change(core): use a lockfile to prevent multiple executions of crop

cmd/clean.go

@@ -19,6 +19,7 @@ var cleanCmd = &cobra.Command{
 	Run: func(cmd *cobra.Command, args []string) {
 		// init core
 		initCore(true)
+		defer releaseFileLock()
 
 		// iterate uploader's
 		started := time.Now().UTC()

cmd/manual.go

@@ -30,6 +30,7 @@ var manualCmd = &cobra.Command{
 		// init core
 		initCore(true)
 		defer cache.Close()
+		defer releaseFileLock()
 
 		// determine destination remotes
 		syncRemotes := make([]string, 0)

cmd/root.go

@@ -9,10 +9,12 @@ import (
 	"github.com/l3uddz/crop/rclone"
 	"github.com/l3uddz/crop/runtime"
 	"github.com/l3uddz/crop/stringutils"
+	"github.com/nightlyone/lockfile"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"os"
 	"path/filepath"
+	"time"
 )
 
 var (
@@ -22,14 +24,15 @@ var (
 	flagConfigFile   = "config.yaml"
 	flagCachePath    = "cache"
 	flagLogFile      = "activity.log"
-
-	flagDryRun bool
+	flagLockFile     = "crop.lock"
+	flagDryRun       bool
 
 	// Global command specific
 	flagUploader string
 
 	// Global vars
-	log *logrus.Entry
+	log   *logrus.Entry
+	flock lockfile.Lockfile
 )
 
 var rootCmd = &cobra.Command{
@@ -69,13 +72,20 @@ func initCore(showAppInfo bool) {
 		flagLogFile = filepath.Join(flagConfigFolder, flagLogFile)
 	}
 
+	flagLockFile = filepath.Join(flagConfigFolder, flagLockFile)
+
 	// Init Logging
 	if err := logger.Init(flagLogLevel, flagLogFile); err != nil {
 		log.WithError(err).Fatal("Failed to initialize logging")
 	}
 
 	log = logger.GetLogger("crop")
 
+	// Init File Lock
+	if err := acquireFileLock(); err != nil {
+		log.WithError(err).Fatalf("Failed acquiring file lock for %q", flagLockFile)
+	}
+
 	// Init Config
 	if err := config.Init(flagConfigFile); err != nil {
 		log.WithError(err).Fatal("Failed to initialize config")
@@ -106,6 +116,38 @@ func setConfigOverrides() {
 	}
 }
 
+func acquireFileLock() error {
+	f, err := lockfile.New(flagLockFile)
+	if err != nil {
+		return err
+	}
+
+	flock = f
+
+	// loop until lock has been acquired
+	for {
+		err = flock.TryLock()
+		switch {
+		case err == nil:
+			// lock has been acquired
+			return nil
+		case err == lockfile.ErrBusy:
+			// another instance is already running
+			log.Warnf("There is another crop instance running, re-checking in 1 minute...")
+			time.Sleep(1 * time.Minute)
+		default:
+			// an un-expected error, propagate down-stream
+			return err
+		}
+	}
+}
+
+func releaseFileLock() {
+	if err := flock.Unlock(); err != nil {
+		log.WithError(err).Fatalf("Failed releasing file lock for %q", flagLockFile)
+	}
+}
+
 func showUsing() {
 	// show app info
 	log.Infof("Using %s = %s (%s@%s)", stringutils.LeftJust("VERSION", " ", 10),

cmd/sync.go

@@ -30,6 +30,7 @@ var syncCmd = &cobra.Command{
 		// init core
 		initCore(true)
 		defer cache.Close()
+		defer releaseFileLock()
 
 		// create workers
 		var wg sync.WaitGroup

cmd/update.go

@@ -19,6 +19,7 @@ var updateCmd = &cobra.Command{
 		// init core
 		initCore(false)
 		defer cache.Close()
+		defer releaseFileLock()
 
 		// parse current version
 		v, err := semver.Parse(runtime.Version)

cmd/upload.go

@@ -27,6 +27,7 @@ var uploadCmd = &cobra.Command{
 		// init core
 		initCore(true)
 		defer cache.Close()
+		defer releaseFileLock()
 
 		// iterate uploader's
 		started := time.Now().UTC()

go.mod

@@ -13,13 +13,15 @@ require (
 	github.com/gofiber/fiber v1.9.6
 	github.com/gofiber/recover v0.0.5
 	github.com/golang/protobuf v1.4.2 // indirect
+	github.com/klauspost/compress v1.10.6 // indirect
 	github.com/mattn/go-colorable v0.1.6 // indirect
 	github.com/mgutz/ansi v0.0.0-20170206155736-9520e82c474b // indirect
-	github.com/mitchellh/mapstructure v1.3.0 // indirect
+	github.com/mitchellh/mapstructure v1.3.1 // indirect
 	github.com/natefinch/lumberjack v2.0.0+incompatible
+	github.com/nightlyone/lockfile v1.0.0
 	github.com/onsi/ginkgo v1.12.0 // indirect
 	github.com/onsi/gomega v1.9.0 // indirect
-	github.com/pelletier/go-toml v1.7.0 // indirect
+	github.com/pelletier/go-toml v1.8.0 // indirect
 	github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2
 	github.com/pkg/errors v0.9.1
 	github.com/rhysd/go-github-selfupdate v1.2.2
@@ -36,11 +38,10 @@ require (
 	github.com/yale8848/gorpool v0.1.0
 	github.com/zippoxer/bow v0.0.0-20200229231453-bf1012ae7ab9
 	golang.org/x/crypto v0.0.0-20200510223506-06a226fb4e37 // indirect
-	golang.org/x/net v0.0.0-20200513185701-a91f0712d120 // indirect
+	golang.org/x/net v0.0.0-20200520182314-0ba52f642ac2 // indirect
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d // indirect
-	golang.org/x/sys v0.0.0-20200515095857-1151b9dac4a9 // indirect
+	golang.org/x/sys v0.0.0-20200523222454-059865788121 // indirect
 	google.golang.org/appengine v1.6.6 // indirect
 	gopkg.in/ini.v1 v1.56.0 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
-	gopkg.in/yaml.v2 v2.3.0 // indirect
 )

