Getting Started

This guide should help describe the basics of deploying stuff with pyinfra.

Install pyinfra with pip or pipx (see full install instructions):

pip install pyinfra

To do something with pyinfra you need two things:

Inventory:

Hosts, groups and data. Hosts are targets for pyinfra to execute commands or state changes. Hosts can belong to one or more groups, and both groups and hosts can have data associated with them.

By default pyinfra assumes hosts can be reached over SSH. pyinfra can connect to other systems using connectors, for example: a Docker container or the local machine.

Operations:
Commands to execute or state to apply to the target hosts in the inventory. These can be simple shell commands “execute the uptime command” or state definitions such as “ensure the iftop apt package is installed”.

Ad-hoc commands with pyinfra

Let’s start off executing a simple ad-hoc shell command. The first argument always specifies the inventory and the following arguments specify the operations:

pyinfra INVENTORY OPERATIONS...

# Execute an arbitrary shell command over SSH
pyinfra my-server.net exec -- echo "hello world"

# Execute a shell command within a docker container
pyinfra @docker/ubuntu:18.04 exec -- bash --version

As you’ll see, pyinfra runs the echo command and prints the output. The CLI page contains more examples of ad-hoc commands.

State definitions

Now that we can execute ad-hoc shell commands, let’s define some state to ensure. The key feature here is that when you run these commands for a second time, pyinfra won’t need to do execute anything because the target is already up to date. You can read more about how this works in Executing Deploys.

# Ensure a package is installed on a Centos 8 instance
pyinfra @docker/centos:8 dnf.packages vim sudo=true

# Ensure a package is installed on multiple instances
pyinfra @docker/ubuntu:18.04,@docker/debian:9 apt.packages vim sudo=true

# Stop a service on a remote host over SSH
pyinfra my-server.net init.systemd httpd sudo=True running=False

In this case you can re-run the above commands and in the second instance pyinfra will report no changes need to be made.

Create a Deploy

A deploy is a collection of inventories and operations defined in Python files. These deploys can be saved and reused (committed to git, etc). Think of a deploy like Ansible’s playbook or Chef’s cookbook. We’ll now replicate the above hello world ad-hoc command as a deploy.

To get started let’s create an inventory.py containing our hosts to target:

my_hosts = ['my-server.net', '@docker/ubuntu:18.04']  # define a group as a list of hosts

Now we need a deploy.py containing our operations to execute:

from pyinfra.operations import apt, server

server.shell(
    name='Run an ad-hoc command',  # optional name for the operation
    commands='echo "hello world"',
)

# Define some state - this operation will do nothing on subsequent runs
apt.packages(
    name='Ensure the vim apt package is installed',
    packages=['vim'],
    sudo=True,  # use sudo when installing the packages
)

We can now execute this deploy like so:

pyinfra inventory.py deploy.py

That’s the basics of pyinfra! Possible next steps: