[JENKINS-25106] Support minimumNoInstances

pom.xml

@@ -244,6 +244,7 @@ THE SOFTWARE.
                 <artifactId>aws-java-sdk-bom</artifactId>
                 <version>${aws-java-sdk.version}</version>
                 <type>pom</type>
+                <scope>import</scope>
             </dependency>
         </dependencies>
     </dependencyManagement>

src/main/java/hudson/plugins/ec2/AmazonEC2Cloud.java

@@ -186,7 +186,7 @@ public ListBoxModel doFillRegionItems(
             return model;
         }
 
-        // Will use the alternate EC2 endpoint if provided by the UI (via a @QueryParamter field), or use the default
+        // Will use the alternate EC2 endpoint if provided by the UI (via a @QueryParameter field), or use the default
         // value if not specified.
         @VisibleForTesting
         URL determineEC2EndpointURL(@Nullable String altEC2Endpoint) throws MalformedURLException {

src/main/java/hudson/plugins/ec2/EC2Cloud.java

@@ -639,6 +639,47 @@ else if (jenkinsInstance.isTerminating()) {
         }
     }
 
+    public void provision(SlaveTemplate t, int number) {
+
+        Jenkins jenkinsInstance = Jenkins.get();
+        if (jenkinsInstance.isQuietingDown()) {
+            LOGGER.log(Level.FINE, "Not provisioning nodes, Jenkins instance is quieting down");
+            return;
+        } else if (jenkinsInstance.isTerminating()) {
+            LOGGER.log(Level.FINE, "Not provisioning nodes, Jenkins instance is terminating");
+            return;
+        }
+
+        try {
+            LOGGER.log(Level.INFO, "{0}. Attempting to provision {1} slave(s)", new Object[]{t, number});
+            final List<EC2AbstractSlave> slaves = getNewOrExistingAvailableSlave(t, number, false);
+
+            if (slaves == null || slaves.isEmpty()) {
+                LOGGER.warning("Can't raise nodes for " + t);
+                return;
+            }
+
+            for (final EC2AbstractSlave slave : slaves) {
+                if (slave == null) {
+                    LOGGER.warning("Can't raise node for " + t);
+                    continue;
+                }
+
+                Computer c = slave.toComputer();
+                if (slave.getStopOnTerminate() && c != null) {
+                    c.connect(false);
+                }
+                jenkinsInstance.addNode(slave);
+            }
+
+            LOGGER.log(Level.INFO, "{0}. Attempting provision finished", t);
+            LOGGER.log(Level.INFO, "We have now {0} computers, waiting for {1} more",
+              new Object[]{Jenkins.get().getComputers().length, number});
+        } catch (AmazonClientException | IOException e) {
+            LOGGER.log(Level.WARNING, t + ". Exception during provisioning", e);
+        }
+    }
+
     private PlannedNode createPlannedNode(final SlaveTemplate t, final EC2AbstractSlave slave) {
         return new PlannedNode(t.getDisplayName(),
                 Computer.threadPoolForRemoting.submit(new Callable<Node>() {

src/main/java/hudson/plugins/ec2/EC2OndemandSlave.java

@@ -28,7 +28,7 @@
  *
  * @author Kohsuke Kawaguchi
  */
-public final class EC2OndemandSlave extends EC2AbstractSlave {
+public class EC2OndemandSlave extends EC2AbstractSlave {
     private static final Logger LOGGER = Logger.getLogger(EC2OndemandSlave.class.getName());
 
     @Deprecated

src/main/java/hudson/plugins/ec2/EC2RetentionStrategy.java

@@ -31,11 +31,10 @@
 import hudson.model.Executor;
 import hudson.model.ExecutorListener;
 import hudson.model.Queue;
+import hudson.plugins.ec2.util.MinimumInstanceChecker;
 import hudson.slaves.RetentionStrategy;
 import jenkins.model.Jenkins;
 
-import java.io.IOException;
-import java.lang.reflect.Field;
 import java.time.Clock;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;
@@ -129,6 +128,16 @@ private long internalCheck(EC2Computer computer) {
             return 1;
         }
 
