dynlay

cmd/dkl/main.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	cmddynlay "novit.nc/direktil/inits/pkg/cmd/dynlay"
 	cmdinit "novit.nc/direktil/inits/pkg/cmd/init"
 )
 
@@ -12,6 +13,7 @@ func main() {
 	root := &cobra.Command{}
 
 	root.AddCommand(cmdinit.Command())
+	root.AddCommand(cmddynlay.Command())
 
 	if err := root.Execute(); err != nil {
 		log.Fatal("error: ", err)

go.mod

@@ -3,13 +3,16 @@ module novit.nc/direktil/inits
 go 1.15
 
 require (
+	github.com/antage/mntent v0.0.0-20141129103236-834970000c6c
 	github.com/fsnotify/fsnotify v1.4.9
 	github.com/go-ping/ping v0.0.0-20201001214134-671c40f29adc
+	github.com/paultag/go-loopback v0.0.0-20180807022812-2589a042248e // indirect
 	github.com/spf13/cobra v1.0.0
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/ulikunitz/xz v0.5.8 // indirect
 	golang.org/x/net v0.0.0-20200930145003-4acb6c075d10 // indirect
 	golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f // indirect
+	gonum.org/v1/gonum v0.8.1 // indirect
 	gopkg.in/yaml.v2 v2.3.0 // indirect
 	novit.nc/direktil/pkg v0.0.0-20191211161950-96b0448b84c2
 )

go.sum

@@ -1,8 +1,11 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
+github.com/ajstarks/svgo v0.0.0-20180226025133-644b8db467af/go.mod h1:K08gAheRH3/J6wwsYMMT4xOr94bZjxIelGM0+d/wbFw=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
+github.com/antage/mntent v0.0.0-20141129103236-834970000c6c h1:6g5LfUYqDR1rEL54hKdK7edwAp2R4baYmtDpJgm6+5Q=
+github.com/antage/mntent v0.0.0-20141129103236-834970000c6c/go.mod h1:AsQhRqephGS4znB7Z793C63GgcW2I6xUsInepL9EOdE=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
@@ -17,11 +20,13 @@ github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsr
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
+github.com/fogleman/gg v1.2.1-0.20190220221249-0403632d5b90/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9 h1:hsms1Qyu0jgnwNXIxa+/V/PDsU6CfLf6CNO8H7IWoS4=
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
+github.com/go-kit/kit v0.8.0 h1:Wz+5lgoB0kkuqLEc6NVmwRknTKP6dTGbSqvhZtBI/j0=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
@@ -30,10 +35,12 @@ github.com/go-ping/ping v0.0.0-20201001214134-671c40f29adc/go.mod h1:35JbSyV/BYq
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
@@ -46,6 +53,7 @@ github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NH
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
+github.com/jung-kurt/gofpdf v1.0.3-0.20190309125859-24315acbbda5/go.mod h1:7Id9E/uU8ce6rXgefFLlgrJj/GYY22cpxn+r32jIOes=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
@@ -61,6 +69,8 @@ github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrk
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
+github.com/paultag/go-loopback v0.0.0-20180807022812-2589a042248e h1:qoHpC8Xx84+Uqod6i8DjIgxMKXUyiv16rinyly8XT7A=
+github.com/paultag/go-loopback v0.0.0-20180807022812-2589a042248e/go.mod h1:a8zVTnQlIjBriq5Q5MOS9xmfBQHGCyrBilmLyKZW9Ls=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -105,6 +115,11 @@ go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/exp v0.0.0-20180321215751-8460e604b9de/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
+golang.org/x/exp v0.0.0-20180807140117-3d87b88a115f/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
+golang.org/x/exp v0.0.0-20190125153040-c74c464bbbf2 h1:y102fOLFqhV41b+4GPiJoa0k/x+pJcEi2/HB1Y5T6fU=
+golang.org/x/exp v0.0.0-20190125153040-c74c464bbbf2/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
+golang.org/x/image v0.0.0-20180708004352-c73c2afc3b81/go.mod h1:ux5Hcp/YLpHSI86hEcLt0YII63i6oz57MZXIpbrjZUs=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -131,14 +146,24 @@ golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f h1:+Nyd8tzPX9R7BWHguqsrbFdRx3WQ/1ib8I44HXV5yTA=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/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/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20180525024113-a5b4c53f6e8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190206041539-40960b6deb8e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+gonum.org/v1/gonum v0.0.0-20180816165407-929014505bf4/go.mod h1:Y+Yx5eoAFn32cQvJDxZx5Dpnq+c3wtXuadVZAcxbbBo=
+gonum.org/v1/gonum v0.8.1 h1:wGtP3yGpc5mCLOLeTeBdjeui9oZSz5De0eOjMLC/QuQ=
+gonum.org/v1/gonum v0.8.1/go.mod h1:oe/vMfY3deqTw+1EZJhuvEW2iwGF1bW9wwu7XCu0+v0=
+gonum.org/v1/netlib v0.0.0-20190313105609-8cb42192e0e0/go.mod h1:wa6Ws7BG/ESfp6dHfk7C6KdzKA7wR7u/rKwOGE66zvw=
+gonum.org/v1/plot v0.0.0-20190515093506-e2840ee46a6b/go.mod h1:Wt8AAjI+ypCyYX3nZBvf6cAIx93T+c/OS2HFAYskSZc=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
+google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8 h1:Nw54tB0rB7hY/N0NQvRW8DG4Yk3Q6T9cu9RcFQDu1tc=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
+google.golang.org/grpc v1.21.0 h1:G+97AoqBnmZIT91cLG/EkCoK9NSelj64P8bOHHNmGn0=
 google.golang.org/grpc v1.21.0/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
@@ -156,3 +181,4 @@ 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=
 novit.nc/direktil/pkg v0.0.0-20191211161950-96b0448b84c2 h1:LN3K19gAJ1GamJXkzXAQmjbl8xCV7utqdxTTrM89MMc=
 novit.nc/direktil/pkg v0.0.0-20191211161950-96b0448b84c2/go.mod h1:zwTVO6U0tXFEaga73megQIBK7yVIKZJVePaIh/UtdfU=
+rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=

