Introduce seqID field to ConfigSettings and have ConfigProvider set this in getString method

Author: mtoffl01

internal-api/src/main/java/datadog/trace/api/ConfigCollector.java

@@ -34,6 +34,14 @@ public void put(String key, Object value, ConfigOrigin origin) {
     originMap.put(origin, setting); // replaces any previous value for this origin
   }
 
+  // TODO: Replace old `put` with this `put`
+  public void put(String key, Object value, ConfigOrigin origin, int seqId) {
+    ConfigSetting setting = ConfigSetting.of(key, value, origin, seqId);
+    Map<ConfigOrigin, ConfigSetting> originMap =
+        collected.computeIfAbsent(key, k -> new ConcurrentHashMap<>());
+    originMap.put(origin, setting); // replaces any previous value for this origin
+  }
+
   public void putAll(Map<String, Object> keysAndValues, ConfigOrigin origin) {
     for (Map.Entry<String, Object> entry : keysAndValues.entrySet()) {
       put(entry.getKey(), entry.getValue(), origin);

internal-api/src/main/java/datadog/trace/api/ConfigSetting.java

@@ -11,19 +11,25 @@ public final class ConfigSetting {
   public final String key;
   public final Object value;
   public final ConfigOrigin origin;
+  public final int seqID;
 
   private static final Set<String> CONFIG_FILTER_LIST =
       new HashSet<>(
           Arrays.asList("DD_API_KEY", "dd.api-key", "dd.profiling.api-key", "dd.profiling.apikey"));
 
   public static ConfigSetting of(String key, Object value, ConfigOrigin origin) {
-    return new ConfigSetting(key, value, origin);
+    return new ConfigSetting(key, value, origin, 0);
   }
 
-  private ConfigSetting(String key, Object value, ConfigOrigin origin) {
+  public static ConfigSetting of(String key, Object value, ConfigOrigin origin, int seqID) {
+    return new ConfigSetting(key, value, origin, seqID);
+  }
+
+  private ConfigSetting(String key, Object value, ConfigOrigin origin, int seqID) {
     this.key = key;
     this.value = CONFIG_FILTER_LIST.contains(key) ? "<hidden>" : value;
     this.origin = origin;
+    this.seqID = seqID;
   }
 
   public String normalizedKey() {
@@ -99,7 +105,10 @@ public boolean equals(Object o) {
     if (this == o) return true;
     if (o == null || getClass() != o.getClass()) return false;
     ConfigSetting that = (ConfigSetting) o;
-    return key.equals(that.key) && Objects.equals(value, that.value) && origin == that.origin;
+    return key.equals(that.key)
+        && Objects.equals(value, that.value)
+        && origin == that.origin
+        && seqID == that.seqID;
   }
 
   @Override
@@ -117,6 +126,8 @@ public String toString() {
         + stringValue()
         + ", origin="
         + origin
+        + ", seq_id="
+        + seqID
         + '}';
   }
 }

internal-api/src/main/java/datadog/trace/bootstrap/config/provider/ConfigProvider.java

@@ -32,13 +32,16 @@ private static final class Singleton {
 
   private final ConfigProvider.Source[] sources;
 
+  private final int numSources;
+
   private ConfigProvider(ConfigProvider.Source... sources) {
     this(true, sources);
   }
 
   private ConfigProvider(boolean collectConfig, ConfigProvider.Source... sources) {
     this.collectConfig = collectConfig;
     this.sources = sources;
+    this.numSources = sources.length;
   }
 
   public String getConfigFileStatus() {
@@ -75,11 +78,18 @@ public <T extends Enum<T>> T getEnum(String key, Class<T> enumType, T defaultVal
 
   public String getString(String key, String defaultValue, String... aliases) {
     String foundValue = null;
+    int ctr = numSources + 1;
     for (ConfigProvider.Source source : sources) {
       String value = source.get(key, aliases);
       if (value != null) {
         if (collectConfig) {
-          ConfigCollector.get().put(key, value, source.origin());
+          if (ctr <= 1) {
+            // log a developer error? Report some log to telemetry for developer use?
+            ConfigCollector.get().put(key, value, source.origin()); // report without seq_id
+          } else {
+            ctr--;
+            ConfigCollector.get().put(key, value, source.origin(), ctr);
+          }
         }
         if (foundValue == null) {
           foundValue = value;

internal-api/src/test/groovy/datadog/trace/api/ConfigCollectorTest.groovy

@@ -16,7 +16,6 @@ import static datadog.trace.api.ConfigDefaults.DEFAULT_IAST_WEAK_HASH_ALGORITHMS
 import static datadog.trace.api.ConfigDefaults.DEFAULT_TELEMETRY_HEARTBEAT_INTERVAL
 
 class ConfigCollectorTest extends DDSpecification {
-
   def "non-default config settings get collected"() {
     setup:
     injectEnvConfig(Strings.toEnvVar(configKey), configValue)
@@ -83,6 +82,7 @@ class ConfigCollectorTest extends DDSpecification {
     setting != null
     setting.stringValue() == expectedValue
     setting.origin == ConfigOrigin.JVM_PROP
+    // TODO: Add check for env origin as well
 
     where:
     configKey                                                 | configValue1                                   | configValue2              | expectedValue
@@ -248,4 +248,25 @@ class ConfigCollectorTest extends DDSpecification {
     "logs.injection.enabled" | "false"
     "trace.sample.rate"      | "0.3"
   }
+
+  def "seqID increases with precedence"() {
+    setup:
+    def configKey = IastConfig.IAST_TELEMETRY_VERBOSITY
+    def envValue = Verbosity.DEBUG.toString()
+    def sysValue = Verbosity.MANDATORY.toString()
+    injectEnvConfig(Strings.toEnvVar(configKey), envValue)
+    injectSysConfig(configKey, sysValue)
+
+    expect:
+    def configsByOrigin = ConfigCollector.get().collect().get(configKey)
+    configsByOrigin != null
+    def sysSetting = configsByOrigin.get(ConfigOrigin.JVM_PROP)
+    sysSetting != null
+    def envSetting = configsByOrigin.get(ConfigOrigin.ENV)
+    envSetting != null
+    def defaultSetting = configsByOrigin.get(ConfigOrigin.DEFAULT)
+    defaultSetting != null
+    sysSetting.seqID > envSetting.seqID
+    envSetting.seqID > defaultSetting.seqID
+  }
 }