Complete rewrite of the bootstraper tool

pkg/templater/files.go

@@ -0,0 +1,153 @@
+package templater
+
+import (
+	"log"
+	"path/filepath"
+	"strconv"
+
+	"bytes"
+	encjson "encoding/json"
+	"fmt"
+	"os"
+	"text/template"
+
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+	"github.com/zclconf/go-cty/cty"
+	ctyjson "github.com/zclconf/go-cty/cty/json"
+
+	"forge.cadoles.com/pcaseiro/templatefile/pkg/utils"
+)
+
+type ConfigFile struct {
+	Destination  string `form:"destination" json:"destination"` // Where do we write the configuration file
+	Source       string `form:"source" json:"source"`           // The template file short name
+	TemplateType string `json:"type"`                           // The template file type (hcl or gotemplate)
+	Mode         string `form:"mod" json:"mode"`                // The configuration file final permissions (mode)
+	Owner        string `json:"owner"`                          // The configuration file owner
+	Service      string `json:"service"`                        // Service to restart after configuration generation
+	Group        string `json:"group"`                          // The configuration file group owner
+}
+
+// Generate the configuration file from the template (hcl or json)
+func (cf *ConfigFile) Generate(root string, templateDir string, values []byte) error {
+	var template string
+	dest := filepath.Join(root, cf.Destination)
+	source := filepath.Join(templateDir, cf.Source)
+	intMod, err := strconv.ParseInt(cf.Mode, 8, 64)
+	if err != nil {
+		return (err)
+	}
+
+	template, err = cf.ProcessTemplate(source, values)
+	if err != nil {
+		return fmt.Errorf("Process templates failed with error: %v", err)
+	}
+	dirname := filepath.Dir(dest)
+	err = os.MkdirAll(dirname, os.FileMode(int(0700)))
+	if err != nil {
+		return fmt.Errorf("Process templates failed with error: %v", err)
+	}
+	err = os.WriteFile(dest, []byte(template), os.FileMode(intMod))
+	if err != nil {
+		return fmt.Errorf("Process templates failed with error: %v", err)
+	}
+	log.Printf("\tFile %s generated\n", dest)
+	return nil
+}
+
+// Process the template with the provided values
+func (cf *ConfigFile) ProcessTemplate(source string, values []byte) (string, error) {
+	var result string
+	var err error
+
+	if cf.TemplateType == "hcl" {
+		// The template is an hcl template so we call processHCLTemplate
+		result, err = cf.processHCLTemplate(source, values)
+		if err != nil {
+			return "", fmt.Errorf("Process HCL template failed with error: %v", err)
+		}
+	} else if cf.TemplateType == "go" {
+		// The template is a go template so we call processGoTemplate
+		result, err = cf.processGoTemplate(source, values)
+		if err != nil {
+			return "", fmt.Errorf("Process GO template failed with error: %v", err)
+		}
+	}
+	return result, nil
+}
+
+// The actual template processing for Go templates
+func (cf *ConfigFile) processGoTemplate(file string, configValues []byte) (string, error) {
+
+	// The JSON configuration
+	var confData map[string]interface{}
+	var res bytes.Buffer
+
+	err := encjson.Unmarshal(configValues, &confData)
+	utils.CheckErr(err)
+
+	// Read the template
+	data, err := os.ReadFile(file)
+	utils.CheckErr(err)
+
+	tpl, err := template.New("conf").Parse(string(data))
+	utils.CheckErr(err)
+
+	utils.CheckErr(tpl.Execute(&res, confData["Config"]))
+
+	return res.String(), nil
+}
+
+// The actual template processing for HCL templates
+func (cf *ConfigFile) processHCLTemplate(file string, config []byte) (string, error) {
+
+	fct, err := os.ReadFile(file)
+	utils.CheckErr(err)
+
+	expr, diags := hclsyntax.ParseTemplate(fct, file, hcl.Pos{Line: 0, Column: 1})
+	utils.CheckDiags(diags)
+
+	// Retrieve values from JSON
+	var varsVal cty.Value
+	ctyType, err := ctyjson.ImpliedType(config)
+	if err != nil {
+		return "", err
+		/* Maybe one day
+		cexpr, diags := hclsyntax.ParseExpression(config, "", hcl.Pos{Line: 0, Column: 1})
+		if diags.HasErrors() {
+			panic(diags.Error())
+		}
+		varsVal, diags = cexpr.Value(&hcl.EvalContext{})
+		fmt.Println(cexpr.Variables())
+		checkDiags(diags)
+		*/
+	} else {
+		varsVal, err = ctyjson.Unmarshal(config, ctyType)
+		utils.CheckErr(err)
+	}
+
+	ctx := &hcl.EvalContext{
+		Variables: varsVal.AsValueMap(),
+	}
+
+	for n := range ctx.Variables {
+		if !hclsyntax.ValidIdentifier(n) {
+			return "", fmt.Errorf("invalid template variable name %q: must start with a letter, followed by zero or more letters, digits, and underscores", n)
+		}
+	}
+
+	for _, traversal := range expr.Variables() {
+		root := traversal.RootName()
+		if _, ok := ctx.Variables[root]; !ok {
+			return "", fmt.Errorf("vars map does not contain key %q, referenced at %s", root, traversal[0].SourceRange())
+		}
+	}
+
+	val, diags := expr.Value(ctx)
+	if diags.HasErrors() {
+		return "", diags
+	}
+
+	return val.AsString(), nil
+}