+        /*
+        * If we have equal or less number of slaves than the template's minimum instance count, don't perform check.
+        */
+        SlaveTemplate slaveTemplate = computer.getSlaveTemplate();
+        if (slaveTemplate != null) {
+            long numberOfCurrentInstancesForTemplate = MinimumInstanceChecker.countCurrentNumberOfSlaves(slaveTemplate);
+            if (numberOfCurrentInstancesForTemplate > 0 && numberOfCurrentInstancesForTemplate <= slaveTemplate.getMinimumNumberOfInstances()) {
+                return 1;
+            }
+        }
 
         if (computer.isIdle() && !DISABLED) {
             final long uptime;
@@ -148,7 +157,7 @@ private long internalCheck(EC2Computer computer) {
             // * Already Terminated
             // * We use stop-on-terminate and the instance is currently stopped or stopping
             if (InstanceState.TERMINATED.equals(state)
-                  || computer.getSlaveTemplate().stopOnTerminate && (InstanceState.STOPPED.equals(state) || InstanceState.STOPPING.equals(state))) {
+                  || (slaveTemplate != null && slaveTemplate.stopOnTerminate) && (InstanceState.STOPPED.equals(state) || InstanceState.STOPPING.equals(state))) {
                 if (computer.isOnline()) {
                     LOGGER.info("External Stop of " + computer.getName() + " detected - disconnecting. instance status" + state.toString());
                     computer.disconnect(null);

src/main/java/hudson/plugins/ec2/EC2SlaveMonitor.java

@@ -10,6 +10,7 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import hudson.plugins.ec2.util.MinimumInstanceChecker;
 import jenkins.model.Jenkins;
 
 import com.amazonaws.AmazonClientException;
@@ -36,6 +37,11 @@ public long getRecurrencePeriod() {
 
     @Override
     protected void execute(TaskListener listener) throws IOException, InterruptedException {
+        removeDeadNodes();
+        MinimumInstanceChecker.checkForMinimumInstances();
+    }
+
+    private void removeDeadNodes() {
         for (Node node : Jenkins.get().getNodes()) {
             if (node instanceof EC2AbstractSlave) {
                 final EC2AbstractSlave ec2Slave = (EC2AbstractSlave) node;

src/main/java/hudson/plugins/ec2/EC2SpotSlave.java

@@ -27,7 +27,7 @@
 
 import javax.annotation.CheckForNull;
 
-public final class EC2SpotSlave extends EC2AbstractSlave implements EC2Readiness {
+public class EC2SpotSlave extends EC2AbstractSlave implements EC2Readiness {
     private static final Logger LOGGER = Logger.getLogger(EC2SpotSlave.class.getName());
 
     private final String spotInstanceRequestId;

src/main/java/hudson/plugins/ec2/PluginImpl.java

@@ -23,6 +23,7 @@
  */
 package hudson.plugins.ec2;
 
+import hudson.plugins.ec2.util.MinimumInstanceChecker;
 import jenkins.model.Jenkins;
 import hudson.Extension;
 import hudson.Plugin;
@@ -60,4 +61,9 @@ public String getDisplayName() {
             return "EC2 PluginImpl";
         }
     }
+
+    @Override
+    public void postInitialize() {
+        MinimumInstanceChecker.checkForMinimumInstances();
+    }
 }

src/main/java/hudson/plugins/ec2/SlaveTemplate.java

@@ -40,7 +40,10 @@
 
 import javax.servlet.ServletException;
 
-import hudson.plugins.ec2.util.AmazonEC2Factory;
+import hudson.plugins.ec2.util.*;
+
+import hudson.XmlFile;
+import hudson.model.listeners.SaveableListener;
 import hudson.util.Secret;
 import jenkins.model.Jenkins;
 import jenkins.model.JenkinsLocationConfiguration;
@@ -64,7 +67,6 @@
 import hudson.model.*;
 import hudson.model.Descriptor.FormException;
 import hudson.model.labels.LabelAtom;
-import hudson.plugins.ec2.util.DeviceMappingParser;
 import hudson.util.FormValidation;
 import hudson.util.ListBoxModel;
 
@@ -126,6 +128,8 @@ public class SlaveTemplate implements Describable<SlaveTemplate> {
 
     public int instanceCap;
 
+    public int minimumNumberOfInstances;
+
     public final boolean stopOnTerminate;
 
