YARN-8262. get_executable in container-executor should provide meaningful error codes. Contributed by Susheel Gupta

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

@@ -175,8 +175,12 @@ public class LinuxContainerExecutor extends ContainerExecutor {
     COULD_NOT_CREATE_WORK_DIRECTORIES(35),
     COULD_NOT_CREATE_APP_LOG_DIRECTORIES(36),
     COULD_NOT_CREATE_TMP_DIRECTORIES(37),
-    ERROR_CREATE_CONTAINER_DIRECTORIES_ARGUMENTS(38);
-
+    ERROR_CREATE_CONTAINER_DIRECTORIES_ARGUMENTS(38),
+    CANNOT_GET_EXECUTABLE_NAME_FROM_READLINK(80),
+    TOO_LONG_EXECUTOR_PATH(81),
+    CANNOT_GET_EXECUTABLE_NAME_FROM_KERNEL(82),
+    CANNOT_GET_EXECUTABLE_NAME_FROM_PID(83),
+    WRONG_PATH_OF_EXECUTABLE(84);
     private final int code;
 
     ExitCode(int exitCode) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/get_executable.c

@@ -56,17 +56,17 @@ char *__get_exec_readproc(char *procfn) {
   filename = malloc(EXECUTOR_PATH_MAX);
   if (!filename) {
     fprintf(ERRORFILE,"cannot allocate memory for filename before readlink: %s\n",strerror(errno));
-    exit(-1);
+    exit(OUT_OF_MEMORY);
   }
   len = readlink(procfn, filename, EXECUTOR_PATH_MAX);
   if (len == -1) {
-    fprintf(ERRORFILE,"Can't get executable name from %s - %s\n", procfn,
+    fprintf(ERRORFILE,"Cannot get executable name from %s - %s\n", procfn,
             strerror(errno));
-    exit(-1);
+    exit(CANNOT_GET_EXECUTABLE_NAME_FROM_READLINK);
   } else if (len >= EXECUTOR_PATH_MAX) {
     fprintf(ERRORFILE,"Resolved path for %s [%s] is longer than %d characters.\n",
             procfn, filename, EXECUTOR_PATH_MAX);
-    exit(-1);
+    exit(TOO_LONG_EXECUTOR_PATH);
   }
   filename[len] = '\0';
   return filename;
@@ -88,14 +88,14 @@ char *__get_exec_sysctl(int *mib)
 
   len = sizeof(buffer);
   if (sysctl(mib, 4, buffer, &len, NULL, 0) == -1) {
-    fprintf(ERRORFILE,"Can't get executable name from kernel: %s\n",
+    fprintf(ERRORFILE,"Cannot get executable name from kernel: %s\n",
       strerror(errno));
-    exit(-1);
+    exit(CANNOT_GET_EXECUTABLE_NAME_FROM_KERNEL);
   }
   filename=malloc(EXECUTOR_PATH_MAX);
   if (!filename) {
     fprintf(ERRORFILE,"cannot allocate memory for filename after sysctl: %s\n",strerror(errno));
-    exit(-1);
+    exit(OUT_OF_MEMORY);
   }
   snprintf(filename,EXECUTOR_PATH_MAX,"%s",buffer);
   return filename;
@@ -120,13 +120,13 @@ char* get_executable(char *argv0) {
   filename = malloc(PROC_PIDPATHINFO_MAXSIZE);
   if (!filename) {
     fprintf(ERRORFILE,"cannot allocate memory for filename before proc_pidpath: %s\n",strerror(errno));
-    exit(-1);
+    exit(OUT_OF_MEMORY);
   }
   pid = getpid();
   if (proc_pidpath(pid,filename,PROC_PIDPATHINFO_MAXSIZE) <= 0) {
-    fprintf(ERRORFILE,"Can't get executable name from pid %u - %s\n", pid,
+    fprintf(ERRORFILE,"Cannot get executable name from pid %u - %s\n", pid,
             strerror(errno));
-    exit(-1);
+    exit(CANNOT_GET_EXECUTABLE_NAME_FROM_PID);
   }
   return filename;
 }
@@ -194,7 +194,7 @@ char* get_executable (char *argv0) {
 
   if (!filename) {
     fprintf(ERRORFILE,"realpath of executable: %s\n",strerror(errno));
-    exit(-1);
+    exit(WRONG_PATH_OF_EXECUTABLE);
   }
   return filename;
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/util.c

@@ -337,6 +337,16 @@ const char *get_error_message(const int error_code) {
         return "runC run failed";
       case ERROR_RUNC_REAP_LAYER_MOUNTS_FAILED:
         return "runC reap layer mounts failed";
+      case CANNOT_GET_EXECUTABLE_NAME_FROM_READLINK:
+        return "Cannot get executable name from readlink";
+      case TOO_LONG_EXECUTOR_PATH:
+        return "Too long executor path";
+      case CANNOT_GET_EXECUTABLE_NAME_FROM_KERNEL:
+        return "Cannot get executable name from kernel";
+      case CANNOT_GET_EXECUTABLE_NAME_FROM_PID:
+        return "Cannot get executable name from pid";
+      case WRONG_PATH_OF_EXECUTABLE:
+        return "Wrong path of executable";
       default:
         return "Unknown error code";
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/util.h

@@ -104,7 +104,12 @@ enum errorcodes {
   ERROR_RUNC_SETUP_FAILED = 76,
   ERROR_RUNC_RUN_FAILED = 77,
   ERROR_RUNC_REAP_LAYER_MOUNTS_FAILED = 78,
-  ERROR_DOCKER_CONTAINER_EXEC_FAILED = 79
+  ERROR_DOCKER_CONTAINER_EXEC_FAILED = 79,
+  CANNOT_GET_EXECUTABLE_NAME_FROM_READLINK = 80,
+  TOO_LONG_EXECUTOR_PATH = 81,
+  CANNOT_GET_EXECUTABLE_NAME_FROM_KERNEL = 82,
+  CANNOT_GET_EXECUTABLE_NAME_FROM_PID = 83,
+  WRONG_PATH_OF_EXECUTABLE = 84
 };
 
 /* Macros for min/max. */