first commit

internal/ready/ready.go

@@ -0,0 +1,166 @@
+/*
+© Copyright IBM Corporation 2018, 2024
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package ready contains code to provide a ready signal mechanism between processes
+package ready
+
+import (
+	"context"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/ibm-messaging/mq-container/internal/command"
+)
+
+const readyFile string = "/run/runmqserver/ready"
+const readyToSyncFile string = "/run/runmqserver/ready-to-sync"
+
+func fileExists(fileName string) (bool, error) {
+	_, err := os.Stat(fileName)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return false, err
+		}
+		return false, nil
+	}
+	return true, nil
+}
+
+// Clear ensures that any readiness state is cleared
+func Clear() error {
+	err := clearFile(readyFile)
+	if err != nil {
+		return err
+	}
+	err = clearFile(readyToSyncFile)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// clearFile removes the specified file if it exists
+func clearFile(fileName string) error {
+	exist, err := fileExists(fileName)
+	if err != nil {
+		return err
+	}
+	if exist {
+		return os.Remove(fileName)
+	}
+	return nil
+}
+
+// Set lets any subsequent calls to `CheckReady` know that the queue
+// manager has finished its configuration step
+func Set() error {
+	// #nosec G306 - this gives permissions to owner/s group only.
+	return os.WriteFile(readyFile, []byte("1"), 0770)
+}
+
+// Check checks whether or not the queue manager has finished its
+// configuration steps
+func Check() (bool, error) {
+	exists, err := fileExists(readyFile)
+	if err != nil {
+		return false, err
+	}
+	return exists, nil
+}
+
+// SetReadyToSync is used to indicate that a Native-HA queue manager instance is ready-to-sync
+func SetReadyToSync() error {
+
+	exists, err := fileExists(readyToSyncFile)
+	if err != nil {
+		return err
+	} else if exists {
+		return nil
+	}
+
+	readyToSyncStartTime := strconv.FormatInt(time.Now().Unix(), 10)
+	// #nosec G306 - required permissions
+	return os.WriteFile(readyToSyncFile, []byte(readyToSyncStartTime), 0660)
+}
+
+// GetReadyToSyncStartTime returns the start-time a Native-HA queue manager instance was ready-to-sync
+func GetReadyToSyncStartTime() (bool, time.Time, error) {
+
+	exists, err := fileExists(readyToSyncFile)
+	if err != nil {
+		return exists, time.Time{}, err
+	}
+
+	if exists {
+		buf, err := os.ReadFile(readyToSyncFile)
+		if err != nil {
+			return true, time.Time{}, err
+		}
+		readyToSyncStartTime, err := strconv.ParseInt(string(buf), 10, 64)
+		if err != nil {
+			return true, time.Time{}, err
+		}
+		return true, time.Unix(readyToSyncStartTime, 0), nil
+	}
+
+	return false, time.Time{}, nil
+}
+
+// Status returns an enum representing the current running status of the queue manager
+func Status(ctx context.Context, name string) (QMStatus, error) {
+	out, _, err := command.RunContext(ctx, "dspmq", "-n", "-m", name)
+	if err != nil {
+		return StatusUnknown, err
+	}
+	if strings.Contains(string(out), "(RUNNING)") {
+		return StatusActiveQM, nil
+	}
+	if strings.Contains(string(out), "(RUNNING AS STANDBY)") {
+		return StatusStandbyQM, nil
+	}
+	if strings.Contains(string(out), "(REPLICA)") {
+		return StatusStandbyQM, nil
+	}
+	if strings.Contains(string(out), "(RECOVERY GROUP LEADER)") {
+		return StatusRecoveryQM, nil
+	}
+	return StatusUnknown, nil
+}
+
+type QMStatus int
+
+const (
+	StatusUnknown QMStatus = iota
+	StatusActiveQM
+	StatusStandbyQM
+	StatusReplicaQM
+	StatusRecoveryQM
+)
+
+// ActiveQM returns true if the queue manager is running in active mode
+func (s QMStatus) ActiveQM() bool { return s == StatusActiveQM }
+
+// StandbyQM returns true if the queue manager is running in standby mode
+func (s QMStatus) StandbyQM() bool { return s == StatusStandbyQM }
+
+// ReplicaQM returns true if the queue manager is running in replica mode
+func (s QMStatus) ReplicaQM() bool { return s == StatusReplicaQM }
+
+// ReplicaQM returns true if the queue manager is running in recovery mode
+func (s QMStatus) RecoveryQM() bool { return s == StatusRecoveryQM }