     private final List<EC2Tag> tags;
@@ -179,7 +183,7 @@ public class SlaveTemplate implements Describable<SlaveTemplate> {
     public SlaveTemplate(String ami, String zone, SpotConfiguration spotConfig, String securityGroups, String remoteFS,
             InstanceType type, boolean ebsOptimized, String labelString, Node.Mode mode, String description, String initScript,
             String tmpDir, String userData, String numExecutors, String remoteAdmin, AMITypeData amiType, String jvmopts,
-            boolean stopOnTerminate, String subnetId, List<EC2Tag> tags, String idleTerminationMinutes,
+            boolean stopOnTerminate, String subnetId, List<EC2Tag> tags, String idleTerminationMinutes, int minimumNumberOfInstances,
             String instanceCapStr, String iamInstanceProfile, boolean deleteRootOnTermination,
             boolean useEphemeralDevices, boolean useDedicatedTenancy, String launchTimeoutStr, boolean associatePublicIp,
             String customDeviceMapping, boolean connectBySSHProcess, boolean monitoring,
@@ -225,6 +229,8 @@ public SlaveTemplate(String ami, String zone, SpotConfiguration spotConfig, Stri
         this.usePrivateDnsName = this.connectionStrategy.equals(ConnectionStrategy.PRIVATE_DNS);
         this.connectUsingPublicIp = this.connectionStrategy.equals(ConnectionStrategy.PUBLIC_IP);
 
+        this.minimumNumberOfInstances = minimumNumberOfInstances;
+
         if (null == instanceCapStr || instanceCapStr.isEmpty()) {
             this.instanceCap = Integer.MAX_VALUE;
         } else {
@@ -246,6 +252,22 @@ public SlaveTemplate(String ami, String zone, SpotConfiguration spotConfig, Stri
         readResolve(); // initialize
     }
 
+    @Deprecated
+    public SlaveTemplate(String ami, String zone, SpotConfiguration spotConfig, String securityGroups, String remoteFS,
+                         InstanceType type, boolean ebsOptimized, String labelString, Node.Mode mode, String description, String initScript,
+                         String tmpDir, String userData, String numExecutors, String remoteAdmin, AMITypeData amiType, String jvmopts,
+                         boolean stopOnTerminate, String subnetId, List<EC2Tag> tags, String idleTerminationMinutes,
+                         String instanceCapStr, String iamInstanceProfile, boolean deleteRootOnTermination,
+                         boolean useEphemeralDevices, boolean useDedicatedTenancy, String launchTimeoutStr, boolean associatePublicIp,
+                         String customDeviceMapping, boolean connectBySSHProcess, boolean monitoring,
+                         boolean t2Unlimited, ConnectionStrategy connectionStrategy, int maxTotalUses) {
+        this(ami, zone, spotConfig, securityGroups, remoteFS, type, ebsOptimized, labelString, mode, description, initScript,
+          tmpDir, userData, numExecutors, remoteAdmin, amiType, jvmopts, stopOnTerminate, subnetId, tags,
+          idleTerminationMinutes, 0, instanceCapStr, iamInstanceProfile, deleteRootOnTermination, useEphemeralDevices,
+          useDedicatedTenancy, launchTimeoutStr, associatePublicIp, customDeviceMapping, connectBySSHProcess,
+          monitoring, t2Unlimited, connectionStrategy, maxTotalUses);
+    }
+
     @Deprecated
     public SlaveTemplate(String ami, String zone, SpotConfiguration spotConfig, String securityGroups, String remoteFS,
             InstanceType type, boolean ebsOptimized, String labelString, Node.Mode mode, String description, String initScript,
@@ -482,6 +504,10 @@ public void setAmiType(AMITypeData amiType) {
         this.amiType = amiType;
     }
 
+    public int getMinimumNumberOfInstances() {
+        return minimumNumberOfInstances;
+    }
+
     public int getInstanceCap() {
         return instanceCap;
     }
@@ -1107,16 +1133,57 @@ private HashSet<Tag> buildTags(String slaveType) {
     }
 
     protected EC2OndemandSlave newOndemandSlave(Instance inst) throws FormException, IOException {
-        return new EC2OndemandSlave(getSlaveName(inst.getInstanceId()), inst.getInstanceId(), description, remoteFS, getNumExecutors(), labels, mode, initScript,
-                tmpDir, Collections.emptyList(), remoteAdmin, jvmopts, stopOnTerminate, idleTerminationMinutes, inst.getPublicDnsName(),
-                inst.getPrivateDnsName(), EC2Tag.fromAmazonTags(inst.getTags()), parent.name,
-                useDedicatedTenancy, getLaunchTimeout(), amiType, connectionStrategy, maxTotalUses);
+        EC2SlaveConfig.OnDemand config = new EC2SlaveConfig.OnDemandBuilder()
+            .withName(getSlaveName(inst.getInstanceId()))
+            .withInstanceId(inst.getInstanceId())
+            .withDescription(description)
+            .withRemoteFS(remoteFS)
+            .withNumExecutors(getNumExecutors())
+            .withLabelString(labels)
+            .withMode(mode)
+            .withInitScript(initScript)
+            .withTmpDir(tmpDir)
+            .withNodeProperties(Collections.emptyList())
+            .withRemoteAdmin(remoteAdmin)
+            .withJvmopts(jvmopts)
+            .withStopOnTerminate(stopOnTerminate)
+            .withIdleTerminationMinutes(idleTerminationMinutes)
+            .withPublicDNS(inst.getPublicDnsName())
+            .withPrivateDNS(inst.getPrivateDnsName())
+            .withTags(EC2Tag.fromAmazonTags(inst.getTags()))
+            .withCloudName(parent.name)
+            .withUseDedicatedTenancy(useDedicatedTenancy)
+            .withLaunchTimeout(getLaunchTimeout())
+            .withAmiType(amiType)
+            .withConnectionStrategy(connectionStrategy)
+            .withMaxTotalUses(maxTotalUses)
+            .build();
+        return EC2SlaveFactory.getInstance().createOnDemandSlave(config);
     }
 
