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Do you know all the YAML tricks and gotchas?
Are there any YAML tips for Kubernetes?
Read along!
Are there any YAML tips for Kubernetes?
Read along!
1/
Let's cover the basics first.
YAML has three basic rules:
1. Indentation — only 2 or 4 spaces
2. Maps — key-value pairs
3. Lists — collections of things
Let's cover the basics first.
YAML has three basic rules:
1. Indentation — only 2 or 4 spaces
2. Maps — key-value pairs
3. Lists — collections of things
2/
Maps and lists are the basic building blocks of any YAML file.
Any value that is part of a list or of map's value can be a string, a number, a boolean, `null`, or another dictionary.
In most cases, strings don't require quotes.
But sometimes if you miss them...
Maps and lists are the basic building blocks of any YAML file.
Any value that is part of a list or of map's value can be a string, a number, a boolean, `null`, or another dictionary.
In most cases, strings don't require quotes.
But sometimes if you miss them...
3/
Apart from edge cases, there are some actual useful features if you write Kubernetes manifests:
- You can use `---` to delimit docs
- You can define snippets with `*` and reference them with `&`
Apart from edge cases, there are some actual useful features if you write Kubernetes manifests:
- You can use `---` to delimit docs
- You can define snippets with `*` and reference them with `&`
4/
What if you make a mistake?
How do you know?
You could use:
1. an online YAML linter like http://www.yamllint.com/
2. a CLI like https://yamllint.readthedocs.io/en/stable/
3. if you use Visual Studio Code, install the YAML extension from Red Hat for autocomplete https://marketplace.visualstudio.com/items?itemName=redhat.vscode-yaml
What if you make a mistake?
How do you know?
You could use:
1. an online YAML linter like http://www.yamllint.com/
2. a CLI like https://yamllint.readthedocs.io/en/stable/
3. if you use Visual Studio Code, install the YAML extension from Red Hat for autocomplete https://marketplace.visualstudio.com/items?itemName=redhat.vscode-yaml
5/
Is there any useful tool to edit YAML other than by hand?
`yq` https://mikefarah.github.io/yq/ is a command-line tool designed to transform YAML.
It is similar to another more popular tool called `jq` that focuses on JSON instead of YAML.
Is there any useful tool to edit YAML other than by hand?
`yq` https://mikefarah.github.io/yq/ is a command-line tool designed to transform YAML.
It is similar to another more popular tool called `jq` that focuses on JSON instead of YAML.
6/
That's it! This was a short intro to YAML (and YAML's gotchas). Do you know more tips? Let me know!
You might enjoy the previous threads too! You can find all of them here: https://twitter.com/danielepolencic/status/1298543151901155330
What would you like to see next? Please reply and let me know!
That's it! This was a short intro to YAML (and YAML's gotchas). Do you know more tips? Let me know!
You might enjoy the previous threads too! You can find all of them here: https://twitter.com/danielepolencic/status/1298543151901155330
What would you like to see next? Please reply and let me know!
