When comparing SaltStack vs Ansible, the Slant community recommends SaltStack for most people. In the question“What are the best configuration management tools?” SaltStack is ranked 1st while Ansible is ranked 2nd. The most important reason people chose SaltStack is:
Salt has an impressive welcoming and active community of users. There are user groups all over the world (Stockhom, Silicon Valley, Paris, and lots more), and an active [live chat.](http://saltstack.com/community/)
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Friendly and open community
Salt has an impressive welcoming and active community of users. There are user groups all over the world (Stockhom, Silicon Valley, Paris, and lots more), and an active live chat.
Pro Easy to read output
Salt's configuration files and setups are organized into YAML files. This makes them very easy to read and understand since YAML is considered very readable.
Pro Agentless via SSH is an option
Salt can run agentless just like ansible, allowing it to manage devices that you can't run an agent on (routers/switches, etc).
Pro Communicates through SSH or agents
Salt can communicate with clients through agents called minions, or through SSH.
Pro Scalable
With Salt you can have multiple layers of masters which result in an arrangement which distributes load and increases redundancy. Upstream masters can then control downstream masters and their minions.
Pro Cross-platform
Salt has support for Windows, Linux and Unix. Though it's fair to say that it's easier to use and it's more useful in Unix and Linux systems.
Pro Fast execution of commands
Salt works around a Salt master which has multiple agents (Salt minions) that have a persistent connection to the master. Because of this persistent connection, commands to the master are fast to reach the minions. Furthermore, the minions also save various data to the cache in order to make execution faster.
When compared against other tools to run the same actions, Salt almost always completes the actions in significantly less time.
Pro Agentless
Ansible does not use agents. Instead, all master-agent communications are handled via SSH commands or through the Paramiko module which provides a Python interface to SSH.
Pro Gentle learning curve
Ansible is agentless, making it quick and painless to setup. Ansible has clear and detailed documentation and provides plenty of built-in modules. Its DSL is obtained using YAML and a familiar template system.
Pro Simple tasks can be run from the command line
Some simple tasks such as triggering updates or reboots, or even checking if the service is running can be done without configuration files. These commands can be run from the command line instead.
Pro Support for major cloud providers
Ansible supports managing major cloud devices (AWS, RackSpace, Digital Ocean, OpenStack) through a collection of modules which are available.
Pro Extensible in any language / runtime
Although you may need to preinstall favorite programming environment, Ansible modules are accessed via shell calls and therefore any executable on the remote system built for use with Ansible may be used as an Ansible module.
Pro Web UI
Ansible has a Web UI in the form of AnsibleWorks AWX which unfortunately does not tie directly into the CLI. So configuration elements present in the CLI can not appear in the UI unless a sync pass is run. Although the Web UI is helpful and functional, it's still not as complete feature-wise as the CLI.
Pro Easy to customize
Ansible is very easy to customize. It doesn't force you to use a language with which you are unfamiliar. Instead, all commands are packaged into YAML modules which are called playbooks. So as long as you use a programming language that can output JSON, you are able to customize it.
Pro Rich diff
Modules that support rich diffs can expose nearly every detail of what will change. However not all core modules support diffs, so there may still be some opaque chances made.
Pro Creating reusable components is simple
Making roles modular and reusable is a fast process with Ansible.
Cons
Con Slow
Compared to other tools, Ansible requires more time to complete the same actions.
Con Somewhat weak documentation
Ansible is still relatively new, as far as server automation tools go. This is the reason that many users have found it's documentation lacking in some parts. Although this is mitigated by the fact that it's very easy to learn to use.
Con Too easy to move the port in the crappy scripts you've been using for years
If you have an extensive codebase of scripts, your users might find it too easy to just port in the same unsupportable crappy scripts they've been using for years.
Con Doesn't have its own inventory system
Ansible really depends on you to provide it a list of nodes to run on and doesn't actively maintain a central inventory
Con No Python API available, despite the fact that Ansible is written in Python
Despite being written and taking good advantage of the python environment, Ansible offers no python api for programming, and does not make it possible to follow best practices for writing custom Ansible modules.