     protected EC2SpotSlave newSpotSlave(SpotInstanceRequest sir) throws FormException, IOException {
-        return new EC2SpotSlave(getSlaveName(sir.getSpotInstanceRequestId()), sir.getSpotInstanceRequestId(), description, remoteFS, getNumExecutors(), mode, initScript,
-                tmpDir, labels, Collections.emptyList(), remoteAdmin, jvmopts, idleTerminationMinutes, EC2Tag.fromAmazonTags(sir.getTags()), parent.name,
-                getLaunchTimeout(), amiType, connectionStrategy, maxTotalUses);
+        EC2SlaveConfig.Spot config = new EC2SlaveConfig.SpotBuilder()
+            .withName(getSlaveName(sir.getSpotInstanceRequestId()))
+            .withSpotInstanceRequestId(sir.getSpotInstanceRequestId())
+            .withDescription(description)
+            .withRemoteFS(remoteFS)
+            .withNumExecutors(getNumExecutors())
+            .withMode(mode)
+            .withInitScript(initScript)
+            .withTmpDir(tmpDir)
+            .withLabelString(labels)
+            .withNodeProperties(Collections.emptyList())
+            .withRemoteAdmin(remoteAdmin)
+            .withJvmopts(jvmopts)
+            .withIdleTerminationMinutes(idleTerminationMinutes)
+            .withTags(EC2Tag.fromAmazonTags(sir.getTags()))
+            .withCloudName(parent.name)
+            .withLaunchTimeout(getLaunchTimeout())
+            .withAmiType(amiType)
+            .withConnectionStrategy(connectionStrategy)
+            .withMaxTotalUses(maxTotalUses)
+            .build();
+        return EC2SlaveFactory.getInstance().createSpotSlave(config);
     }
 
     /**
@@ -1289,6 +1356,16 @@ public boolean isUseHTTPS() {
         return amiType.isWindows() && ((WindowsData) amiType).isUseHTTPS();
     }
 
+    @Extension
+    public static final class OnSaveListener extends SaveableListener {
+        @Override
+        public void onChange(Saveable o, XmlFile file) {
+            if (o instanceof Hudson) {
+                MinimumInstanceChecker.checkForMinimumInstances();
+            }
+        }
+    }
+
     @Extension
     public static final class DescriptorImpl extends Descriptor<SlaveTemplate> {
 
@@ -1425,6 +1502,30 @@ public FormValidation doCheckMaxTotalUses(@QueryParameter String value) {
             return FormValidation.error("Maximum Total Uses must be greater or equal to -1");
         }
 
+        public FormValidation doCheckMinimumNumberOfInstances(@QueryParameter String value, @QueryParameter String instanceCapStr) {
+            if (value == null || value.trim().isEmpty())
+                return FormValidation.ok();
+            try {
+                int val = Integer.parseInt(value);
+                if (val > 0) {
+                    int instanceCap;
+                    try {
+                        instanceCap = Integer.parseInt(instanceCapStr);
+                    } catch (NumberFormatException ignore) {
+                        instanceCap = Integer.MAX_VALUE;
+                    }
+                    if (val > instanceCap) {
+                        return FormValidation
+                          .error("Minimum number of instances must not be larger than AMI Instance Cap %d",
+                            instanceCap);
+                    }
+                    return FormValidation.ok();
+                }
+            } catch (NumberFormatException ignore) {
+            }
+            return FormValidation.error("Minimum number of instances must be a non-negative integer (or null)");
+        }
+
         public FormValidation doCheckInstanceCapStr(@QueryParameter String value) {
             if (value == null || value.trim().isEmpty())
                 return FormValidation.ok();