Merge pull request #1328 from shirou/feature/check-file-contents

fix(host,linux): Check if path exists and is nonempty before reading host files

host/host_linux.go

@@ -179,26 +179,26 @@ func PlatformInformationWithContext(ctx context.Context) (platform string, famil
 		lsb = &lsbStruct{}
 	}
 
-	if common.PathExists(common.HostEtc("oracle-release")) {
+	if common.PathExistsWithContents(common.HostEtc("oracle-release")) {
 		platform = "oracle"
 		contents, err := common.ReadLines(common.HostEtc("oracle-release"))
 		if err == nil {
 			version = getRedhatishVersion(contents)
 		}
 
-	} else if common.PathExists(common.HostEtc("enterprise-release")) {
+	} else if common.PathExistsWithContents(common.HostEtc("enterprise-release")) {
 		platform = "oracle"
 		contents, err := common.ReadLines(common.HostEtc("enterprise-release"))
 		if err == nil {
 			version = getRedhatishVersion(contents)
 		}
-	} else if common.PathExists(common.HostEtc("slackware-version")) {
+	} else if common.PathExistsWithContents(common.HostEtc("slackware-version")) {
 		platform = "slackware"
 		contents, err := common.ReadLines(common.HostEtc("slackware-version"))
 		if err == nil {
 			version = getSlackwareVersion(contents)
 		}
-	} else if common.PathExists(common.HostEtc("debian_version")) {
+	} else if common.PathExistsWithContents(common.HostEtc("debian_version")) {
 		if lsb.ID == "Ubuntu" {
 			platform = "ubuntu"
 			version = lsb.Release
@@ -206,7 +206,7 @@ func PlatformInformationWithContext(ctx context.Context) (platform string, famil
 			platform = "linuxmint"
 			version = lsb.Release
 		} else {
-			if common.PathExists("/usr/bin/raspi-config") {
+			if common.PathExistsWithContents("/usr/bin/raspi-config") {
 				platform = "raspbian"
 			} else {
 				platform = "debian"
@@ -279,6 +279,8 @@ func PlatformInformationWithContext(ctx context.Context) (platform string, famil
 		version = lsb.Release
 	}
 
+	platform = strings.Trim(platform, `"`)
+
 	switch platform {
 	case "debian", "ubuntu", "linuxmint", "raspbian":
 		family = "debian"

internal/common/common.go

@@ -311,6 +311,15 @@ func PathExists(filename string) bool {
 	return false
 }
 
+// PathExistsWithContents returns the filename exists and it is not empty
+func PathExistsWithContents(filename string) bool {
+	info, err := os.Stat(filename)
+	if err != nil {
+		return false
+	}
+	return info.Size() > 4 // at least 4 bytes
+}
+
 // GetEnv retrieves the environment variable key. If it does not exist it returns the default.
 func GetEnv(key string, dfault string, combineWith ...string) string {
 	value := os.Getenv(key)

internal/common/common_test.go

@@ -102,6 +102,25 @@ func TestPathExists(t *testing.T) {
 	}
 }
 
+func TestPathExistsWithContents(t *testing.T) {
+	if !PathExistsWithContents("common_test.go") {
+		t.Error("exists but return not exists")
+	}
+	if PathExistsWithContents("should_not_exists.go") {
+		t.Error("not exists but return exists")
+	}
+
+	f, err := os.CreateTemp("", "empty_test.txt")
+	if err != nil {
+		t.Errorf("CreateTemp failed, %s", err)
+	}
+	defer os.Remove(f.Name()) // clean up
+
+	if PathExistsWithContents(f.Name()) {
+		t.Error("exists but no content file return true")
+	}
+}
+
 func TestHostEtc(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("windows doesn't have etc")