piku/README.md

piku, inspired by dokku, allows you do git push deployments to your own servers, no matter how small they are.

Demo

Documentation: Using | Install | Procfile | ENV | Examples | Roadmap | Contributing | LinuxConf Talk | Fast Web App Tutorial | Discussion Forum

Project Activity

piku is considered STABLE. It is actively maintained, but "actively" here means the feature set is pretty much done, so it is only updated when new language runtimes are added or reproducible bugs crop up.

It is currently being refactored to require Python 3.7 or above, since even though 3.8+ is now the baseline Python 3 version in Ubuntu LTS 20.04 and Debian 11 has already moved on to 3.9, there are no substantial differences between those versions.

Deprecation Notices

Since most of its users run it on LTS distributions, there is no rush to introduce disruption. The current plan is to throw up a warning for older runtimes and do regression testing for 3.7, 3.8, 3.9 and 3.10 (replacing the current bracket of tests from 3.5 to 3.8), and make sure we also cover Ubuntu 22.04, Debian 11 and Fedora 37+.

Goals and Motivation

I kept finding myself wanting an Heroku/CloudFoundry-like way to deploy stuff on a few ARM boards and my Raspberry Pi cluster, but since dokku didn't work on ARM at the time and even docker can be overkill sometimes, I decided to roll my own.

piku is currently able to deploy, manage and independently scale multiple applications per host on both ARM and Intel architectures, and works on any cloud provider (as well as bare metal) that can run Python, nginx and uwsgi.

Core values

• Must run on low end devices.
• Accessible to hobbyists and K-12 schools.
• ~1500 lines readable code.
• Functional code style.
• Few (single?) dependencies
• 12 factor app.
• Simplify user experience.
• Cover 80% of common use cases.
• Sensible defaults for all features.
• Leverage distro packages in Raspbian/Debian/Ubuntu (Alpine and RHEL support is WIP)
• Leverage standard tooling (git, ssh, uwsgi, nginx).
• Preserve backwards compatibility where possible

Using piku

piku supports a Heroku-like workflow:

• Create a git SSH remote pointing to your piku server with the app name as repo name: git remote add piku piku@yourserver:appname.
• Push your code: git push piku master (or if you want to push a different branch than the current one use git push piku release-branch-name).
• piku determines the runtime and installs the dependencies for your app (building whatever's required).
  • For Python, it segregates each app's dependencies into a virtualenv.
  • For Go, it defines a separate GOPATH for each app.
  • For Node, it installs whatever is in package.json into node_modules.
  • For Java, it builds your app depending on either pom.xml or build.gradle file.
  • For Clojure, it can use either leiningen or the Clojure CLI and a eps.edn file.
  • For Ruby, it does bundle install of your gems in an isolated folder.
• It then looks at a Procfile which is documented here and starts the relevant workers using uWSGI as a generic process manager.
• You can optionally also specify a release worker which is run once when the app is deployed.
• You can then remotely change application settings (config:set) or scale up/down worker processes (ps:scale).
• You can also bake application and nginx settings into an ENV file which is documented here.

You can also deploy a gh-pages style static site using a static worker type, with the root path as the argument, and run a release task to do some processing on the server after git push.

Virtual Hosts and SSL

piku has full virtual host support - i.e., you can host multiple apps on the same VPS and use DNS aliases to access them via different hostnames.

piku will also set up either a private certificate or obtain one via Let's Encrypt to enable SSL.

If you are on a LAN and are accessing piku from macOS/iOS/Linux clients, you can try using piku/avahi-aliases to announce different hosts for the same IP address via Avahi/mDNS/Bonjour.

Caching and Static Paths

Besides static sites, piku also supports directly mapping specific URL prefixes to filesystem paths (to serve static assets) or caching back-end responses (to remove load from applications).

These features are configured by setting appropriate values in the ENV file.

Supported Platforms

piku is intended to work in any POSIX-like environment where you have Python, nginx, uWSGI and SSH: it has been deployed on Linux, FreeBSD, Cygwin and the Windows Subsystem for Linux.

As a baseline, it began its development on an original 256MB Rasbperry Pi Model B, and still runs reliably on it.

But its main use is as a micro-PaaS to run applications on cloud servers with both Intel and ARM CPUs, with Debian and Ubuntu Linux as target platforms.

Supported Runtimes

piku currently supports apps written in Python, Node, Clojure, Java and a few other languages (like Go) in the works.

But as a general rule, if it can be invoked from a shell, it can be run inside piku.

Install

piku can manage multiple apps on a single machine, and all you need is a VPS, Raspberry Pi, or other server.

There are two main ways of deploying piku onto a new server:

• Use piku-bootstrap to reconfigure a new or existing Ubuntu virtual machine.
• Use cloud-init when creating a new virtual machine or barebones automated deployment (check this repository for examples).

Manage - via the piku helper

To make life easier you can also install the piku helper into your path (e.g. ~/bin).

curl https://raw.githubusercontent.com/piku/piku/master/piku > ~/bin/piku && chmod 755 ~/bin/piku

This shell script simplifies working with multiple piku remotes and applications:

• If you cd into a project folder that has a git remote called piku the helper will infer the remote server and app name and use them automatically:

$ piku logs
$ piku config:set MYVAR=12
$ piku stop
$ piku deploy
$ piku destroy
$ piku # <- show available remote and local commands

• If you are starting a new project, piku init will download example Procfile and ENV files into the current folder:

$ piku init
Wrote ./ENV file.
Wrote ./Procfile.

• The piku helper also lets you pass settings to the underlying SSH command: -t to run interactive commands remotely, and -A to proxy authentication credentials in order to do remote git pulls.

For instance, here's how to use the -t flag to obtain a bash shell in the app directory of one of your piku apps:

$ piku -t run bash
Piku remote operator.
Server: piku@cloud.mccormickit.com
App: dashboard

piku@piku:~/.piku/apps/dashboard$ ls
data  ENV  index.html  package.json  package-lock.json  Procfile  server.wisp