Containerfile: new file

This Containerfile allows us to build the OpenShift node image on top
of the base RHCOS/SCOS image (i.e. built from the `c9s` or `rhel-9.4`
image).

Currently, the resulting image is at parity with the base image you'd
get from building the `okd-c9s` or `ocp-rhel-9.4` variant. In the
future, those variants will go away and this will become the only way to
build the node image.

Part of: #799

Containerfile

@@ -0,0 +1,33 @@
+# This builds the final OCP node image on top of the base RHCOS image. The
+# latter may be RHEL or CentOS Stream-based. This is currently only buildable
+# using podman/buildah as it uses some mounting options only available there.
+#
+# To build this, you will want to pass `--security-opt=label=disable` to avoid
+# having to relabel the context directory. Any repos found in `/run/yum.repos.d`
+# will be imported into `/etc/yum.repos.d/` and then removed in the same step (so
+# as to not end up in the final image).
+#
+# Use `--from` to override the base RHCOS image. E.g.:
+#
+# podman build --from quay.io/openshift-release-dev/ocp-v4.0-art-dev:rhel-coreos-base-9.4 ...
+#
+# Or to use a locally built OCI archive:
+#
+# podman build --from oci-archive:builds/latest/x86_64/scos-9-20240416.dev.0-ostree.x86_64.ociarchive ...
+
+# If consuming from repos hosted within the RH network, you'll want to mount in
+# certs too:
+#
+# podman build -v /etc/pki/ca-trust:/etc/pki-ca-trust:ro ...
+#
+# Example invocation:
+#
+# podman build --from oci-archive:$(ls builds/latest/x86_64/*.ociarchive) \
+#   -v rhel-9.4.repo:/run/yum.repos.d/rhel-9.4.repo:ro \
+#   -v /etc/pki/ca-trust:/etc/pki/ca-trust:ro \
+#   --security-opt label=disable -t localhost/openshift-node-c9s \
+#   src/config
+
+FROM quay.io/openshift-release-dev/ocp-v4.0-art-dev:rhel-coreos-base-c9s
+RUN --mount=type=bind,target=/run/src /run/src/scripts/apply-manifest /run/src/packages-openshift.yaml && \
+  ostree container commit

scripts/apply-manifest

@@ -0,0 +1,75 @@
+#!/usr/bin/python3 -u
+
+# This is a hacky temporary script to apply an rpm-ostree manifest as part of a
+# derived container build. It's only required because we're in this transitional
+# state where some streams use the old way, and others use layering. Once all
+# streams use layering, we could stop using manifests for the layered bits. (An
+# obvious question here is whether we should keep extending the `rpm-ostree ex
+# rebuild` stuff to keep using manifests even in a layered build. Though likely
+# similar functionality will live in dnf instead.)
+
+# Note this only supports the subset of the manifest spec actually used in
+# `packages-openshift.yaml`.
+
+import os
+import shutil
+import subprocess
+import sys
+import yaml
+
+
+def runcmd(args):
+    print("Running:", ' '.join(args))
+    subprocess.check_call(args)
+
+
+manifest_file = sys.argv[1]
+manifest_dir = os.path.dirname(manifest_file)
+
+with open(manifest_file) as f:
+    manifest = yaml.safe_load(f)
+
+if len(manifest.get('packages', [])):
+
+    packages = []
+    for pkg in manifest['packages']:
+        packages += pkg.split()
+    rpmostree_install = ['rpm-ostree', 'install', '-y'] + packages
+
+    # XXX: temporary hack for cri-o, which wants to create dirs under /opt
+    # https://github.com/CentOS/centos-bootc/issues/393
+    if 'cri-o' in packages:
+        os.makedirs("/var/opt", exist_ok=True)
+
+    # inject mounted-in repo files
+    extra_repos_dir = '/run/yum.repos.d'
+    copied_repo_files = []
+    if os.path.isdir(extra_repos_dir):
+        for file in os.listdir(extra_repos_dir):
+            src_path = os.path.join(extra_repos_dir, file)
+            if not os.path.isfile(src_path):
+                continue
+            if not file.endswith(".repo"):
+                continue
+            dest_path = os.path.join('/etc/yum.repos.d', file)
+            if os.path.exists(dest_path):
+                raise Exception(f"Repo file {dest_path} already exists")
+            print(f"Copying repo file {file} to /etc/yum.repos.d/")
+            shutil.copy(src_path, dest_path)
+            copied_repo_files += [dest_path]
+
+    runcmd(rpmostree_install)
+
+    # delete the repo files we injected
+    for repo in copied_repo_files:
+        os.unlink(repo)
+
+
+if len(manifest.get('postprocess', [])):
+    for i, script in enumerate(manifest['postprocess']):
+        name = f"/tmp/postprocess-script-{i}"
+        with open(name, 'w') as f:
+            f.write(script)
+        os.chmod(name, 0o755)
+        runcmd([name])
+        os.unlink(name)