Some tweaks to the contraints checking for releases.

headless-services/commons/commons-yaml/src/main/java/org/springframework/ide/vscode/commons/yaml/ast/NodeUtil.java

@@ -116,6 +116,18 @@ public class NodeUtil {
 		return null;
 	}
 
+	public static NodeTuple getPropertyTuple(Node node, String propName) {
+		if (node instanceof MappingNode) {
+			for (NodeTuple entry : ((MappingNode)node).getValue()) {
+				String key = NodeUtil.asScalar(entry.getKeyNode());
+				if (propName.equals(key)) {
+					return entry;
+				}
+			}
+		}
+		return null;
+	}
+
 	public static Node getProperty(Node node, String propName) {
 		if (node instanceof MappingNode) {
 			for (NodeTuple entry : ((MappingNode)node).getValue()) {

headless-services/commons/commons-yaml/src/main/java/org/springframework/ide/vscode/commons/yaml/schema/constraints/Constraints.java

@@ -49,17 +49,28 @@ public class Constraints {
 	public static Constraint requireAtMostOneOf(String... properties) {
 		return new RequireOneOf(properties).allowFewer(true);
 	}
+	
+	public static Constraint requireAtLeastOneOf(String... properties) {
+		return new RequireOneOf(properties).allowMultiple(true);
+	}
+
 
 	static private class RequireOneOf implements Constraint {
 
 		private final String[] _requiredProps;
 		private boolean allowFewer = false;
+		private boolean allowMultiple = false;
 
 		public RequireOneOf(String[] properties) {
 			Assert.isLegal(properties.length>1);
 			this._requiredProps = properties;
 		}
 
+		public Constraint allowMultiple(boolean b) {
+			this.allowMultiple = b;
+			return this;
+		}
+
 		public Constraint allowFewer(boolean b) {
 			this.allowFewer = b;
 			return this;
@@ -80,7 +91,7 @@ public class Constraints {
 						problems.accept(missingProperty(
 								"One of "+requiredProps+" is required for '"+type+"'", doc, parent, map));
 					}
-				} else if (foundPropsCount>1) {
+				} else if (foundPropsCount>1 && !allowMultiple) {
 					//Mark each of the found keys as a violation:
 					for (NodeTuple entry : map.getValue()) {
 						String key = NodeUtil.asScalar(entry.getKeyNode());
@@ -144,4 +155,5 @@ public class Constraints {
 			}
 		};	
 	}
+
 }