[core] Beginning of confsys.Service for configuration overhaul

Author: teo

core/confsys/service.go

@@ -0,0 +1,124 @@
+/*
+ * === This file is part of ALICE O² ===
+ *
+ * Copyright 2019 CERN and copyright holders of ALICE O².
+ * Author: Teo Mrnjavac <teo.mrnjavac@cern.ch>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * In applying this license CERN does not waive the privileges and
+ * immunities granted to it by virtue of its status as an
+ * Intergovernmental Organization or submit itself to any jurisdiction.
+ */
+
+package confsys
+
+import (
+	"io/ioutil"
+	"strconv"
+	"strings"
+
+	"github.com/AliceO2Group/Control/configuration"
+)
+
+
+type Service struct {
+	src configuration.Source
+}
+
+/* Expected structure:
+/o2/aliecs/
+{
+	run_number_file: "/path/to/rn/file",
+        - or -
+	run_number: 47102,
+
+	settings: {
+		log_level: "DEBUG"
+	},
+	global_vars: {
+		n_flps: 42
+	},
+	repositories: {
+		base: {
+			url: "https://gitlab.cern.ch/foo/bar",
+			user: "gituser",
+			pass: "gitpass"
+		},
+		extra: {...}
+	}
+}
+
+*/
+func formatKey(key string) (consulKey string) {
+	// Trim leading slashes
+	consulKey = strings.TrimLeft(key, "/")
+	return
+}
+
+func NewService(uri string) (svc *Service, err error) {
+	var src configuration.Source
+	src, err = configuration.NewSource(uri)
+	return &Service{src: src}, err
+}
+
+func (s *Service) NewRunNumber() (runNumber uint64, err error) {
+	if cSrc, ok := s.src.(*configuration.ConsulSource); ok {
+		return cSrc.GetNextUInt64("o2/control/run_number")
+	} else {
+		// Unsafe check-and-set, only for file backend
+		var rnf string
+		rnf, err = s.src.Get("o2/control/run_number_file")
+		if err != nil {
+			return
+		}
+		var raw []byte
+		raw, err = ioutil.ReadFile(rnf)
+		if err != nil {
+			return
+		}
+		runNumber, err = strconv.ParseUint(string(raw[:]), 10, 64)
+		if err != nil {
+			return
+		}
+		runNumber++
+		raw = []byte(strconv.FormatUint(runNumber, 10))
+		err = ioutil.WriteFile(rnf, raw, 0)
+		return
+	}
+}
+
+func (s *Service) GetROSource() configuration.ROSource {
+	return s.src
+}
+
+// maybe this one shouldn't exist at all, because vars should get inserted
+// response: but not all of them! some vars will likely only get parsed at deployment time i.e. right
+//    before pushing TaskInfos
+func (s *Service) GetVars() map[string]string {
+	//FIXME: implement
+	return nil
+}
+
+// Or maybe even "RefreshConfig" which will refresh all the things that happen to be runtime-refreshable
+func (s *Service) RefreshRepositories() {
+	panic("not implemented yet")
+}
+
+// Returns a YAML file OR even a structure made of Roles or Nodes with:
+// import() functions already computed and resolved
+// vars inserted (todo: figure out which vars get parsed when and where)
+func (s *Service) GenerateWorkflowDescriptor(wfPath string, vars map[string]string /*vars from cli/gui*/) string {
+	panic("not implemented yet")
+}