[qemu-xen staging] docker.py: fix fetching of FROM layers

[patchbot@xxxxxxx]

commit f73e485285bc2da944a08e1dd20a30df93e23f25
Author:     Alex Bennée <alex.bennee@xxxxxxxxxx>
AuthorDate: Mon Jul 13 21:04:07 2020 +0100
Commit:     Alex Bennée <alex.bennee@xxxxxxxxxx>
CommitDate: Wed Jul 15 11:52:43 2020 +0100

    docker.py: fix fetching of FROM layers
    
    This worked on a system that was already bootstrapped because the
    stage 2 images already existed even if they wouldn't be used. What we
    should have pulled down was the FROM line containers first because
    building on gitlab doesn't have the advantage of using our build
    system to build the pre-requisite bits.
    
    We still pull the image we want to build just in case we can use the
    cached data.
    
    Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
    Reviewed-by: Daniel P. Berrangé <berrange@xxxxxxxxxx>
    Tested-by: Philippe Mathieu-Daudé <f4bug@xxxxxxxxx>
    Message-Id: <20200713200415.26214-4-alex.bennee@xxxxxxxxxx>
---
 tests/docker/docker.py | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/tests/docker/docker.py b/tests/docker/docker.py
index 2d67bbd15a..c9f20d8d09 100755
--- a/tests/docker/docker.py
+++ b/tests/docker/docker.py
@@ -306,14 +306,18 @@ class Docker(object):
         checksum = _text_checksum(_dockerfile_preprocess(dockerfile))
 
         if registry is not None:
-            # see if we can fetch a cache copy, may fail...
-            pull_args = ["pull", "%s/%s" % (registry, tag)]
-            if self._do(pull_args, quiet=quiet) == 0:
+            sources = re.findall("FROM qemu\/(.*)", dockerfile)
+            # Fetch any cache layers we can, may fail
+            for s in sources:
+                pull_args = ["pull", "%s/qemu/%s" % (registry, s)]
+                if self._do(pull_args, quiet=quiet) != 0:
+                    registry = None
+                    break
+            # Make substitutions
+            if registry is not None:
                 dockerfile = dockerfile.replace("FROM qemu/",
                                                 "FROM %s/qemu/" %
                                                 (registry))
-            else:
-                registry = None
 
         tmp_df = tempfile.NamedTemporaryFile(mode="w+t",
                                              encoding='utf-8',
@@ -339,6 +343,8 @@ class Docker(object):
             build_args += ["--build-arg", "BUILDKIT_INLINE_CACHE=1"]
 
         if registry is not None:
+            pull_args = ["pull", "%s/%s" % (registry, tag)]
+            self._do(pull_args, quiet=quiet)
             cache = "%s/%s" % (registry, tag)
             build_args += ["--cache-from", cache]
         build_args += argv
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#staging