read WRITE_TO_STDOUT env var to the Configuration object

Author: Paul Schellenberg

src/main/java/software/amazon/cloudwatchlogs/emf/config/Configuration.java

@@ -59,6 +59,8 @@ public class Configuration {
     /** Queue length for asynchronous sinks. */
     @Setter @Getter int asyncBufferSize = Constants.DEFAULT_ASYNC_BUFFER_SIZE;
 
+    @Setter private boolean shouldWriteToStdout;
+
     public Optional<String> getServiceName() {
         return getStringOptional(serviceName);
     }
@@ -92,4 +94,8 @@ private Optional<String> getStringOptional(String value) {
         }
         return Optional.of(value);
     }
+
+    public boolean shouldWriteToStdout() {
+        return shouldWriteToStdout;
+    }
 }

src/main/java/software/amazon/cloudwatchlogs/emf/config/ConfigurationKeys.java

@@ -28,4 +28,5 @@ public class ConfigurationKeys {
     public static final String AGENT_ENDPOINT = "AGENT_ENDPOINT";
     public static final String ENVIRONMENT_OVERRIDE = "ENVIRONMENT";
     public static final String ASYNC_BUFFER_SIZE = "ASYNC_BUFFER_SIZE";
+    public static final String WRITE_TO_STDOUT = "WRITE_TO_STDOUT";
 }

src/main/java/software/amazon/cloudwatchlogs/emf/config/EnvironmentConfigurationProvider.java

@@ -42,7 +42,8 @@ static Configuration createConfig() {
                 getEnvVar(ConfigurationKeys.AGENT_ENDPOINT),
                 getEnvironmentOverride(),
                 getIntOrDefault(
-                        ConfigurationKeys.ASYNC_BUFFER_SIZE, Constants.DEFAULT_ASYNC_BUFFER_SIZE));
+                        ConfigurationKeys.ASYNC_BUFFER_SIZE, Constants.DEFAULT_ASYNC_BUFFER_SIZE),
+                Boolean.parseBoolean(getEnvVar(ConfigurationKeys.WRITE_TO_STDOUT)));
     }
 
     private static Environments getEnvironmentOverride() {

src/main/java/software/amazon/cloudwatchlogs/emf/environment/AgentBasedEnvironment.java

@@ -30,16 +30,11 @@
 
 @Slf4j
 public abstract class AgentBasedEnvironment implements Environment {
-    private static final String WRITE_TO_STDOUT = "WRITE_TO_STDOUT";
-    private final boolean shouldWriteToStdout;
     private final Configuration config;
     private ISink sink;
 
     protected AgentBasedEnvironment(Configuration config) {
         this.config = config;
-        shouldWriteToStdout = Optional.ofNullable(SystemWrapper.getenv(WRITE_TO_STDOUT))
-            .map(Boolean::parseBoolean)
-            .orElse(false);
     }
 
     @Override
@@ -74,7 +69,7 @@ public String getLogStreamName() {
     @Override
     public ISink getSink() {
         if (sink == null) {
-            if (shouldWriteToStdout) {
+            if (config.shouldWriteToStdout()) {
                 sink = new ConsoleSink();
             } else {
                 Endpoint endpoint;

src/test/java/software/amazon/cloudwatchlogs/emf/config/EnvironmentConfigurationProviderTest.java

@@ -40,6 +40,7 @@ public void getGetConfig() {
         putEnv("AWS_EMF_AGENT_ENDPOINT", "Endpoint");
         putEnv("AWS_EMF_ENVIRONMENT", "Agent");
         putEnv("AWS_EMF_ASYNC_BUFFER_SIZE", "9999");
+        putEnv("AWS_EMF_WRITE_TO_STDOUT", "true");
 
         Configuration config = EnvironmentConfigurationProvider.createConfig();
 
@@ -50,6 +51,7 @@ public void getGetConfig() {
         assertEquals("Endpoint", config.getAgentEndpoint().get());
         assertEquals(Environments.Agent, config.getEnvironmentOverride());
         assertEquals(9999, config.getAsyncBufferSize());
+        assertTrue(config.shouldWriteToStdout());
     }
 
     @Test
@@ -59,10 +61,20 @@ public void invalidEnvironmentValuesFallbackToExpectedDefaults() {
 
         // act
         putEnv("AWS_EMF_ASYNC_BUFFER_SIZE", "NaN");
+        putEnv("AWS_EMF_WRITE_TO_STDOUT", "notABool");
 
         // assert
         Configuration config = EnvironmentConfigurationProvider.createConfig();
         assertEquals(100, config.getAsyncBufferSize());
+        assertFalse(config.shouldWriteToStdout());
+    }
+
+    @Test
+    public void emptyEnvironmentValuesFallbackToExpectedDefaults() {
+        // assert
+        Configuration config = EnvironmentConfigurationProvider.createConfig();
+        assertEquals(100, config.getAsyncBufferSize());
+        assertFalse(config.shouldWriteToStdout());
     }
 
     private void putEnv(String key, String value) {

src/test/java/software/amazon/cloudwatchlogs/emf/environment/AgentBasedEnvironmentTest.java

@@ -71,8 +71,7 @@ public void testGetSinkWithConfiguredEndpoint() throws Exception {
 
     @Test
     public void testGetSinkOverrideToStdOut() {
-        PowerMockito.mockStatic(SystemWrapper.class);
-        PowerMockito.when(SystemWrapper.getenv("WRITE_TO_STDOUT")).thenReturn("true");
+        configuration.setShouldWriteToStdout(true);
 
         AgentBasedEnvironment env = new AgentBasedEnvironmentTestImplementation(configuration);
         ISink sink = env.getSink();
@@ -82,9 +81,7 @@ public void testGetSinkOverrideToStdOut() {
 
     @Test
     public void testGetSinkOverrideToStdOutFailFastOnImproperOverride() throws Exception {
-        PowerMockito.mockStatic(SystemWrapper.class);
-        // Will only override if this env is explicitly "true"
-        PowerMockito.when(SystemWrapper.getenv("WRITE_TO_STDOUT")).thenReturn("notABool");
+        configuration.setShouldWriteToStdout(false);
 
         testGetSinkWithDefaultEndpoint();
     }