Render a configuration template

Use WithTemplate when one configuration file needs values that your program already knows at startup. Fuda renders the Go template before it parses YAML.

type TemplateData struct {
    Environment string
    Region      string
}

loader, err := fuda.New().
    FromFile("config.yaml").
    WithTemplate(TemplateData{
        Environment: "production",
        Region:      "us-east-1",
    }).
    Build()

Write template expressions in the YAML file:

environment: "{{ .Environment }}"
endpoint: "https://api.{{ .Region }}.example.com"

Quote template output when YAML should treat it as a string. If your file needs literal {{ or }}, pass custom delimiters with fuda.WithDelimiters.

Order with overrides

Fuda renders the template first. It applies WithOverrides to that rendered source next, then decodes YAML. An env tag can still override the decoded field after that step.

Next step

Apply a programmatic override to a rendered configuration.