the value of {@link DockerTemplateBase#getImage()}, so that we
+     * can recognize our own containers later.
+     */
+    static final String CONTAINER_IMAGE = PLUGIN_LABEL_KEY_NAMESPACE + "JenkinsContainerImage";
+
+    /**
+     * Name of the Docker "label" that we'll put into every container we start,
+     * setting its value to our {@link Node#getNodeName()}, so that we
+     * can recognize our own containers later.
+     */
+    @Restricted(NoExternalUse.class) 
+    static final String NODE_NAME = PLUGIN_LABEL_KEY_NAMESPACE + "JenkinsNodeName";
+
+    /**
+     * Name of the Docker "label" that we'll put into every container we start,
+     * setting its value to the value of {@link DockerTemplate#getName()}, so that we
+     * can recognize our own containers later.
+     */
+    @Restricted(NoExternalUse.class) 
+    static final String TEMPLATE_NAME = PLUGIN_LABEL_KEY_NAMESPACE + "JenkinsTemplateName";
+
+}

src/main/java/com/nirima/jenkins/plugins/docker/DockerTemplate.java

@@ -59,22 +59,6 @@ public class DockerTemplate implements Describable<DockerTemplate> {
 
     private static final UniqueIdGenerator ID_GENERATOR = new UniqueIdGenerator(36);
 
-    /**
-     * Name of the Docker "label" that we'll put into every container we start,
-     * setting its value to our {@link #getName()}, so that we
-     * can recognize our own containers later.
-     */
-    @Restricted(NoExternalUse.class)
-    static String CONTAINER_LABEL_TEMPLATE_NAME = "JenkinsTemplateName";
-
-    /**
-     * Name of the Docker "label" that we'll put into every container we start,
-     * setting its value to our {@link Node#getNodeName()}, so that we
-     * can recognize our own containers later.
-     */
-    @Restricted(NoExternalUse.class)
-    static String CONTAINER_LABEL_NODE_NAME = "JenkinsNodeName";
-
     /** Default value for {@link #getName()} if {@link #name} is null. */
     private static final String DEFAULT_NAME = "docker";
 
@@ -239,14 +223,14 @@ public CreateContainerCmd fillContainerConfig(CreateContainerCmd containerConfig
         final CreateContainerCmd result = dockerTemplateBase.fillContainerConfig(containerConfig);
         final String templateName = getName();
         final String nodeName = calcUnusedNodeName(templateName);
-        result.getLabels().put(CONTAINER_LABEL_TEMPLATE_NAME, templateName);
+        result.getLabels().put(DockerContainerLabelKeys.TEMPLATE_NAME, templateName);
         setNodeNameInContainerConfig(result, nodeName);
         return result;
     }
 
     @Restricted(NoExternalUse.class) // public for tests only
     public static void setNodeNameInContainerConfig(CreateContainerCmd containerConfig, String nodeName) {
-        containerConfig.getLabels().put(CONTAINER_LABEL_NODE_NAME, nodeName);
+        containerConfig.getLabels().put(DockerContainerLabelKeys.NODE_NAME, nodeName);
     }
 
     /**
@@ -260,7 +244,7 @@ public static void setNodeNameInContainerConfig(CreateContainerCmd containerConf
      *         node for the container that will be created by this command.
      */
     public static String getNodeNameFromContainerConfig(CreateContainerCmd containerConfig) {
-        return containerConfig.getLabels().get(CONTAINER_LABEL_NODE_NAME);
+        return containerConfig.getLabels().get(DockerContainerLabelKeys.NODE_NAME);
     }
 
     // --

src/main/java/com/nirima/jenkins/plugins/docker/DockerTemplateBase.java

@@ -55,25 +55,6 @@
  */
 public class DockerTemplateBase implements Describable<DockerTemplateBase>, Serializable {
 
-    /**
-     * Name of the Docker "label" that we'll put into every container we start,
-     * setting its value to our {@link #getJenkinsInstanceIdForContainerLabel()}, so that we
-     * can recognize our own containers later.
-     */
-    static String CONTAINER_LABEL_JENKINS_INSTANCE_ID = "JenkinsId";
-    /**
-     * Name of the Docker "label" that we'll put into every container we start,
-     * setting its value to our {@link Jenkins#getRootUrl()}, so that we
-     * can recognize our own containers later.
-     */
-    static String CONTAINER_LABEL_JENKINS_URL = "JenkinsServerUrl";
-    /**
-     * Name of the Docker "label" that we'll put into every container we start,
-     * setting its value to our {@link #getImage()}, so that we
-     * can recognize our own containers later.
-     */
-    static String CONTAINER_LABEL_IMAGE = "JenkinsContainerImage";
-
     private final String image;
 
     private String pullCredentialsId;
@@ -499,9 +480,9 @@ public CreateContainerCmd fillContainerConfig(CreateContainerCmd containerConfig
         containerConfig.withPrivileged(privileged);
 
         Map<String,String> map = new HashMap<>();
-        map.put(CONTAINER_LABEL_JENKINS_INSTANCE_ID, getJenkinsInstanceIdForContainerLabel());
-        map.put(CONTAINER_LABEL_JENKINS_URL, getJenkinsUrlForContainerLabel());
-        map.put(CONTAINER_LABEL_IMAGE, getImage());
+        map.put(DockerContainerLabelKeys.JENKINS_INSTANCE_ID, getJenkinsInstanceIdForContainerLabel());
+        map.put(DockerContainerLabelKeys.JENKINS_URL, getJenkinsUrlForContainerLabel());
+        map.put(DockerContainerLabelKeys.CONTAINER_IMAGE, getImage());
 
         containerConfig.withLabels(map);
 
@@ -591,7 +572,7 @@ public CreateContainerCmd fillContainerConfig(CreateContainerCmd containerConfig
 
     /**
      * Calculates the value we use for the Docker label called
-     * {@link #CONTAINER_LABEL_JENKINS_URL} that we put into every
+     * {@link DockerContainerLabelKeys#JENKINS_URL} that we put into every
      * container we make, so that we can recognize our own containers later.
      */
     static String getJenkinsUrlForContainerLabel() {
@@ -602,7 +583,7 @@ static String getJenkinsUrlForContainerLabel() {
 
     /**
      * Calculates the value we use for the Docker label called
-     * {@link #CONTAINER_LABEL_JENKINS_INSTANCE_ID} that we put into every
+     * {@link DockerContainerLabelKeys#JENKINS_INSTANCE_ID} that we put into every
      * container we make, so that we can recognize our own containers later.
      */
     static String getJenkinsInstanceIdForContainerLabel() {