Fixed bug #687

zip-based implementation of http.FileSystem did not have `http.File::Seek()`
implementation.

Makefile

@@ -2,7 +2,7 @@
 # Naming convention:
 #	for stable releases we use "1.0.0" format
 #   for pre-releases, we use   "1.0.0-beta.2" format
-VERSION=1.3.1
+VERSION=1.3.2
 
 # These are standard autotools variables, don't change them please
 BUILDDIR ?= build

constants.go

@@ -37,6 +37,9 @@ const (
 	// ComponentTunClient is a tunnel client
 	ComponentTunClient = "tunclient"
 
+	// DebugEnvVar tells tests to use verbose debug output
+	DebugEnvVar = "DEBUG"
+
 	// DefaultTimeout sets read and wrie timeouts for SSH server ops
 	DefaultTimeout time.Duration = 30 * time.Second
 

lib/web/static.go

@@ -28,13 +28,21 @@ import (
 	"strings"
 
 	log "github.com/Sirupsen/logrus"
+
+	"github.com/gravitational/teleport"
 	"github.com/gravitational/trace"
+
 	"github.com/kardianos/osext"
 )
 
 // relative path to static assets. this is useful during development.
 var debugAssetsPath string
 
+const (
+	webAssetsMissingError = "the teleport binary was built without web assets, try building with `make release`"
+	webAssetsReadError    = "failure reading web assets from the binary"
+)
+
 // NewStaticFileSystem returns the initialized implementation of http.FileSystem
 // interface which can be used to serve Teleport Proxy Web UI
 //
@@ -71,8 +79,8 @@ func NewStaticFileSystem(debugMode bool) (http.FileSystem, error) {
 // isDebugMode determines if teleport is running in a "debug" mode.
 // It looks at DEBUG environment variable
 func isDebugMode() bool {
-	v, err := strconv.ParseBool(os.Getenv("DEBUG"))
-	return v && err == nil
+	v, _ := strconv.ParseBool(os.Getenv(teleport.DebugEnvVar))
+	return v
 }
 
 // LoadWebResources returns a filesystem implementation compatible
@@ -107,7 +115,10 @@ func readZipArchive(archivePath string) (ResourceMap, error) {
 		// this often happens when teleport is launched without the web assets
 		// zip file attached to the binary. for launching it in such mode
 		// set DEBUG environment variable to 1
-		return nil, trace.NotFound("Failed reading web assets from the binary. %v", err)
+		if err == zip.ErrFormat {
+			return nil, trace.NotFound(webAssetsMissingError)
+		}
+		return nil, trace.NotFound("%s %v", webAssetsReadError, err)
 	}
 	entries := make(ResourceMap)
 	for _, file := range zreader.File {
@@ -127,14 +138,43 @@ func readZipArchive(archivePath string) (ResourceMap, error) {
 type resource struct {
 	reader io.ReadCloser
 	file   *zip.File
+	pos    int64
 }
 
 func (rsc *resource) Read(p []byte) (n int, err error) {
-	return rsc.reader.Read(p)
+	n, err = rsc.reader.Read(p)
+	rsc.pos += int64(n)
+	return n, err
 }
 
 func (rsc *resource) Seek(offset int64, whence int) (int64, error) {
-	return offset, nil
+	var (
+		pos int64
+		err error
+	)
+	// zip.File does not support seeking. To implement Seek on top of it,
+	// we close the existing reader, re-open it, and read 'offset' bytes from
+	// the beginning
+	if err = rsc.reader.Close(); err != nil {
+		return 0, err
+	}
+	if rsc.reader, err = rsc.file.Open(); err != nil {
+		return 0, err
+	}
+	switch whence {
+	case io.SeekStart:
+		pos = offset
+	case io.SeekCurrent:
+		pos = rsc.pos + offset
+	case io.SeekEnd:
+		pos = int64(rsc.file.UncompressedSize64) + offset
+	}
+	if pos > 0 {
+		b := make([]byte, pos)
+		rsc.reader.Read(b)
+	}
+	rsc.pos = pos
+	return pos, nil
 }
 
 func (rsc *resource) Readdir(count int) ([]os.FileInfo, error) {
@@ -162,5 +202,5 @@ func (rm ResourceMap) Open(name string) (http.File, error) {
 	if err != nil {
 		return nil, trace.Wrap(err)
 	}
-	return &resource{reader, f}, nil
+	return &resource{reader, f, 0}, nil
 }

lib/web/static_test.go

@@ -17,9 +17,13 @@ limitations under the License.
 package web
 
 import (
+	"io"
 	"io/ioutil"
+	"net/http"
 	"os"
 
