OpenTelemetry: fix the Redis instrumenter in case of a tainted connec…

…tion

The Vert.x Redis client does not always report the database instance number,
because sometimes, it simply isn't known. Specifically, that occurs when
the connection is tainted; for example, when a custom database is selected
using the `SELECT` command.

In this case, the trace simply will not include the dabatase instance number.

extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/tracing/intrumentation/vertx/RedisClientInstrumenterVertxTracer.java

@@ -124,8 +124,9 @@ public String peerAddress() {
             return attributes.get(PEER_ADDRESS);
         }
 
-        public long dbIndex() {
-            return Long.parseLong(attributes.get(DB_INSTANCE));
+        public Long dbIndex() {
+            String dbInstance = attributes.get(DB_INSTANCE);
+            return dbInstance != null ? Long.valueOf(dbInstance) : null;
         }
     }
 

integration-tests/opentelemetry-redis-instrumentation/src/main/java/io/quarkus/io/opentelemetry/RedisResource.java

@@ -68,4 +68,14 @@ public Uni<Void> getReactiveInvalidOperation() {
                 .replaceWithVoid();
     }
 
+    // tainted
+    @GET
+    @Path("/tainted")
+    public String getTainted() {
+        ds.withConnection(conn -> {
+            conn.select(7); // taints the connection
+            conn.value(String.class).get("foobar");
+        });
+        return "OK";
+    }
 }

integration-tests/opentelemetry-redis-instrumentation/src/test/java/io/quarkus/it/opentelemetry/QuarkusOpenTelemetryRedisTest.java

@@ -13,6 +13,8 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.time.Duration;
 import java.util.List;
@@ -195,6 +197,24 @@ public void reactiveInvalidOperation() {
         checkForException(exception);
     }
 
+    @Test
+    public void taintedConnection() {
+        RestAssured.get("redis/tainted")
+                .then()
+                .statusCode(200)
+                .body(CoreMatchers.is("OK"));
+
+        Awaitility.await().atMost(Duration.ofSeconds(10)).until(() -> getSpans().size() == 3);
+
+        Map<String, Object> span = findSpan(getSpans(), m -> SpanKind.CLIENT.name().equals(m.get("kind"))
+                && "get".equals(m.get("name")));
+        Map<String, Object> attributes = (Map<String, Object>) span.get("attributes");
+
+        assertEquals("redis", attributes.get("db.system"));
+        assertEquals("get", attributes.get("db.operation"));
+        assertFalse(span.containsKey("db.redis.database_index"));
+    }
+
     private List<Map<String, Object>> getSpans() {
         return get("/opentelemetry/export").body().as(new TypeRef<>() {
         });