HDFS Shell UI (CLI tool)

HDFS Shell is a HDFS manipulation tool to work with functions integrated in Hadoop DFS

Image of HDFS-Shell

Build Status - Master Linux Windows Apache 2

Purpose

There are 3 possible usecases:

Why such UI shell?

Advantages UI against direct calling hdfs dfs function:

Disadvantages UI against direct calling hdfs dfs function:

Using HDFS Shell UI

Launching HDFS Shell UI

Requirements:

Download

Configuring launch script(s) for your environment

HDFS-Shell is a standard Java application. For its launch you need to define 2 things on your classpath:

  1. All ./lib/*.jar on classpath (the dependencies ./lib are included in the binary bundle or they are located in Gradle build/distributions/*.zip)
  2. Path to directory with your Hadoop Cluster config files (hdfs-site.xml, core-site.xml etc.) - without these files the HDFS Shell will work in local filesystem mode
    • on Linux it's usually located in /etc/hadoop/conf folder
    • on Windows it's usually located in %HADOOP_HOME%\etc\hadoop\ folder

Note that paths inside java -cp switch are separated by : on Linux and ; on Windows.

Pre-defined launch scripts are located in the zip file. You can modify it locally as needed.

Possible commands inside shell

Additional commands

For our purposes we also integrated following commands:

Edit Command

Since the version 1.0.4 the simple command 'edit' is available. The command gets selected file from HDFS to the local temporary directory and launches the editor. Once the editor saves the file (with a result code 0), the file is uploaded back into HDFS (target file is overwritten). By default the editor path is taken from $EDITOR environment variable. If $EDITOR is not set, vim (Linux, Mac) or notepad.exe (Windows) is used.

How to change command (shell) prompt

HDFS Shell supports customized bash-like prompt setting! I implemented support for these switches listed in this table (include colors!, exclude \!, \#). You can also use this online prompt generator to create prompt value of your wish. To setup your favorite prompt simply add export HDFS_SHELL_PROMPT="value" to your .bashrc (or set env variable on Windows) and that's it. Restart HDFS Shell to apply change. Default value is currently set to \e[36m\[email protected]\h \e[0;39m\e[33m\w\e[0;39m\e[36m\\$ \e[37;0;39m.

Running Daemon mode

Image of HDFS-Shell

Project programming info

The project is using Gradle 3.x to build. By default it's using Hadoop 2.6.0, but it also has been succesfully tested with version 2.7.x. It's based on Spring Shell (includes JLine component). Using Spring Shell mechanism you can easily add your own commands into HDFS Shell. (see com.avast.server.hdfsshell.commands.ContextCommands or com.avast.server.hdfsshell.commands.HadoopDfsCommands for more details)

All suggestions and merge requests are welcome.

Other tech info:

For developing, add to JVM args in your IDE launch config dialog: -Djline.WindowsTerminal.directConsole=false -Djline.terminal=jline.UnsupportedTerminal

Known limitations & problems

Contact

Author&Maintainer: Ladislav Vitasek - vitasek/@/avast.com

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