pkg/templater/main.go

@@ -1,89 +1,88 @@
 package templater
 
 import (
-	"bytes"
-	encjson "encoding/json"
 	"fmt"
+	"io/ioutil"
+	"log"
 	"os"
-	"text/template"
 
-	"github.com/hashicorp/hcl/v2"
-	"github.com/hashicorp/hcl/v2/hclsyntax"
-	"github.com/zclconf/go-cty/cty"
-	ctyjson "github.com/zclconf/go-cty/cty/json"
-
-	"forge.cadoles.com/pcaseiro/templatefile/pkg/utils"
+	"github.com/imdario/mergo"
 )
 
-func ProcessGoTemplate(file string, config []byte) string {
+var CacheFilePath = "/var/cache/templater.db"
 
-	// The JSON configuration
-	var confData map[string]interface{}
-	var res bytes.Buffer
-
-	err := encjson.Unmarshal(config, &confData)
-	utils.CheckErr(err)
-
-	// Read the template
-	data, err := os.ReadFile(file)
-	utils.CheckErr(err)
-
-	tpl, err := template.New("conf").Parse(string(data))
-	utils.CheckErr(err)
-
-	utils.CheckErr(tpl.Execute(&res, confData))
-
-	return res.String()
+type TemplaterConfig struct {
+	Name              string             `json:"Name"`
+	TemplateDirectory string             `json:"TemplateDirectory"`
+	Services          map[string]Service `json:"Services"`
+	GlobalService     Service            `json:"Global"`
 }
 
-func ProcessHCLTemplate(file string, config []byte) string {
-
-	fct, err := os.ReadFile(file)
-	utils.CheckErr(err)
-
-	expr, diags := hclsyntax.ParseTemplate(fct, file, hcl.Pos{Line: 0, Column: 1})
-	utils.CheckDiags(diags)
-
-	// Retrieve values from JSON
-	var varsVal cty.Value
-	ctyType, err := ctyjson.ImpliedType(config)
+func (tc *TemplaterConfig) loadCache() error {
+	// Load globals from cache
+	var cache Service
+	err := Load(CacheFilePath, &cache)
 	if err != nil {
-		panic(err)
-		/* Maybe one day
-		cexpr, diags := hclsyntax.ParseExpression(config, "", hcl.Pos{Line: 0, Column: 1})
-		if diags.HasErrors() {
-			panic(diags.Error())
-		}
-		varsVal, diags = cexpr.Value(&hcl.EvalContext{})
-		fmt.Println(cexpr.Variables())
-		checkDiags(diags)
-		*/
-	} else {
-		varsVal, err = ctyjson.Unmarshal(config, ctyType)
-		utils.CheckErr(err)
+		fmt.Printf("Warning: No globals to load\n")
 	}
 
