Programming Languages and YAML

[Trevor]

YAML is can be used with programming languages, such as Ruby,
Python, or Bash.  Are there others?

[bonnevil · Accepted solution]

Yeah, many other languages. YAML's just a data serialization language that's typically UTF-8 encoded text, so really you could use it with any arbitrary programming language as a way to structure objects. The real question is whether the language in question has libraries or other facilities that make it easy to parse YAML files/input or to provide YAML output.

There's a fairly long list at yaml.org under "YAML Frameworks and Tools" that includes, in addition to the languages you mention, C/C++, C#/.Net, Golang, Haskell, Java, JavaScript, PHP, Rust, and a bunch I'm skipping over.

Ansible uses YAML for a bunch of things, of course. If you think of a playbook as a series of structured objects (plays) that contain other structures (hosts, tasks, handlers, play variables), it's really reasonable for that.  Likewise, structuring an inventory as YAML is also a reasonable application.  You should be aware that Ansible (to the best of my knowledge) uses YAML 1.1 syntax; YAML 1.2 has some additional restrictions, including the requirement that Booleans are `true` or `false`; not `True`, `yes`, or other variations that Ansible currently accepts.  (This is one reason why Red Hat teaches `true` and `false` as the preferred syntax for Booleans in playbooks, if at some point upstream decides to switch to YAML 1.2.)

[Travis · Accepted solution]

@Trevor -

Additionally, YAML is just a file format with lists, dictionaries, and key value pairs. It is very useful for Ansible, Python, and programming languages, but we are also able to use it for a ton of other things. For example, it can be even used in BASH scripts to get things like environment variables, etc.

Both YAML and JSON are used quite often to get formatted data and values because there are such nice tools like jq and yq for processing and accessing this data. I prefer the structure of YAML quite a bit for readability, but for programming languages and parsing things out, sometimes JSON is easier.