devenv-docker

A repository for the Nexus development environment Dockerfile and documentation. The nexus_dev Docker image provides everything a new developer might need to start working on Nexus' toolchain. It also allows for a consistent environment between developers, which can help with duplicating reported bugs.

The image currently contains:

• NodeJS
• Python + pip
• solc
• IPFS
• geth
• Git
• Vim
• inotifytools
• All of Nexus' Github repositories
• An FTP server
• A unprivileged default user

The image is based on a stripped-down Ubuntu distribution and may also contain other tools as a result. For a deeper understanding of this image, feel free to examine the Dockerfile.

Installation

A shell script called docker-run is provided to save you some typing. It wraps the docker run command, setting the --daemon flag and binding to host ports all the container ports the contained services need. If you want more control over this process (e.g., changing the host ports the container ports bind to), you may consider using docker run directly.

$ ./docker-run --name nexus ryepdx/nexus_dev

To get into the container, you will need to provide an SSH key via FTP. If you don't have an SSH key ready, you can generate one using ssh-keygen on Unix-like systems and Putty on Windows systems.

The default password for the "dev" user is "nexus". You will use these login credentials to connect to the container via FTP. Below is a demonstration of this process using the ftp command provided on most Unix-like systems. Windows also sometimes comes with an ftp command, but if your copy is missing that, you can use something like SmartFTP.

$ ifconfig

...
docker0   Link encap:Ethernet  HWaddr 02:42:2A:19:B8:B2
          inet addr:172.17.42.1  Bcast:0.0.0.0  Mask:255.255.0.0
...

$ ftp 172.17.42.1 2121

Name: dev
Password:

230 OK. Current directory is /home/dev
Remote system type is UNIX.
Using binary mode to transfer files.

ftp> put ~/.ssh/docker.pub .ssh/authorized_keys
local: /home/ryepdx/.ssh/docker.pub remote: .ssh/authorized_keys
200 PORT command successful
150 Connecting to port 42773
226-File successfully transferred

As long as you're FTPed in, you might as well also transfer over any Github keys you have.

ftp> put ~/.ssh/github.key .ssh/github.key
local: /home/ryepdx/.ssh/github.key remote: .ssh/github.key
200 PORT command successful
150 Connecting to port 42773
226-File successfully transferred

local: /home/ryepdx/.ssh/github.pub remote: .ssh/github.pub
200 PORT command successful
150 Connecting to port 54191
226-File successfully transferred

And that's it for the FTPing.

ftp> bye
221 Goodbye.

Then you can use SSH to login to your Docker container as the unprivileged dev user via the private counterpart to the public key you uploaded. This is the way you should normally access your container.

$ ssh -i ~/.ssh/docker.key -p 2222 dev@172.17.42.1

You might consider aliasing that SSH command to something shorter to save yourself time in the future.

To complete setup, you should change the dev user's password to something more secure and set the correct permissions on your keys.

$ passwd
Changing password for dev.
(current) UNIX password:
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
$ chmod 400 ~/.ssh/*.key*

Be aware that the Docker container does not start automatically when your system boots up. You may need to run docker start nexus after restarting or logging out of your computer before you can SSH in again.

If you are using SSH keys to connect to Github, you might want to use ssh-agent and ssh-add to cut down on the number of times you have to enter your SSH key's password when pulling from and pushing to Github.

In particular, you might consider adding these lines to your container's ~/.bashrc file:

if [ $(pgrep -c ssh-agent) -eq 0 ]; then
  rm ~/.ssh/ssh_auth_sock > /dev/null
fi

if [ ! -S ~/.ssh/ssh_auth_sock ]; then
  eval `ssh-agent` > /dev/null
  ln -sf "$SSH_AUTH_SOCK" ~/.ssh/ssh_auth_sock
fi
export SSH_AUTH_SOCK=~/.ssh/ssh_auth_sock
ssh-add -l | grep "The agent has no identities" && ssh-add -t 10800 ~/.ssh/github.key

This will make it so you're prompted upon SSHing in for your Github key's password and then left alone for three hours following.

Finally, while the image ships with Vim installed, you may also use FTP to modify files in the container using an editor of your choice.