Package org.apache.hadoop.util

Class ZKUtil

java.lang.Object

org.apache.hadoop.util.ZKUtil

@Private
public class ZKUtil
extends Object

Utilities for working with ZooKeeper.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ZKUtil.BadAclFormatException
static class	ZKUtil.BadAuthFormatException
static class	ZKUtil.ZKAuthInfo	An authentication token passed to ZooKeeper.addAuthInfo

Constructor Summary

Constructors

Constructor	Description
ZKUtil()

Method Summary

Modifier and Type	Method	Description
static List<org.apache.zookeeper.data.ACL>	parseACLs(String aclString)	Parse comma separated list of ACL entries to secure generated nodes, e.g.
static List<ZKUtil.ZKAuthInfo>	parseAuth(String authString)	Parse a comma-separated list of authentication mechanisms.
static int	removeSpecificPerms(int perms, int remove)	Helper method to remove a subset of permissions (remove) from a given set (perms).
static String	resolveConfIndirection(String valInConf)	Because ZK ACLs and authentication information may be secret, allow the configuration values to be indirected through a file by specifying the configuration as "@/path/to/file".

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ZKUtil

public ZKUtil()

Method Details

removeSpecificPerms

public static int removeSpecificPerms(int perms,
 int remove)

Helper method to remove a subset of permissions (remove) from a given set (perms).

Parameters:

perms - The permissions flag to remove from. Should be an OR of a some combination of ZooDefs.Perms

remove - The permissions to be removed. Should be an OR of a some combination of ZooDefs.Perms

Returns:

A permissions flag that is an OR of ZooDefs.Perms present in perms and not present in remove

parseACLs

public static List<org.apache.zookeeper.data.ACL> parseACLs(String aclString)
                                                     throws ZKUtil.BadAclFormatException

Parse comma separated list of ACL entries to secure generated nodes, e.g. sasl:hdfs/host1@MY.DOMAIN:cdrwa,sasl:hdfs/host2@MY.DOMAIN:cdrwa

Parameters:

aclString - aclString.

Returns:

ACL list

Throws:

ZKUtil.BadAclFormatException - if an ACL is invalid

parseAuth

public static List<ZKUtil.ZKAuthInfo> parseAuth(String authString)
                                         throws ZKUtil.BadAuthFormatException

Parse a comma-separated list of authentication mechanisms. Each such mechanism should be of the form 'scheme:auth' -- the same syntax used for the 'addAuth' command in the ZK CLI.

Parameters:

authString - the comma-separated auth mechanisms

Returns:

a list of parsed authentications

Throws:

ZKUtil.BadAuthFormatException - if the auth format is invalid

resolveConfIndirection

public static String resolveConfIndirection(String valInConf)
                                     throws IOException

Because ZK ACLs and authentication information may be secret, allow the configuration values to be indirected through a file by specifying the configuration as "@/path/to/file". If this syntax is used, this function will return the contents of the file as a String.

Parameters:

valInConf - the value from the Configuration

Returns:

either the same value, or the contents of the referenced file if the configured value starts with "@"

Throws:

IOException - if the file cannot be read