Re: [Qemu-devel] [PATCH v3 03/24] docker: rebuild image if 'extra files' checksum does not match

[Philippe Mathieu-Daudé]

On 05/24/2017 02:24 AM, Fam Zheng wrote:
> On Sun, 05/21 00:29, Philippe Mathieu-Daudé wrote:
> > Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> > ---
> >  tests/docker/docker.py | 15 ++++++++++++---
> >  1 file changed, 12 insertions(+), 3 deletions(-)
> >
> > diff --git a/tests/docker/docker.py b/tests/docker/docker.py
> > index eef92a54f1..0dd6a3304f 100755
> > --- a/tests/docker/docker.py
> > +++ b/tests/docker/docker.py
> > @@ -38,6 +38,9 @@ def _text_checksum(text):
> >      """Calculate a digest string unique to the text content"""
> >      return hashlib.sha1(text).hexdigest()
> >
> > +def _file_checksum(filename):
> > +    return _text_checksum(open(filename, 'rb').read())
> > +
> >  def _guess_docker_command():
> >      """ Guess a working docker command or raise exception if not found"""
> >      commands = [["docker"], ["sudo", "-n", "docker"]]
> > @@ -154,7 +157,7 @@ class Docker(object):
> >          return labels.get("com.qemu.dockerfile-checksum", "")
> >
> >      def build_image(self, tag, docker_dir, dockerfile,
> > -                    quiet=True, user=False, argv=None):
> > +                    quiet=True, user=False, argv=None, extra_files_cksum=[]):
> >          if argv == None:
> >              argv = []
> >
> > @@ -170,7 +173,7 @@ class Docker(object):
> >
> >          tmp_df.write("\n")
> >          tmp_df.write("LABEL com.qemu.dockerfile-checksum=%s" %
> > -                     _text_checksum(dockerfile))
> > +                     _text_checksum(dockerfile + "-".join(extra_files_cksum)))
>
> Since @dockerfile is the content of the the Dockerfile, how about concatenating
> with "\n":
>
>                         _text_checksum("\n".join([dockerfile] + 
> extra_files_cksum))
>
> ?

This is only the text to hash, I don't think it will make a difference 
since it isn't useful even debugging the script, but it may be cleaner 
so I'll do it (nonetheless python ends up weirdly indented).

> >          tmp_df.flush()
> >
> >          self._do(["build", "-t", tag, "-f", tmp_df.name] + argv + \
> > @@ -276,16 +279,22 @@ class BuildCommand(SubCommand):
> >                      return 1
> >
> >              # Include files used by ADD directives found within the Dockerfile.
> > +            cksum = []
> >              if args.include_executable:
> > +                # FIXME: there is no checksum of this executable and the linked
> > +                # libraries, once the image built any change of this executable
> > +                # or any library won't trigger another build.
> >                  _copy_binary_with_libs(args.include_executable, docker_dir)
> >              for filename in args.include_files or []:
> >                  _copy_with_mkdir(filename, docker_dir)
> > +                cksum += [_file_checksum(filename)]
> >
> >              argv += ["--build-arg=" + k.lower() + "=" + v
> >                          for k, v in os.environ.iteritems()
> >                          if k.lower() in FILTERED_ENV_NAMES]
> >              dkr.build_image(tag, docker_dir, dockerfile,
> > -                            quiet=args.quiet, user=args.user, argv=argv)
> > +                            quiet=args.quiet, user=args.user, argv=argv,
> > +                            extra_files_cksum=cksum)
> >
> >              rmtree(docker_dir)
> >
> > --
> > 2.11.0