Revert "YARN-7677. Docker image cannot set HADOOP_CONF_DIR. Contributed by Jim Brennan"

This reverts commit 12eaae383a.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/ContainerExecutor.java

@@ -346,6 +346,7 @@ public abstract class ContainerExecutor implements Configurable {
   public void writeLaunchEnv(OutputStream out, Map<String, String> environment,
       Map<Path, List<String>> resources, List<String> command, Path logDir,
       String user, String outFilename) throws IOException {
+    updateEnvForWhitelistVars(environment);
 
     ContainerLaunch.ShellScriptBuilder sb =
         ContainerLaunch.ShellScriptBuilder.create();
@@ -363,19 +364,6 @@ public abstract class ContainerExecutor implements Configurable {
       for (Map.Entry<String, String> env : environment.entrySet()) {
         sb.env(env.getKey(), env.getValue());
       }
-      // Whitelist environment variables are treated specially.
-      // Only add them if they are not already defined in the environment.
-      // Add them using special syntax to prevent them from eclipsing
-      // variables that may be set explicitly in the container image (e.g,
-      // in a docker image)
-      for(String var : whitelistVars) {
-        if (!environment.containsKey(var)) {
-          String val = getNMEnvVar(var);
-          if (val != null) {
-            sb.whitelistedEnv(var, val);
-          }
-        }
-      }
     }
 
     if (resources != null) {
@@ -675,6 +663,23 @@ public abstract class ContainerExecutor implements Configurable {
     }
   }
 
+  /**
+   * Propagate variables from the nodemanager's environment into the
+   * container's environment if unspecified by the container.
+   * @param env the environment to update
+   * @see org.apache.hadoop.yarn.conf.YarnConfiguration#NM_ENV_WHITELIST
+   */
+  protected void updateEnvForWhitelistVars(Map<String, String> env) {
+    for(String var : whitelistVars) {
+      if (!env.containsKey(var)) {
+        String val = getNMEnvVar(var);
+        if (val != null) {
+          env.put(var, val);
+        }
+      }
+    }
+  }
+
   @VisibleForTesting
   protected String getNMEnvVar(String varname) {
     return System.getenv(varname);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/LinuxContainerExecutor.java

@@ -66,6 +66,7 @@ import java.net.InetSocketAddress;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 import java.util.regex.Pattern;
 
 import static org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.runtime.LinuxContainerRuntimeConstants.*;
@@ -471,6 +472,13 @@ public class LinuxContainerExecutor extends ContainerExecutor {
     }
   }
 
+  @Override
+  protected void updateEnvForWhitelistVars(Map<String, String> env) {
+    if (linuxContainerRuntime.useWhitelistEnv(env)) {
+      super.updateEnvForWhitelistVars(env);
+    }
+  }
+
   @Override
   public int launchContainer(ContainerStartContext ctx)
       throws IOException, ConfigurationException {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerLaunch.java

@@ -1135,9 +1135,6 @@ public class ContainerLaunch implements Callable<Integer> {
 
     public abstract void env(String key, String value) throws IOException;
 
-    public abstract void whitelistedEnv(String key, String value)
-        throws IOException;
-
     public abstract void echo(String echoStr) throws IOException;
 
     public final void symlink(Path src, Path dst) throws IOException {
@@ -1257,11 +1254,6 @@ public class ContainerLaunch implements Callable<Integer> {
       line("export ", key, "=\"", value, "\"");
     }
 
-    @Override
-    public void whitelistedEnv(String key, String value) throws IOException {
-      line("export ", key, "=${", key, ":-", "\"", value, "\"}");
-    }
-
     @Override
     public void echo(final String echoStr) throws IOException {
       line("echo \"" + echoStr + "\"");
@@ -1352,11 +1344,6 @@ public class ContainerLaunch implements Callable<Integer> {
       errorCheck();
     }
 
-    @Override
-    public void whitelistedEnv(String key, String value) throws IOException {
-      env(key, value);
-    }
-
     @Override
     public void echo(final String echoStr) throws IOException {
       lineWithLenCheck("@echo \"", echoStr, "\"");
@@ -1456,6 +1443,8 @@ public class ContainerLaunch implements Callable<Integer> {
     
     environment.put(Environment.PWD.name(), pwd.toString());
     
