From 0f492e6eb62748be53b935097b46996f6e72faaf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dalibor=20Karlovi=C4=87?= <dalibor.karlovic@sigwin.hr>
Date: Thu, 3 Jun 2021 11:42:36 +0200
Subject: [PATCH] initial commit

---
 Dockerfile |  8 ++++++++
 README.md  | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 Dockerfile
 create mode 100644 README.md

diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..2dd0929
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,8 @@
+FROM alpine:3.13
+
+RUN apk add --no-cache --update openssh-client
+CMD ssh \ 
+    -o StrictHostKeyChecking=no \
+    -N ${TUNNEL_HOST} \
+    -L ${FORWARD_DSN}
+
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..12f9376
--- /dev/null
+++ b/README.md
@@ -0,0 +1,36 @@
+# SSH tunnel in Docker
+
+Use case: allow your Docker containers to use SSH tunnels
+to get into those hard to reach places like corporate resources,
+firewalled APIs etc.
+
+## Usage with Docker Compose
+
+```yaml
+services:
+    # your reglar services
+    
+    ssh-tunnel:
+        image: sigwinhq/ssh-tunnel:latest
+        environment:
+            # if the key is password-protected
+            SSH_AUTH_SOCK: "/ssh-agent"
+            # the host via which we tunnel
+            TUNNEL_HOST: "username@ssh.host.you.can.reach.example.com"
+            # what do we want to proxy to?
+            FORWARD_DSN: "*:443:firewalled-api.example.com:443"
+        volumes:
+            # your key is now usable by the tunnel
+            - $HOME/.ssh:/root/ssh:ro
+            # if the key is password-protected
+            - $SSH_AUTH_SOCK:/ssh-agent
+        # this part is to make the tunnel transparent to others
+        networks:
+            default:
+                aliases:
+                    - firewalled-api.example.com
+```
+
+After doing this, your other services should now have access
+to the firewalled API as if it's available directly,
+without even knowing about the proxy.