resources: Add user resource

examples/user1.yaml

@@ -0,0 +1,9 @@
+---
+graph: mygraph
+resources:
+  user:
+  - name: testuser
+    uid: 1002
+    gid: 100
+    state: exists
+edges: []

resources/user.go

@@ -0,0 +1,310 @@
+// Mgmt
+// Copyright (C) 2013-2017+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package resources
+
+import (
+	"fmt"
+	"log"
+	"os/exec"
+	"os/user"
+	"strconv"
+	"syscall"
+
+	"github.com/purpleidea/mgmt/recwatch"
+
+	errwrap "github.com/pkg/errors"
+)
+
+func init() {
+	RegisterResource("user", func() Res { return &UserRes{} })
+}
+
+const passwdFile = "/etc/passwd"
+
+// UserRes is a user account resource.
+type UserRes struct {
+	BaseRes           `yaml:",inline"`
+	State             string  `yaml:"state"` // state: exists, absent
+	UID               *uint32 `yaml:"uid"`
+	GID               *uint32 `yaml:"gid"`
+	HomeDir           *string `yaml:"homedir"`
+	AllowDuplicateUID bool    `yaml:"allowduplicateuid"`
+
+	recWatcher *recwatch.RecWatcher
+}
+
+// Default returns some sensible defaults for this resource.
+func (obj *UserRes) Default() Res {
+	return &UserRes{
+		BaseRes: BaseRes{
+			MetaParams: DefaultMetaParams, // force a default
+		},
+	}
+}
+
+// Validate if the params passed in are valid data.
+func (obj *UserRes) Validate() error {
+	if obj.State != "exists" && obj.State != "absent" {
+		return fmt.Errorf("State must be 'exists' or 'absent'")
+	}
+	return obj.BaseRes.Validate()
+}
+
+// Init initializes the resource.
+func (obj *UserRes) Init() error {
+	return obj.BaseRes.Init() // call base init, b/c we're overriding
+}
+
+// Watch is the primary listener for this resource and it outputs events.
+func (obj *UserRes) Watch() error {
+	var err error
+	obj.recWatcher, err = recwatch.NewRecWatcher(passwdFile, false)
+	if err != nil {
+		return err
+	}
+	defer obj.recWatcher.Close()
+
+	// notify engine that we're running
+	if err := obj.Running(); err != nil {
+		return err // bubble up a NACK...
+	}
+
+	var send = false // send event?
+	var exit *error
+
+	for {
+		if obj.debug {
+			log.Printf("Watching: %s", passwdFile) // attempting to watch...
+		}
+
+		select {
+		case event, ok := <-obj.recWatcher.Events():
+			if !ok { // channel shutdown
+				return nil
+			}
+			if err := event.Error; err != nil {
+				return errwrap.Wrapf(err, "Unknown %s watcher error", obj)
+			}
+			if obj.debug { // don't access event.Body if event.Error isn't nil
+				log.Printf("%s: Event(%s): %v", obj, event.Body.Name, event.Body.Op)
+			}
+			send = true
+			obj.StateOK(false) // dirty
+
+		case event := <-obj.Events():
+			if exit, send = obj.ReadEvent(event); exit != nil {
+				return *exit // exit
+			}
+			//obj.StateOK(false) // dirty // these events don't invalidate state
+		}
+
+		// do all our event sending all together to avoid duplicate msgs
+		if send {
+			send = false
+			obj.Event()
+		}
+	}
+}
+
+// CheckApply method for User resource.
+func (obj *UserRes) CheckApply(apply bool) (checkOK bool, err error) {
+	log.Printf("%s: CheckApply(%t)", obj, apply)
+
+	var exists = true
+	usr, err := user.Lookup(obj.GetName())
+	if err != nil {
+		if _, ok := err.(user.UnknownUserError); !ok {
+			return false, errwrap.Wrapf(err, "error looking up user")
+		}
+		log.Printf("the user: %s does not exist", obj.GetName())
+		exists = false
+	}
+
+	if obj.AllowDuplicateUID == false && obj.UID != nil {
+		existingUID, err := user.LookupId(strconv.Itoa(int(*obj.UID)))
+		if err != nil {
+			if _, ok := err.(user.UnknownUserIdError); !ok {
+				return false, errwrap.Wrapf(err, "error looking up UID")
+			}
+		} else if existingUID.Username != obj.GetName() {
+			return false, fmt.Errorf("the requested UID is already taken")
+		}
+	}
+
+	if obj.State == "absent" && !exists {
+		return true, nil
+	}
+
+	if usercheck := true; exists && obj.State == "exists" {
+		intUID, err := strconv.Atoi(usr.Uid)
+		if err != nil {
+			return false, errwrap.Wrapf(err, "error casting UID to int")
