Add InfluxDB support for traefik metrics

vendor/github.com/influxdata/influxdb/errors.go

@@ -0,0 +1,42 @@
+package influxdb
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// ErrFieldTypeConflict is returned when a new field already exists with a
+// different type.
+var ErrFieldTypeConflict = errors.New("field type conflict")
+
+// ErrDatabaseNotFound indicates that a database operation failed on the
+// specified database because the specified database does not exist.
+func ErrDatabaseNotFound(name string) error { return fmt.Errorf("database not found: %s", name) }
+
+// ErrRetentionPolicyNotFound indicates that the named retention policy could
+// not be found in the database.
+func ErrRetentionPolicyNotFound(name string) error {
+	return fmt.Errorf("retention policy not found: %s", name)
+}
+
+// IsAuthorizationError indicates whether an error is due to an authorization failure
+func IsAuthorizationError(err error) bool {
+	e, ok := err.(interface {
+		AuthorizationFailed() bool
+	})
+	return ok && e.AuthorizationFailed()
+}
+
+// IsClientError indicates whether an error is a known client error.
+func IsClientError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	if strings.HasPrefix(err.Error(), ErrFieldTypeConflict.Error()) {
+		return true
+	}
+
+	return false
+}