Add parser for PVE storage

Makefile

@@ -1,12 +1,15 @@
 BIN := vct
 VERSION := $(shell git describe --tags --always --dirty)
 
-.PHONY: all $(BIN) clean
+.PHONY: all $(BIN) test clean
 
 all: $(BIN)
 
 $(BIN):
 	go build -ldflags='-s -w -X main.version=$(VERSION)'
 
+test:
+	go test -v ./...
+
 clean:
 	rm -f $(BIN)

cmd/iolimit/iolimit.go

@@ -34,5 +34,11 @@ func MakeCmd() *cobra.Command {
 }
 
 func iolimitMain(ctid string, iops cgroup.IOPS) error {
-	return cgroup.SetIOPSForLXC(ctid, cgroup.IOPSLine{IOPS: iops})
+	// TODO: Find major:minor
+	iopsline := cgroup.IOPSLine{
+		Major: 0,
+		Minor: 0,
+		IOPS:  iops,
+	}
+	return cgroup.SetIOPSForLXC(ctid, iopsline)
 }

go.mod

@@ -5,10 +5,14 @@ go 1.20
 require (
 	github.com/ryanuber/columnize v2.1.2+incompatible
 	github.com/spf13/cobra v1.8.0
-	golang.org/x/exp v0.0.0-20240112132812-db7319d0e0e3
+	github.com/stretchr/testify v1.9.0
+	golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,14 +1,22 @@
 github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/ryanuber/columnize v2.1.2+incompatible h1:C89EOx/XBWwIXl8wm8OPJBd7kPF25UfsK2X7Ph/zCAk=
 github.com/ryanuber/columnize v2.1.2+incompatible/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
 github.com/spf13/cobra v1.8.0 h1:7aJaZx1B85qltLMc546zn58BxxfZdR/W22ej9CFoEf0=
 github.com/spf13/cobra v1.8.0/go.mod h1:WXLWApfZ71AjXPya3WOlMsY9yMs7YeiHhFVlvLyhcho=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
-golang.org/x/exp v0.0.0-20240112132812-db7319d0e0e3 h1:hNQpMuAJe5CtcUqCXaWga3FHu+kQvCqcsoVaQgSV60o=
-golang.org/x/exp v0.0.0-20240112132812-db7319d0e0e3/go.mod h1:idGWGoKP1toJGkd5/ig9ZLuPcZBC3ewk7SzmH0uou08=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8 h1:aAcj0Da7eBAtrTp03QXWvm88pSyOt+UgdZw2BFZ+lEw=
+golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8/go.mod h1:CQ1k9gNrJ50XIzaKCRR2hssIjF07kZFEiieALBM/ARQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

pkg/pve/pct.go

@@ -1,8 +1,18 @@
 package pve
 
-import "os/exec"
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+)
 
-const PctPath = "/usr/sbin/pct"
+const (
+	EtcPve  = "/etc/pve"
+	PctPath = "/usr/sbin/pct"
+)
 
 func PctCmd(args ...string) *exec.Cmd {
 	return exec.Command(PctPath, args...)
@@ -11,3 +21,42 @@ func PctCmd(args ...string) *exec.Cmd {
 func StopCmd(vmid string) *exec.Cmd {
 	return PctCmd("stop", vmid)
 }
+
+func parseConfig(r io.Reader) map[string]string {
+	config := make(map[string]string)
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if comment, ok := strings.CutPrefix(line, "#"); ok {
+			config["#"] += comment + "\n"
+			continue
+		}
+		fields := strings.Fields(line)
+		if len(fields) != 2 {
+			// Invalid line?
+			continue
+		}
+		config[fields[0]] = fields[1]
+	}
+	return config
+}
+
+func GetConfig(typ, vmid string) (map[string]string, error) {
+	if typ == "qemu" {
+		typ = "qemu-server"
+	}
+	f, err := os.Open(fmt.Sprintf("%s/%s/%s.cfg", EtcPve, typ, vmid))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseConfig(f), nil
+}
+
+func GetLXCConfig(vmid string) (map[string]string, error) {
+	return GetConfig("lxc", vmid)
+}
+
+func GetQemuConfig(vmid string) (map[string]string, error) {
+	return GetConfig("qemu", vmid)
+}

