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 os.FileInfo and os.PathError.
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
Since it doesn't have to wait for the JVM to start up, it's also a lot faster
hadoop -fs:
$ 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!
To install the library, once you have Go all set up:
$ go get github.com/colinmarc/hdfs
Or, to install just the commandline client:
$ go get github.com/colinmarc/hdfs/cmd/hdfs
You'll also want to add two lines to your .bashrc or .profile:
source $GOPATH/src/github.com/colinmarc/hdfs/cmd/hdfs/bash_completion
HADOOP_NAMENODE="namenode:8020"
Or, to install tab completion globally on linux:
ln -sT $GOPATH/src/github.com/colinmarc/hdfs/cmd/hdfs/bash_completion /etc/bash_completion.d/gohdfs
This library is heavily indebted to snakebite.