YAML Syntax
YAML syntax is based on indentation and key-value pairs. Indentation is used to indicate the data hierarchy and key-value pairs are used to store data. For example, the following YAML code defines a server with two ports:
Server:
name: ninja-server
image: ninja-image
ports:
- 80:80
- 440:440
The server key is indented one level, which indicates that it is a parent of the name, image, and port keys.
The name and image keys are indented on two levels, indicating that they are the server key's children port key is indented on three levels, which indicates that it is a child of the server key and a grandchild of the name key.
Why to choose Yaml for DevOps?
YAML is a human-readable data serialization language and YAML for DevOps is used because:
-
Human-Readable: YAML for DevOps is simple to understand even for non-programmers. It is very easy to adapt and modification of the CI/CD pipelines becomes an easy task.
-
Flexible: With the use of YAML, a variety of data structures can be represented. This makes it the perfect choice for developers who want to modify CI/CD pipelines.
-
Version control Friendly: YAML files are version control friendly, as they can be easily versioned in a Git repository. This makes it simple to track changes to the CI/CD pipelines and can roll back to a previous version if required.
- Improved Collaboration: Team members can easily share and collaborate on YAML files. This ensures constant change to CI/CD pipelines and keeps everyone on the same page.
YAML Tools
Let's see some of the popular tools to use with YAML for better writing and features:
-
YAML Lint: It is a linter which is used to validate YAML code and to find out potential errors or bugs.
- YAML Editor: It is a text editor that has some unique features for editing YAML code.
YAML for DevOps
DevOps is a set of practices that combines software development (Dev) and IT operations (Ops). YAML for DevOps can be used for a variety of tasks, such as:
Configuring infrastructure
YAML can be used to configure infrastructure, such as servers, networks, and storage. This helps ensure that infrastructure is consistent and can be easily managed.
A typical example of YAML code which is use to configure a server:
server:
name: ninja-server
image: ninja-image
ports:
- 80:80
Defining pipelines
YAML can be used to define pipelines, a series of steps executed to build, test, and deploy code. This can automate the development process and improve the efficiency of DevOps teams.
A typical example of YAML code that is use to define a pipeline that builds, tests, and deploys code:
pipeline:
stages:
- build:
steps:
- checkout:
path:
- run:
command: make build
- test:
steps:
- run:
command: make test
- deploy:
steps:
- run:
command: make deploy
Managing deployments
YAML is used to manage deployments which is the process of delivering code to the production level. This helps ensure that deployments are successful. Also, the changes can be rolled back if needed.
The following YAML code snippet can use to manage a deployment:
deployment:
name: test-deploy
environment: staging
strategy: blue-green
rollback:
enabled: false
Secrets management
YAML can manage secrets, such as passwords and API keys. This can help to keep secrets secure and prevent them from being accidentally exposed.
The following YAML code snipped can use to store a password in a secret file:
secrets:
password: ninjas
Configuration management
YAML is widely used to manage configuration and infrastructure for applications. This ensures that the configuration set is consistent and can easily manage.
A typical example of YAML code that can use to configure a web application:
application:
name: test-app
environment: production
port: 8000
YAML Best Practices
Let us see some important best practices to follow when using YAML:
-
Consistent indentation: Indentation is used to indicate the hierarchy of data, so it is important to use consistent indentation throughout your YAML code. For example, if we have a list of items then each item has to be indented by one level.
-
Adding comments: Comments are used to deliver and explain the meaning of the YAML code which make it easier to maintain. Comments are started with ‘#’ and are ignored by the parser.
-
Use YAML schema: schema helps in defining the structure of the data. It helps in data assurance and provides easier access to other tools.
-
Use spaces instead tabs: using tabs in YAML can cause errors as it only supports spaces for indentation.
-
Validating YAML files: A YAML validator can be used to ensure that your YAML files are valid or not. To name a few editors such as yaml-validate and yaml-lint. These editors can help to prevent any errors caused by indentation, tabs use etc.
- Use meaningful names: key and value names should be meaningful as it helps to understand what the YAML file is doing.
Frequently Asked Questions
How is YAML different from other Markup languages?
YAML is very different from other languages in many aspects as it is human-readable and more powerful than JSON or XML. Also, it allows for comments and uses indentation to indicate a structure, etc.
Can we use YAML for DevOps for both data configuration and data serialisation?
Yes, YAML can be used for both configuration and data serialisation as it is a human-readable data serialisation language so, it is often used to write configuration files.
Which tools and frameworks are supported in YAML for DevOps?
YAML has a wide range of tools and frameworks to support, such as Jenkins, ansible, docker, Chef, and Terraform. These tools use YAML to define configuration files that are used to automate tasks such as deployment etc.
What are the common mistakes while using YAML for DevOps?
There are many common mistakes that should be avoided like using tabs instead of space for indentation, not using a consistent style and not using version control for file tracking.
Conclusion
Congratulations, you did a fantastic job!! This article has gone through the fundamentals of YAML for DevOps and discussed various use cases of it with the help of code examples. At last, some frequently asked questions have been discussed.
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