Add prometheus.case-insensitive-name-matching option

docs/src/main/sphinx/connector/prometheus.rst

@@ -58,6 +58,7 @@ Property name                                 Description
 ``prometheus.auth.password``                  Password for basic authentication
 ``prometheus.bearer.token.file``              File holding bearer token if needed for access to Prometheus
 ``prometheus.read-timeout``                   How much time a query to Prometheus has before timing out
+``prometheus.case-insensitive-name-matching`` Match Prometheus metric names case insensitively. Defaults to ``false``
 ============================================= ============================================================================================
 
 Not exhausting your Trino available heap

plugin/trino-prometheus/pom.xml

@@ -67,6 +67,11 @@
             <artifactId>jackson-datatype-jsr310</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>com.google.code.findbugs</groupId>
+            <artifactId>jsr305</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>

plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusClient.java

@@ -29,6 +29,7 @@
 import okhttp3.Request;
 import okhttp3.Response;
 
+import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import java.io.File;
@@ -41,6 +42,7 @@
 import java.util.Set;
 import java.util.function.Supplier;
 
+import static com.google.common.base.Verify.verify;
 import static com.google.common.net.HttpHeaders.AUTHORIZATION;
 import static io.trino.plugin.prometheus.PrometheusErrorCode.PROMETHEUS_TABLES_METRICS_RETRIEVE_ERROR;
 import static io.trino.plugin.prometheus.PrometheusErrorCode.PROMETHEUS_UNKNOWN_ERROR;
@@ -50,6 +52,7 @@
 import static io.trino.spi.type.VarcharType.VARCHAR;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.nio.file.Files.readString;
+import static java.util.Locale.ENGLISH;
 import static java.util.Objects.requireNonNull;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 
@@ -61,6 +64,7 @@ public class PrometheusClient
     private final OkHttpClient httpClient;
     private final Supplier<Map<String, Object>> tableSupplier;
     private final Type varcharMapType;
+    private final boolean caseInsensitiveNameMatching;
 
     @Inject
     public PrometheusClient(PrometheusConnectorConfig config, JsonCodec<Map<String, Object>> metricCodec, TypeManager typeManager)
@@ -80,6 +84,7 @@ public PrometheusClient(PrometheusConnectorConfig config, JsonCodec<Map<String,
                 config.getCacheDuration().toMillis(),
                 MILLISECONDS);
         varcharMapType = typeManager.getType(mapType(VARCHAR.getTypeSignature(), VARCHAR.getTypeSignature()));
+        this.caseInsensitiveNameMatching = config.isCaseInsensitiveNameMatching();
     }
 
     private static URI getPrometheusMetricsURI(URI prometheusUri)
@@ -106,6 +111,7 @@ public Set<String> getTableNames(String schema)
         throw new TrinoException(PROMETHEUS_TABLES_METRICS_RETRIEVE_ERROR, "Prometheus did no return metrics list (table names): " + status);
     }
 
+    @Nullable
     public PrometheusTable getTable(String schema, String tableName)
     {
         requireNonNull(schema, "schema is null");
@@ -114,21 +120,43 @@ public PrometheusTable getTable(String schema, String tableName)
             return null;
         }
 
-        List<String> tableNames = (List<String>) tableSupplier.get().get("data");
-        if (tableNames == null) {
-            return null;
-        }
-        if (!tableNames.contains(tableName)) {
+        String remoteTableName = toRemoteTableName(tableName);
+        if (remoteTableName == null) {
             return null;
         }
         return new PrometheusTable(
-                tableName,
+                remoteTableName,
                 ImmutableList.of(
                         new PrometheusColumn("labels", varcharMapType),
                         new PrometheusColumn("timestamp", TIMESTAMP_COLUMN_TYPE),
                         new PrometheusColumn("value", DoubleType.DOUBLE)));
     }
 
+    @Nullable
+    private String toRemoteTableName(String tableName)
+    {
+        verify(tableName.equals(tableName.toLowerCase(ENGLISH)), "tableName not in lower-case: %s", tableName);
+        List<String> tableNames = (List<String>) tableSupplier.get().get("data");
+        if (tableNames == null) {
+            return null;
+        }
+
+        if (!caseInsensitiveNameMatching) {
+            if (tableNames.contains(tableName)) {
+                return tableName;
+            }
+        }
+        else {
+            for (String remoteTableName : tableNames) {
+                if (tableName.equals(remoteTableName.toLowerCase(ENGLISH))) {
+                    return remoteTableName;
+                }
+            }
+        }
+
+        return null;
+    }
+
     private Map<String, Object> fetchMetrics(JsonCodec<Map<String, Object>> metricsCodec, URI metadataUri)
     {
         return metricsCodec.fromJson(fetchUri(metadataUri));

plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusConnectorConfig.java

@@ -40,6 +40,7 @@ public class PrometheusConnectorConfig
     private File bearerTokenFile;
     private String user;
     private String password;
+    private boolean caseInsensitiveNameMatching;
 
     @NotNull
     public URI getPrometheusURI()
@@ -151,6 +152,19 @@ public PrometheusConnectorConfig setReadTimeout(Duration readTimeout)
         return this;
     }
 
