be strict about validation scheme validation

Signed-off-by: Gregor Zeitlinger <[email protected]>

Author: zeitlinger

prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/NamingProperties.java

@@ -1,25 +1,42 @@
 package io.prometheus.metrics.config;
 
 import java.util.Map;
+import javax.annotation.Nullable;
 
 public class NamingProperties {
 
   private static final String PREFIX = "io.prometheus.naming";
   private static final String VALIDATION_SCHEME = "validationScheme";
-  private final String validationScheme;
+  private final ValidationScheme validationScheme;
 
-  private NamingProperties(String validation) {
+  private NamingProperties(ValidationScheme validation) {
     this.validationScheme = validation;
   }
 
-  public String getValidationScheme() {
+  public ValidationScheme getValidationScheme() {
     return validationScheme;
   }
 
   static NamingProperties load(Map<Object, Object> properties)
       throws PrometheusPropertiesException {
     String validationScheme = Util.loadString(PREFIX + "." + VALIDATION_SCHEME, properties);
-    return new NamingProperties(validationScheme);
+    return new NamingProperties(parseValidationScheme(validationScheme));
+  }
+
+  static ValidationScheme parseValidationScheme(@Nullable String scheme) {
+    if (scheme == null || scheme.isEmpty()) {
+      return ValidationScheme.LEGACY_VALIDATION;
+    }
+
+    switch (scheme) {
+      case "utf-8":
+        return ValidationScheme.UTF_8_VALIDATION;
+      case "legacy":
+        return ValidationScheme.LEGACY_VALIDATION;
+      default:
+        throw new PrometheusPropertiesException(
+            "Unknown validation scheme: " + scheme + ". Valid values are: utf-8, legacy.");
+    }
   }
 
   public static Builder builder() {
@@ -28,11 +45,11 @@ public static Builder builder() {
 
   public static class Builder {
 
-    private String validationScheme;
+    private ValidationScheme validationScheme;
 
     private Builder() {}
 
-    public Builder validation(String validationScheme) {
+    public Builder validation(ValidationScheme validationScheme) {
       this.validationScheme = validationScheme;
       return this;
     }

prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/ValidationScheme.java

@@ -0,0 +1,16 @@
+package io.prometheus.metrics.config;
+
+/**
+ * ValidationScheme is an enum for determining how metric and label names will be validated by this
+ * library.
+ */
+public enum ValidationScheme {
+  /**
+   * LEGACY_VALIDATION is a setting that requires that metric and label names conform to the
+   * original character requirements.
+   */
+  LEGACY_VALIDATION,
+
+  /** UTF_8_VALIDATION only requires that metric and label names be valid UTF-8 strings. */
+  UTF_8_VALIDATION
+}

prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/NamingPropertiesTest.java

@@ -0,0 +1,29 @@
+package io.prometheus.metrics.config;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+
+import org.junit.jupiter.api.Test;
+
+class NamingPropertiesTest {
+  @Test
+  void testBuilder() {
+    NamingProperties properties =
+        NamingProperties.builder().validation(ValidationScheme.UTF_8_VALIDATION).build();
+    assertThat(properties.getValidationScheme()).isEqualTo(ValidationScheme.UTF_8_VALIDATION);
+  }
+
+  @Test
+  void parseValidationScheme() {
+    assertThat(NamingProperties.parseValidationScheme("utf-8"))
+        .isEqualTo(ValidationScheme.UTF_8_VALIDATION);
+    assertThat(NamingProperties.parseValidationScheme("legacy"))
+        .isEqualTo(ValidationScheme.LEGACY_VALIDATION);
+    assertThat(NamingProperties.parseValidationScheme(null))
+        .isEqualTo(ValidationScheme.LEGACY_VALIDATION);
+    assertThatCode(() -> NamingProperties.parseValidationScheme("unknown"))
+        .isInstanceOf(PrometheusPropertiesException.class)
+        .hasMessageContaining(
+            "Unknown validation scheme: unknown. Valid values are: utf-8, legacy.");
+  }
+}

prometheus-metrics-exposition-textformats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java

@@ -1,8 +1,8 @@
 package io.prometheus.metrics.expositionformats;
 
+import io.prometheus.metrics.config.ValidationScheme;
 import io.prometheus.metrics.model.snapshots.Labels;
 import io.prometheus.metrics.model.snapshots.PrometheusNaming;
-import io.prometheus.metrics.model.snapshots.ValidationScheme;
 import java.io.IOException;
 import java.io.Writer;
 

prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Labels.java

@@ -3,6 +3,7 @@
 import static io.prometheus.metrics.model.snapshots.PrometheusNaming.isValidLabelName;
 import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
 
+import io.prometheus.metrics.config.ValidationScheme;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;

prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricMetadata.java

@@ -1,5 +1,7 @@
 package io.prometheus.metrics.model.snapshots;
 
+import io.prometheus.metrics.config.ValidationScheme;
+
 /** Immutable container for metric metadata: name, help, unit. */
 public final class MetricMetadata {
 

prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java

@@ -6,6 +6,7 @@
 
 import io.prometheus.metrics.config.PrometheusProperties;
 import io.prometheus.metrics.config.PrometheusPropertiesLoader;
+import io.prometheus.metrics.config.ValidationScheme;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
@@ -28,7 +29,7 @@ public class PrometheusNaming {
    * is intended to be set by UTF-8-aware binaries as part of their startup via a properties file.
    */
   public static ValidationScheme nameValidationScheme =
-      initValidationScheme(PrometheusProperties.get());
+      PrometheusProperties.get().getNamingProperties().getValidationScheme();
 
   /** Default escaping scheme for names when not specified. */
   public static final EscapingScheme DEFAULT_ESCAPING_SCHEME =
@@ -77,17 +78,10 @@ public class PrometheusNaming {
     ".total", ".created", ".bucket", ".info"
   };
 
-  static ValidationScheme initValidationScheme(PrometheusProperties properties) {
-    if ("utf-8".equals(properties.getNamingProperties().getValidationScheme())) {
-      return ValidationScheme.UTF_8_VALIDATION;
-    }
-
-    return ValidationScheme.LEGACY_VALIDATION;
-  }
-
   // VisibleForTesting
   public static void resetForTest() {
-    nameValidationScheme = initValidationScheme(PrometheusPropertiesLoader.load());
+    nameValidationScheme =
+        PrometheusPropertiesLoader.load().getNamingProperties().getValidationScheme();
   }
 
   /**

prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/ValidationScheme.java

@@ -1,15 +1,5 @@
 package io.prometheus.metrics.model.snapshots;
 
-import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.CsvSource;
-import org.junit.jupiter.params.provider.MethodSource;
-import org.junitpioneer.jupiter.SetSystemProperty;
-
-import java.util.stream.Stream;
-
 import static io.prometheus.metrics.model.snapshots.PrometheusNaming.escapeMetricSnapshot;
 import static io.prometheus.metrics.model.snapshots.PrometheusNaming.escapeName;
 import static io.prometheus.metrics.model.snapshots.PrometheusNaming.isValidLabelName;
@@ -23,6 +13,15 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
+import java.util.stream.Stream;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.CsvSource;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.junitpioneer.jupiter.SetSystemProperty;
+
 class PrometheusNamingTest {
 
   @AfterEach