Package org.apache.hadoop.registry.client.binding

Class RegistryUtils

java.lang.Object
org.apache.hadoop.registry.client.binding.RegistryUtils
@Public @Evolving public class RegistryUtils extends Object
Utility methods for working with a registry.

  • Constructor Details

    • RegistryUtils

      public RegistryUtils()

  • Method Details

    • homePathForUser

      public static String homePathForUser(String username)
      Buld the user path -switches to the system path if the user is "". It also cross-converts the username to ascii via punycode
      Parameters:
      username - username or ""
      Returns:
      the path to the user

    • convertUsername

      public static String convertUsername(String username)
      Convert the username to that which can be used for registry entries. Lower cases it, Strip the kerberos realm off a username if needed, and any "/" hostname entries
      Parameters:
      username - user
      Returns:
      the converted username

    • serviceclassPath

      public static String serviceclassPath(String user, String serviceClass)
      Create a service classpath
      Parameters:
      user - username or ""
      serviceClass - service name
      Returns:
      a full path

    • servicePath

      public static String servicePath(String user, String serviceClass, String serviceName)
      Create a path to a service under a user and service class
      Parameters:
      user - username or ""
      serviceClass - service name
      serviceName - service name unique for that user and service class
      Returns:
      a full path

    • componentListPath

      public static String componentListPath(String user, String serviceClass, String serviceName)
      Create a path for listing components under a service
      Parameters:
      user - username or ""
      serviceClass - service name
      serviceName - service name unique for that user and service class
      Returns:
      a full path

    • componentPath

      public static String componentPath(String user, String serviceClass, String serviceName, String componentName)
      Create the path to a service record for a component
      Parameters:
      user - username or ""
      serviceClass - service name
      serviceName - service name unique for that user and service class
      componentName - unique name/ID of the component
      Returns:
      a full path

    • listServiceRecords

      public static Map<String,ServiceRecord> listServiceRecords(RegistryOperations registryOperations, String path) throws IOException
      List service records directly under a path
      Parameters:
      registryOperations - registry operations instance
      path - path to list
      Returns:
      a mapping of the service records that were resolved, indexed by their full path
      Throws:
      IOException

    • statChildren

      public static Map<String,RegistryPathStatus> statChildren(RegistryOperations registryOperations, String path) throws org.apache.hadoop.fs.PathNotFoundException, InvalidPathnameException, IOException
      List children of a directory and retrieve their RegistryPathStatus values.

      This is not an atomic operation; A child may be deleted during the iteration through the child entries. If this happens, the PathNotFoundException is caught and that child entry ommitted.

      Parameters:
      path - path
      Returns:
      a possibly empty map of child entries listed by their short name.
      Throws:
      org.apache.hadoop.fs.PathNotFoundException - path is not in the registry.
      InvalidPathnameException - the path is invalid.
      IOException - Any other IO Exception

    • homePathForCurrentUser

      public static String homePathForCurrentUser()
      Get the home path of the current user.

      In an insecure cluster, the environment variable HADOOP_USER_NAME is queried first.

      This means that in a YARN container where the creator set this environment variable to propagate their identity, the defined user name is used in preference to the actual user.

      In a secure cluster, the kerberos identity of the current user is used.

      Returns:
      a path for the current user's home dir.
      Throws:
      RuntimeException - if the current user identity cannot be determined from the OS/kerberos.

    • getCurrentUsernameUnencoded

      @VisibleForTesting public static String getCurrentUsernameUnencoded(String env_hadoop_username)
      Get the current username, using the value of the parameter env_hadoop_username if it is set on an insecure cluster. This ensures that the username propagates correctly across processes started by YARN.

      This method is primarly made visible for testing.

      Parameters:
      env_hadoop_username - the environment variable
      Returns:
      the selected username
      Throws:
      RuntimeException - if there is a problem getting the short user name of the current user.

    • currentUser

      public static String currentUser()
      Get the current user path formatted for the registry

      In an insecure cluster, the environment variable HADOOP_USER_NAME is queried first.

      This means that in a YARN container where the creator set this environment variable to propagate their identity, the defined user name is used in preference to the actual user.

      In a secure cluster, the kerberos identity of the current user is used.

      Returns:
      the encoded shortname of the current user
      Throws:
      RuntimeException - if the current user identity cannot be determined from the OS/kerberos.

    • registryUser

      public static String registryUser(String shortUserName)
      Convert the given user name formatted for the registry.
      Parameters:
      shortUserName -
      Returns:
      converted user name

    • extractServiceRecords

      public static Map<String,ServiceRecord> extractServiceRecords(RegistryOperations operations, String parentpath, Collection<RegistryPathStatus> stats) throws IOException
      Extract all service records under a list of stat operations...this skips entries that are too short or simply not matching
      Parameters:
      operations - operation support for fetches
      parentpath - path of the parent of all the entries
      stats - Collection of stat results
      Returns:
      a possibly empty map of fullpath:record.
      Throws:
      IOException - for any IO Operation that wasn't ignored.

    • extractServiceRecords

      public static Map<String,ServiceRecord> extractServiceRecords(RegistryOperations operations, String parentpath, Map<String,RegistryPathStatus> stats) throws IOException
      Extract all service records under a list of stat operations...this non-atomic action skips entries that are too short or simply not matching.

      Parameters:
      operations - operation support for fetches
      parentpath - path of the parent of all the entries
      Returns:
      a possibly empty map of fullpath:record.
      Throws:
      IOException - for any IO Operation that wasn't ignored.

    • extractServiceRecords

      public static Map<String,ServiceRecord> extractServiceRecords(RegistryOperations operations, String parentpath) throws IOException
      Extract all service records under a list of stat operations...this non-atomic action skips entries that are too short or simply not matching.

      Parameters:
      operations - operation support for fetches
      parentpath - path of the parent of all the entries
      Returns:
      a possibly empty map of fullpath:record.
      Throws:
      IOException - for any IO Operation that wasn't ignored.