docker-documentation/images/docker-endlessh.md

title
endlessh

linuxserver/endlessh

Endlessh is an SSH tarpit that very slowly sends an endless, random SSH banner. It keeps SSH clients locked up for hours or even days at a time. The purpose is to put your real SSH server on another port and then let the script kiddies get stuck in this tarpit instead of bothering a real server.

Supported Architectures

We utilise the docker manifest for multi-platform awareness. More information is available from docker here and our announcement here.

Simply pulling lscr.io/linuxserver/endlessh:latest should retrieve the correct image for your arch, but you can also pull specific arch images via tags.

The architectures supported by this image are:

Architecture	Available	Tag
x86-64	✅	amd64-<version tag>
arm64	✅	arm64v8-<version tag>
armhf	✅	arm32v7-<version tag>

Application Setup

The app listens on the port mapped for ssh connections. To log to file, set the environment variable LOGFILE to true and map a volume for /config. The logs will be under /config/logs/endlessh.

Usage

To help you get started creating a container from this image you can either use docker-compose or the docker cli.

docker-compose (recommended, click here for more info)

---
version: "2.1"
services:
  endlessh:
    image: lscr.io/linuxserver/endlessh:latest
    container_name: endlessh
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Europe/London
      - MSDELAY=10000 #optional
      - MAXLINES=32 #optional
      - MAXCLIENTS=4096 #optional
      - LOGFILE=false #optional
      - BINDFAMILY= #optional
    volumes:
      - /path/to/appdata:/config #optional
    ports:
      - 22:2222
    restart: unless-stopped

docker cli (click here for more info)

docker run -d \
  --name=endlessh \
  -e PUID=1000 \
  -e PGID=1000 \
  -e TZ=Europe/London \
  -e MSDELAY=10000 `#optional` \
  -e MAXLINES=32 `#optional` \
  -e MAXCLIENTS=4096 `#optional` \
  -e LOGFILE=false `#optional` \
  -e BINDFAMILY= `#optional` \
  -p 22:2222 \
  -v /path/to/appdata:/config `#optional` \
  --restart unless-stopped \
  lscr.io/linuxserver/endlessh:latest

Parameters

Docker images are configured using parameters passed at runtime (such as those above). These parameters are separated by a colon and indicate <external>:<internal> respectively. For example, -p 8080:80 would expose port 80 from inside the container to be accessible from the host's IP on port 8080 outside the container.

Ports (-p)

Parameter	Function
2222	ssh port

Environment Variables (-e)

Env	Function
PUID=1000	for UserID - see below for explanation
PGID=1000	for GroupID - see below for explanation
TZ=Europe/London	Specify a timezone to use EG Europe/London
MSDELAY=10000	The endless banner is sent one line at a time. This is the delay in milliseconds between individual lines.
MAXLINES=32	The length of each line is randomized. This controls the maximum length of each line. Shorter lines may keep clients on for longer if they give up after a certain number of bytes.
MAXCLIENTS=4096	Maximum number of connections to accept at a time. Connections beyond this are not immediately rejected, but will wait in the queue.
LOGFILE=false	By default, the app logs to container log. If this is set to true, the log will be output to file under /config/logs/endlessh (/config needs to be mapped).
BINDFAMILY=	By default, the app binds to IPv4 and IPv6 addresses. Set it to 4 or 6 to bind to IPv4 only or IPv6 only, respectively. Leave blank to bind to both.

Volume Mappings (-v)

Volume	Function
/config	Required if LOGFILE is set to true.

Miscellaneous Options

Parameter	Function

Environment variables from files (Docker secrets)

You can set any environment variable from a file by using a special prepend FILE__.

As an example:

-e FILE__PASSWORD=/run/secrets/mysecretpassword

Will set the environment variable PASSWORD based on the contents of the /run/secrets/mysecretpassword file.

Umask for running applications

For all of our images we provide the ability to override the default umask settings for services started within the containers using the optional -e UMASK=022 setting. Keep in mind umask is not chmod it subtracts from permissions based on it's value it does not add. Please read up here before asking for support.

User / Group Identifiers

When using volumes (-v flags), permissions issues can arise between the host OS and the container, we avoid this issue by allowing you to specify the user PUID and group PGID.

Ensure any volume directories on the host are owned by the same user you specify and any permissions issues will vanish like magic.

In this instance PUID=1000 and PGID=1000, to find yours use id user as below:

  $ id username
    uid=1000(dockeruser) gid=1000(dockergroup) groups=1000(dockergroup)

Docker Mods

We publish various Docker Mods to enable additional functionality within the containers. The list of Mods available for this image (if any) as well as universal mods that can be applied to any one of our images can be accessed via the dynamic badges above.

Support Info

• Shell access whilst the container is running:
  • docker exec -it endlessh /bin/bash
• To monitor the logs of the container in realtime:
  • docker logs -f endlessh
• Container version number
  • docker inspect -f '{{ index .Config.Labels "build_version" }}' endlessh
• Image version number
  • docker inspect -f '{{ index .Config.Labels "build_version" }}' lscr.io/linuxserver/endlessh:latest

Versions

• 23.09.22: - Migrate to s6v3.
• 20.07.22: - Rebase to Alpine 3.16.
• 16.04.22: - Rebase to Alpine 3.15.
• 07.10.21: - Fix typo on MAXLINES var.
• 08.06.21: - Add BINDFAMILY option.
• 16.04.21: - Initial Release.