Added mod for ssh tunneling

.travis.yml

@@ -4,16 +4,16 @@ language: shell
 
 branches:
   only:
-    - <baseimagename>-<modname> #replace variables, omit brackets
+    - openssh-server-ssh-tunnel
 
 services:
   - docker
 
 env:
   global:
-    - DOCKERHUB="linuxserver/mods" #don't modify
-    - BASEIMAGE="baseimagename" #replace
-    - MODNAME="modname" #replace
+    - DOCKERHUB="linuxserver/mods"
+    - BASEIMAGE="openssh-server"
+    - MODNAME="ssh-tunnel"
 
 jobs:
   include:
@@ -32,4 +32,4 @@ jobs:
         - echo $DOCKERPASS | docker login -u $DOCKERUSER --password-stdin
         # Push all of the tags
         - docker push ${DOCKERHUB}:${BASEIMAGE}-${MODNAME}-${TRAVIS_COMMIT}
-        - docker push ${DOCKERHUB}:${BASEIMAGE}-${MODNAME}
+        - docker push ${DOCKERHUB}:${BASEIMAGE}-${MODNAME}

README.md

@@ -1,15 +1,35 @@
 # Docker mod for openssh-server
 
-This mod adds rsync to openssh-server, to be installed/updated during container start.
+This mod adds ssh tunnelling to openssh-server, by enabling tcp forwarding during container start.
 
-In openssh-server docker arguments, set an environment variable `DOCKER_MODS=linuxserver/mods:openssh-server-rsync`
+In openssh-server docker arguments, set an environment variable `DOCKER_MODS=linuxserver/mods:openssh-server-ssh-tunnel`
 
-# Mod creation instructions
+If adding multiple mods, enter them in an array separated by `|`, such as `DOCKER_MODS=linuxserver/mods:openssh-server-ssh-tunnel|linuxserver/mods:openssh-server-mod2`
 
-* Ask the team to create a new branch named `<baseimagename>-<modname>`. Baseimage should be the name of the image the mod will be applied to. The new branch will be based on the `template` branch.
-* Fork the repo, checkout the template branch.
-* Edit the `Dockerfile` for the mod. `Dockerfile.complex` is only an example and included for reference; it should be deleted when done.
-* Inspect the `root` folder contents. Edit, add and remove as necessary.
-* Edit this readme with pertinent info, delete thse instructions.
-* Finally edit the `travis.yml`. Customize the build branch,and the vars for `BASEIMAGE` and `MODNAME`
-* Submit PR against the branch created by the team
+Note: `GatewayPorts` is set to `clientspecified`, this moves the responsibility to define the gateway host of the port to the client that opens the tunnel, e.g. `*:8080` to forward 8080 to all connection, default is localhost only.
+In addition it is still necessary to expose the same port on the container level, using either the `--expose` (only to other containers) or the `--port` (expose on host level/internet) run options (or the counterparts in docker-compose).
+
+Example:
+
+When creating the container with the following setup:
+```
+version: '2'
+services:
+  openssh-server:
+    image: linuxserver/openssh-server
+    environment:
+      - DOCKER_MODS=linuxserver/mods:openssh-server-ssh-tunnel
+    volumes:
+      - /path/to/appdata/config:/config
+    expose:
+      - 30000
+    ports:
+      - 2222:2222
+```
+
+It's possible to expose the client's port 8080 through the container's port 30000 like this:
+```
+ssh -R *:30000:localhost:8080 example.com -p 2222
+```
+
+Port 30000 will then only be available to other containers (e.g. a web server acting as a reverse proxy). When using `ports` instead of `expose` the port would be accessible from the host (and the network it resides in, e.g. the internet). The client command can be automated using autossh.

root/etc/cont-init.d/99-ssh-tunnel-config

@@ -0,0 +1,6 @@
+#!/usr/bin/with-contenv bash
+
+# allow tcp forwarding within openssh settings
+sed -i '/^AllowTcpForwarding/c\AllowTcpForwarding yes' /etc/ssh/sshd_config
+sed -i '/^GatewayPorts/c\GatewayPorts clientspecified' /etc/ssh/sshd_config
+echo "TcpForwarding is enabled"