From 9edc1f9bc437aa2c231c273337dbcf13e78110ac Mon Sep 17 00:00:00 2001
From: Martin Polden <mpolden@mpolden.no>
Date: Thu, 24 Aug 2023 13:48:47 +0200
Subject: Implement basic services.xml parser

---
 .../application/pkg/BasicServicesXml.java          | 92 ++++++++++++++++++++++
 .../application/pkg/BasicServicesXmlTest.java      | 54 +++++++++++++
 2 files changed, 146 insertions(+)
 create mode 100644 controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXml.java
 create mode 100644 controller-server/src/test/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXmlTest.java

diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXml.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXml.java
new file mode 100644
index 00000000000..9eb10857526
--- /dev/null
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXml.java
@@ -0,0 +1,92 @@
+package com.yahoo.vespa.hosted.controller.application.pkg;
+
+import com.yahoo.text.XML;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+/**
+ * A partially parsed variant of services.xml, for use by the {@link com.yahoo.vespa.hosted.controller.Controller}.
+ *
+ * @author mpolden
+ */
+public record BasicServicesXml(List<Container> containers) {
+
+    public static final BasicServicesXml empty = new BasicServicesXml(List.of());
+
+    private static final String SERVICES_TAG = "services";
+    private static final String CONTAINER_TAG = "container";
+    private static final String CLIENTS_TAG = "clients";
+    private static final String CLIENT_TAG = "client";
+    private static final String TOKEN_TAG = "token";
+
+    public BasicServicesXml(List<Container> containers) {
+        this.containers = List.copyOf(Objects.requireNonNull(containers));
+    }
+
+    /** Parse a services.xml from given document */
+    public static BasicServicesXml parse(Document document) {
+        Element root = document.getDocumentElement();
+        if (!root.getTagName().equals("services")) {
+            throw new IllegalArgumentException("Root tag must be <" + SERVICES_TAG + ">");
+        }
+        List<BasicServicesXml.Container> containers = new ArrayList<>();
+        for (var childNode : XML.getChildren(root)) {
+            if (childNode.getTagName().equals(CONTAINER_TAG)) {
+                String id = childNode.getAttribute("id");
+                if (id.isEmpty()) throw new IllegalArgumentException(CONTAINER_TAG + " tag requires 'id' attribute");
+                List<Container.AuthMethod> methods = parseAuthMethods(childNode);
+                containers.add(new Container(id, methods));
+            }
+        }
+        return new BasicServicesXml(containers);
+    }
+
+    private static List<BasicServicesXml.Container.AuthMethod> parseAuthMethods(Element containerNode) {
+        List<BasicServicesXml.Container.AuthMethod> methods = new ArrayList<>();
+        for (var node : XML.getChildren(containerNode)) {
+            if (node.getTagName().equals(CLIENTS_TAG)) {
+                for (var clientNode : XML.getChildren(node)) {
+                    if (clientNode.getTagName().equals(CLIENT_TAG)) {
+                        boolean tokenEnabled = XML.getChildren(clientNode).stream()
+                                                  .anyMatch(n -> n.getTagName().equals(TOKEN_TAG));
+                        methods.add(tokenEnabled ? Container.AuthMethod.token : Container.AuthMethod.mtls);
+                    }
+                }
+            }
+        }
+        if (methods.isEmpty()) {
+            methods.add(Container.AuthMethod.mtls);
+        }
+        return methods;
+    }
+
+    /**
+     * A Vespa container service.
+     *
+     * @param id          ID of container
+     * @param authMethods Authentication methods supported by this container
+     */
+    public record Container(String id, List<AuthMethod> authMethods) {
+
+        public Container(String id, List<AuthMethod> authMethods) {
+            this.id = Objects.requireNonNull(id);
+            this.authMethods = Objects.requireNonNull(authMethods).stream()
+                                      .distinct()
+                                      .sorted()
+                                      .collect(Collectors.toList());
+            if (authMethods.isEmpty()) throw new IllegalArgumentException("Container must have at least one auth method");
+        }
+
+        public enum AuthMethod {
+            mtls,
+            token,
+        }
+
+    }
+
+}
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXmlTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXmlTest.java
new file mode 100644
index 00000000000..7d377ef6361
--- /dev/null
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/application/pkg/BasicServicesXmlTest.java
@@ -0,0 +1,54 @@
+package com.yahoo.vespa.hosted.controller.application.pkg;
+
+import com.yahoo.text.XML;
+import com.yahoo.vespa.hosted.controller.application.pkg.BasicServicesXml.Container;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * @author mpolden
+ */
+class BasicServicesXmlTest {
+
+    @Test
+    public void parse() {
+        assertServices(new BasicServicesXml(List.of()), "<services/>");
+        assertServices(new BasicServicesXml(List.of(new Container("foo", List.of(Container.AuthMethod.mtls)),
+                                                    new Container("bar", List.of(Container.AuthMethod.mtls)))),
+                       """
+                               <services>
+                                 <container id="foo"/>
+                                 <container id="bar"/>
+                               </services>
+                               """);
+        assertServices(new BasicServicesXml(List.of(
+                               new Container("foo",
+                                             List.of(Container.AuthMethod.mtls,
+                                                     Container.AuthMethod.token)),
+                               new Container("bar", List.of(Container.AuthMethod.mtls)))),
+                       """
+                               <services>
+                                 <container id="foo">
+                                   <clients>
+                                     <client id="mtls"/>
+                                     <client id="token">
+                                       <token id="my-token"/>
+                                     </client>
+                                     <client id="token2">
+                                       <token id="other-token"/>
+                                     </client>
+                                   </clients>
+                                 </container>
+                                 <container id="bar"/>
+                               </services>
+                               """);
+    }
+
+    private void assertServices(BasicServicesXml expected, String xmlForm) {
+        assertEquals(expected, BasicServicesXml.parse(XML.getDocument(xmlForm)));
+    }
+
+}
-- 
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