import: write stdin to tmp file

If importing an archive via stdin write it to a temporary file such that
the temporary file can be opened multiple times later on.  Otherwise, we
may end up with an empty image.

Also fix a bug in the URL parsing code; we need to check whether there's
actually a scheme.

Add system tests for `podman import` exercising the basics.

Fixes: #10994
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

2 files changed, 24 insertions, 2 deletions

diff --git a/cmd/podman/images/import.go b/cmd/podman/images/import.go
index bed2d4105..bc80417cc 100644
--- a/cmd/podman/images/import.go
+++ b/cmd/podman/images/import.go
@@ -3,6 +3,9 @@ package images
 import (
 	"context"
 	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
 	"strings"
 
 	"github.com/containers/common/pkg/completion"
@@ -97,6 +100,22 @@ func importCon(cmd *cobra.Command, args []string) error {
 	default:
 		return errors.Errorf("too many arguments. Usage TARBALL [REFERENCE]")
 	}
+
+	if source == "-" {
+		outFile, err := ioutil.TempFile("", "podman")
+		if err != nil {
+			return errors.Errorf("error creating file %v", err)
+		}
+		defer os.Remove(outFile.Name())
+		defer outFile.Close()
+
+		_, err = io.Copy(outFile, os.Stdin)
+		if err != nil {
+			return errors.Errorf("error copying file %v", err)
+		}
+		source = outFile.Name()
+	}
+
 	errFileName := parse.ValidateFileName(source)
 	errURL := parse.ValidURL(source)
 	if errURL == nil {
diff --git a/cmd/podman/parse/net.go b/cmd/podman/parse/net.go
index f93c4ab1e..870690db3 100644
--- a/cmd/podman/parse/net.go
+++ b/cmd/podman/parse/net.go
@@ -180,9 +180,12 @@ func ValidateFileName(filename string) error {
 
 // ValidURL checks a string urlStr is a url or not
 func ValidURL(urlStr string) error {
-	_, err := url.ParseRequestURI(urlStr)
+	url, err := url.ParseRequestURI(urlStr)
 	if err != nil {
-		return errors.Wrapf(err, "invalid url path: %q", urlStr)
+		return errors.Wrapf(err, "invalid url %q", urlStr)
+	}
+	if url.Scheme == "" {
+		return errors.Errorf("invalid url %q: missing scheme", urlStr)
 	}
 	return nil
 }