Introduction YAML Syntax

YAML Configuration

A YAML file is used to represent the data that want to configure or settings on the applications to make easy and readible. The case configuration data here is a quick comparison of sample data in three different formats.

The one on the left is the XML where we display the list of servers and the information is the same as the data

represented in Json format in the middle and finally in YAML format on the right.

Example of YAML Usage

YAML is a structure that represents data from a created configuration. For example, configure a server with details:

• name: Server1
• owner: Ihsan
• created: 12122024
• status: active

then implement it into a YAML file like this

servers:
     - name: Server1
       owner: Ihsan
       created: 12122024
       status: active

We can see that the - sign indicates an array that has the fields name, owner, created and status.

Meanwhile, if we convert it to JSON from the YAML file it will look like this.

{
     "servers":[
         {
             "name": "Server1",
             "owner": "Ihsan",
             "created": 12122024,
             "status": "active"
         }
     ]
}

Then if we want to just add an array of values from a key then we can add it, for example, like this.

servers:
     - name: Server1
       owner: Ihsan
       created: 12122024
       status: active
       labels:
         - backend
         - services
         - apps

and if we convert it into a JSON file it will be like below.

{
     "servers":[
         {
             "name": "Server1",
             "owner": "Ihsan",
             "created": 12122024,
             "status": "active",
             "labels": [
                 "backend",
                 "services",
                 "apps"
             ]
         }
     ]
}

Learning about the YAML file format is very easy, it just takes a lot of practice to create this configuration using YAML files.

Things to pay attention to about YAML files

• The indentation of each line determines the parent child object.
• If we create an array of values from Yaml then it will be read sequentially if we change the order then the execution order will also change.
• If we want to make a comment, we can use the # sign at the beginning of the line.

Why do we study YAML Files

In this Kubernetes configuration, many files are created using YAML format, so we need to memorize and understand how the mechanism and creation of file formats use YAML. So that later when we create a Kubernetes service configuration we will not have difficulty digesting and understanding the configuration or structure of the YAML file that we have created.