[elbe-devel] [PATCH v1 2/2] RPCAPTCache now duplicate file descriptor

[dion at linutronix.de]

From: Olivier Dion <dion at linutronix.de>

Instead of opening a log file, we shall pass now a logging
object to 'get_rpcaptcache'.  The worker will automatically
redirect both of its outputs to the logging's file
descriptor if any.  If the logging's file descriptor is
already closed, the worker will open the corresponding log
file in append mode with 0 buffering.

Signed-off-by: Olivier Dion <dion at linutronix.de>
---
 elbepack/cdroms.py      |  6 +++---
 elbepack/elbeproject.py |  2 +-
 elbepack/finetuning.py  |  2 +-
 elbepack/rpcaptcache.py | 33 ++++++++++++++++++++++++---------
 4 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/elbepack/cdroms.py b/elbepack/cdroms.py
index 3f2ecc21..3ef765e5 100644
--- a/elbepack/cdroms.py
+++ b/elbepack/cdroms.py
@@ -49,7 +49,7 @@ def mk_source_cdrom(
                         cdrom_size,
                         mirror)
 
-    cache = get_rpcaptcache(rfs, "aptcache.log", arch)
+    cache = get_rpcaptcache(rfs, log, arch)
     cache.update()
     pkglist = cache.get_installed_pkgs()
 
@@ -150,7 +150,7 @@ def mk_binary_cdrom(
                                target_repo_path, log, cdrom_size, mirror)
 
     if xml is not None:
-        cache = get_rpcaptcache(rfs, "aptcache.log", arch)
+        cache = get_rpcaptcache(rfs, log, arch)
         for p in xml.node("debootstrappkgs"):
             pkg = XMLPackage(p, arch)
             try:
@@ -179,7 +179,7 @@ def mk_binary_cdrom(
                     pkg.installed_version +
                     " missing name or version")
 
-    cache = get_rpcaptcache(rfs, "aptcache.log", arch)
+    cache = get_rpcaptcache(rfs, log, arch)
     pkglist = cache.get_installed_pkgs()
     for pkg in pkglist:
         try:
diff --git a/elbepack/elbeproject.py b/elbepack/elbeproject.py
index 073bfb15..1040d281 100644
--- a/elbepack/elbeproject.py
+++ b/elbepack/elbeproject.py
@@ -809,7 +809,7 @@ class ElbeProject (object):
         if env.rpcaptcache is None:
             env.rpcaptcache = get_rpcaptcache(
                 env.rfs,
-                self.log.fp.name,
+                self.log,
                 arch,
                 self.rpcaptcache_notifier,
                 norecommend,
diff --git a/elbepack/finetuning.py b/elbepack/finetuning.py
index 97342862..1e710fa7 100644
--- a/elbepack/finetuning.py
+++ b/elbepack/finetuning.py
@@ -445,7 +445,7 @@ class UpdatedAction(FinetuningAction):
 
         buildenv.rfs.mkdir_p('/tmp/pkgs')
         with buildenv:
-            cache = get_rpcaptcache(buildenv.rfs, "updated-repo.log", arch)
+            cache = get_rpcaptcache(buildenv.rfs, log, arch)
 
             pkglist = cache.get_installed_pkgs()
             for pkg in pkglist:
diff --git a/elbepack/rpcaptcache.py b/elbepack/rpcaptcache.py
index 5f35d419..bcd7c538 100644
--- a/elbepack/rpcaptcache.py
+++ b/elbepack/rpcaptcache.py
@@ -28,6 +28,27 @@ class MyMan(BaseManager):
         BaseManager.register(cls.typeid, cls)
         return cls
 
+    @staticmethod
+    def redirect_outputs(out):
+        # This won't work for Python3.  We can't have 0 buffering in
+        # write mode .. only in binary.
+        buffering = 0
+        sys.stdout = os.fdopen(sys.stdout.fileno(), "w", buffering)
+        sys.stderr = os.fdopen(sys.stderr.fileno(), "w", buffering)
+        os.dup2(out, sys.stdout.fileno())
+        os.dup2(out, sys.stderr.fileno())
+
+    def start(self, log):
+        try:
+            fd = log.fp.fileno()
+        except ValueError:
+            # It's very important to do this on _2 lines_.  Otherwise
+            # Python will GC the file and we would have a bad file
+            # descriptor!
+            f = open(log.fname, "a", buffering=0)
+            fd = f.fileno()
+        super(MyMan, self).start(MyMan.redirect_outputs, [fd])
+
 
 class InChRootObject(object):
     def __init__(self, rfs):
@@ -44,18 +65,12 @@ class RPCAPTCache(InChRootObject):
     def __init__(
             self,
             rfs,
-            log,
             arch,
             notifier=None,
             norecommend=False,
             noauth=True):
 
         # pylint: disable=too-many-arguments
-
-        sys.stdout = open(log, 'a', buffering=0)
-        sys.stderr = open(log, 'a', buffering=0)
-        self.logfile = open(log, 'a', buffering=0)
-
         InChRootObject.__init__(self, rfs)
 
         self.notifier = notifier
@@ -177,7 +192,7 @@ class RPCAPTCache(InChRootObject):
         os.environ["DEBIAN_FRONTEND"] = "noninteractive"
         os.environ["DEBONF_NONINTERACTIVE_SEEN"] = "true"
         self.cache.commit(ElbeAcquireProgress(),
-                          ElbeInstallProgress(fileno=self.logfile.fileno()))
+                          ElbeInstallProgress(fileno=sys.stdout.fileno()))
         self.cache.open(progress=ElbeOpProgress())
 
     def clear(self):
@@ -297,11 +312,11 @@ def get_rpcaptcache(
     # pylint: disable=too-many-arguments
 
     mm = MyMan()
-    mm.start()
+    mm.start(log)
 
     # Disable false positive, because pylint can not
     # see the creation of MyMan.RPCAPTCache by
     # MyMan.register()
     #
     # pylint: disable=no-member
-    return mm.RPCAPTCache(rfs, log, arch, notifier, norecommend, noauth)
+    return mm.RPCAPTCache(rfs, arch, notifier, norecommend, noauth)
-- 
2.11.0