Initial commit to add golib

Signed-off-by: Sebastien Douheret <sebastien.douheret@iot.bzh>

4 files changed, 505 insertions, 0 deletions

diff --git a/golib/error.go b/golib/error.go
new file mode 100644
index 0000000..6873d82
--- /dev/null
+++ b/golib/error.go
@@ -0,0 +1,16 @@
+package common
+
+import (
+	"fmt"
+
+	"github.com/gin-gonic/gin"
+)
+
+// APIError returns an uniform json formatted error
+func APIError(c *gin.Context, format string, args ...interface{}) {
+	errMsg := fmt.Sprintf(format, args...)
+	c.JSON(500, gin.H{
+		"status": "error",
+		"error":  errMsg,
+	})
+}
diff --git a/golib/execPipeWs.go b/golib/execPipeWs.go
new file mode 100644
index 0000000..9bb4517
--- /dev/null
+++ b/golib/execPipeWs.go
@@ -0,0 +1,151 @@
+package common
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"time"
+
+	"syscall"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/googollee/go-socket.io"
+)
+
+// EmitOutputCB is the function callback used to emit data
+type EmitOutputCB func(sid string, cmdID int, stdout, stderr string, data *map[string]interface{})
+
+// EmitExitCB is the function callback used to emit exit proc code
+type EmitExitCB func(sid string, cmdID int, code int, err error, data *map[string]interface{})
+
+// Inspired by :
+// https://github.com/gorilla/websocket/blob/master/examples/command/main.go
+
+// ExecPipeWs executes a command and redirect stdout/stderr into a WebSocket
+func ExecPipeWs(cmd []string, env []string, so *socketio.Socket, sid string, cmdID int,
+	cmdExecTimeout int, log *logrus.Logger, eoCB EmitOutputCB, eeCB EmitExitCB, data *map[string]interface{}) error {
+
+	outr, outw, err := os.Pipe()
+	if err != nil {
+		return fmt.Errorf("Pipe stdout error: " + err.Error())
+	}
+
+	// XXX - do we need to pipe stdin one day ?
+	inr, inw, err := os.Pipe()
+	if err != nil {
+		outr.Close()
+		outw.Close()
+		return fmt.Errorf("Pipe stdin error: " + err.Error())
+	}
+
+	bashArgs := []string{"/bin/bash", "-c", strings.Join(cmd, " ")}
+	proc, err := os.StartProcess("/bin/bash", bashArgs, &os.ProcAttr{
+		Files: []*os.File{inr, outw, outw},
+		Env:   append(os.Environ(), env...),
+	})
+	if err != nil {
+		outr.Close()
+		outw.Close()
+		inr.Close()
+		inw.Close()
+		return fmt.Errorf("Process start error: " + err.Error())
+	}
+
+	go func() {
+		defer outr.Close()
+		defer outw.Close()
+		defer inr.Close()
+		defer inw.Close()
+
+		stdoutDone := make(chan struct{})
+		go cmdPumpStdout(so, outr, stdoutDone, sid, cmdID, log, eoCB, data)
+
+		// Blocking function that poll input or wait for end of process
+		cmdPumpStdin(so, inw, proc, sid, cmdID, cmdExecTimeout, log, eeCB, data)
+
+		// Some commands will exit when stdin is closed.
+		inw.Close()
+
+		defer outr.Close()
+
+		if status, err := proc.Wait(); err == nil {
+			// Other commands need a bonk on the head.
+			if !status.Exited() {
+				if err := proc.Signal(os.Interrupt); err != nil {
+					log.Errorln("Proc interrupt:", err)
+				}
+
+				select {
+				case <-stdoutDone:
+				case <-time.After(time.Second):
+					// A bigger bonk on the head.
