replacing syserr with log

Author: mhlidd

components/environment/src/main/java/datadog/environment/ConfigHelper.java

@@ -5,6 +5,8 @@
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 @SuppressForbidden
 public class ConfigHelper {
@@ -13,6 +15,8 @@ public class ConfigHelper {
   // Default to production source
   private static SupportedConfigurationSource configSource = new SupportedConfigurationSource();
 
+  private static final Logger log = LoggerFactory.getLogger(ConfigHelper.class);
+
   public static void setConfigInversionStrict(ConfigInversionStrictStyle configInversionStrict) {
     ConfigHelper.configInversionStrict = configInversionStrict;
   }
@@ -56,7 +60,6 @@ public static Map<String, String> getEnvironmentVariables() {
             }
           }
         }
-
         // TODO: Follow-up - Add deprecation handling
         //        if (configSource.getDeprecatedConfigurations().containsKey(key)) {
         //          String warning = "Environment variable " + key + " is deprecated. " +
@@ -77,10 +80,13 @@ public static String getEnvironmentVariable(String name) {
         && !configSource.getAliasMapping().containsKey(name)
         && !configSource.getSupportedConfigurations().contains(name)) {
       if (configInversionStrict != ConfigInversionStrictStyle.TEST) {
-        System.err.println(
-            "Warning: Missing environment variable "
-                + name
-                + " from supported-configurations.json.");
+        // TODO: Replace this log with Telemetry
+        //        System.err.println(
+        //            "Warning: Missing environment variable "
+        //                + name
+        //                + " from supported-configurations.json.");
+        log.error(
+            "Warning: Missing environment variable {} from supported-configurations.json.", name);
       }
 
       if (configInversionStrict == ConfigInversionStrictStyle.STRICT) {