Make Slave 🠦 Jenkins conn. timeout configurable

For certain slaves, there might be a need to perform some runtime
configuration/steps after getting scheduled, but before starting the
jenkins job. The default timeout of 100s might not be sufficient for
such a scenario. To cater to this use case, this patch introduces the
ability to configure the slave to jenkins connection timeout, defaulting
to 100s for backwards compatibility.

src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesCloud.java

@@ -697,6 +697,8 @@ public Node call() throws Exception {
                     throw new IllegalStateException("Container is not running after " + j + " attempts, status: " + status);
                 }
 
+                j = t.getSlaveConnectTimeout();
+
                 // now wait for slave to be online
                 for (; i < j; i++) {
                     if (slave.getComputer() == null) {

src/main/java/org/csanchez/jenkins/plugins/kubernetes/PodTemplate.java

@@ -57,6 +57,8 @@ public class PodTemplate extends AbstractDescribableImpl<PodTemplate> implements
 
     private int instanceCap = Integer.MAX_VALUE;
 
+    private int slaveConnectTimeout = 100;
+
     private int idleMinutes;
 
     private String label;
@@ -202,6 +204,18 @@ public int getInstanceCap() {
         return instanceCap;
     }
 
+    public void setSlaveConnectTimeout(int slaveConnectTimeout) {
+        if (slaveConnectTimeout < 0) {
+            this.slaveConnectTimeout = 0;
+        } else {
+            this.slaveConnectTimeout = slaveConnectTimeout;
+        }
+    }
+
+    public int getSlaveConnectTimeout() {
+        return slaveConnectTimeout;
+    }
+
     @DataBoundSetter
     public void setInstanceCapStr(String instanceCapStr) {
         if (StringUtils.isBlank(instanceCapStr)) {
@@ -219,6 +233,19 @@ public String getInstanceCapStr() {
         }
     }
 
+    @DataBoundSetter
+    public void setSlaveConnectTimeoutStr(String slaveConnectTimeoutStr) {
+        if (StringUtils.isBlank(slaveConnectTimeoutStr)) {
+            setSlaveConnectTimeout(100); // default
+        } else {
+            setSlaveConnectTimeout(Integer.parseInt(slaveConnectTimeoutStr));
+        }
+    }
+
+    public String getSlaveConnectTimeoutStr() {
+        return String.valueOf(slaveConnectTimeout);
+    }
+
     public void setIdleMinutes(int i) {
         this.idleMinutes = i;
     }

src/main/resources/org/csanchez/jenkins/plugins/kubernetes/PodTemplate/config.jelly

@@ -40,6 +40,10 @@
     <f:textbox/>
   </f:entry>
 
+  <f:entry field="slaveConnectTimeoutStr" title="${%Timeout in seconds for slave 🡒 jenkins conn.}">
+    <f:textbox/>
+  </f:entry>
+
     <f:entry title="${%Annotations}" description="${%List of annotations to set in slave pod}" field="annotations">
       <f:repeatableHeteroProperty field="annotations" hasHeader="true" addCaption="Add Annotation"
                                   deleteCaption="Delete annotation Variable" />