+					if err := proc.Signal(os.Kill); err != nil {
+						log.Errorln("Proc term:", err)
+					}
+					<-stdoutDone
+				}
+			}
+		}
+	}()
+
+	return nil
+}
+
+func cmdPumpStdin(so *socketio.Socket, w io.Writer, proc *os.Process,
+	sid string, cmdID int, tmo int, log *logrus.Logger, exitFuncCB EmitExitCB,
+	data *map[string]interface{}) {
+	/* XXX - code to add to support stdin through WS
+	for {
+		_, message, err := so. ?? ReadMessage()
+		if err != nil {
+			break
+		}
+		message = append(message, '\n')
+		if _, err := w.Write(message); err != nil {
+			break
+		}
+	}
+	*/
+
+	// Monitor process exit
+	type DoneChan struct {
+		status int
+		err    error
+	}
+	done := make(chan DoneChan, 1)
+	go func() {
+		status := 0
+		sts, err := proc.Wait()
+		if !sts.Success() {
+			s := sts.Sys().(syscall.WaitStatus)
+			status = s.ExitStatus()
+		}
+		done <- DoneChan{status, err}
+	}()
+
+	// Wait cmd complete
+	select {
+	case dC := <-done:
+		exitFuncCB(sid, cmdID, dC.status, dC.err, data)
+	case <-time.After(time.Duration(tmo) * time.Second):
+		exitFuncCB(sid, cmdID, -99,
+			fmt.Errorf("Exit Timeout for command ID %v", cmdID), data)
+	}
+}
+
+func cmdPumpStdout(so *socketio.Socket, r io.Reader, done chan struct{},
+	sid string, cmdID int, log *logrus.Logger, emitFuncCB EmitOutputCB, data *map[string]interface{}) {
+	defer func() {
+	}()
+
+	sc := bufio.NewScanner(r)
+	for sc.Scan() {
+		emitFuncCB(sid, cmdID, string(sc.Bytes()), "", data)
+	}
+	if sc.Err() != nil {
+		log.Errorln("scan:", sc.Err())
+	}
+	close(done)
+}
diff --git a/golib/filepath.go b/golib/filepath.go
new file mode 100644
index 0000000..5a923b4
--- /dev/null
+++ b/golib/filepath.go
@@ -0,0 +1,81 @@
+package common
+
+import (
+	"fmt"
+	"os"
+	"os/user"
+	"path"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
+)
+
+// Exists returns whether the given file or directory exists or not
+func Exists(path string) bool {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true
+	}
+	if os.IsNotExist(err) {
+		return false
+	}
+	return true
+}
+
+// ResolveEnvVar Resolved environment variable regarding the syntax ${MYVAR}
+// or $MYVAR following by a slash or a backslash
+func ResolveEnvVar(s string) (string, error) {
+	if s == "" {
+		return s, nil
+	}
+
+	// Resolved tilde : ~/
+	if len(s) > 2 && s[:2] == "~/" {
+		if usr, err := user.Current(); err == nil {
+			s = filepath.Join(usr.HomeDir, s[2:])
+		}
+	}
+
+	// Resolved ${MYVAR}
+	re := regexp.MustCompile("\\${([^}]+)}")
+	vars := re.FindAllStringSubmatch(s, -1)
+	res := s
+	for _, v := range vars {
+		val := os.Getenv(v[1])
+		if val == "" {
+			// Specific case to resolved $HOME or ${HOME} on Windows host
+			if runtime.GOOS == "windows" && v[1] == "HOME" {
+				if usr, err := user.Current(); err == nil {
+					val = usr.HomeDir
+				}
+			} else {
+				return res, fmt.Errorf("ERROR: %s env variable not defined", v[1])
+			}
+		}
+
+		rer := regexp.MustCompile("\\${" + v[1] + "}")
+		res = rer.ReplaceAllString(res, val)
+	}
+
+	// Resolved $MYVAR following by a slash (or a backslash for Windows)
+	// TODO
+	//re := regexp.MustCompile("\\$([^\\/])+/")
+
+	return path.Clean(res), nil
+}
+
+// PathNormalize
+func PathNormalize(p string) string {
+	sep := string(filepath.Separator)
+	if sep != "/" {
+		return p
+	}
+	// Replace drive like C: by C/
