From f15761fcbef37e487515f9636f0833cf472aa97e Mon Sep 17 00:00:00 2001
From: Tomas Kopecek <tkopecek@redhat.com>
Date: Oct 08 2019 16:14:52 +0000
Subject: use preferred arch if there is more options


https://pagure.io/koji/pull-request/323 introduced option to force an
arch for noarch packages. Nevertheless, it is only task architecture and
not buildroot one. So, if builder can provide more possible archs (32/64
bit), it will pick one of these randomly and can go against preferred arch.

Patch introduces "preferred_arch" option for find_arch and use the
task's one when it works with noarch rpm.

Fixes: https://pagure.io/koji/issue/789

---

diff --git a/builder/kojid b/builder/kojid
index d96a8ae..54d7ee5 100755
--- a/builder/kojid
+++ b/builder/kojid
@@ -1349,8 +1349,17 @@ class BuildArchTask(BaseBuildTask):
 
         rootopts = {
             'repo_id': repo_id
-            }
-        br_arch = self.find_arch(arch, self.session.host.getHost(), self.session.getBuildConfig(root, event=event_id))
+        }
+        if arch == "noarch":
+            # There could have been forced taskarch Exclusive/ExcludeArch,
+            # so we should honor it here.
+            task = self.session.getTaskInfo(self.id)
+            preferred_arch = task['arch']
+        else:
+            preferred_arch = None
+        br_arch = self.find_arch(arch, self.session.host.getHost(),
+                                 self.session.getBuildConfig(root, event=event_id),
+                                 preferred_arch=preferred_arch)
         broot = BuildRoot(self.session, self.options, root, br_arch, self.id, **rootopts)
         broot.workdir = self.workdir
 
diff --git a/koji/tasks.py b/koji/tasks.py
index 6ed02b6..9284d53 100644
--- a/koji/tasks.py
+++ b/koji/tasks.py
@@ -495,10 +495,12 @@ class BaseTaskHandler(object):
     def subtask2(self, __taskopts, __method, *args, **kwargs):
         return self.session.host.subtask2(self.id, __taskopts, __method, *args, **kwargs)
 
-    def find_arch(self, arch, host, tag):
+    def find_arch(self, arch, host, tag, preferred_arch=None):
         """
         For noarch tasks, find a canonical arch that is supported by both the host and tag.
         If the arch is anything other than noarch, return it unmodified.
+
+        If preferred_arch is set, try to get it, but not fail on that
         """
         if arch != "noarch":
             return arch
@@ -521,6 +523,10 @@ class BaseTaskHandler(object):
         # find the intersection of host and tag arches
         common_arches = list(host_arches & tag_arches)
         if common_arches:
+            if preferred_arch and preferred_arch in common_arches:
+                self.logger.info('Valid arches: %s, using preferred: %s' %
+                                 (' '.join(sorted(common_arches)), preferred_arch))
+                return preferred_arch
             # pick one of the common arches randomly
             # need to re-seed the prng or we'll get the same arch every time,
             # because we just forked from a common parent