go.sum

@@ -173,6 +173,8 @@ github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvW
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/klauspost/compress v1.10.4 h1:jFzIFaf586tquEB5EhzQG0HwGNSlgAJpG53G6Ss11wc=
 github.com/klauspost/compress v1.10.4/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
+github.com/klauspost/compress v1.10.6 h1:SP6zavvTG3YjOosWePXFDlExpKIWMTO4SE/Y8MZB2vI=
+github.com/klauspost/compress v1.10.6/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
@@ -206,14 +208,16 @@ github.com/mitchellh/iochan v1.0.0/go.mod h1:JwYml1nuB7xOzsp52dPpHFffvOCDupsG0Qu
 github.com/mitchellh/mapstructure v0.0.0-20160808181253-ca63d7c062ee/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
-github.com/mitchellh/mapstructure v1.3.0 h1:iDwIio/3gk2QtLLEsqU5lInaMzos0hDTz8a6lazSFVw=
-github.com/mitchellh/mapstructure v1.3.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+github.com/mitchellh/mapstructure v1.3.1 h1:cCBH2gTD2K0OtLlv/Y5H01VQCqmlDxz30kS5Y5bqfLA=
+github.com/mitchellh/mapstructure v1.3.1/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.1 h1:9f412s+6RmYXLWZSEzVVgPGK7C2PphHj5RJrvfx9AWI=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/natefinch/lumberjack v2.0.0+incompatible h1:4QJd3OLAMgj7ph+yZTuX13Ld4UpgHp07nNdFX7mqFfM=
 github.com/natefinch/lumberjack v2.0.0+incompatible/go.mod h1:Wi9p2TTF5DG5oU+6YfsmYQpsTIOm0B1VNzQg9Mw6nPk=
+github.com/nightlyone/lockfile v1.0.0 h1:RHep2cFKK4PonZJDdEl4GmkabuhbsRMgk/k3uAmxBiA=
+github.com/nightlyone/lockfile v1.0.0/go.mod h1:rywoIealpdNse2r832aiD9jRk8ErCatROs6LzC841CI=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.12.0 h1:Iw5WCbBcaAAd0fpRb1c9r5YCylv4XDoCSigm1zLevwU=
@@ -225,8 +229,8 @@ github.com/onsi/gomega v1.9.0/go.mod h1:Ho0h+IUsWyvy1OpqCwxlQ/21gkhVunqlU8fDGcoT
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
 github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
-github.com/pelletier/go-toml v1.7.0 h1:7utD74fnzVc/cpcyy8sjrlFr5vYpypUixARcHIMIGuI=
-github.com/pelletier/go-toml v1.7.0/go.mod h1:vwGMzjaWMwyfHwgIBhI2YUM4fB6nL6lVAvS1LBMMhTE=
+github.com/pelletier/go-toml v1.8.0 h1:Keo9qb7iRJs2voHvunFtuuYFsbWeOBh8/P9v/kVMFtw=
+github.com/pelletier/go-toml v1.8.0/go.mod h1:D6yutnOGMveHEPV7VQOuvI/gXY61bv+9bAOTRnLElKs=
 github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2 h1:JhzVVoYvbOACxoUmOs6V/G4D5nPVUW73rKvXxP4XUJc=
 github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2/go.mod h1:iIss55rKnNBTvrwdmkUpLnDpZoAHvWaiq5+iMmen4AE=
 github.com/philhofer/fwd v1.0.0 h1:UbZqGr5Y38ApvM/V/jEljVxwocdweyH+vmYvRPBnbqQ=
@@ -383,8 +387,8 @@ golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
-golang.org/x/net v0.0.0-20200513185701-a91f0712d120 h1:EZ3cVSzKOlJxAd8e8YAJ7no8nNypTxexh/YE/xW3ZEY=
-golang.org/x/net v0.0.0-20200513185701-a91f0712d120/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
+golang.org/x/net v0.0.0-20200520182314-0ba52f642ac2 h1:eDrdRpKgkcCqKZQwyZRyeFZgfqt37SL7Kv3tok06cKE=
+golang.org/x/net v0.0.0-20200520182314-0ba52f642ac2/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20181106182150-f42d05182288 h1:JIqe8uIcRBHXDQVvZtHwp80ai3Lw3IJAeJEs55Dc1W0=
 golang.org/x/oauth2 v0.0.0-20181106182150-f42d05182288/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
@@ -422,8 +426,8 @@ golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae h1:/WDfKMnPU+m5M4xB+6x4kaepxRw6jWvR5iDRdvjHgy8=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200515095857-1151b9dac4a9 h1:YTzHMGlqJu67/uEo1lBv0n3wBXhXNeUbB1XfN2vmTm0=
-golang.org/x/sys v0.0.0-20200515095857-1151b9dac4a9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200523222454-059865788121 h1:rITEj+UZHYC927n8GT97eC3zrpzXdb/voyeOuVKS46o=
+golang.org/x/sys v0.0.0-20200523222454-059865788121/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -509,8 +513,6 @@ gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bl
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
-gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=