Re: [Newsletter] Re: [gentoo-catalyst] Re: [PATCH 2/2] Move from PORTDIR_OVERLAY to repos.conf

[Felix Bier <Felix.Bier@rohde-schwarz.com>]

This commit fixes the following issues:

  * The PORTDIR_OVERLAY variable has been deprecated by Gentoo.

    With this commit, the variable is no longer written to the
    generated make.conf. Instead, a config file
    /etc/portage/repos.conf/<repo-name>.conf
    is generated for each overlay. The repo name is read from the
    overlay using the portage API. Internally, portage parses
    metadata/layout.conf and profiles/repo_name to obtain the name.

    References:
    https://wiki.gentoo.org/wiki//etc/portage/make.conf
    https://wiki.gentoo.org/wiki//etc/portage/repos.conf

  * All overlays were copied into the same target directory. If the
    same file name occurred in multiple overlays, the last overlay
    would overwrite all previous files with this name. In particular,
    only the metadata/layout.conf of the last overlay was retained,
    so it was not possible to reference the other overlays e.g. via
    the masters entry in the layout.conf or the portage-2 syntax
    for specifying a parent profile from another overlay. Also,
    this created problems when the overlays contained ebuilds
    for the same package, but with differing versions, because
    after copying, the target directory contained both versions of the
    ebuild but only the manifest file of the last overlay.

    With this commit, each overlay is copied into a separate
    sub-directory, e.g. /var/db/repos/<repo-name>.
    This directory is referenced via the location entry in the
    generated /etc/portage/repos.conf/<repo-name>.conf.

Signed-off-by: Felix Bier <felix.bier@rohde-schwarz.com>
---
 catalyst/base/stagebase.py | 84 ++++++++++++++++++++++++++++----------
 catalyst/defaults.py       |  2 +-
 catalyst/support.py        | 18 ++++++++
 3 files changed, 81 insertions(+), 23 deletions(-)

diff --git a/catalyst/base/stagebase.py b/catalyst/base/stagebase.py
index 21cf96a0..fe79b55a 100644
--- a/catalyst/base/stagebase.py
+++ b/catalyst/base/stagebase.py
@@ -1,4 +1,5 @@
 
+import configparser
 import copy
 import os
 import platform
@@ -19,8 +20,8 @@ from catalyst import log
 from catalyst.context import namespace
 from catalyst.defaults import (confdefaults, MOUNT_DEFAULTS, PORT_LOGDIR_CLEAN)
 from catalyst.support import (CatalystError, file_locate, normpath,
-                              cmd, read_makeconf, ismount, file_check,
-                              sanitize_name)
+                              cmd, read_makeconf, get_repo_name, ismount,
+                              file_check, sanitize_name)
 from catalyst.base.targetbase import TargetBase
 from catalyst.base.clearbase import ClearBase
 from catalyst.base.genbase import GenBase
@@ -786,17 +787,55 @@ class StageBase(TargetBase, ClearBase, GenBase):
                 env=self.env)
             self.resume.enable("setup_confdir")
 
+    def to_chroot(self, path):
+        """ Prepend chroot path to the given path. """
+
+        chroot = Path(self.settings['chroot_path'])
+        return chroot / path.relative_to(path.anchor)
+
+    def get_repo_conf_path(self, repo_name):
+        """ Construct repo conf path: {repos_conf}/{name}.conf """
+        return Path(self.settings['repos_conf'], repo_name + ".conf")
+
+    def get_repo_location(self, repo_name):
+        """ Construct overlay repo path: {repo_basedir}/{name} """
+        return Path(self.settings['repo_basedir'], repo_name)
+
+    def write_repo_conf(self, repo_name, config):
+        """ Write ConfigParser to {chroot}/{repos_conf}/{name}.conf """
+
+        repo_conf = self.get_repo_conf_path(repo_name)
+
+        repo_conf_chroot = self.to_chroot(repo_conf)
+        repo_conf_chroot.parent.mkdir(mode=0o755, parents=True, exist_ok=True)
+
+        log.info(f'Creating repo config {repo_conf_chroot}.')
+
+        try:
+            with open(repo_conf_chroot, 'w') as f:
+                config.write(f)
+        except OSError as e:
+            raise CatalystError(f'Could not write {repo_conf_chroot}: {e}') from e
+
     def portage_overlay(self):
-        """ We copy the contents of our overlays to /usr/local/portage """
+        """ We copy the contents of our repos to get_repo_location(repo_name) """
         if "portage_overlay" in self.settings:
             for x in self.settings["portage_overlay"]:
                 if os.path.exists(x):
-                    log.info('Copying overlay dir %s', x)
-                    ensure_dirs(
-                        self.settings['chroot_path'] + self.settings['local_overlay'])
-                    cmd("cp -a " + x + "/* " + self.settings["chroot_path"] +
-                        self.settings["local_overlay"],
-                        env=self.env)
+                    name = get_repo_name(x)
+
+                    location = self.get_repo_location(name)
+                    config = configparser.ConfigParser()
+                    config[name] = {'location': location}
+                    self.write_repo_conf(name, config)
+
+                    location_chroot = self.to_chroot(location)
+                    location_chroot.mkdir(mode=0o755, parents=True, exist_ok=True)
+
+                    log.info(f'Copying overlay dir {x} to {location_chroot}')
+                    cmd(f'cp -a {x}/* {location_chroot}', env=self.env)
+                else:
+                    log.warning(f'Skipping missing overlay {x}.')
 