-	ctx := &hcl.EvalContext{
-		Variables: varsVal.AsValueMap(),
+	err = mergo.Merge(&tc.GlobalService, cache)
+	if err != nil {
+		return err
 	}
-
-	for n := range ctx.Variables {
-		if !hclsyntax.ValidIdentifier(n) {
-			panic(fmt.Errorf("invalid template variable name %q: must start with a letter, followed by zero or more letters, digits, and underscores", n))
-		}
-	}
-
-	for _, traversal := range expr.Variables() {
-		root := traversal.RootName()
-		if _, ok := ctx.Variables[root]; !ok {
-			panic(fmt.Errorf("vars map does not contain key %q, referenced at %s", root, traversal[0].SourceRange()))
-		}
-	}
-
-	val, diags := expr.Value(ctx)
-	if diags.HasErrors() {
-		panic(diags.Error())
-	}
-
-	return val.AsString()
+	return nil
+}
+
+func (tc *TemplaterConfig) New(confpath string, templateDir string) error {
+	// Load stored globals if needed
+	lerr := tc.loadCache()
+	if lerr != nil {
+		return lerr
+	}
+	// Check if the configuration path is a Directory or a file
+	fileInfo, err := os.Stat(confpath)
+	if err != nil {
+		return err
+	}
+
+	if fileInfo.IsDir() {
+		// The conf path is a directory we load all the files and merge data
+		files, err := ioutil.ReadDir(confpath)
+		if err != nil {
+			return fmt.Errorf("Templater configuration load failed with error: %v", err)
+		}
+		for _, file := range files {
+			fname := fmt.Sprintf("%s/%s", confpath, file.Name())
+			var ntc TemplaterConfig
+			err := Load(fname, &ntc)
+			if err != nil {
+				return fmt.Errorf("Templater configuration load failed with error: %v", err)
+			}
+			err = mergo.Merge(tc, ntc)
+			if err != nil {
+				return fmt.Errorf("Templater configuration load failed with error: %v", err)
+			}
+		}
+	} else {
+		// The conf path is a file we only load this file (of course)
+		err = Load(confpath, tc)
+		if err != nil {
+			return fmt.Errorf("Confiuration read failed with error: %v", err)
+		}
+	}
+
+	tc.TemplateDirectory = templateDir
+
+	return nil
+}
+
+func (tc *TemplaterConfig) ManageServices(rootDir string) error {
+	for name, svr := range tc.Services {
+		log.Printf("*** Working on service %s", name)
+		if err := svr.Manage(tc.TemplateDirectory, rootDir); err != nil {
+			return err
+		}
+		log.Printf("*** Service %s processed", name)
+	}
+	return nil
 }

pkg/templater/packages.go

@@ -0,0 +1,74 @@
+package templater
+
+import (
+	"fmt"
+	"log"
+	"runtime"
+
+	"forge.cadoles.com/pcaseiro/templatefile/pkg/utils"
+)
+
+type SystemPackage struct {
+	Name         string `json:"name"`
+	Type         string `json:"type"`
+	Action       string `json:"action"`
+	OS           string `json:"os"`
+	Distribution string `json:"distribution"`
+}
+
+func (p *SystemPackage) SetDistribution() error {
+	OSConfig, err := utils.ReadOSRelease()
+	if err != nil {
+		return err
+	}
+
+	p.Distribution = OSConfig["ID_LIKE"]
+	return nil
+}
+func (p *SystemPackage) SetOS() error {
+	p.OS = runtime.GOOS
+	return nil
+}
+
+func (p *SystemPackage) Manage() error {
+	var pkErr error
+	var stdErr []byte
+
+	if p.OS == "" {
+		if err := p.SetOS(); err != nil {
+			return err
+		}
+	}
+
+	if p.Distribution == "" {
+		if err := p.SetDistribution(); err != nil {
+			return err
+		}
+	}
+
+	log.Printf("\tInstalling %s package\n", p.Name)
+	switch os := p.Distribution; os {
+	case "debian", "ubuntu":
+		_, stdErr, pkErr = utils.RunSystemCommand("apt", "install", "-y", p.Name)
+	case "alpine":
+		_, stdErr, pkErr = utils.RunSystemCommand("apk", "add", p.Name)
+	case "redhat":
+		_, stdErr, pkErr = utils.RunSystemCommand("yum", "install", "-y", p.Name)
+	case "arch":
+		_, stdErr, pkErr = utils.RunSystemCommand("pacman", "-Suy", p.Name)
+	default:
+		pkErr = fmt.Errorf("Unsupported OS %s [%s]", p.OS, stdErr)
+	}
+
+	if pkErr != nil {
+		var msg string
+		if len(stdErr) != 0 {
+			msg = string(stdErr)
+		} else {
+			msg = pkErr.Error()
+		}
+		return fmt.Errorf("Package %s, os %s, failed with error: %v", p.Name, p.OS, msg)
+	}
+
+	return nil
+}

pkg/templater/persist.go

@@ -0,0 +1,51 @@
+package templater
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"sync"
+)
+
+var lock sync.Mutex
+
+func marshal(v interface{}) (io.Reader, error) {
+	b, err := json.MarshalIndent(v, "", "\t")
+	if err != nil {
+		return nil, err
+	}
+	return bytes.NewReader(b), nil
+}
+
+func unmarshal(r io.Reader, v interface{}) error {
+	return json.NewDecoder(r).Decode(v)
+}
+
+func Save(path string, v interface{}) error {
+	lock.Lock()
+	defer lock.Unlock()
+	f, err := os.Create(path)
+	if err != nil {
+		return fmt.Errorf("Saving Templater configuration failed with error : %v", err)
+	}
+	defer f.Close()
+	r, err := marshal(v)
+	if err != nil {
+		return err
+	}
+	_, err = io.Copy(f, r)
+	return err
+}
+
+func Load(path string, v interface{}) error {
+	lock.Lock()
+	defer lock.Unlock()
+	f, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	return unmarshal(f, v)
+}

pkg/templater/repo-apk.go

@@ -0,0 +1,102 @@
+package templater
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"strings"
+
+	"forge.cadoles.com/pcaseiro/templatefile/pkg/utils"
+)
+
+var APKConfigFile = "/etc/apk/repositories"
+
+type APKRepository struct {
+	Repository
+}
+
+func (hr *APKRepository) urlIsPresent() (bool, error) {
+	f, err := os.Open(APKConfigFile)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	// Splits on newlines by default.
+	scanner := bufio.NewScanner(f)
+
+	line := 1
+	for scanner.Scan() {
+		if strings.Contains(scanner.Text(), hr.URL) {
+			log.Printf("\tRepository %s already present\n", hr.Name)
+			return true, nil
+		}
+		line++
+	}
+
+	if err := scanner.Err(); err != nil {
+		return false, err
+	}
+	return false, nil
+
+}
+
+func (hr *APKRepository) Add() error {
+
+	URLIsPresent, err := hr.urlIsPresent()
+	if err != nil {
+		return err
+	}
+
+	if URLIsPresent {
+		return nil
+	} else {
+		data := fmt.Sprintf("%s\n", hr.URL)
+		file, err := os.OpenFile(APKConfigFile, os.O_APPEND|os.O_WRONLY, 0644)
+		if err != nil {
+			return err
+		}
+		defer file.Close()
+		if _, err := file.WriteString(data); err != nil {
+			return err
+		} else {
+			log.Printf("Repository %s added\n", hr.Name)
+		}
+		return nil
+	}
+
+}
+
+func (hr *APKRepository) Update() error {
+	if _, stdErr, err := utils.RunSystemCommand("apk", "update"); err != nil {
+		return fmt.Errorf("%s [%s]", stdErr, err)
+	}
+	return nil
+}
+
+// FIXME
+func (hr *APKRepository) Delete() error {
+	fileBytes, err := ioutil.ReadFile("/etc/apk/repositories")
+	if err != nil {
+		return err
+	}
+	lines := strings.Split(string(fileBytes), "\n")
+	for _, line := range lines {
+		fmt.Printf("DEBUG TODO %s", line)
+	}
+	return nil
+}
+
+func (hr *APKRepository) Manage() error {
+	if hr.Enabled {
+		if err := hr.Add(); err != nil {
+			return err
+		}
+		log.Println("\tUpdating apk repositories")
+		return hr.Update()
+	} else {
+		return hr.Delete()
+	}
+}

pkg/templater/repo-deb.go

@@ -0,0 +1,43 @@
+package templater
+
+import (
+	"fmt"
+	"os"
+
+	"forge.cadoles.com/pcaseiro/templatefile/pkg/utils"
+)
+
+type DebRepository struct {
+	Repository
+}
+
+func (hr *DebRepository) Add() error {
+	//deb http://fr.archive.ubuntu.com/ubuntu/ focal main restricted
+
+	data := fmt.Sprintf("deb %s", hr.URL)
+	if err := os.WriteFile("/etc/apt/source.list.d", []byte(data), 0600); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (hr *DebRepository) Update() error {
+	if _, stdErr, err := utils.RunSystemCommand("apt", "update", "-y"); err != nil {
+		return fmt.Errorf("%s [%s]", stdErr, err)
+	}
+
+	return nil
+}
+
+func (hr *DebRepository) Delete() error {
+	//TODO
+	return nil
+}
+func (hr *DebRepository) Manage() error {
+	if hr.Enabled {
+		return hr.Add()
+	} else {
+		return hr.Delete()
+	}
+}

pkg/templater/repo-helm.go

@@ -0,0 +1,25 @@
+package templater
+
+type HelmRepository struct {
+	Repository
+}
+
+func (hr *HelmRepository) Add() error {
+	return nil
+}
+
+func (hr *HelmRepository) Update() error {
+	return nil
+}
+
+func (hr *HelmRepository) Delete() error {
+	return nil
+}
+
+func (hr *HelmRepository) Manage() error {
+	if hr.Enabled {
+		return hr.Add()
+	} else {
+		return hr.Delete()
+	}
+}

pkg/templater/repo.go

@@ -0,0 +1,17 @@
+package templater
+
+type PackageRepository interface {
+	Manage() error
+	Update() error
+	Add() error
+	Delete() error
+}
+
+type Repository struct {
+	Actions PackageRepository
+
+	Name    string `json:"name"`
+	Type    string `json:"type"`
+	URL     string `json:"url"`
+	Enabled bool   `json:"enabled"`
+}

pkg/templater/services.go

@@ -0,0 +1,122 @@
+package templater
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"path/filepath"
+)
+
+type Service struct {
+	ConfigFiles []ConfigFile             `json:"ConfigFiles"`
+	Vars        map[string]interface{}   `json:"Vars"`
+	Daemons     map[string]SystemService `json:"Daemons"`
+	Users       map[string]SystemUser    `json:"Users"`
+	Repos       map[string]Repository    `json:"Repositories"`
+	Packages    map[string]SystemPackage `json:"Packages"`
+}
+
+func (s *Service) manageRepos(repos map[string]Repository) error {
+	for _, repo := range s.Repos {
+		if repo.Type == "helm" {
+			rp := HelmRepository{repo}
+			if err := rp.Manage(); err != nil {
+				return err
+			}
+		}
+		if repo.Type == "apk" {
+			rp := APKRepository{repo}
+			if err := rp.Manage(); err != nil {
+				return err
+			}
+		}
+		if repo.Type == "deb" {
+			rp := DebRepository{}
+			if err := rp.Manage(); err != nil {
+				return err
+			}
+		}
+
+	}
+	return nil
+}
+
+func (s *Service) Manage(templateDir string, rootDir string) error {
+	// Manage packages repositories
+	log.Print(" Managing package repositories")
+	err := s.manageRepos(s.Repos)
+	if err != nil {
+		return err
+	}
+
+	// Create system users
+	log.Print(" Managing system users")
+	for _, user := range s.Users {
+		err := user.Manage()
+		if err != nil {
+			return err
+		}
+	}
+
+	// Manage system packages
+	log.Print(" Installing packages")
+	for _, pack := range s.Packages {
+		err := pack.Manage()
+		if err != nil {
+			return err
+		}
+		log.Printf("\tPackage %s installed\n", pack.Name)
+	}
+
+	log.Print(" Generating configuration files\n")
+	err = processConfigFiles(s, templateDir, rootDir)
+	if err != nil {
+		return fmt.Errorf("ProcessingTemplatesFailed with error: %v", err)
+	}
+
+	log.Print(" Managing services:\n")
+	for _, daemon := range s.Daemons {
+		err = daemon.Manage()
+		if err != nil {
+			return fmt.Errorf("Error managing service daemons: %v", err)
+		}
+	}
+	return nil
+}
+
+func processConfigFiles(s *Service, templateDir string, rootDir string) error {
+	values, err := json.Marshal(s)
+	if err != nil {
+		return fmt.Errorf("Error unmarshaling values on template process; %v", err)
+	}
+
+	var servicesToRestart []string
+	for _, tpl := range s.ConfigFiles {
+		fileExt := filepath.Ext(tpl.Source)
+		if fileExt == ".hcl" {
+			tpl.TemplateType = "hcl"
+		} else if fileExt == ".tpl" {
+			tpl.TemplateType = "go"
+		} else {
+			return fmt.Errorf("Unsupported file type %s, templates extensions have to be '.hcl' or '.tpl'", fileExt)
+		}
+		if err := tpl.Generate(rootDir, templateDir, values); err != nil {
+			return fmt.Errorf("Template %s generation failed with error %v", tpl.Source, err)
+		}
+
+		if len(tpl.Service) != 0 {
+			servicesToRestart = append(servicesToRestart, tpl.Service)
+		}
+	}
+
+	for _, srv := range servicesToRestart {
+		sv := SystemService{
+			Name:    srv,
+			Enabled: true,
+			Type:    "",
+			ToStart: true,
+		}
+		return sv.Restart()
+	}
+	return nil
+}

pkg/templater/system_services.go

@@ -0,0 +1,132 @@
+package templater
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"forge.cadoles.com/pcaseiro/templatefile/pkg/utils"
+)
+
+type SystemService struct {
+	Name    string `json:"name"`
+	Enabled bool   `json:"enabled"`
+	Type    string `json:"type"`
+	ToStart bool   `json:"start"`
+}
+
+func (sys *SystemService) SetType() {
+	systemdRunDirectory := "/run/systemd/system"
+	openRcBinaryFile := "/sbin/openrc"
+
+	// Check if the configuration path is a Directory or a file
+	fileInfo, err := os.Stat(systemdRunDirectory)
+	if err == nil {
+		if fileInfo.IsDir() {
+			sys.Type = "systemd"
+		}
+	}
+
+	fileInfo, err = os.Stat(openRcBinaryFile)
+	if err == nil {
+		if fileInfo.IsDir() {
+			return
+		}
+		sys.Type = "openrc"
+	}
+}
+
+func (sys *SystemService) Action() error {
+	if sys.ToStart {
+		return sys.Start()
+	}
+	return nil
+}
+
+func (sys *SystemService) Manage() error {
+	// By default if the property sys.ToStart is empty
+	if sys.Type == "" || sys.Type == "auto" {
+		sys.SetType()
+	}
+	if sys.Enabled {
+		err := sys.Enable()
+		if err != nil {
+			return err
+		}
+		if err = sys.Action(); err != nil {
+			return err
+		}
+
+	} else {
+		log.Printf("\nNothing to do for daemon %s\n", sys.Name)
+	}
+	return nil
+}
+
+func (sys *SystemService) Start() error {
+	log.Printf("\tStarting system service : %s\n", sys.Name)
+	if sys.Type == "systemd" {
+		_, stdErr, err := utils.RunSystemCommand("systemctl", "start", sys.Name)
+		if err != nil {
+			return fmt.Errorf("System service %s \n * Start error:\n    - %s", sys.Name, stdErr)
+		}
+	} else if sys.Type == "openrc" {
+		_, stdErr, err := utils.RunSystemCommand("service", sys.Name, "start")
+		if err != nil {
+			return fmt.Errorf("System service %s \n * Enable error:\n    - %s", sys.Name, stdErr)
+		}
+	} else {
+		return fmt.Errorf("Unsupported service type %s for service %s", sys.Type, sys.Name)
+	}
+	return nil
+}
+
+func (sys *SystemService) Stop() error {
+	log.Printf("\tStopping system service : %s\n", sys.Name)
+	if sys.Type == "systemd" {
+		_, stdErr, err := utils.RunSystemCommand("systemctl", "stop", sys.Name)
+		if err != nil {
+			return fmt.Errorf("System service %s \n * Stop error:\n    - %s", sys.Name, stdErr)
+		}
+	} else if sys.Type == "openrc" {
+		_, stdErr, err := utils.RunSystemCommand("service", sys.Name, "stop")
+		if err != nil {
+			return fmt.Errorf("System service %s \n * Enable error:\n    - %s", sys.Name, stdErr)
+		}
+	} else {
+		return fmt.Errorf("Unsupported service type %s for service %s", sys.Type, sys.Name)
+	}
+	return nil
+}
+
+func (sys *SystemService) Restart() error {
+	if sys.Type == "" || sys.Type == "auto" {
+		sys.SetType()
+	}
+	if err := sys.Stop(); err != nil {
+		return err
+	}
+	if err := sys.Start(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (sys *SystemService) Enable() error {
+	if sys.Type == "systemd" {
+		_, stdErr, err := utils.RunSystemCommand("systemctl", "enable", sys.Name)
+		if err != nil {
+			return fmt.Errorf("System service %s \n * Enable error:\n    - %s", sys.Name, stdErr)
+		}
+		log.Printf("\tSystemd service %s enabled", sys.Name)
+	} else if sys.Type == "openrc" {
+		_, stdErr, err := utils.RunSystemCommand("rc-update", "add", sys.Name, "default")
+		if err != nil {
+			return fmt.Errorf("System service %s \n * Enable error:\n    - %s", sys.Name, stdErr)
+		}
+		log.Printf("\tOpenRC service %s enabled", sys.Name)
+	} else {
+		return fmt.Errorf("Unsupported service type %s for service %s", sys.Type, sys.Name)
+	}
+	return nil
+}

pkg/templater/system_users.go

@@ -0,0 +1,51 @@
+package templater
+
+import (
+	"log"
+
+	"forge.cadoles.com/pcaseiro/templatefile/pkg/utils"
+)
+
+type SystemUser struct {
+	UserName string `json:"username"`
+	Group    string `json:"group"`
+	Home     string `json:"home"`
+	Shell    string `json:"shell"`
+}
+
+func (su *SystemUser) exists() (bool, error) {
+	_, _, err := utils.RunSystemCommand("getent", "passwd", su.UserName)
+	if err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+func (su *SystemUser) Manage() error {
+	exist, _ := su.exists()
+	if exist {
+		log.Printf("\tUser %s already exists", su.UserName)
+		return nil
+	}
+	return su.Create()
+}
+
+func (su *SystemUser) Create() error {
+	_, _, err := utils.RunSystemCommand("useradd", "-b", su.Home, "-m", "-G", su.Group, su.UserName)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (su *SystemUser) Delete() error {
+	_, _, err := utils.RunSystemCommand("userdel", su.UserName)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (su *SystemUser) Update() error {
+	return nil
+}

pkg/utils/main.go

@@ -1,6 +1,9 @@
 package utils
 
 import (
+	"bytes"
+	"os/exec"
+
 	"github.com/hashicorp/hcl/v2"
 )
 
@@ -15,3 +18,15 @@ func CheckDiags(diag hcl.Diagnostics) {
 		panic(diag.Error())
 	}
 }
+
+// Execute a system command ...
+func RunSystemCommand(name string, arg ...string) ([]byte, []byte, error) {
+	var stdOut bytes.Buffer
+	var stdErr bytes.Buffer
+
+	cmd := exec.Command(name, arg...)
+	cmd.Stderr = &stdErr
+	cmd.Stdout = &stdOut
+	err := cmd.Run()
+	return stdOut.Bytes(), stdErr.Bytes(), err
+}

pkg/utils/os.go

@@ -0,0 +1,27 @@
+package utils
+
+import (
+	"fmt"
+
+	ini "gopkg.in/ini.v1"
+)
+
+var osReleaseFile = "/etc/os-release"
+
+func ReadOSRelease() (map[string]string, error) {
+	cfg, err := ini.Load(osReleaseFile)
+	if err != nil {
+		return nil, fmt.Errorf("Fail to read file: %v ", err)
+	}
+
+	ConfigParams := make(map[string]string)
+	ConfigParams["ID"] = cfg.Section("").Key("ID").String()
+	idLike := cfg.Section("").Key("ID_LIKE").String()
+	if idLike != "" {
+		ConfigParams["ID_LIKE"] = idLike
+	} else {
+		ConfigParams["ID_LIKE"] = ConfigParams["ID"]
+	}
+
+	return ConfigParams, nil
+}