HDFS for Go
This is a native golang client for hdfs. It connects directly to the namenode using the protocol buffers API.
It tries to be idiomatic by aping the stdlib
os package, where possible, and
implements the interfaces from it, including
Here's what it looks like in action:
client, _ := hdfs.New("namenode:8020") file, _ := client.Open("/mobydick.txt") buf := make(byte, 59) file.ReadAt(buf, 48847) fmt.Println(string(buf)) // => Abominable are the tumblers into which he pours his poison.
For complete documentation, check out the Godoc.
Along with the library, this repo contains a commandline client for HDFS. Like the library, its primary aim is to be idiomatic, by enabling your favorite unix verbs:
$ hdfs --help Usage: hdfs COMMAND The flags available are a subset of the POSIX ones, but should behave similarly. Valid commands: ls [-lah] [FILE]... rm [-rf] FILE... mv [-fT] SOURCE... DEST mkdir [-p] FILE... touch [-amc] FILE... chmod [-R] OCTAL-MODE FILE... chown [-R] OWNER[:GROUP] FILE... cat SOURCE... head [-n LINES | -c BYTES] SOURCE... tail [-n LINES | -c BYTES] SOURCE... du [-sh] FILE... checksum FILE... get SOURCE [DEST] getmerge SOURCE DEST put SOURCE DEST
Since it doesn't have to wait for the JVM to start up, it's also a lot faster
$ time hadoop fs -ls / > /dev/null real 0m2.218s user 0m2.500s sys 0m0.376s $ time hdfs ls / > /dev/null real 0m0.015s user 0m0.004s sys 0m0.004s
Best of all, it comes with bash tab completion for paths!
Installing the library
To install the library, once you have Go all set up:
$ go get -u github.com/colinmarc/hdfs
Installing the commandline client
Grab a tarball from the releases page and unzip it wherever you like.
You'll want to add the following line to your
To install tab completion globally on linux, copy or link the
file which comes with the tarball into the right place:
ln -sT bash_completion /etc/bash_completion.d/gohdfs
By default, the HDFS user is set to the currently-logged-in user. You can
override this in your
This library uses "Version 9" of the HDFS protocol, which means it should work with hadoop distributions based on 2.2.x and above. The tests run against CDH 5.x and HDP 2.x.
This library is heavily indebted to snakebite.