fix sp.
add note on existence anchor
@@ -42,7 +42,7 @@ Anchors allow conditional processing (i.e. "if-then-else) and other logical chec
|------------- |----- |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Conditional | () | If tag with the given value (including child elements) is specified, then peer elements will be processed. <br/>e.g. If image has tag latest then imagePullPolicy cannot be IfNotPresent. <br/>&nbsp;&nbsp;&nbsp;&nbsp;(image): "*:latest" <br>&nbsp;&nbsp;&nbsp;&nbsp;imagePullPolicy: "!IfNotPresent"<br/> |
| Equality | =() | If tag is specified, then processing continues. For tags with scalar values, the value must match. For tags with child elements, the child element is further evaluated as a validation pattern. <br/>e.g. If hostPath is defined then the path cannot be /var/lib<br/>&nbsp;&nbsp;&nbsp;&nbsp;=(hostPath):<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;path: "!/var/lib"<br/> |
-| Existence | ^() | Works on the list/array type only. If at least one element in the satisfies the pattern. <br/>e.g. At least one container with image nginx:latest must exist. <br/>&nbsp;&nbsp;&nbsp;&nbsp;^(containers):<br/>&nbsp;&nbsp;&nbsp;&nbsp;- image: nginx:latest<br/> |
+| Existence | ^() | Works on the list/array type only. If at least one element in the list satisfies the pattern. In contrast, a conditional anchor would validate that all elements in the list match the pattern. <br/>e.g. At least one container with image nginx:latest must exist. <br/>&nbsp;&nbsp;&nbsp;&nbsp;^(containers):<br/>&nbsp;&nbsp;&nbsp;&nbsp;- image: nginx:latest<br/> |
| Negation | X() | The tag cannot be specified. The value of the tag is not evaulated. <br/>e.g. Hostpath tag cannot be defined.<br/>&nbsp;&nbsp;&nbsp;&nbsp;X(hostPath):<br/> |
## Anchors and child elements
@@ -113,9 +113,9 @@ spec :
````
-### Check if one exist
+### Existence anchor: at least one
-A variation of an anchor, is to check existance of one element. This is done by using the ^(...) notation for the field.
+A variation of an anchor, is to check that in a list of elements at least one element exists that matches the patterm. This is done by using the ^(...) notation for the field.
For example, this pattern will check that at least one container has memory requests and limits defined and that the request is less than the limit:
