versed

README

versed

A tool for string replacement in automation.

Rationale

In many situations when working with pipelines there is not always a good way to handle versioning. A common way to get around this is to introduce sed in a pipeline to replace certain parts. However, if you would like the versions to be stored as Infrastructure as Code (IaC) and be able to update these through a pipeline, then it's more convenient to store the data structured.

A use case which triggered this project was the poor version handling in Terraform. Terrafile implementations all relied on pulling down entire repositories beforehand which is very clumsy if working with a monorepo or multiple modules in a repository.

How it works

Versed is a lightweight approach to versioning, which basically replaces variables in text files in a given folder and puts the output in a different folder.

Versed uses a versed.yml file to configure the variables to replace.

A versed.yml could look like this:

target: data
output: output
sources:
  source1: v1
  source2: v2

In order for versed to update values, the target files would need to be tagged like the following, using the &(versed.SOURCE_NAME) format.

So, if a target file looks like this:

[
  "&(versed.source1)",
  "&(versed.source2)"
]

When running versed with the above config and target file, it would produce:

[
  "v1",
  "v2"
]

Action

Usage

The recommended approach is that the versed.yml is put in the stage folder for the particular environment you want to represent. If you are in a GitOps environment with multiple stages and regions, you might have something like this:

    steps:
    - name: Set versions
      uses: fehlhabers/versed@v2
      with:
        dir: 'environment/westeurope/prod'

    - name: Apply terraform
    ...
    ...

Stand-alone

Apart from being used in a pipeline, versed is packaged as a binary which can be used stand alone in local development as well.

Installation

Linux

Download the binary from the release pages and move it to a folder which is in your path. For example: ~/.local/bin would work for Ubuntu.

Others

Multiple OS builds will come, but until then, the project can be built locally. In order to build, Golang is needed. Clone the repository and run go build . in order to build an executable.

Usage

Versed is simply run in the same folder as where you have your versed.yml or you specify a different config file.

versed -f test/versed.yml
versed