+	"github.com/gravitational/teleport"
+
 	"gopkg.in/check.v1"
 )
 
@@ -34,39 +38,64 @@ func (s *StaticSuite) SetUpSuite(c *check.C) {
 
 func (s *StaticSuite) TestDebugModeEnv(c *check.C) {
 	c.Assert(isDebugMode(), check.Equals, false)
-	os.Setenv("DEBUG", "no")
+	os.Setenv(teleport.DebugEnvVar, "no")
 	c.Assert(isDebugMode(), check.Equals, false)
-	os.Setenv("DEBUG", "0")
+	os.Setenv(teleport.DebugEnvVar, "0")
 	c.Assert(isDebugMode(), check.Equals, false)
-	os.Setenv("DEBUG", "1")
+	os.Setenv(teleport.DebugEnvVar, "1")
 	c.Assert(isDebugMode(), check.Equals, true)
-	os.Setenv("DEBUG", "true")
+	os.Setenv(teleport.DebugEnvVar, "true")
 	c.Assert(isDebugMode(), check.Equals, true)
 }
 
 func (s *StaticSuite) TestLocalFS(c *check.C) {
-	// load FS from the local
 	fs, err := NewStaticFileSystem(true)
 	c.Assert(err, check.IsNil)
 	c.Assert(fs, check.NotNil)
 
-	f, err := fs.Open("/index.html")
-	c.Assert(err, check.IsNil)
-	bytes, err := ioutil.ReadAll(f)
-	c.Assert(err, check.IsNil)
-	c.Assert(len(bytes) > 600, check.Equals, true)
-	c.Assert(f.Close(), check.IsNil)
+	checkFS(fs, c)
 }
 
 func (s *StaticSuite) TestZipFS(c *check.C) {
 	fs, err := readZipArchive("../../fixtures/assets.zip")
 	c.Assert(err, check.IsNil)
 	c.Assert(fs, check.NotNil)
 
+	checkFS(fs, c)
+}
+
+func checkFS(fs http.FileSystem, c *check.C) {
+	// test simple full read:
 	f, err := fs.Open("/index.html")
 	c.Assert(err, check.IsNil)
 	bytes, err := ioutil.ReadAll(f)
 	c.Assert(err, check.IsNil)
-	c.Assert(len(bytes) > 600, check.Equals, true)
+	c.Assert(len(bytes), check.Equals, 813)
 	c.Assert(f.Close(), check.IsNil)
+
+	// seek + read
+	f, err = fs.Open("/index.html")
+	c.Assert(err, check.IsNil)
+	defer f.Close()
+
+	n, err := f.Seek(10, io.SeekStart)
+	c.Assert(err, check.IsNil)
+	c.Assert(n, check.Equals, int64(10))
+
+	bytes, err = ioutil.ReadAll(f)
+	c.Assert(err, check.IsNil)
+	c.Assert(len(bytes), check.Equals, 803)
+
+	n, err = f.Seek(-50, io.SeekEnd)
+	c.Assert(err, check.IsNil)
+	bytes, err = ioutil.ReadAll(f)
+	c.Assert(err, check.IsNil)
+	c.Assert(len(bytes), check.Equals, 50)
+
+	f.Seek(-50, io.SeekEnd)
+	n, err = f.Seek(-50, io.SeekCurrent)
+	c.Assert(err, check.IsNil)
+	bytes, err = ioutil.ReadAll(f)
+	c.Assert(err, check.IsNil)
+	c.Assert(len(bytes), check.Equals, 100)
 }

version.go

@@ -2,7 +2,7 @@
 package teleport
 
 const (
-	Version = "1.3.1"
+	Version = "1.3.2"
 )
 
 var Gitref string