For local images copied from an image store other than the default, we
need to be able to specify the `storage-location`. This commit enables
this functionality.
Jira: https://issues.redhat.com/browse/HMS-3235
Update the skopeo sources stage to check other container-transports [1]
for downloading container images. This commit adds a transport for
`containers-storage` in addition to the existing `docker://`
transport.
Jira: https://issues.redhat.com/browse/HMS-3235
[1] CONTAINERS-TRANSPORTS(5)
Change the local storage format for containers to the `dir` format.
The `dir` format will be used to retain signatures and manifests.
The remove-signatures option is removed since the storage format now
supports them.
The final move (os.rename()) at the end of the fetch_one() method now
creates the checksum directory if it doesn't exist and moves the child
archive into it, adding to any existing archives that might exist in
other formats (from a previous version downloading a `docker-archive`).
Dropped the .tar suffix from the symlink in the skopeo stage since it's
not necessary and the target of the link might be a directory now.
The parent class exists() method checks if there is a *file* in the
sources cache that matches the checksum. For containers, this used to
be a file called container-image.tar under a directory that matches the
checksum, so for containers it always returned False. Added an override
for the skopeo source that checks for the new directory archive.
Instead of downloading the image directly to the temporary directory
and then moving that temporary directory into the cache use one more
intermediate directory and move that into the cache. The reason is
that on Python 3.6 removing the temporary directory itself will make
Python crash like this:
Python 3.6.8 (default, Sep 9 2021, 07:49:02)
[GCC 8.5.0 20210514 (Red Hat 8.5.0-3)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import tempfile
>>> with tempfile.TemporaryDirectory(prefix="tmp-download-") as tmpdir:
... import os
... os.rename(tmpdir, "/tmp/foo")
Traceback (most recent call last):
File "<stdin>", line 3, in <module>
File "/usr/lib64/python3.6/tempfile.py", line 809, in __exit__
self.cleanup()
File "/usr/lib64/python3.6/tempfile.py", line 813, in cleanup
_shutil.rmtree(self.name)
File "/usr/lib64/python3.6/shutil.py", line 477, in rmtree
onerror(os.lstat, path, sys.exc_info())
File "/usr/lib64/python3.6/shutil.py", line 475, in rmtree
orig_st = os.lstat(path)
FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tmp-download-adl86mwa'
Use `subprocess.check_output` instead of `run(..., capture_output=True)`
since the latter only got added in Python 3.7 and our codebase needs to
be compatible with 3.6 due to RHEL 8.x.
Before, the download method was defined in the inherited class of each
program. With the same kind of workflow redefined every time. This
contribution aims at making the workflow more clear and to generalize
what can be in the SourceService class.
The download worklow is as follow:
Setup -> Filter -> Prepare -> Download
The setup mainly step sets up caches. Where the download data will be
stored in the end.
The filter step is used to discard some of the items to download based
on some criterion. By default, it is used to verify if an item is
already in the cache using the item's checksum.
The Prepare step goes from each element and let the overloading step the
ability to alter each item before downloading it. This is used mainly
for the curl command which for rhel must generate the subscriptions.
Then the download step will call fetch_one for each item. Here the
download can be performed sequentially or in parallel depending on the
number of workers selected.
Introduce a new class member `content_type` that specifies what type of
items the source will store in the cache. Use that to generalize the
setup step, which is shared across all sources.
This adds a stage called org.osbuild.skopeo that installs docker and
oci archive files into the container storage of the tree being
constructed.
The source can either be a file from another pipeline, for example one
created with the existing org.osbuild.oci-archive stage, or it can
be using the new org.osbuild.skopeo source and org.osbuild.containers
input, which will download an image from a registry and install that.
There is an optional option in the install stage that lets you
configure a custom storage location, which allows the use of the
additionalimagestores option in the container storage.conf
to use a read-only image stores (instead of /var/lib/container).
Note: skopeo fails to start if /etc/containers/policy.json is
not available, so we bind mount it from the build tree to the
buildroot if available.
