mq-container/cmd/runmqserver/main.go

/*
© Copyright IBM Corporation 2017, 2018

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.
*/

// runmqserver initializes, creates and starts a queue manager, as PID 1 in a container
package main

import (
	"context"
	"errors"
	"io"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"sync"

	"github.com/sirupsen/logrus"
	log "github.com/sirupsen/logrus"

	"github.com/ibm-messaging/mq-container/internal/command"
	"github.com/ibm-messaging/mq-container/internal/name"
	"github.com/ibm-messaging/mq-container/internal/ready"
)

// createDirStructure creates the default MQ directory structure under /var/mqm
func createDirStructure() error {
	out, _, err := command.Run("/opt/mqm/bin/crtmqdir", "-f", "-s")
	if err != nil {
		log.Printf("Error creating directory structure: %v\n", string(out))
		return err
	}
	log.Println("Created directory structure under /var/mqm")
	return nil
}

// createQueueManager creates a queue manager, if it doesn't already exist.
// It returns true if one was created, or false if one already existed
func createQueueManager(name string) (bool, error) {
	log.Printf("Creating queue manager %v", name)
	out, rc, err := command.Run("crtmqm", "-q", "-p", "1414", name)
	if err != nil {
		// 8=Queue manager exists, which is fine
		if rc == 8 {
			log.Printf("Detected existing queue manager %v", name)
			return false, nil
		}
		log.Printf("crtmqm returned %v", rc)
		log.Println(string(out))
		return false, err
	}
	return true, nil
}

func updateCommandLevel() error {
	level, ok := os.LookupEnv("MQ_CMDLEVEL")
	if ok && level != "" {
		log.Printf("Setting CMDLEVEL to %v", level)
		out, rc, err := command.Run("strmqm", "-e", "CMDLEVEL="+level)
		if err != nil {
			log.Printf("Error %v setting CMDLEVEL: %v", rc, string(out))
			return err
		}
	}
	return nil
}

func startQueueManager() error {
	log.Println("Starting queue manager")
	out, rc, err := command.Run("strmqm")
	if err != nil {
		log.Printf("Error %v starting queue manager: %v", rc, string(out))
		return err
	}
	log.Println("Started queue manager")
	return nil
}

func configureQueueManager() error {
	const configDir string = "/etc/mqm"
	files, err := ioutil.ReadDir(configDir)
	if err != nil {
		log.Println(err)
		return err
	}

	for _, file := range files {
		if strings.HasSuffix(file.Name(), ".mqsc") {
			abs := filepath.Join(configDir, file.Name())
			cmd := exec.Command("runmqsc")
			stdin, err := cmd.StdinPipe()
			if err != nil {
				log.Println(err)
				return err
			}
			// Open the MQSC file for reading
			f, err := os.Open(abs)
			if err != nil {
				log.Printf("Error opening %v: %v", abs, err)
			}
			// Copy the contents to stdin of the runmqsc process
			_, err = io.Copy(stdin, f)
			if err != nil {
				log.Printf("Error reading %v: %v", abs, err)
			}
			f.Close()
			stdin.Close()
			// Run the command and wait for completion
			out, err := cmd.CombinedOutput()
			if err != nil {
				log.Println(err)
			}
			// Print the runmqsc output, adding tab characters to make it more readable as part of the log
			log.Printf("Output for \"runmqsc\" with %v:\n\t%v", abs, strings.Replace(string(out), "\n", "\n\t", -1))
		}
	}
	return nil
}

func stopQueueManager(name string) error {
	log.Println("Stopping queue manager")
	out, _, err := command.Run("endmqm", "-w", name)
	if err != nil {
		log.Printf("Error stopping queue manager: %v", string(out))
		return err
	}
	log.Println("Stopped queue manager")
	return nil
}

func doMain() error {
	configureLogger()
	err := ready.Clear()
	if err != nil {
		return err
	}
	debugEnv, ok := os.LookupEnv("DEBUG")
	if ok && (debugEnv == "true" || debugEnv == "1") {
		debug = true
		logrus.SetLevel(logrus.DebugLevel)
		logDebug("Debug mode enabled")
	}
	name, err := name.GetQueueManagerName()
	if err != nil {
		log.Println(err)
		return err
	}
	accepted, err := checkLicense()
	if err != nil {
		return err
	}
	if !accepted {
		return errors.New("License not accepted")
	}
	log.Printf("Using queue manager name: %v", name)

	// Start signal handler
	signalControl := signalHandler(name)

	logConfig()
	err = createVolume("/mnt/mqm")
	if err != nil {
		log.Println(err)
		return err
	}
	err = createDirStructure()
	if err != nil {
		return err
	}
	newQM, err := createQueueManager(name)
	if err != nil {
		return err
	}
	var wg sync.WaitGroup
	ctx, cancelMirror := context.WithCancel(context.Background())
	defer func() {
		log.Debugln("Cancel log mirroring")
		cancelMirror()
	}()
	// TODO: Use the error channel
	_, err = mirrorLogs(ctx, &wg, name, newQM)
	if err != nil {
		return err
	}
	defer func() {
		log.Debugln("Waiting for log mirroring to complete")
		wg.Wait()
	}()
	err = updateCommandLevel()
	if err != nil {
		return err
	}
	err = startQueueManager()
	if err != nil {
		return err
	}
	configureQueueManager()
	// Start reaping zombies from now on.
	// Start this here, so that we don't reap any sub-processes created
	// by this process (e.g. for crtmqm or strmqm)
	signalControl <- startReaping
	// Reap zombies now, just in case we've already got some
	signalControl <- reapNow
	// Write a file to indicate that chkmqready should now work as normal
	ready.Set()
	// Wait for terminate signal
	<-signalControl
	return nil
}

var osExit = os.Exit

func main() {
	err := doMain()
	if err != nil {
		osExit(1)
	}
}