Docker alpine-ext images

Alpine Linux Docker image with additional stuff included

Tags

• 1.2-rich (based on alpine:3.7 - with edge repositories)
• 1.3-rich (based on alpine:3.7 - with edge repositories)

About the *-rich tags

Alpine Linux with following packages installed:

• bash
• dropbear
• openssh
• sudo
• iptables
• openjdk8
• rsync
• dstat
• curl
• procps

The dropbear is a lightweight SSH server and client.

The image uses a new /docker-entrypoint.sh script to configure and start the SSH server.

The OpenSSH server is not started in the default configuration. The package is installed mainly to provide scp and sftp-server functionality to the dropbear.

The image adds new alpine user which has entry in sudoers file. Password for the user is generated and stored in /tmp/password.alpine. The root's password is also stored on filesystem (/tmp/password.root) and in case it's not provided by environment variable it's newly generated.

Environment variables

The environment variables can be used to configure SSH server

Variable	Default	Description
SSH_PORT	22	TCP port on which SSH server will be started
ROOT_PASSWORD		root's password
ROOT_AUTHORIZED_KEY		entry to be added to /root/.ssh/authorized_keys
USER_PASSWORD		alpine user's password
USER_AUTHORIZED_KEY		entry to be added to /home/alpine/.ssh/authorized_keys

Sample usage

Start the container with root's password configured to "alpine". The dropbear SSH server will run on foreground.

docker run -e "ROOT_PASSWORD=alpine" -it kwart/alpine

Start the container with SSH private key authentication configured. The dropbear SSH server will run on background and bash on foreground

docker run -e "ROOT_AUTHORIZED_KEY=`cat ~/.ssh/id_rsa.pub`" -it kwart/alpine /bin/bash