Relative to agent jar

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/ConfigurationBuilder.java

@@ -159,7 +159,7 @@ public static Configuration create(Path agentJarPath, RpConfiguration rpConfigur
               + " so no need to enable it under preview configuration");
     }
 
-    overlayFromEnv(config);
+    overlayFromEnv(config, agentJarPath.getParent());
     config.sampling.percentage = roundToNearest(config.sampling.percentage, true);
     for (SamplingOverride override : config.preview.sampling.overrides) {
       override.percentage = roundToNearest(override.percentage, true);
@@ -355,11 +355,11 @@ public static void logConfigurationWarnMessages() {
   }
 
   // visible for testing
-  static void overlayFromEnv(Configuration config) throws IOException {
+  static void overlayFromEnv(Configuration config, Path baseDir) throws IOException {
     // load connection string from a file if connection string is in the format of
     // "${file:mounted_connection_string_file.txt}"
     Map<String, StringLookup> stringLookupMap =
-        Collections.singletonMap(StringLookupFactory.KEY_FILE, FileStringLookup.INSTANCE);
+        Collections.singletonMap(StringLookupFactory.KEY_FILE, new FileStringLookup(baseDir));
     StringLookup stringLookup =
         StringLookupFactory.INSTANCE.interpolatorStringLookup(stringLookupMap, null, false);
     StringSubstitutor stringSubstitutor = new StringSubstitutor(stringLookup);

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/FileStringLookup.java

@@ -25,19 +25,21 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
-import java.nio.file.Paths;
-import javax.annotation.Nullable;
+import java.nio.file.Path;
 import org.apache.commons.text.lookup.StringLookup;
 
 final class FileStringLookup implements StringLookup {
 
-  static final FileStringLookup INSTANCE = new FileStringLookup();
+  private final Path baseDir;
+
+  FileStringLookup(Path baseDir) {
+    this.baseDir = baseDir;
+  }
 
   @Override
-  @Nullable
   public String lookup(String key) {
     try {
-      return new String(Files.readAllBytes(Paths.get(key)), StandardCharsets.UTF_8);
+      return new String(Files.readAllBytes(baseDir.resolve(key)), StandardCharsets.UTF_8);
     } catch (IOException | InvalidPathException e) {
       throw new IllegalArgumentException(
           "Error occurs when reading connection string from the file '"
@@ -46,6 +48,4 @@ public String lookup(String key) {
           e);
     }
   }
-
-  private FileStringLookup() {}
 }

agent/agent-tooling/src/test/java/com/microsoft/applicationinsights/agent/internal/configuration/ConfigurationBuilderTest.java

@@ -32,6 +32,7 @@
 import java.io.Writer;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -168,31 +169,31 @@ void testRpConfigurationOverlayWithEnvVarAndSysPropPopulated() throws Exception
   void testOverlayWithEnvVarWithGoodFileStringLookupFormat() throws Exception {
     Configuration configuration = new Configuration();
     configuration.connectionString = "${file:" + connectionStringFile.getAbsolutePath() + "}";
-    ConfigurationBuilder.overlayFromEnv(configuration);
+    ConfigurationBuilder.overlayFromEnv(configuration, Paths.get("."));
     assertThat(configuration.connectionString).isEqualTo(CONNECTION_STRING);
   }
 
   @Test
   void testOverlayWithEnvVarWithBadFileStringLookupFormat() throws Exception {
     Configuration configuration = new Configuration();
     configuration.connectionString = "${file:" + connectionStringFile.getAbsolutePath();
-    ConfigurationBuilder.overlayFromEnv(configuration);
+    ConfigurationBuilder.overlayFromEnv(configuration, Paths.get("."));
     assertThat(configuration.connectionString).isEqualTo(configuration.connectionString);
 
     configuration.connectionString = "${xyz:" + connectionStringFile.getAbsolutePath() + "}";
-    ConfigurationBuilder.overlayFromEnv(configuration);
+    ConfigurationBuilder.overlayFromEnv(configuration, Paths.get("."));
     assertThat(configuration.connectionString).isEqualTo(configuration.connectionString);
 
     configuration.connectionString = "file:" + connectionStringFile.getAbsolutePath() + "}";
-    ConfigurationBuilder.overlayFromEnv(configuration);
+    ConfigurationBuilder.overlayFromEnv(configuration, Paths.get("."));
     assertThat(configuration.connectionString).isEqualTo(configuration.connectionString);
 
     configuration.connectionString = "file:" + connectionStringFile.getAbsolutePath();
-    ConfigurationBuilder.overlayFromEnv(configuration);
+    ConfigurationBuilder.overlayFromEnv(configuration, Paths.get("."));
     assertThat(configuration.connectionString).isEqualTo(configuration.connectionString);
 
     configuration.connectionString = CONNECTION_STRING;
-    ConfigurationBuilder.overlayFromEnv(configuration);
+    ConfigurationBuilder.overlayFromEnv(configuration, Paths.get("."));
     assertThat(configuration.connectionString).isEqualTo(configuration.connectionString);
   }
 
@@ -206,7 +207,7 @@ void testConnectionStringEnvVarHasHigherPrecedenceOverFileLookup() throws Except
 
               configuration.connectionString =
                   "${file:" + connectionStringFile.getAbsolutePath() + "}";
-              ConfigurationBuilder.overlayFromEnv(configuration);
+              ConfigurationBuilder.overlayFromEnv(configuration, Paths.get("."));
 
               assertThat(configuration.connectionString).isEqualTo(testConnectionString);
             });