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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FastForward
Flexible operating-system event and metric forwarding agent. Receives input and forwards output using plugins.
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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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Gauntlt
Gauntlt provides hooks to a variety of security tools and puts them within reach of security, dev and ops teams to collaborate to build rugged software. It is built to facilitate testing and communication between groups and create actionable tests that can be hooked into your deploy and testing processes.
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jclouds
A Java Library for controlling cloud resources, with various plugins for many popular cloud providers.
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KairosDB
KairosDB is a fast distributed scalable time series database written on top of Cassandra. RESTful JSON-based query/results. Includes flot-based visualization.
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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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