+    public boolean isCaseInsensitiveNameMatching()
+    {
+        return caseInsensitiveNameMatching;
+    }
+
+    @Config("prometheus.case-insensitive-name-matching")
+    @ConfigDescription("Where to match the prometheus metric name case insensitively ")
+    public PrometheusConnectorConfig setCaseInsensitiveNameMatching(boolean caseInsensitiveNameMatching)
+    {
+        this.caseInsensitiveNameMatching = caseInsensitiveNameMatching;
+        return this;
+    }
+
     @PostConstruct
     public void checkConfig()
     {

plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusCaseInsensitiveNameMatching.java

@@ -0,0 +1,96 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.trino.plugin.prometheus;
+
+import io.trino.spi.connector.SchemaTableName;
+import org.testng.annotations.AfterClass;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+import static io.trino.plugin.prometheus.MetadataUtil.METRIC_CODEC;
+import static io.trino.type.InternalTypeManager.TESTING_TYPE_MANAGER;
+import static java.util.Locale.ENGLISH;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertNotNull;
+import static org.testng.Assert.assertNull;
+import static org.testng.Assert.assertTrue;
+
+public class TestPrometheusCaseInsensitiveNameMatching
+{
+    private PrometheusHttpServer prometheusHttpServer;
+    private static final String DEFAULT_SCHEMA = "default";
+    private static final String UPPER_CASE_METRIC = "UpperCase-Metric";
+
+    @BeforeClass
+    public void setUp()
+    {
+        prometheusHttpServer = new PrometheusHttpServer();
+    }
+
+    @AfterClass(alwaysRun = true)
+    public void tearDown()
+    {
+        if (prometheusHttpServer != null) {
+            prometheusHttpServer.stop();
+        }
+    }
+
+    @Test
+    public void testCaseInsensitiveNameMatchingFalse()
+    {
+        PrometheusConnectorConfig config = new PrometheusConnectorConfig();
+        config.setPrometheusURI(prometheusHttpServer.resolve("/prometheus-data/uppercase-metrics.json"));
+
+        PrometheusClient client = new PrometheusClient(config, METRIC_CODEC, TESTING_TYPE_MANAGER);
+
+        Set<String> tableNames = client.getTableNames(DEFAULT_SCHEMA);
+        assertThat(tableNames).hasSize(1);
+        assertTrue(tableNames.contains(UPPER_CASE_METRIC));
+
+        PrometheusMetadata metadata = new PrometheusMetadata(client);
+        List<SchemaTableName> tables = metadata.listTables(null, Optional.of(DEFAULT_SCHEMA));
+        assertThat(tableNames).hasSize(1);
+        assertEquals(UPPER_CASE_METRIC.toLowerCase(ENGLISH), tables.get(0).getTableName());
+
+        assertNull(client.getTable(DEFAULT_SCHEMA, tables.get(0).getTableName()));
+    }
+
+    @Test
+    public void testCaseInsensitiveNameMatchingTrue()
+    {
+        PrometheusConnectorConfig config = new PrometheusConnectorConfig();
+        config.setPrometheusURI(prometheusHttpServer.resolve("/prometheus-data/uppercase-metrics.json"));
+        config.setCaseInsensitiveNameMatching(true);
+
+        PrometheusClient client = new PrometheusClient(config, METRIC_CODEC, TESTING_TYPE_MANAGER);
+
+        Set<String> tableNames = client.getTableNames(DEFAULT_SCHEMA);
+        assertThat(tableNames).hasSize(1);
+        assertTrue(tableNames.contains(UPPER_CASE_METRIC));
+
+        PrometheusMetadata metadata = new PrometheusMetadata(client);
+        List<SchemaTableName> tables = metadata.listTables(null, Optional.of(DEFAULT_SCHEMA));
+        assertThat(tableNames).hasSize(1);
+        SchemaTableName table = tables.get(0);
+        assertEquals(UPPER_CASE_METRIC.toLowerCase(ENGLISH), table.getTableName());
+
+        assertNotNull(client.getTable(DEFAULT_SCHEMA, tables.get(0).getTableName()));
+        assertEquals(UPPER_CASE_METRIC, client.getTable(DEFAULT_SCHEMA, tables.get(0).getTableName()).getName());
+    }
+}

plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusConnectorConfig.java

@@ -44,7 +44,8 @@ public void testDefaults()
                 .setBearerTokenFile(null)
                 .setUser(null)
                 .setPassword(null)
-                .setReadTimeout(new Duration(10, SECONDS)));
+                .setReadTimeout(new Duration(10, SECONDS))
+                .setCaseInsensitiveNameMatching(false));
     }
 
     @Test
@@ -59,6 +60,7 @@ public void testExplicitPropertyMappings()
                 .put("prometheus.auth.user", "admin")
                 .put("prometheus.auth.password", "password")
                 .put("prometheus.read-timeout", "30s")
+                .put("prometheus.case-insensitive-name-matching", "true")
                 .buildOrThrow();
 
         URI uri = URI.create("file://test.json");
@@ -71,6 +73,7 @@ public void testExplicitPropertyMappings()
         expected.setUser("admin");
         expected.setPassword("password");
         expected.setReadTimeout(new Duration(30, SECONDS));
+        expected.setCaseInsensitiveNameMatching(true);
 
         assertFullMapping(properties, expected);
     }

plugin/trino-prometheus/src/test/resources/prometheus-data/uppercase-metrics.json

@@ -0,0 +1,6 @@
+{
+    "status": "success",
+    "data": [
+        "UpperCase-Metric"
+    ]
+}