The KnoxShell release artifact provides a small footprint client environment that removes all unnecessary server dependencies, configuration, binary scripts, etc. It is comprised of a couple different things that empower different sorts of users.
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This article will go over the creation of a simple SQL client that we will call "knoxline" by using the KnoxShell Groovy based DSL.
This particular article should work using the 0.14.0 knoxshell download and with previous gateway server releases as well.
We will show how to use a simple groovy script to write a SQL client that can do something like the following:
Download
In the 0.14.0 release, you may get to the knoxshell download through the Apache Knox site.
From this above page click the Gateway client binary archive link or just use the one here.
Unzip this file into your preferred location which will result in a knoxshell-0.14.0 directory and we will refer to that location as the {GATEWAY_HOME}.
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- if you have access to the server you may use the command
knoxcli.sh export-cert –type--type JKS
- copy the resulting gateway-client-identity.jks to your user home directory
- you may also ask your Knox administrator to provide you with the public cert for the gateway and create your own truststore within your user home directory
NOTE: if you see errors related to SSL and PKIX your truststore is not properly setup
Add Hive Client Libraries
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import java.sql.DriverManager
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.sql.DriverManagerSQLException
import org.apache.hadoop.gateway.shell.CredentialsgatewayHost = "localhost";
gatewayPort = 8443;
trustStore = System.getProperty('user.home') + "/gateway-client-trust.jks";
trustStorePassword = "changeit";
contextPath = "gateway/sandbox/hive";
sql = ""if (args.length == 0) {
// accept defaults
System.out.println(String.format("\nDefault connection args: %s, %d, %s, %s, %s", gatewayHost, gatewayPort, trustStore, trustStorePassword, contextPath))
} else if (args[0] == "?" || args[0] == "help") {
System.out.println("\nExpected arguments: {host, port, truststore, truststore-pass, context-path}\n")
System.exit(0);
} else if (args.length == 5) {
gatewayHost = args[0];
gatewayPort = args[1].toInteger();
trustStore = args[2];
trustStorePassword = args[3];
contextPath = args[4];
System.out.println(String.format("\nProvided connection args: %s, %d, %s, %s, %s", gatewayHost, gatewayPort, trustStore, trustStorePassword, contextPath))
} else if (args.length > 0) {
System.out.println("\nERROR: Expected arguments: NONE for defaults or {host, port, truststore, truststore-pass, context-path}\n")
System.exit(1);
}connectionString = String.format( "jdbc:hive2://%s:%d/;ssl=true;sslTrustStore=%s;trustStorePassword=%s?hive.server2.transport.mode=http;hive.server2.thrift.http.path=/%s", gatewayHost, gatewayPort, trustStore, trustStorePassword, contextPath );
System.out.println("<======KnoxLine======>");
System.out.println("powered by Apache Knox");
System.out.println("");credentials = new Credentials()
credentials.add("ClearInput", "Enter username: ", "user")
.add("HiddenInput", "Enter pas" + "sword: ", "pass")
credentials.collect()user = credentials.get("user").string()
pass = credentials.get("pass").string()// Load Hive JDBC Driver
Class.forName( "org.apache.hive.jdbc.HiveDriver" );// Configure JDBC connection
connection = DriverManager.getConnection( connectionString, user, pass );while(1) {
def sql = System.console().readLine 'knoxline> '
if (!sql.equals("")) {
System.out.println(sql)
rs = true;
statement = connection.createStatement();
try {
if (statement.execute( sql )) {
resultSet = statement.getResultSet()
int colcount = 0
colcount = resultSet.getMetaData().getColumnCount();
row = 0
header = "| "
while ( resultSet.next() ) {
line = "| "
for (int i = 1; i <= colcount; i++) {
colvalue = resultSet.getString( i )
if (colvalue == null) colvalue = ""
colsize = colvalue.length()
headerSize = resultSet.getMetaData().getColumnLabel( i ).length()
if (headerSize > colsize) colsize = headerSize
if (row == 0) {
header += resultSet.getMetaData().getColumnLabel( i ).center(colsize) + " | ";
}
line += colvalue.center(colsize) + " | ";
}
if (row == 0) {System.out.println("".padLeft(header.length()-1, "="))
System.out.println(header);
System.out.println("".padLeft(header.length()-1, "="))
}
System.out.println(line);
row++
}
System.out.println("\nRows: " + row + "\n");
resultSet.close();
}
}
}catch(SQLException e) {
//e.printStackTrace()
System.out.println("SQL Exception encountered... " + e.getMessage())if (e.getMessage().contains("org.apache.thrift.transport.TTransportException")) catch(Exception e) {
e.printStackTrace( System.out.println("reconnecting... ")
connection connection = DriverManager.getConnection( connectionString, user, pass );
}
}
statement.close();
}
}
connectionconnection.close();
Execute a SQL Commands using KnoxLine
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Enter the knoxline sql client at the command line:
I will use the defaults for the arguments in the script:
Default connection args: localhost, 8443, /Users/larry/gateway-client-trust.jks, changeit, gateway/sandbox/hive
Depending on your deployment, you may want to set the above arguments on the CLI below:
knoxshell-0.14.0 larry$ bin/knoxline.sh
Let's check for existing tables:
knoxline> show tables
Let's create a table by loading file from the local disk of the cluster machine:
knoxline> CREATE TABLE logs(column1 string, column2 string, column3 string, column4 string, column5 string, column6 string, column7 string) ROW FORMAT DELIMITED FIELDS TERMINATED BY ' '
Show the created table:
Show the table description:
knoxline> desc logs
Load the data from the samples.log file in /tmp (copy the sample.log file from ./samples/hive/sample.log to the /tmp directory on your hiveserver2 host):
knoxline> LOAD DATA LOCAL INPATH '/tmp/sample.log' OVERWRITE INTO TABLE logs
knoxline> select * from logs where column2='20:11:56' and column4='[TRACE]'
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