JumpGet

This tool makes sense if your network drops packets a lot. It works as if a file CDN on demand, assuming you have a good network connectivity on your VPS & you've set better TCP params on your VPS. I have a shitty network and this tool is making my life easier.

jumpget

JumpGet client submits download url to the JumpGet server with ssh tunnel, then JumpGet server downloads & serves the file only to the JumpGet client IPs(whitelisted).

Why?

scp, rsync are slow
wget vs JumpGet

Installation

JumpGet Server

You need a VPS instance with fast network. You can get a cheap instance from Linode ( referral link), Digital Ocean or AWS Lightsail etc.
Add your SSH public key to the server(~/.ssh/authorized_keys).
Setup the JumpGet Server

Without TLS

docker run --name jumpget -p 3100:3100 \
  -p 127.0.0.1:4100:4100 -d \
  -e JUMPGET_PUBLIC_PORT=3100 -e JUMPGET_LOCAL_PORT=4100 \
  -e JUMPGET_PUBLIC_URL="http://example.com:3100"  jumpget/jumpget

JumpGet Server with LetsEncrypt TLS

You can setup TLS with Traefik or Nginx. Checkout docker-compose.yaml for Traefik setup.

replace [email protected] with your own email address
relpace jumpget.example.com with your own domain name,

assuming the DNS has been configured correctly
docker-compose up -d

JumpGet Client

Checkout Releases for CircleCi built binaries.

For *nix systems:

JUMPGET_LATEST_VERSION=$(curl -s https://api.github.com/repos/jumpget/jumpget/releases/latest | grep "tag_name" | cut -d'v' -f2 | cut -d'"' -f1)
sudo curl -L https://github.com/lsgrep/jumpget/releases/download/v${JUMPGET_LATEST_VERSION}/jumpget_$(uname -s|tr '[:upper:]' '[:lower:]')_amd64 -o /usr/local/bin/jumpget
sudo chmod +x /usr/local/bin/jumpget

or just: go get -u github.com/lsgrep/jumpget

Configuration

Server Side Environment Variables

JUMPGET_LOCAL_PORT
JUMPGET_PUBLIC_PORT
JUMPGET_PUBLIC_URL
JUMPGET_FILE_RETAIN_DURATION default value 12, files will be deleted after 12 hours.

Client Configuration

$HOME/.jumpget.yaml stores client configuration info.

# $HOME/.jumpget.yaml
host: "example.com"
user: "example_user"
ssh-port: "2253"

jumpget --help to detailed information

JUMPGET_LOCAL_PORT default value 4100, this value should be consistent with server

Security

If you put JumpGet server on the same machine with the proxy or VPN, keep in mind that your traffic will go directly to the server.
Download tasks are submitted through ssh
Public File Server can only accessed through whitelisted IPs
whitelisted IPs are fetched through:
- $SSH_CONNECTION on JumpGet server

Performance

Enable better TCP congestion control method on JumpGet server

# /etc/sysctl.conf
# you have to have >= 4.15 Linux kernel to use bbr
net.ipv4.tcp_congestion_control=bbr

Here are the full set of params I've tweaked for my VPS instance for better connectivity.

net.ipv4.ip_forward=1

# Uncomment the next line to enable packet forwarding for IPv6
#  Enabling this option disables Stateless Address Autoconfiguration
#  based on Router Advertisements for this host
net.ipv6.conf.all.forwarding=1
net.ipv4.conf.all.proxy_arp = 1
net.core.netdev_max_backlog = 250000


# Usually SIP uses TCP or UDP to carry the SIP signaling messages over the internet (<=> TCP/UDP sockets).
# The receive buffer (socket receive buffer) holds the received data until it is read by the application.
# The send buffer (socket transmit buffer) holds the data until it is read by the underling protocol in the network stack.

net.core.rmem_max = 67108864

net.core.wmem_max = 33554432

net.core.rmem_default = 31457280
net.core.wmem_default = 31457280

net.ipv4.tcp_rmem = 10240 87380 10485760
net.ipv4.tcp_wmem= 10240 87380 10485760

# Increase the write-buffer-space allocatable
net.ipv4.udp_rmem_min = 131072
net.ipv4.udp_wmem_min = 131072
# net.ipv4.udp_mem = 65536 131072 262144
net.ipv4.udp_mem = 19257652 19257652 19257652
net.ipv4.tcp_mem = 786432 1048576 26777216

# Increase the maximum amount of option memory buffers
net.core.optmem_max = 25165824


# Set the value of somaxconn. This is the Max value of the backlog. The default value is 128.
# If the backlog is greater than somaxconn, it will truncated to it.
net.core.somaxconn = 65535

# The kernel parameter "netdev_max_backlog" is the maximum size of the receive queue.
net.core.netdev_max_backlog = 300000

# change the maximum number of open files
# be sure that /proc/sys/fs/inode-max is 3-4 times the new value of
# /proc/sys/fs/file-max, or you will run out of inodes.
# The upper limit on fs.file-max is recorded in fs.nr_open (which is 1024*1024)
fs.file-max = 500000

# The value 0 makes the kernel swap only to avoid out of memory condition.
# Do less swapping
vm.swappiness = 10
vm.dirty_ratio = 60
vm.dirty_background_ratio = 2

# The default operating system limits on mmap counts is likely to be too low
# used by vmtouch
vm.max_map_count=262144

# the maximum size (in bytes) of a single shared segment that a Linux process can allocate in its virtual address space.
# 1/2 of physical RAM,  shared memory segment theoretically is 2^64bytes. This is correspond to all physical RAM that you have.
kernel.shmmax = 1073741824

# total port range
net.ipv4.ip_local_port_range = 1024 65535


# fast fast fast
net.ipv4.tcp_fastopen = 3

# bbr 
net.core.default_qdisc=fq
net.ipv4.tcp_congestion_control=bbr

TODO

find a way to detect JumpGet server availability
make fetch IP process robust

# README