test/mod: use proper host runner

Instead of hard-coding the use of the "org.osbuild.linux" runner,
use the new `osbuild.pipeline.detect_host_runner` function to
dynamically detect the runner for the host system. That should fix
the tests on RHEL systems, where python3 is by default not present
and even if it is manually installed, is an indirection via
alternatives (i.e. a link to /etc/alternatives), which must be
explicitly configured in the build root container for the host.

test/mod/test_buildroot.py

@@ -10,6 +10,7 @@ import unittest
 
 from osbuild.buildroot import BuildRoot
 from osbuild.monitor import LogMonitor, NullMonitor
+from osbuild.pipeline import detect_host_runner
 from .. import test
 
 
@@ -23,7 +24,7 @@ class TestBuildRoot(test.TestBase):
         self.tmp.cleanup()
 
     def test_basic(self):
-        runner = "org.osbuild.linux"
+        runner = detect_host_runner()
         libdir = os.path.abspath(os.curdir)
         var = pathlib.Path(self.tmp.name, "var")
         var.mkdir()
@@ -64,7 +65,7 @@ class TestBuildRoot(test.TestBase):
         self.assertEqual(log, r.output)
 
     def test_output(self):
-        runner = "org.osbuild.linux"
+        runner = detect_host_runner()
         libdir = os.path.abspath(os.curdir)
         var = pathlib.Path(self.tmp.name, "var")
         var.mkdir()
@@ -81,7 +82,7 @@ class TestBuildRoot(test.TestBase):
 
     @unittest.skipUnless(test.TestBase.have_test_data(), "no test-data access")
     def test_bind_mounts(self):
-        runner = "org.osbuild.linux"
+        runner = detect_host_runner()
         libdir = os.path.abspath(os.curdir)
         var = pathlib.Path(self.tmp.name, "var")
         var.mkdir()
@@ -118,7 +119,7 @@ class TestBuildRoot(test.TestBase):
         # because RPM and other tools must not assume the policy
         # of the host is the valid policy
 
-        runner = "org.osbuild.linux"
+        runner = detect_host_runner()
         libdir = os.path.abspath(os.curdir)
         var = pathlib.Path(self.tmp.name, "var")
         var.mkdir()

test/mod/test_monitor.py

@@ -12,6 +12,7 @@ from collections import defaultdict
 import osbuild
 import osbuild.meta
 from osbuild.monitor import LogMonitor
+from osbuild.pipeline import detect_host_runner
 from .. import test
 
 
@@ -53,7 +54,8 @@ class TestMonitor(unittest.TestCase):
     @unittest.skipUnless(test.TestBase.can_bind_mount(), "root-only")
     def test_log_monitor_vfuncs(self):
         # Checks the basic functioning of the LogMonitor
-        pipeline = osbuild.Pipeline("org.osbuild.linux")
+        runner = detect_host_runner()
+        pipeline = osbuild.Pipeline(runner=runner)
         pipeline.add_stage("org.osbuild.noop", {}, {
             "isthisthereallife": False
         })
@@ -83,7 +85,8 @@ class TestMonitor(unittest.TestCase):
     @unittest.skipUnless(test.TestBase.can_bind_mount(), "root-only")
     def test_monitor_integration(self):
         # Checks the monitoring API is called properly from the pipeline
-        pipeline = osbuild.Pipeline("org.osbuild.linux")
+        runner = detect_host_runner()
+        pipeline = osbuild.Pipeline(runner=runner)
         pipeline.add_stage("org.osbuild.noop", {}, {
             "isthisthereallife": False
         })

test/mod/test_osbuild.py

@@ -12,6 +12,7 @@ import unittest
 import osbuild
 import osbuild.meta
 from osbuild.monitor import NullMonitor
+from osbuild.pipeline import detect_host_runner
 from .. import test
 
 
@@ -52,7 +53,7 @@ class TestDescriptions(unittest.TestCase):
             data = pathlib.Path(tmpdir, "data")
             cache = pathlib.Path(tmpdir, "cache")
             root = pathlib.Path("/")
-            runner = "org.osbuild.linux"
+            runner = detect_host_runner()
             monitor = NullMonitor(sys.stderr.fileno())
             libdir = os.path.abspath(os.curdir)
 
@@ -86,7 +87,7 @@ class TestDescriptions(unittest.TestCase):
             cache = pathlib.Path(tmpdir, "cache")
             output = pathlib.Path(tmpdir, "output")
             root = pathlib.Path("/")
-            runner = "org.osbuild.linux"
+            runner = detect_host_runner()
             monitor = NullMonitor(sys.stderr.fileno())
             libdir = os.path.abspath(os.curdir)