tests/docker: allow "update" to add the current user

The current user functionality is used for cross compiling to avoid
complications with permissions when building test programs. However
for images that come from the registry we still need the ability to
add the user after the fact.

Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210512102051.12134-5-alex.bennee@linaro.org>

tests/docker/docker.py

@@ -517,14 +517,17 @@ def run(self, args, argv):
 
 
 class UpdateCommand(SubCommand):
-    """ Update a docker image with new executables. Args: <tag> <executable>"""
+    """ Update a docker image. Args: <tag> <actions>"""
     name = "update"
 
     def args(self, parser):
         parser.add_argument("tag",
                             help="Image Tag")
         parser.add_argument("--executable",
                             help="Executable to copy")
+        parser.add_argument("--add-current-user", "-u", dest="user",
+                            action="store_true",
+                            help="Add the current user to image's passwd")
 
     def run(self, args, argv):
         # Create a temporary tarball with our whole build context and
@@ -564,6 +567,13 @@ def run(self, args, argv):
 
             df.write(u"ADD . /\n")
 
+        if args.user:
+            uid = os.getuid()
+            uname = getpwuid(uid).pw_name
+            df.write("\n")
+            df.write("RUN id %s 2>/dev/null || useradd -u %d -U %s" %
+                     (uname, uid, uname))
+
         df_bytes = BytesIO(bytes(df.getvalue(), "UTF-8"))
 
         df_tar = TarInfo(name="Dockerfile")