temp commit

vendor/github.com/projectcalico/libcalico-go/lib/apiconfig/load.go

@@ -0,0 +1,76 @@
+package apiconfig
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/kelseyhightower/envconfig"
+	yaml "github.com/projectcalico/go-yaml-wrapper"
+	apiv3 "github.com/projectcalico/libcalico-go/lib/apis/v3"
+	log "github.com/sirupsen/logrus"
+)
+
+// LoadClientConfig loads the ClientConfig from the specified file (if specified)
+// or from environment variables (if the file is not specified).
+func LoadClientConfig(filename string) (*CalicoAPIConfig, error) {
+
+	// Override / merge with values loaded from the specified file.
+	if filename != "" {
+		b, err := ioutil.ReadFile(filename)
+		if err != nil {
+			return nil, err
+		}
+
+		c, err := LoadClientConfigFromBytes(b)
+		if err != nil {
+			return nil, fmt.Errorf("syntax error in %s: %v", filename, err)
+		}
+		return c, nil
+	}
+	return LoadClientConfigFromEnvironment()
+}
+
+// LoadClientConfig loads the ClientConfig from the supplied bytes containing
+// YAML or JSON format data.
+func LoadClientConfigFromBytes(b []byte) (*CalicoAPIConfig, error) {
+	var c CalicoAPIConfig
+
+	// Default the backend type to be etcd v3.  This will be overridden if
+	// explicitly specified in the file.
+	log.Debug("Loading config from JSON or YAML data")
+	c = CalicoAPIConfig{
+		Spec: CalicoAPIConfigSpec{
+			DatastoreType: EtcdV3,
+		},
+	}
+
+	if err := yaml.UnmarshalStrict(b, &c); err != nil {
+		return nil, err
+	}
+
+	// Validate the version and kind.
+	if c.APIVersion != apiv3.GroupVersionCurrent {
+		return nil, errors.New("invalid config file: unknown APIVersion '" + c.APIVersion + "'")
+	}
+	if c.Kind != KindCalicoAPIConfig {
+		return nil, errors.New("invalid config file: expected kind '" + KindCalicoAPIConfig + "', got '" + c.Kind + "'")
+	}
+
+	log.Debug("Datastore type: ", c.Spec.DatastoreType)
+	return &c, nil
+}
+
+// LoadClientConfig loads the ClientConfig from the specified file (if specified)
+// or from environment variables (if the file is not specified).
+func LoadClientConfigFromEnvironment() (*CalicoAPIConfig, error) {
+	c := NewCalicoAPIConfig()
+
+	// Load client config from environment variables.
+	log.Debug("Loading config from environment")
+	if err := envconfig.Process("calico", &c.Spec); err != nil {
+		return nil, err
+	}
+
+	return c, nil
+}