pkg/pve/storage.go

@@ -0,0 +1,121 @@
+package pve
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"slices"
+	"strings"
+	"syscall"
+)
+
+const StorageConf = "/etc/pve/storage.cfg"
+
+type PVEStorage struct {
+	Type string
+	Name string
+	Attr map[string]string
+}
+
+func newPVEStorage() PVEStorage {
+	return PVEStorage{
+		Attr: make(map[string]string),
+	}
+}
+
+func parseStorage(r io.Reader) []PVEStorage {
+	items := make([]PVEStorage, 0)
+	item := newPVEStorage()
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if strings.HasPrefix(line, "#") {
+			continue
+		}
+		fields := strings.Fields(line)
+		if len(fields) != 2 {
+			// Invalid line?
+			continue
+		}
+		if strings.HasSuffix(fields[0], ":") {
+			if item.Type != "" {
+				items = append(items, item)
+				item = newPVEStorage()
+			}
+			item.Type = strings.TrimSuffix(fields[0], ":")
+			item.Name = fields[1]
+		} else {
+			item.Attr[fields[0]] = fields[1]
+		}
+	}
+	if item.Type != "" {
+		items = append(items, item)
+	}
+	return items
+}
+
+func GetStorage() ([]PVEStorage, error) {
+	f, err := os.Open(StorageConf)
+	if os.IsNotExist(err) {
+		return nil, nil
+	} else if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseStorage(f), nil
+}
+
+func devMajorMinor(device uint64) (major, minor uint64) {
+	major = (device >> 8) & 0xfff
+	minor = (device & 0xff) | ((device >> 12) & 0xfff00)
+	return
+}
+
+func getBlockDevForDir(dir string) (uint64, uint64, error) {
+	fileInfo, err := os.Lstat(dir)
+	if err != nil {
+		return 0, 0, err
+	}
+	stat, ok := fileInfo.Sys().(*syscall.Stat_t)
+	if !ok {
+		return 0, 0, fmt.Errorf("failed to get backing device for %s: %w", dir, err)
+	}
+	major, minor := devMajorMinor(stat.Dev)
+	return major, minor, nil
+}
+
+func getBlockDevForLVM(vgname, lvname string) (uint64, uint64, error) {
+	fileInfo, err := os.Stat(fmt.Sprintf("/dev/%s/%s", vgname, lvname))
+	if err != nil {
+		return 0, 0, err
+	}
+	stat, ok := fileInfo.Sys().(*syscall.Stat_t)
+	if !ok {
+		return 0, 0, fmt.Errorf("failed to get device number for %s/%s: %w", vgname, lvname, err)
+	}
+	major, minor := devMajorMinor(stat.Rdev)
+	return major, minor, nil
+}
+
+// Finds the block device for the given storage and name.
+// The "aux" parameter is used to help determine the type of the storage.
+func GetBlockDevForStorage(storage, name string, aux []PVEStorage) (uint64, uint64, error) {
+	i := slices.IndexFunc(aux, func(s PVEStorage) bool {
+		return s.Name == name
+	})
+	if i == -1 {
+		return 0, 0, fs.ErrNotExist
+	}
+	info := aux[i]
+	switch info.Type {
+	case "dir":
+		return getBlockDevForDir(storage)
+	case "lvm", "lvmthin":
+		vgname := info.Attr["vgname"]
+		return getBlockDevForLVM(vgname, name)
+	default:
+		return 0, 0, fmt.Errorf("unsupported storage type %s", info.Type)
+	}
+}

pkg/pve/storage_test.go

@@ -0,0 +1,57 @@
+package pve
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const testStorageCfg = `dir: local
+	path /var/lib/vz
+	content vztmpl,iso,images
+
+lvmthin: local-lvm
+	thinpool data
+	vgname pve
+	content rootdir,images
+
+dir: nfs-template
+	path /mnt/vz
+	content vztmpl,iso,images
+	shared 1
+`
+
+var testStorage = []PVEStorage{
+	{
+		Type: "dir",
+		Name: "local",
+		Attr: map[string]string{
+			"path":    "/var/lib/vz",
+			"content": "vztmpl,iso,images",
+		},
+	},
+	{
+		Type: "lvmthin",
+		Name: "local-lvm",
+		Attr: map[string]string{
+			"thinpool": "data",
+			"vgname":   "pve",
+			"content":  "rootdir,images",
+		},
+	},
+	{
+		Type: "dir",
+		Name: "nfs-template",
+		Attr: map[string]string{
+			"path":    "/mnt/vz",
+			"content": "vztmpl,iso,images",
+			"shared":  "1",
+		},
+	},
+}
+
+func TestParseStorage(t *testing.T) {
+	as := assert.New(t)
+	as.Equal(testStorage, parseStorage(strings.NewReader(testStorageCfg)))
+}