modd.conf

@@ -1,7 +1,12 @@
+modd.conf {}
+
 **/*.go layer/**/* test-vm update-test-data {
   prep: go test ./... #./pkg/... ./cmd/dkl
   prep: mkdir -p dist
-  prep: CGO_ENABLED=0 go build -o dist ./cmd/...
+  prep: CGO_ENABLED=0 go build -o dist -trimpath ./cmd/...
+
+  prep: rsync -za --stats dist/dkl bw:/usr/local/bin/
+  prep: ssh bw dkl dynlay --url-prefix https://dkl.nwrk.info/dist/layers kubernetes v1.19.4_containerd.1.4.1
 
   #prep: ./update-test-data
   #daemon: ./test-vm 1

pkg/cmd/dynlay/dynlay.go

@@ -0,0 +1,190 @@
+package dynlay
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/antage/mntent"
+	"github.com/spf13/cobra"
+)
+
+var urlPrefix = "https://dkl.novit.nc/dist/layers"
+
+func Command() (c *cobra.Command) {
+	c = &cobra.Command{
+		Use:   "dynlay <layer> <version>",
+		Short: "set dynamic layer",
+		Args:  cobra.ExactArgs(2),
+
+		Run: run,
+	}
+
+	c.Flags().StringVar(&urlPrefix, "url-prefix", urlPrefix, "Layer URL prefix")
+
+	return c
+}
+
+func run(_ *cobra.Command, args []string) {
+	layer, version := args[0], args[1]
+
+	layDir := filepath.Join("/opt/dynlay", layer)
+
+	err := os.MkdirAll(layDir, 0755)
+	fail(err)
+
+	layPath := filepath.Join(layDir, version)
+
+	// fetch if not exist
+	_, err = os.Stat(layPath)
+	if os.IsNotExist(err) {
+		fetch(layPath, urlPrefix+"/"+layer+"/"+version)
+	}
+
+	mounted := map[string]bool{}
+	{
+		mounts, err := mntent.Parse("/etc/mtab")
+		fail(err)
+		for _, mount := range mounts {
+			mounted[mount.Directory] = true
+		}
+	}
+
+	// mount
+	mountPath := filepath.Join("/run/dynlay", layer, version)
+
+	if !mounted[mountPath] {
+		err = os.MkdirAll(mountPath, 0755)
+		fail(err)
+
+		cmd := exec.Command("mount", "-t", "squashfs", layPath, mountPath)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		err = cmd.Run()
+		if err != nil {
+			os.Remove(mountPath)
+			fail(err)
+		}
+	}
+
+	// update links
+	existing := map[string]bool{}
+	{
+		paths, err := linkableFrom(mountPath)
+		fail(err)
+
+		for _, path := range paths {
+			existing[path] = true
+
+			fmt.Println("linking", path)
+
+			target := "/" + path
+			os.Remove(target)
+
+			os.MkdirAll(filepath.Dir(target), 0755)
+
+			err := os.Symlink(filepath.Join(mountPath, path), target)
+			if err != nil {
+				log.Print("warning: symlink of ", path, " failed: ", err)
+			}
+		}
+	}
+
+	// remove expired links
+	basePaths, err := filepath.Glob(filepath.Join(filepath.Dir(mountPath), "*"))
+	fail(err)
+
+	for _, base := range basePaths {
+		if base == mountPath {
+			continue
+		}
+
+		stat, err := os.Stat(base)
+		fail(err)
+
+		if !stat.IsDir() {
+			continue
+		}
+
+		paths, err := linkableFrom(base)
+		fail(err)
+
+		for _, path := range paths {
+			if existing[path] {
+				continue
+			}
+
+			_, err := os.Stat("/" + path)
+			if os.IsNotExist(err) {
+				continue
+			}
+
+			fmt.Print("unlinking ", path, " (from ", filepath.Base(base), ")\n")
+
+			err = os.Remove("/" + path)
+			if err != nil {
+				log.Print("warning: failed to unlink ", path, ": ", err)
+			}
+		}
+
+		if mounted[base] {
+			cmd := exec.Command("umount", "-l", base)
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+			cmd.Run()
+		}
+
+		os.Remove(base)
+	}
+}
+
+func linkableFrom(dir string) (paths []string, err error) {
+	err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if info.IsDir() {
+			return nil
+		}
+
+		path, err = filepath.Rel(dir, path)
+		paths = append(paths, path)
+		return nil
+	})
+	return
+}
+
+func fetch(outPath string, url string) {
+	f, err := os.Create(outPath + ".part")
+	fail(err)
+
+	defer f.Close()
+
+	log.Print("fetching ", url)
+	resp, err := http.Get(url)
+	fail(err)
+
+	if resp.StatusCode != 200 {
+		log.Fatal("GET failed on ", url, ": ", resp.Status)
+	}
+
+	_, err = io.Copy(f, resp.Body)
+	fail(err)
+
+	f.Close()
+
+	os.Rename(outPath+".part", outPath)
+}
+
+func fail(err error) {
+	if err != nil {
+		log.SetFlags(log.Flags() | log.Lshortfile)
+		log.Output(2, err.Error())
+		os.Exit(-1)
+	}
+}