+    putEnvIfAbsent(environment, Environment.HADOOP_CONF_DIR.name());
+
     if (!Shell.WINDOWS) {
       environment.put("JVM_PID", "$$");
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/runtime/DefaultLinuxContainerRuntime.java

@@ -37,6 +37,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.List;
+import java.util.Map;
 
 import static org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.runtime.LinuxContainerRuntimeConstants.*;
 
@@ -72,6 +73,11 @@ public class DefaultLinuxContainerRuntime implements LinuxContainerRuntime {
     this.conf = conf;
   }
 
+  @Override
+  public boolean useWhitelistEnv(Map<String, String> env) {
+    return true;
+  }
+
   @Override
   public void prepareContainer(ContainerRuntimeContext ctx)
       throws ContainerExecutionException {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/runtime/DelegatingLinuxContainerRuntime.java

@@ -94,6 +94,17 @@ public class DelegatingLinuxContainerRuntime implements LinuxContainerRuntime {
     }
   }
 
+  @Override
+  public boolean useWhitelistEnv(Map<String, String> env) {
+    try {
+      LinuxContainerRuntime runtime = pickContainerRuntime(env);
+      return runtime.useWhitelistEnv(env);
+    } catch (ContainerExecutionException e) {
+      LOG.debug("Unable to determine runtime");
+      return false;
+    }
+  }
+
   @VisibleForTesting
   LinuxContainerRuntime pickContainerRuntime(
       Map<String, String> environment) throws ContainerExecutionException {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/runtime/DockerLinuxContainerRuntime.java

@@ -366,6 +366,13 @@ public class DockerLinuxContainerRuntime implements LinuxContainerRuntime {
     return capabilities;
   }
 
+  @Override
+  public boolean useWhitelistEnv(Map<String, String> env) {
+    // Avoid propagating nodemanager environment variables into the container
+    // so those variables can be picked up from the Docker image instead.
+    return false;
+  }
+
   private String runDockerVolumeCommand(DockerVolumeCommand dockerVolumeCommand,
       Container container) throws ContainerExecutionException {
     try {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/runtime/ContainerRuntime.java

@@ -24,6 +24,8 @@ import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container;
 
+import java.util.Map;
+
 /**
  * An abstraction for various container runtime implementations. Examples
  * include Process Tree, Docker, Appc runtimes etc. These implementations
@@ -83,4 +85,13 @@ public interface ContainerRuntime {
    * and hostname
    */
   String[] getIpAndHost(Container container) throws ContainerExecutionException;
+
+  /**
+   * Whether to propagate the whitelist of environment variables from the
+   * nodemanager environment into the container environment.
+   * @param env the container's environment variables
+   * @return true if whitelist variables should be propagated, false otherwise
+   * @see org.apache.hadoop.yarn.conf.YarnConfiguration#NM_ENV_WHITELIST
+   */
+  boolean useWhitelistEnv(Map<String, String> env);
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/TestContainerLaunch.java

@@ -337,8 +337,7 @@ public class TestContainerLaunch extends BaseContainerManagerTest {
     Assert.assertFalse(shellContent.contains("HADOOP_HDFS_HOME"));
     // Available in env and in whitelist
     Assert.assertTrue(shellContent.contains(
-        "export HADOOP_YARN_HOME=${HADOOP_YARN_HOME:-\"nodemanager_yarn_home\"}"
-      ));
+        "export HADOOP_YARN_HOME=\"nodemanager_yarn_home\""));
     fos.flush();
     fos.close();
   }
@@ -383,12 +382,9 @@ public class TestContainerLaunch extends BaseContainerManagerTest {
     // Whitelisted variable overridden by container
     Assert.assertTrue(shellContent.contains(
         "export HADOOP_MAPRED_HOME=\"/opt/hadoopbuild\""));
-    // Available in env but not in whitelist
+    // Verify no whitelisted variables inherited from NM env
     Assert.assertFalse(shellContent.contains("HADOOP_HDFS_HOME"));
-    // Available in env and in whitelist
-    Assert.assertTrue(shellContent.contains(
-        "export HADOOP_YARN_HOME=${HADOOP_YARN_HOME:-\"nodemanager_yarn_home\"}"
-    ));
+    Assert.assertFalse(shellContent.contains("HADOOP_YARN_HOME"));
     fos.flush();
     fos.close();
   }