Using Array Variables in Scripts

Oct 13, 2025 by wbrum.org 50 views

Introduction

GitLab CI/CD is a powerful tool for automating the build, test, and deployment of software projects. One of the key features of GitLab CI/CD is its ability to use variables in the .gitlab-ci.yml file to customize the build process. However, when it comes to using arrays as variables, things can get a bit tricky. In this article, we'll explore how to use array variables in GitLab CI/CD YAML and provide some tips on how to avoid common pitfalls.

What are Array Variables?

Array variables are variables that store multiple values in a single variable. They are useful when you need to store a list of values that can be used in a script or a command. In GitLab CI/CD YAML, array variables are defined using the following syntax:

variables:
  myarray: ['abc', 'dcef']

Using Array Variables in Scripts

Once you've defined an array variable, you can use it in a script or a command using the following syntax:

script:
  - echo ${myarray[0]} ${myarray[1]}

However, as you may have noticed, the lint tool in GitLab CI/CD will throw an error when you try to use an array variable in a script. This is because the lint tool is not aware of the array syntax used in the variable definition.

Workaround: Using a String Variable

One way to work around this issue is to define a string variable that contains the array values separated by a delimiter, such as a comma or a space. Here's an example:

variables:
  myarray: "abc,dcef"

You can then use the string variable in a script or a command using the following syntax:

script:
  - echo ${myarray//,/ }

This will output the values of the array variable separated by spaces.

Using a Bash Array

Another way to work around this issue is to use a Bash array to store the values of the array variable. Here's an example:

script:
  - myarray=("abc" "dcef")
  - echo "${myarray[0]} ${myarray[1]}"

This will output the values of the array variable separated by spaces.

Using a YAML Array

GitLab CI/CD YAML also supports arrays as values in the YAML file. Here's an example:

variables:
  myarray:
    - abc
    - dcef

You can then use the YAML array in a script or a command using the following syntax:

script:
  - echo ${myarray[0]} ${myarray[1]}

This will output the values of the array variable separated by spaces.

Conclusion

In this article, we've explored how to use array variables in GitLab CI/CD YAML. We've discussed the different ways to define and use array variables, including using a string variable, a Bash array, and a YAML array. We've also provided some tips on how to avoid common pitfalls when using array variables in GitLab CI/CD YAML.

Best Practices

Here are some best practices to keep in mind when using array variables in GitLab CI/CD YAML:

Use a string variable to store the array values separated by a delimiter.
Use a Bash array to store the array values.
Use a YAML array to store the array values.
Avoid using the array syntax in the variable definition.
Use the correct syntax to access the array values in a script or a command.

Common Pitfalls

Here are some common pitfalls to avoid when using array variables in GitLab CI/CD YAML:

Using the array syntax in the variable definition.
Not using the correct syntax to access the array values in a script or a command.
Not defining the array variable before using it in a script or a command.

Conclusion

Introduction

In our previous article, we explored how to use array variables in GitLab CI/CD YAML. We discussed the different ways to define and use array variables, including using a string variable, a Bash array, and a YAML array. In this article, we'll answer some frequently asked questions about array variables in GitLab CI/CD YAML.

Q: What is the difference between a string variable and a YAML array?

A: A string variable is a variable that stores a single value as a string, while a YAML array is a variable that stores multiple values as an array. For example:

variables:
  mystring: "abc,dcef"
  myarray:
    - abc
    - dcef

Q: How do I access the values of a YAML array in a script or a command?

A: You can access the values of a YAML array in a script or a command using the following syntax:

script:
  - echo ${myarray[0]} ${myarray[1]}

Q: Can I use a Bash array to store the values of a YAML array?

A: Yes, you can use a Bash array to store the values of a YAML array. Here's an example:

script:
  - myarray=("abc" "dcef")
  - echo "${myarray[0]} ${myarray[1]}"

Q: How do I define a YAML array in a GitLab CI/CD YAML file?

A: You can define a YAML array in a GitLab CI/CD YAML file using the following syntax:

variables:
  myarray:
    - abc
    - dcef

Q: Can I use a YAML array to store multiple values of different types?

A: Yes, you can use a YAML array to store multiple values of different types. Here's an example:

variables:
  myarray:
    - abc
    - 123
    - true

Q: How do I access the values of a YAML array in a script or a command if the array has multiple values of different types?

A: You can access the values of a YAML array in a script or a command using the following syntax:

script:
  - echo ${myarray[0]} ${myarray[1]} ${myarray[2]}

Q: Can I use a YAML array to store a list of files or directories?

A: Yes, you can use a YAML array to store a list of files or directories. Here's an example:

variables:
  myarray:
    - file1.txt
    - file2.txt
    - dir1/
    - dir2/

Q: How do I access the values of a YAML array in a script or a command if the array stores a list of files or directories?

A: You can access the values of a YAML array in a script or a command using the following syntax:

script:
  - echo ${myarray[0]} ${myarray[1]} ${myarray[2]} ${myarray[3]}

Conclusion

In this article, we've answered some frequently asked questions about array variables in GitLab CI/CD YAML. We've discussed the different ways to define and use array variables, including using a string variable, a Bash array, and a YAML array. We've also provided some tips on how to access the values of a YAML array in a script or a command. By following these tips, you can use array variables effectively in your GitLab CI/CD YAML files.