xds: add header matching special cases for hiding/exposing some gRPC …

…headers (v1.31.x backport) (#7224) (#7313) Expose "content-type" header (hard-coded) at header matching, pretend it's already there.
grpc · Aug 11, 2020 · 491c9e2 · 491c9e2
1 parent 9e58c52
commit 491c9e2
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Showing 2 changed files with 37 additions and 4 deletions.
diff --git a/xds/src/main/java/io/grpc/xds/RouteMatch.java b/xds/src/main/java/io/grpc/xds/RouteMatch.java
@@ -65,7 +65,16 @@ boolean matches(String path, Map<String, Iterable<String>> headers) {
       return false;
     }
     for (HeaderMatcher headerMatcher : headerMatchers) {
-      if (!headerMatcher.matchesValue(headers.get(headerMatcher.getName()))) {
+      Iterable<String> headerValues = headers.get(headerMatcher.getName());
+      // Special cases for hiding headers: "grpc-previous-rpc-attempts".
+      if (headerMatcher.getName().equals("grpc-previous-rpc-attempts")) {
+        headerValues = null;
+      }
+      // Special case for exposing headers: "content-type".
+      if (headerMatcher.getName().equals("content-type")) {
+        headerValues = Collections.singletonList("application/grpc");
+      }
+      if (!headerMatcher.matchesValue(headerValues)) {
         return false;
       }
     }

diff --git a/xds/src/test/java/io/grpc/xds/RouteMatchTest.java b/xds/src/test/java/io/grpc/xds/RouteMatchTest.java
@@ -40,7 +40,7 @@ public class RouteMatchTest {
 
   @Before
   public void setUp() {
-    headers.put("content-type", Collections.singletonList("application/grpc"));
+    headers.put("authority", Collections.singletonList("foo.googleapis.com"));
     headers.put("grpc-encoding", Collections.singletonList("gzip"));
     headers.put("user-agent", Collections.singletonList("gRPC-Java"));
     headers.put("content-length", Collections.singletonList("1000"));
@@ -79,7 +79,7 @@ public void routeMatching_withHeaders() {
             new HeaderMatcher(
                 "grpc-encoding", "gzip", null, null, null, null, null, false),
             new HeaderMatcher(
-                "content-type", null, Pattern.compile(".*grpc.*"), null, null, null,
+                "authority", null, Pattern.compile(".*googleapis.*"), null, null, null,
                 null, false),
             new HeaderMatcher(
                 "content-length", null, null, new Range(100, 10000), null, null, null, false),
@@ -93,7 +93,7 @@ public void routeMatching_withHeaders() {
         new PathMatcher("/FooService/barMethod", null, null),
         Collections.singletonList(
             new HeaderMatcher(
-                "content-type", null, Pattern.compile(".*grpc.*"), null, null, null,
+                "authority", null, Pattern.compile(".*googleapis.*"), null, null, null,
                 null, true)),
         null);
     assertThat(routeMatch2.matches("/FooService/barMethod", headers)).isFalse();
@@ -161,6 +161,30 @@ public void  routeMatching_withRuntimeFraction() {
     assertThat(routeMatch2.matches("/FooService/barMethod", headers)).isFalse();
   }
 
+  @Test
+  public void headerMatching_specialCaseGrpcHeaders() {
+    Map<String, Iterable<String>> headers = new HashMap<>();
+    headers.put("grpc-previous-rpc-attempts", Collections.singletonList("0"));
+
+    RouteMatch routeMatch1 =
+        new RouteMatch(new PathMatcher("/FooService/barMethod", null, null),
+            Arrays.asList(
+                new HeaderMatcher(
+                    "grpc-previous-rpc-attempts", "0", null, null, null, null,
+                    null, false)),
+            null);
+    assertThat(routeMatch1.matches("/FooService/barMethod", headers)).isFalse();
+
+    RouteMatch routeMatch2 =
+        new RouteMatch(new PathMatcher("/FooService/barMethod", null, null),
+            Arrays.asList(
+                new HeaderMatcher(
+                    "content-type", "application/grpc", null, null, null, null,
+                    null, false)),
+            null);
+    assertThat(routeMatch2.matches("/FooService/barMethod", headers)).isTrue();
+  }
+
   private static final class FakeRandom implements ThreadSafeRandom {
     private final int value;