Demonstrating that API in JENKINS-44892 can be used as a replacement for the special methods in StepDescriptor.

Author: jglick

pom.xml

@@ -31,9 +31,10 @@
     <properties>
         <revision>1.19</revision>
         <changelist>-SNAPSHOT</changelist>
-        <jenkins.version>2.60.3</jenkins.version>
+        <jenkins.version>2.121.1</jenkins.version>
         <java.level>8</java.level>
-        <workflow-step-api-plugin.version>2.18</workflow-step-api-plugin.version>
+        <useBeta>true</useBeta>
+        <workflow-step-api-plugin.version>2.20-rc517.251dd3bdb066</workflow-step-api-plugin.version> <!-- TODO https://github.com/jenkinsci/workflow-step-api-plugin/pull/43 -->
         <workflow-support-plugin.version>2.12</workflow-support-plugin.version>
         <workflow-cps-plugin.version>2.25</workflow-cps-plugin.version>
     </properties>
@@ -130,4 +131,13 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.jenkins-ci.plugins</groupId>
+                <artifactId>structs</artifactId>
+                <version>1.18-rc266.794506c68411</version> <!-- TODO https://github.com/jenkinsci/structs-plugin/pull/43 -->
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
 </project>

src/main/java/org/jenkinsci/plugins/docker/workflow/RegistryEndpointStep.java

@@ -33,7 +33,6 @@
 import hudson.model.Run;
 import hudson.model.TaskListener;
 import java.io.IOException;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
@@ -43,6 +42,7 @@
 import org.jenkinsci.plugins.docker.commons.credentials.DockerRegistryEndpoint;
 import org.jenkinsci.plugins.docker.commons.credentials.KeyMaterialFactory;
 import org.jenkinsci.plugins.docker.commons.tools.DockerTool;
+import org.jenkinsci.plugins.structs.describable.CustomDescribableModel;
 import org.jenkinsci.plugins.structs.describable.UninstantiatedDescribable;
 import org.jenkinsci.plugins.workflow.steps.Step;
 import org.jenkinsci.plugins.workflow.steps.StepContext;
@@ -105,7 +105,7 @@ public static class Execution extends AbstractEndpointStepExecution {
 
     }
 
-    @Extension public static class DescriptorImpl extends StepDescriptor {
+    @Extension public static class DescriptorImpl extends StepDescriptor implements CustomDescribableModel {
 
         @Override public String getFunctionName() {
             return "withDockerRegistry";
@@ -123,17 +123,7 @@ public static class Execution extends AbstractEndpointStepExecution {
             return true;
         }
 
-        @Override public UninstantiatedDescribable uninstantiate(Step step) throws UnsupportedOperationException {
-            RegistryEndpointStep s = (RegistryEndpointStep) step;
-            Map<String, Object> args = new TreeMap<>();
-            args.put("url", s.registry.getUrl());
-            args.put("credentialsId", s.registry.getCredentialsId());
-            args.put("toolName", s.toolName);
-            args.values().removeAll(Collections.singleton(null));
-            return new UninstantiatedDescribable(args);
-        }
-
-        @Override public Step newInstance(Map<String, Object> arguments) throws Exception {
+        @Override public Map<String, Object> customInstantiate(Map<String, Object> arguments) {
             arguments = new HashMap<>(arguments);
             if (arguments.containsKey("url") || arguments.containsKey("credentialsId")) {
                 if (arguments.containsKey("registry")) {
@@ -143,9 +133,20 @@ public static class Execution extends AbstractEndpointStepExecution {
             } else if (!arguments.containsKey("registry")) {
                 throw new IllegalArgumentException("must specify url/credentialsId (or registry)");
             }
-            return super.newInstance(arguments);
+            return arguments;
         }
 
+        @Override public UninstantiatedDescribable customUninstantiate(UninstantiatedDescribable ud) {
+            Object registry = ud.getArguments().get("registry");
+            if (registry instanceof UninstantiatedDescribable) {
+                Map<String, Object> arguments = new TreeMap<>(ud.getArguments());
+                arguments.remove("registry");
+                arguments.putAll(((UninstantiatedDescribable) registry).getArguments());
+                return ud.withArguments(arguments);
+            }
+            return ud;
+        }
+        
         @SuppressWarnings("unchecked")
         @Override public Set<? extends Class<?>> getRequiredContext() {
             return ImmutableSet.of(TaskListener.class, EnvVars.class, Node.class, Run.class, FilePath.class, Launcher.class);

src/test/java/org/jenkinsci/plugins/docker/workflow/RegistryEndpointStepTest.java

@@ -72,13 +72,18 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
+import java.util.logging.Level;
+import org.jenkinsci.plugins.structs.describable.DescribableModel;
+import org.jvnet.hudson.test.LoggerRule;
 
 public class RegistryEndpointStepTest {
 
     @Rule public JenkinsRule r = new JenkinsRule();
+    @Rule public LoggerRule logging = new LoggerRule();
 
     @Issue("JENKINS-51395")
     @Test public void configRoundTrip() throws Exception {
+        logging.record(DescribableModel.class, Level.FINE);
         { // Recommended syntax.
             SnippetizerTester st = new SnippetizerTester(r);
             RegistryEndpointStep step = new RegistryEndpointStep(new DockerRegistryEndpoint("https://myreg/", null));