Add help text to dialog box that explains how to create an SSH key

Change-Id: I4ac2aed5eef46cc1477b08ea17ed06ca0c89b03c
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
diff --git a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/client/CreateServiceUserForm.java b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/client/CreateServiceUserForm.java
index 8125819..8f5f4a0 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/client/CreateServiceUserForm.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/client/CreateServiceUserForm.java
@@ -27,6 +27,8 @@
 import com.google.gwt.user.client.rpc.AsyncCallback;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.DialogBox;
+import com.google.gwt.user.client.ui.DisclosurePanel;
+import com.google.gwt.user.client.ui.HTML;
 import com.google.gwt.user.client.ui.HorizontalPanel;
 import com.google.gwt.user.client.ui.Label;
 import com.google.gwt.user.client.ui.Panel;
@@ -82,6 +84,27 @@
 
     Panel sshKeyPanel = new VerticalPanel();
     sshKeyPanel.add(new Label("Public SSH Key:"));
+    DisclosurePanel dp = new DisclosurePanel("How to generate an SSH Key");
+    StringBuilder b = new StringBuilder();
+    b.append("<ol>")
+        .append("<li>From the Terminal or Git Bash, run <em>ssh-keygen</em></li>")
+        .append("<li>")
+            .append("Enter a path for the key, e.g. <em>id_rsa</em>. If you are generating the key<br />")
+            .append("on your local system take care to not overwrite your own SSH key.")
+        .append("</li>")
+        .append("<li>")
+            .append("Enter a passphrase only if the service where you intend to use this<br />")
+            .append("service user is able to deal with passphrases, otherwise leave it blank.<br />")
+            .append("Remember this passphrase, as you will need it to unlock the key.")
+        .append("</li>")
+        .append("<li>")
+            .append("Open <em>id_rsa.pub</em> and copy &amp; paste the contents into the box below.<br />")
+            .append("Note that <em>id_rsa.pub</em> is your public key and can be shared,<br />")
+            .append("while <em>id_rsa</em> is your private key and should be kept secret.")
+        .append("</li>")
+     .append("</ol>");
+    dp.add(new HTML(b.toString()));
+    sshKeyPanel.add(dp);
     sshKeyTxt = new TextArea();
     sshKeyTxt.addKeyPressHandler(new KeyPressHandler() {
       @Override