     def root_overlay(self):
         """ Copy over the root_overlay """
@@ -852,8 +891,8 @@ class StageBase(TargetBase, ClearBase, GenBase):
                 cxt = libmount.Context(source=source, target=target,
                                        fstype=fstype, options=options)
                 cxt.mount()
-            except OSError as e:
-                raise CatalystError(f"Couldn't mount: {source}, {e.strerror}")
+            except Exception as e:
+                raise CatalystError(f"Couldn't mount: {source}, {e}")
 
     def chroot_setup(self):
         self.makeconf = read_makeconf(normpath(self.settings["chroot_path"] +
@@ -1018,12 +1057,6 @@ class StageBase(TargetBase, ClearBase, GenBase):
                     varname = x.split('_')[1].upper()
                     myf.write(f'{varname}="{self.settings[x]}"\n')
 
-            if setup:
-                # Setup the portage overlay
-                if "portage_overlay" in self.settings:
-                    myf.write('PORTDIR_OVERLAY="%s"\n' %
-                              self.settings["local_overlay"])
-
             # Set default locale for system responses. #478382
             myf.write(
                 '\n'
@@ -1097,11 +1130,18 @@ class StageBase(TargetBase, ClearBase, GenBase):
             log.warning("You've been hacking. Clearing target patches: %s", target)
             clear_path(target)
 
-        # Remove our overlay
-        overlay = normpath(
-            self.settings["chroot_path"] + self.settings["local_overlay"])
-        if os.path.exists(overlay):
-            clear_path(overlay)
+        # Remove our overlays
+        if "portage_overlay" in self.settings:
+            for repo_path in self.settings["portage_overlay"]:
+                repo_name = get_repo_name(repo_path)
+
+                repo_conf = self.get_repo_conf_path(repo_name)
+                chroot_repo_conf = self.to_chroot(repo_conf)
+                chroot_repo_conf.unlink()
+
+                location = self.get_repo_location(repo_name)
+                chroot_location = self.to_chroot(location)
+                clear_path(str(chroot_location))
 
         if "sticky-config" not in self.settings["options"]:
             # re-write the make.conf to be sure it is clean
diff --git a/catalyst/defaults.py b/catalyst/defaults.py
index 0f399b56..3f12b8d5 100644
--- a/catalyst/defaults.py
+++ b/catalyst/defaults.py
@@ -38,9 +38,9 @@ confdefaults = {
     "distdir": portage.settings['DISTDIR'],
     "icecream": "/var/cache/icecream",
     'list_xattrs_opt': LIST_XATTRS_OPTIONS['linux'],
-    "local_overlay": "/var/db/repos/local",
     "port_conf": "/etc/portage",
     "make_conf": "%(port_conf)s/make.conf",
+    "repos_conf": "%(port_conf)s/repos.conf",
     "options": set(),
     "pkgdir": "/var/cache/binpkgs",
     "port_tmpdir": "/var/tmp/portage",
diff --git a/catalyst/support.py b/catalyst/support.py
index ddbd9ab9..f3a865a7 100644
--- a/catalyst/support.py
+++ b/catalyst/support.py
@@ -10,6 +10,8 @@ from subprocess import Popen
 
 import libmount
 
+from portage.repository.config import RepoConfig
+
 from catalyst import log
 
 BASH_BINARY = "/bin/bash"
@@ -182,6 +184,22 @@ def read_makeconf(mymakeconffile):
         return makeconf
 
 
+def get_repo_name(repo_path):
+    """ Get the name of the repo at the given repo_path.
+
+         References:
+         https://wiki.gentoo.org/wiki/Repository_format/profiles/repo_name
+         https://wiki.gentoo.org/wiki/Repository_format/metadata/layout.conf#repo-name
+    """
+
+    repo_config = RepoConfig(None, {"location": repo_path})
+
+    if repo_config.missing_repo_name:
+        raise CatalystError(f"Missing name in repository {repo_path}")
+
+    return repo_config.name
+
+
 def ismount(path):
     """Like os.path.ismount, but also support bind mounts"""
     path = Path(path)
-- 
2.29.2