dagger-helm/README.md

# helm-dagger

helm-dagger is a lightweight library that helps users to compile Helm charts
using custom values files. It simplifies the process of customizing Kubernetes
deployments for different environments or configurations. This library uses a
custom delimiter in the values files to avoid conflicts with Helm's default
delimiter.

## Features

- Customizable delimiters for the values files
- Lightweight and easy to integrate into your projects
- Allows using Helm charts with custom values files programmatically

## Dependencies

This library requires Docker to be installed.

## Usage

### 1. Import Helm-Dagger

Import the helm-dagger library into your project:

```bash
go get git.front.kjuulh.io/kjuulh/helm-dagger
```

```go
import (
  "context"
  helmdagger "git.front.kjuulh.io/kjuulh/helm-dagger"
)
```

### 2. Prepare your chart and values files

Store your chart and values files in a known directory. In this example, the
chart files are stored in the "test_data/nginx" directory, and the custom values
file is stored in the "test_data/nginx.values.yaml" file.

### 3. Call the Compile function

The Compile function is the main function to generate an output directory with
the customized chart. It accepts the following parameters:

- `ctx`: a context.Context instance
- `client`: a dagger.Client instance
- `chartPath`: the path to the chart directory
- `valuesFilePath`: the path to the custom values file

```go
helmOutput, err := helmdagger.Compile(ctx, client, "test_data/nginx", "test_data/nginx.values.yaml")
if err != nil {
    log.Fatal(err)
}
```

### 4. Export the customized chart

To export the customized chart, call the `Export` method on the returned
helmOutput:

```go
exported, err := helmOutput.Export(ctx, "test_data/dist")
if err != nil {
    log.Fatal(err)
}

if exported {
    log.Println("Helm chart successfully exported to test_data/dist")
} else {
    log.Fatal("Failed to export Helm chart")
}
```

### 5. Verify the chart

Check the output directory to see the compiled Helm chart:

```go
dir, err := os.ReadDir("test_data/dist/nginx/templates")
if err != nil {
    log.Fatal(err)
}

log.Printf("Found %d templates in the output directory", len(dir))
```

## Example

An example of using helm-dagger to compile a Helm chart with a custom values
file can be found in the test file:

```go
package helmdagger_test

import (
(...) // Import statements

func TestHelmDagger(t *testing.T) {
    (...) // Test setup

    helmoutput, err := daggerhelm.Compile(ctx, client, "test/test_data/nginx", "test/test_data/nginx.values.yaml")
    assert.NoError(t, err)

    exported, err := helmoutput.Export(ctx, "test/test_data/dist")
    assert.NoError(t, err)
    assert.True(t, exported)

    dir, err := os.ReadDir("test/test_data/dist/nginx/templates")
    assert.NoError(t, err)
    assert.Equal(t, 2, len(dir))
}
```

Now you can use Helm-Dagger to compile Helm charts with custom values files
programmatically, making it easier to manage different configurations for your
Kubernetes deployments.