Buildstep
Buildstep uses Docker and small buildpack scripts to build applications like Heroku. It was used by Dokku to create a 100-line Heroku clone. There are many open source Buildpack scripts for various languages like Java, Ruby, Erlang, PHP, etc.
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Eucalyptus
An open source software for building Amazon EC2-compatible private and hybrid cloud platforms
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Fog
The Ruby Cloud API library. Provides a Ruby API for interacting and managing many cloud providers, such as spinning up new instances, terminating old ones, attaching storage, etc. Currently supports more than 20 providers, including EC2, Rackspace, Brightbox, etc.
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Foreman
A complete lifecycle management tool for servers, both self-hosted and in the cloud. It allows you to create and manage instances, build and deploy images, view and audit hosts, and much more! It works with Puppet or Chef, and has multiple interaction facilities like a web frontend, CLI and a RESTful API.
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jclouds
A Java Library for controlling cloud resources, with various plugins for many popular cloud providers.
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Monit
An open source utility for managing and monitoring processes, programs, files, directories and filesystems
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Pallet
A tool to provision and maintain servers across various cloud platforms as well as virtual machine platforms, without any dependencies. Provides cloud and operating system independence.
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SSH KeyBox
An open-source jump box solution with auditing capabilities
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Supervisord Monitor
Supervisord Monitor is multi server monitoring tool for supervisor - watch, start and stop all your supervisord instances and servvices from one place.
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Apache ZooKeeper
ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. It is distributed and highly reliable, with Consensus, group management and presence protocols built-in.
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