+	res := p
+	if p[1:2] == ":" {
+		res = p[0:1] + sep + p[2:]
+	}
+	res = strings.Replace(res, "\\", "/", -1)
+	return filepath.Clean(res)
+}
diff --git a/golib/httpclient.go b/golib/httpclient.go
new file mode 100644
index 0000000..72132bf
--- /dev/null
+++ b/golib/httpclient.go
@@ -0,0 +1,257 @@
+package common
+
+import (
+	"bytes"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	"github.com/Sirupsen/logrus"
+)
+
+type HTTPClient struct {
+	httpClient http.Client
+	endpoint   string
+	apikey     string
+	username   string
+	password   string
+	id         string
+	csrf       string
+	conf       HTTPClientConfig
+	logger     *logrus.Logger
+}
+
+type HTTPClientConfig struct {
+	URLPrefix           string
+	HeaderAPIKeyName    string
+	Apikey              string
+	HeaderClientKeyName string
+	CsrfDisable         bool
+}
+
+const (
+	logError   = 1
+	logWarning = 2
+	logInfo    = 3
+	logDebug   = 4
+)
+
+// Inspired by syncthing/cmd/cli
+
+const insecure = false
+
+// HTTPNewClient creates a new HTTP client to deal with Syncthing
+func HTTPNewClient(baseURL string, cfg HTTPClientConfig) (*HTTPClient, error) {
+
+	// Create w new Http client
+	httpClient := http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{
+				InsecureSkipVerify: insecure,
+			},
+		},
+	}
+	client := HTTPClient{
+		httpClient: httpClient,
+		endpoint:   baseURL,
+		apikey:     cfg.Apikey,
+		conf:       cfg,
+		/* TODO - add user + pwd support
+		username:   c.GlobalString("username"),
+		password:   c.GlobalString("password"),
+		*/
+	}
+
+	if client.apikey == "" {
+		if err := client.getCidAndCsrf(); err != nil {
+			return nil, err
+		}
+	}
+	return &client, nil
+}
+
+// SetLogger Define the logger to use
+func (c *HTTPClient) SetLogger(log *logrus.Logger) {
+	c.logger = log
+}
+
+func (c *HTTPClient) log(level int, format string, args ...interface{}) {
+	if c.logger != nil {
+		switch level {
+		case logError:
+			c.logger.Errorf(format, args...)
+			break
+		case logWarning:
+			c.logger.Warningf(format, args...)
+			break
+		case logInfo:
+			c.logger.Infof(format, args...)
+			break
+		default:
+			c.logger.Debugf(format, args...)
+			break
+		}
+	}
+}
+
+// Send request to retrieve Client id and/or CSRF token
+func (c *HTTPClient) getCidAndCsrf() error {
+	request, err := http.NewRequest("GET", c.endpoint, nil)
+	if err != nil {
+		return err
+	}
+	if _, err := c.handleRequest(request); err != nil {
+		return err
+	}
+	if c.id == "" {
+		return errors.New("Failed to get device ID")
+	}
+	if !c.conf.CsrfDisable && c.csrf == "" {
+		return errors.New("Failed to get CSRF token")
+	}
+	return nil
+}
+
+// GetClientID returns the id
+func (c *HTTPClient) GetClientID() string {
+	return c.id
+}
+
+// formatURL Build full url by concatenating all parts
+func (c *HTTPClient) formatURL(endURL string) string {
+	url := c.endpoint
+	if !strings.HasSuffix(url, "/") {
+		url += "/"
+	}
+	url += strings.TrimLeft(c.conf.URLPrefix, "/")
+	if !strings.HasSuffix(url, "/") {
+		url += "/"
+	}
+	return url + strings.TrimLeft(endURL, "/")
+}
+
+// HTTPGet Send a Get request to client and return an error object
+func (c *HTTPClient) HTTPGet(url string, data *[]byte) error {
+	_, err := c.HTTPGetWithRes(url, data)
+	return err
+}
+
