runner: add the first config struct to read beaver.yml config

go.mod

@@ -6,5 +6,6 @@
 	github.com/go-cmd/cmd v1.4.1 // indirect
 	github.com/orus-io/go-flags v1.4.0
 	github.com/rs/zerolog v1.26.1
+	github.com/spf13/viper v1.11.0 // indirect
 	github.com/stretchr/testify v1.7.1 // indirect
 )

runner/config.go

+package runner
+
+import (
+	"github.com/spf13/viper"
+)
+
+type Variable struct {
+	Name  string `mapstructure:"name"`
+	Value string `mapstructure:"value"`
+}
+
+type Spec struct {
+	Variables []Variable `mapstructure:"variables"`
+}
+
+type Config struct {
+	APIVersion string `mapstructure:"apiVersion"`
+	Kind       string `mapstructure:"kind"`
+	Spec       Spec   `mapstructure:"spec"`
+}
+
+func NewConfig(configDir string) (*Config, error) {
+	// we ONLY search for files named beaver.yml
+	viper.SetConfigName("beaver")
+	viper.AddConfigPath(configDir)
+	if err := viper.ReadInConfig(); err != nil {
+		return nil, err
+	}
+	var config Config
+	if err := viper.Unmarshal(&config); err != nil {
+		return nil, err
+	}
+	return &config, nil
+}

runner/config_test.go

+package runner
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestConfig(t *testing.T) {
+	configDir := "fixtures/"
+	config, err := NewConfig(configDir)
+	require.NoError(t, err)
+	// first config.spec.variables entry name should be VAULT_KV in our test file
+	assert.Equal(t, "VAULT_KV", config.Spec.Variables[0].Name)
+}