+		}
+		intGID, err := strconv.Atoi(usr.Gid)
+		if err != nil {
+			return false, errwrap.Wrapf(err, "error casting GID to int")
+		}
+		if obj.UID != nil && int(*obj.UID) != intUID {
+			usercheck = false
+		}
+		if obj.GID != nil && int(*obj.GID) != intGID {
+			usercheck = false
+		}
+		if obj.HomeDir != nil && *obj.HomeDir != usr.HomeDir {
+			usercheck = false
+		}
+		if usercheck {
+			return true, nil
+		}
+	}
+
+	if !apply {
+		return false, nil
+	}
+
+	var cmdName string
+	var args []string
+	if obj.State == "exists" {
+		if exists {
+			cmdName = "usermod"
+			log.Printf("modifying user: %s", obj.GetName())
+		} else {
+			cmdName = "useradd"
+			log.Printf("adding user: %s", obj.GetName())
+		}
+		if obj.AllowDuplicateUID {
+			args = append(args, "--non-unique")
+		}
+		if obj.UID != nil {
+			args = append(args, "-u", fmt.Sprintf("%d", *obj.UID))
+		}
+		if obj.GID != nil {
+			args = append(args, "-g", fmt.Sprintf("%d", *obj.GID))
+		}
+		if obj.HomeDir != nil {
+			args = append(args, "-d", *obj.HomeDir)
+		}
+	}
+	if obj.State == "absent" {
+		cmdName = "userdel"
+	}
+
+	args = append(args, obj.GetName())
+
+	cmd := exec.Command(cmdName, args...)
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Setpgid: true,
+		Pgid:    0,
+	}
+	if err := cmd.Run(); err != nil {
+		return false, errwrap.Wrapf(err, "cmd failed to run")
+	}
+
+	return false, nil
+}
+
+// UserUID is the UID struct for UserRes.
+type UserUID struct {
+	BaseUID
+	name string
+}
+
+// UIDs includes all params to make a unique identification of this object.
+// Most resources only return one, although some resources can return multiple.
+func (obj *UserRes) UIDs() []ResUID {
+	x := &UserUID{
+		BaseUID: BaseUID{Name: obj.GetName(), Kind: obj.GetKind()},
+		name:    obj.Name,
+	}
+	return []ResUID{x}
+}
+
+// GroupCmp returns whether two resources can be grouped together or not.
+func (obj *UserRes) GroupCmp(r Res) bool {
+	_, ok := r.(*UserRes)
+	if !ok {
+		return false
+	}
+	return false
+}
+
+// Compare two resources and return if they are equivalent.
+func (obj *UserRes) Compare(r Res) bool {
+	// we can only compare UserRes to others of the same resource kind
+	res, ok := r.(*UserRes)
+	if !ok {
+		return false
+	}
+	if !obj.BaseRes.Compare(res) { // call base Compare
+		return false
+	}
+	if obj.Name != res.Name {
+		return false
+	}
+	if obj.State != res.State {
+		return false
+	}
+	if (obj.UID == nil) != (res.UID == nil) {
+		return false
+	}
+	if obj.UID != nil && res.UID != nil {
+		if *obj.UID != *res.UID {
+			return false
+		}
+	}
+	if (obj.GID == nil) != (res.GID == nil) {
+		return false
+	}
+	if obj.GID != nil && res.GID != nil {
+		if *obj.GID != *res.UID {
+			return false
+		}
+	}
+	if (obj.HomeDir == nil) != (res.HomeDir == nil) {
+		return false
+	}
+	if obj.HomeDir != nil && res.HomeDir != nil {
+		if *obj.HomeDir != *obj.HomeDir {
+			return false
+		}
+	}
+	if obj.AllowDuplicateUID != res.AllowDuplicateUID {
+		return false
+	}
+	return true
+}
+
+// UnmarshalYAML is the custom unmarshal handler for this struct.
+// It is primarily useful for setting the defaults.
+func (obj *UserRes) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	type rawRes UserRes // indirection to avoid infinite recursion
+
+	def := obj.Default()      // get the default
+	res, ok := def.(*UserRes) // put in the right format
+	if !ok {
+		return fmt.Errorf("could not convert to UserRes")
+	}
+	raw := rawRes(*res) // convert; the defaults go here
+
+	if err := unmarshal(&raw); err != nil {
+		return err
+	}
+
+	*obj = UserRes(raw) // restore from indirection with type conversion!
+	return nil
+}

yamlgraph/gconfig.go

@@ -68,6 +68,7 @@ type Resources struct {
 	Pkg      []*resources.PkgRes      `yaml:"pkg"`
 	Svc      []*resources.SvcRes      `yaml:"svc"`
 	Timer    []*resources.TimerRes    `yaml:"timer"`
+	User     []*resources.UserRes     `yaml:"user"`
 	Virt     []*resources.VirtRes     `yaml:"virt"`
 }