+// HTTPGetWithRes Send a Get request to client and return both response and error
+func (c *HTTPClient) HTTPGetWithRes(url string, data *[]byte) (*http.Response, error) {
+	request, err := http.NewRequest("GET", c.formatURL(url), nil)
+	if err != nil {
+		return nil, err
+	}
+	res, err := c.handleRequest(request)
+	if err != nil {
+		return res, err
+	}
+	if res.StatusCode != 200 {
+		return res, errors.New(res.Status)
+	}
+
+	*data = c.responseToBArray(res)
+
+	return res, nil
+}
+
+// HTTPPost Send a POST request to client and return an error object
+func (c *HTTPClient) HTTPPost(url string, body string) error {
+	_, err := c.HTTPPostWithRes(url, body)
+	return err
+}
+
+// HTTPPostWithRes Send a POST request to client and return both response and error
+func (c *HTTPClient) HTTPPostWithRes(url string, body string) (*http.Response, error) {
+	request, err := http.NewRequest("POST", c.formatURL(url), bytes.NewBufferString(body))
+	if err != nil {
+		return nil, err
+	}
+	res, err := c.handleRequest(request)
+	if err != nil {
+		return res, err
+	}
+	if res.StatusCode != 200 {
+		return res, errors.New(res.Status)
+	}
+	return res, nil
+}
+
+func (c *HTTPClient) responseToBArray(response *http.Response) []byte {
+	defer response.Body.Close()
+	bytes, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		// TODO improved error reporting
+		fmt.Println("ERROR: " + err.Error())
+	}
+	return bytes
+}
+
+func (c *HTTPClient) handleRequest(request *http.Request) (*http.Response, error) {
+	if c.conf.HeaderAPIKeyName != "" && c.apikey != "" {
+		request.Header.Set(c.conf.HeaderAPIKeyName, c.apikey)
+	}
+	if c.conf.HeaderClientKeyName != "" && c.id != "" {
+		request.Header.Set(c.conf.HeaderClientKeyName, c.id)
+	}
+	if c.username != "" || c.password != "" {
+		request.SetBasicAuth(c.username, c.password)
+	}
+	if c.csrf != "" {
+		request.Header.Set("X-CSRF-Token-"+c.id[:5], c.csrf)
+	}
+
+	c.log(logDebug, "HTTP %s %v", request.Method, request.URL)
+
+	response, err := c.httpClient.Do(request)
+	if err != nil {
+		return nil, err
+	}
+
+	// Detect client ID change
+	cid := response.Header.Get(c.conf.HeaderClientKeyName)
+	if cid != "" && c.id != cid {
+		c.id = cid
+	}
+
+	// Detect CSR token change
+	for _, item := range response.Cookies() {
+		if item.Name == "CSRF-Token-"+c.id[:5] {
+			c.csrf = item.Value
+			goto csrffound
+		}
+	}
+	// OK CSRF found
+csrffound:
+
+	if response.StatusCode == 404 {
+		return nil, errors.New("Invalid endpoint or API call")
+	} else if response.StatusCode == 401 {
+		return nil, errors.New("Invalid username or password")
+	} else if response.StatusCode == 403 {
+		if c.apikey == "" {
+			// Request a new Csrf for next requests
+			c.getCidAndCsrf()
+			return nil, errors.New("Invalid CSRF token")
+		}
+		return nil, errors.New("Invalid API key")
+	} else if response.StatusCode != 200 {
+		data := make(map[string]interface{})
+		// Try to decode error field of APIError struct
+		json.Unmarshal(c.responseToBArray(response), &data)
+		if err, found := data["error"]; found {
+			return nil, fmt.Errorf(err.(string))
+		} else {
+			body := strings.TrimSpace(string(c.responseToBArray(response)))
+			if body != "" {
+				return nil, fmt.Errorf(body)
+			}
+		}
+		return nil, errors.New("Unknown HTTP status returned: " + response.Status)
+	}
+	return response, nil
+}