syscontainers: add generation of an rpm

Add a hidden (for now) option ---generate-rpm to "install --system" to
generate an rpm file instead of installing the container.  The rpm can
be installed on the system and the container won't be managed by
atomic, update and uninstall are disabled.

Differently from containers handled by atomic that installs the
container under /var/lib/containers/atomic, the RPM version installs
its files under /usr/lib/containers and can be integrated in an atomic
image as a normal rpm.

Signed-off-by: Giuseppe Scrivano <[email protected]>

Atomic/install.py

@@ -59,6 +59,9 @@ def cli(subparser):
                 system_xor_user.add_argument("--system", dest="system",
                                              action='store_true', default=False,
                                              help=_('install a system container'))
+                installp.add_argument("---generate-rpm", dest="generate_rpm",
+                                      action='store_true', default=False,
+                                      help=_('generate an rpm instead of installing the container'))
         installp.add_argument("--rootfs", dest="remote",
                               help=_("choose an existing exploded container/image to use "
                                      "its rootfs as a remote, read-only rootfs for the "

Atomic/syscontainers.py

@@ -42,6 +42,7 @@
 SYSTEMD_TMPFILES_DEST_USER = "%s/.containers/tmpfiles" % HOME
 SYSTEMD_UNIT_FILES_DEST_PREFIX = "%s/usr/lib/systemd/system"
 SYSTEMD_TMPFILES_DEST_PREFIX = "%s/usr/lib/tmpfiles.d"
+RPM_NAME_PREFIX = "atomic-container"
 SYSTEMD_UNIT_FILE_DEFAULT_TEMPLATE = """
 [Unit]
 Description=$NAME
@@ -170,6 +171,11 @@ def install(self, image, name):
         if self.args.system and self.user:
             raise ValueError("Only root can use --system")
 
+        if self.args.generate_rpm:
+            if not self.args.system:
+                raise ValueError("Only --system can generate rpms")
+            return self.generate_rpm(repo, name, image)
+
         if not self.user:
             try:
                 util.check_call([util.RUNC_PATH, "--version"], stdout=DEVNULL)
@@ -1355,3 +1361,75 @@ def get_out_checksum(obj): return obj.out_checksum if hasattr(obj, 'out_checksum
         it.init_commit(repo, repo.load_commit(current_rev)[1], OSTree.RepoCommitTraverseFlags.REPO_COMMIT_TRAVERSE_FLAG_NONE)
         traverse(it)
         return ret
+
+    def generate_rpm(self, repo, name, image):
+        image_inspect = self.inspect_system_image(image)
+        temp_dir = tempfile.mkdtemp()
+        rpm_content = os.path.join(temp_dir, "rpmroot")
+        rootfs = os.path.join(rpm_content, "usr/lib/containers/atomic", name)
+        os.makedirs(rootfs)
+        try:
+            spec_file = os.path.join(temp_dir, "container.spec")
+            self._checkout(repo, name, image, 0, False, destination=rootfs, prefix=rpm_content)
+            labels = {k.lower() : v for k, v in image_inspect.get('Labels', {})}
+            summary = labels.get('summary', name)
+            version = labels.get("version", "1.0")
+            release = labels.get("release", "1.0")
+            license = labels.get("license", "GPLv2")
+            url = labels.get("url")
+            source0 = labels.get("source0")
+            requires = labels.get("requires")
+            provides = labels.get("provides")
+            conflicts = labels.get("conflicts")
+            description = labels.get("description")
+
+            self._generate_spec_file(spec_file, rpm_content, name, summary, license, version=version, release=release,
+                                     url=url, source0=source0, requires=requires, provides=provides, conflicts=conflicts,
+                                     description=description)
+
+            cwd = os.getcwd()
+            cmd = ["rpmbuild", "--noclean", "-bb", spec_file,
+                   "--define", "_sourcedir %s" % temp_dir,
+                   "--define", "_specdir %s" % temp_dir,
+                   "--define", "_builddir %s" % temp_dir,
+                   "--define", "_srcrpmdir %s" % cwd,
+                   "--define", "_rpmdir %s" % cwd,
+                   "--build-in-place",
+                   "--buildroot=%s" % rpm_content]
+            util.write_out(" ".join(cmd))
+            if not self.display:
+                util.check_call(cmd)
+            return False
+        finally:
+            shutil.rmtree(temp_dir)
+
+    def _generate_spec_file(self, out, destdir, name, summary, license, version="1.0", release="1", url=None,
+                            source0=None, requires=None, conflicts=None, provides=None, description=None):
+        spec = "%global __requires_exclude_from ^.*$\n"
+        spec = spec + "%global __provides_exclude_from ^.*$\n"
+
+        fields = {"Name" : "%s-%s" % (RPM_NAME_PREFIX, name), "Version" : version, "Release" : release, "Summary" : summary,
+                  "License" : license, "URL" : url, "Source0" : source0, "Requires" : requires,
+                  "Provides" : provides, "Conflicts" : conflicts}
+        for k, v in fields.items():
+            if v is not None:
+                spec = spec + "%s:\t%s\n" % (k, v)
+
+        spec = spec + "\n%description\n"
+        if description:
+            spec = spec + "%s\n" % description
+
+        spec = spec + "\n%files\n"
+        for root, _, files in os.walk(os.path.join(destdir, "etc")):
+            spec += "%config \"%s\"\n" % os.path.join("/", rel_path, f)
+
+        spec += "/usr/lib/containers/atomic/%s\n" % name
+        for root, _, files in os.walk(os.path.join(destdir, "usr/lib/systemd/system")):
+            for f in files:
+                spec = spec + "/usr/lib/systemd/system/%s\n" % f
+        for root, _, files in os.walk(os.path.join(destdir, "usr/lib/tmpfiles.d")):
+            for f in files:
+                spec = spec + "/usr/lib/tmpfiles.d/%s\n" % f
+
+        with open(out, "w") as f:
+            f.write(spec)