Notes on Fabric 2 and Python 3

Fabric 2 is a Python package used for running commands on remote machines via SSH. Fabric 2 supports Python 3 and is a rewrite of the Fabric I used years ago. Here are my notes on using Fabric 2 and Python 3.

Set up SSH config and SSH agent

• Create or edit your ~/.ssh/config file to contain your remote host parameters

  Host myhost
      User myusername
      HostName myhost.com
      IdentityFile ~/.ssh/id_rsa
  

• Add your private key to your SSH agent

  $ ssh-add ~/.ssh/id_rsa
  

Create a project, create a virtualenv, and install fabric2

$ mkdir -p /tmp/my-project
$ cd /tmp/my-project
$ python3 -m venv venv
$ source venv/bin/activate
$ pip install fabric2

Create a fabfile.py script

Create a file /tmp/my-project/fabfile.py with the following contents. Note: "myhost" is the same name used in ~/.ssh/config described above.

from fabric2 import task

hosts = ["myhost"]

@task(hosts=hosts)
def mytask(c):
    print("Starting mytask...")
    with c.cd("/var"):
        c.run("ls -l")
    print("Done.")

Run the fabric script

In /tmp/my-project, with the virtualenv activated, run the fabric task to list the contents of /var on the remote host.

$ fab2 mytask 

Output:

Starting mytask...

total 48
drwxr-xr-x  2 root root   4096 backups
drwxr-xr-x  9 root root   4096 cache
drwxrwxrwt  2 root root   4096 crash
drwxr-xr-x 38 root root   4096 lib
drwxrwsr-x  2 root root   4096 local
drwxrwxrwt  2 root root   4096 lock
drwxrwxr-x 14 root root   4096 log
drwxrwsr-x  2 root root   4096 mail
drwxr-xr-x  2 root root   4096 opt
drwxr-xr-x  5 root root   4096 spool
drwxrwxrwt  2 root root   4096 tmp
drwxr-xr-x  3 root root   4096 www

Done.

See also / References

• Example fabfile (Upgrading from 1.x docs)
• paramiko SSHClient API reference