taosnet/ssh_server repository overview

⁠Description

Provides a lightweight base image to access containers via ssh. Only allows access via Public/Private keys, and disallows root access. Two environmental variables are provided to ease the setup and access of the containers: SSH_USER and SSH_AUTH_KEY. SSH_USER is the initial username to setup with access to the container. SSH_AUTH_KEY is the users public key to use for authentication. Note that using this container without any sort of volume does not make any sense.

⁠Usage

To run a simple container:

docker run --name myssh -d -v mydata:/data -e SSH_USER=myuser -e SSH_AUTH_KEY=myuserkey... -p 2222:22 taosnet/ssh_server

⁠Scenarios

This container can be used with other containers to provide a backup of docker volumes host to host. Consider the scenario where you want to provide backups of an authoritative name server across hosts:

Consider an authoritative name server running on Host A:

docker run --name ns1 -d -p 53:53/tcp -p 53:53/udp -v ns1:/etc/pdns/db taosnet/pdns_server

First create the keys to use for the backup:

docker run --rm -ti -v backup-key:/root/.ssh --entrypoint /bin/sh taosnet/scp
# chmod 700 /root/.ssh
# dropbearkey -t rsa -s 4096 -f /root/.ssh/id_dropbear
# exit

Make sure to copy the public key output to for use on Host B the backup server:

docker run --name ns1-backup -d -p 2222:22 -v ns1:/home/backup/db -e SSH_USER=backup -e 'SSH_AUTH_KEY=public_key_from_above_command_output...' taosnet/ssh_server
docker exec ns1-backup chown backup /home/backup/db

To backup the server:

On Host A:

You should run the first time interactively to accept the host key from the server on Host B.

docker run --rm -ti -v backup-key:/root/.ssh -v ns1:/etc/pdns/db taosnet/scp -P 2222 /etc/pdns/db/zones.db backup@hostb:/home/backup/db

Subsequent runs can be:

docker run --rm -v backup-key:/root/.ssh -v ns1:/etc/pdns/db taosnet/scp -P 2222 /etc/pdns/db/zones.db backup@hostb:/home/backup/db

⁠Utilities

• setupUser.sh: Simple shell script to make it easier to setup multiple users. It has two usages. First to setup new users: setupUser.sh [-g group] [-k sshKey] username. The second use is to add a ssh key to an existing user: setupUser.sh -k sshKey username.

⁠Environmental Variables

• SSH_USER is the username of the initial user to setup.
• SSH_AUTH_KEY is the public key of SSH_USER to setup Public/Private key authentication with.