A question about YAML syntax

General Discussions
1

When I read a YAML file,I find several sentences puzzling me：

      containers:      
      - name: demo     
        image: demo:v1      
        imagePullPolicy: IfNotPresent

Why doesn’t the “-” before “name” need indenting?
I think the list [“name”,“image”, …] should belong to “containers”.

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2

Kubernetes pods can be made up of multiple containers, that’s why containers is an array :+1:

A common example would be a worker container or say a webserver and then another one that is used for shipping logs, or if you’re using a service mesh to act as a ‘router’ to encrypt communication to other pods.

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4

Thanks for your answer.
I know containers is an array,so the “-” before name should be indented,but why doesn’t it do here?

5

Ahh, sorry -
So for arrays in yaml (yaml spec refers to them as collections), the space doesn’t matter because it can tell it’s an element of a collection by looking for a dash then a space “- “.

Because it can clearly parse the elements, the spacing doesn’t matter.

6

In YAML, the - indicates a list item, and it must be at the same indentation level as the parent key (containers). The list items (name, image, etc.) are indented under -, but the - itself aligns with containers to show they belong to it. So containers is a list, and each - starts a new item in that list.