databricks-cli/bundle/config/mutator/set_variables.go

package mutator

import (
	"context"

	"github.com/databricks/cli/bundle"
	"github.com/databricks/cli/bundle/config/variable"
	"github.com/databricks/cli/libs/diag"
	"github.com/databricks/cli/libs/env"
)

const bundleVarPrefix = "BUNDLE_VAR_"

type setVariables struct{}

func SetVariables() bundle.Mutator {
	return &setVariables{}
}

func (m *setVariables) Name() string {
	return "SetVariables"
}

func setVariable(ctx context.Context, v *variable.Variable, name string) diag.Diagnostics {
	// case: variable already has value initialized, so skip
	if v.HasValue() {
		return nil
	}

	// case: read and set variable value from process environment
	envVarName := bundleVarPrefix + name
	if val, ok := env.Lookup(ctx, envVarName); ok {
		if v.IsComplex() {
			return diag.Errorf(`setting via environment variables (%s) is not supported for complex variable %s`, envVarName, name)
		}

		err := v.Set(val)
		if err != nil {
			return diag.Errorf(`failed to assign value "%s" to variable %s from environment variable %s with error: %v`, val, name, envVarName, err)
		}
		return nil
	}

	// case: Defined a variable for named lookup for a resource
	// It will be resolved later in ResolveResourceReferences mutator
	if v.Lookup != nil {
		return nil
	}

	// case: Set the variable to its default value
	if v.HasDefault() {
		err := v.Set(v.Default)
		if err != nil {
			return diag.Errorf(`failed to assign default value from config "%s" to variable %s with error: %v`, v.Default, name, err)
		}
		return nil
	}

	// We should have had a value to set for the variable at this point.
	return diag.Errorf(`no value assigned to required variable %s. Assignment can be done through the "--var" flag or by setting the %s environment variable`, name, bundleVarPrefix+name)
}

func (m *setVariables) Apply(ctx context.Context, b *bundle.Bundle) diag.Diagnostics {
	var diags diag.Diagnostics
	for name, variable := range b.Config.Variables {
		diags = diags.Extend(setVariable(ctx, variable, name))
		if diags.HasError() {
			return diags
		}
	}
	return diags
}