Jenkins SSH slave launcher for 10x faster data transfer rates when archiving/copying artifacts. Leverages the learnings from: http://www.damtp.cam.ac.uk/user/ejb48/sshspeedtests.html

gistfile1.sh

#!/bin/bash

# High-performance, native SSH implementation for Jenkins SSH slaves. Jenkins'
# standard turn-key SSH slave implementation uses an embedded, "pure Java"
# implementation of SSH (https://github.com/jenkinsci/trilead-ssh2).
# That standard implementation combines all of the convenience of a pure Java
# implementation with all of the "performance" of a pure Java implementation :P

# If your distributed build process generates large build artifacts like ISOs,
# VM images, Vagrant boxes, etc, then you will see a substantial benefit from
# switching to this custom slave launcher method. Ex: 5 MB/sec -> 40 MB/sec

# Given a hostname, we copy over Jenkins's "slave.jar" to that host and launch
# it with "java -jar ...".  This script should be run from the Jenkins master
# via a custom "Launch method" on the slave node's configuration page.

# Background on distributed builds w/Jenkins:
#   @see: https://wiki.jenkins-ci.org/display/JENKINS/Distributed+builds

set -ex

JENKINS_SLAVE_HOSTNAME=

JENKINS_DIR=/jenkins
JENKINS_URL=http://`hostname -f`
JENKINS_USER=jenkins

while getopts "d:h:u:" opt; do
  case $opt in
    d) JENKINS_DIR="$OPTARG"
       ;;
    h) JENKINS_SLAVE_HOSTNAME="$OPTARG"
       ;;
    u) JENKINS_USER="$OPTARG"
       ;;
    *) echo "invalid option: $1" 1>&2;
    ;;
  esac
done

if [ -z $JENKINS_SLAVE_HOSTNAME ]; then
  echo "Error: Host name of slave must be specified with '-h <slave hostname>'"
  exit 100
fi


# Tune SSH for performance.
#   @see: http://www.damtp.cam.ac.uk/user/ejb48/sshspeedtests.html
SSH_CIPHERS="arcfour256,arcfour128,arcfour,blowfish-cbc"
SSH_MACS="umac-64@openssh.com,hmac-md5"
SSH_SECURITY_OPTS="-o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no"
SSH_COMMAND="ssh -c ${SSH_CIPHERS} -o MACs=${SSH_MACS} ${SSH_SECURITY_OPTS}"


JENKINS_TMPDIR="${JENKINS_DIR}/tmp"
DOWNLOAD_COMMAND="curl -o ${JENKINS_DIR}/slave.jar ${JENKINS_URL}/jnlpJars/slave.jar"
LAUNCH_SLAVE_COMMAND="java -Djava.io.tmpdir=${JENKINS_TMPDIR} -jar ${JENKINS_DIR}/slave.jar"


# download slave.jar & run it.
#
# NOTE: we need to do this all in one command otherwise Jenkins will fail the
# launching of the slave with a communication exception. I think this is
# because STDIN/STDOUT become polluted and Jenkins master is using those
# streams for communication with the remote Java process?
${SSH_COMMAND} ${JENKINS_USER}@${JENKINS_SLAVE_HOSTNAME} \
    "cd ${JENKINS_DIR} && ${DOWNLOAD_COMMAND} && TMPDIR=${JENKINS_TMPDIR} ${LAUNCH_SLAVE_COMMAND}"