tests: make k3s, incus, and xen tests self-contained

These boot tests previously required manual local.conf changes to set
CONTAINER_PROFILE, DISTRO_FEATURES, and other variables before the
image could be built and tested. This meant complete test coverage
required editing local.conf between runs.

Add build fixtures that use bitbake -R with a temporary conf file to
inject the required variables automatically:
- k3s: builds container-image-host with CONTAINER_PROFILE=k3s-host
- incus: builds container-image-host with CONTAINER_PROFILE=incus
- xen: builds xen-image-minimal with xen/vxn DISTRO_FEATURES

Each test module now builds its own image before booting, using the
same run_bitbake + extra_vars pattern established in
test_container_cross_install.py.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

3 files changed, 159 insertions, 49 deletions

diff --git a/tests/test_incus_runtime.py b/tests/test_incus_runtime.py
index 6de4bd5c..ea5eb1fc 100644
--- a/tests/test_incus_runtime.py
+++ b/tests/test_incus_runtime.py
@@ -5,15 +5,11 @@
 Incus runtime tests - boot container-image-host with incus and verify
 system container management.
 
-Build prerequisites (in local.conf):
-    require conf/distro/include/meta-virt-host.conf
-    require conf/distro/include/container-host-incus.conf
-    MACHINE = "qemux86-64"  # or qemuarm64
-
-    bitbake container-image-host
+The tests automatically build container-image-host with CONTAINER_PROFILE=incus
+before booting. No local.conf changes needed.
 
 Run:
-    pytest tests/test_incus_runtime.py -v --machine qemux86-64
+    pytest tests/test_incus_runtime.py -v --poky-dir /opt/bruce/poky
 
 Options:
     --boot-timeout      QEMU boot timeout (default: 120s)
@@ -22,8 +18,11 @@ Options:
 
 import os
 import re
+import subprocess
+import tempfile
 import time
 import pytest
+from pathlib import Path
 
 try:
     import pexpect
@@ -38,19 +37,61 @@ pytestmark = [
 ]
 
 
+def _run_bitbake(build_dir, recipe, extra_vars=None, timeout=3600):
+    """Run bitbake with optional variable overrides via -R conf file."""
+    bb_cmd = "bitbake"
+    conf_file = None
+    if extra_vars:
+        conf_file = tempfile.NamedTemporaryFile(
+            mode='w', suffix='.conf', prefix='pytest-incus-',
+            dir=str(build_dir / "conf"), delete=False)
+        for var, val in extra_vars.items():
+            conf_file.write(f'{var} = "{val}"\n')
+        conf_file.close()
+        bb_cmd += f" -R {conf_file.name}"
+    bb_cmd += f" {recipe}"
+    poky_dir = build_dir.parent
+    full_cmd = f"bash -c 'cd {poky_dir} && source oe-init-build-env {build_dir} >/dev/null 2>&1 && {bb_cmd}'"
+    try:
+        return subprocess.run(full_cmd, shell=True, cwd=build_dir,
+                              timeout=timeout, capture_output=True, text=True)
+    finally:
+        if conf_file:
+            os.unlink(conf_file.name)
+
+
+@pytest.fixture(scope="module")
+def incus_image(request):
+    """Build container-image-host with incus profile."""
+    poky_dir = Path(request.config.getoption("--poky-dir"))
+    bd = request.config.getoption("--build-dir")
+    build_dir = Path(bd) if bd else poky_dir / "build"
+    result = _run_bitbake(
+        build_dir, "container-image-host",
+        extra_vars={
+            "CONTAINER_PROFILE": "incus",
+            "DISTRO_FEATURES:append": " virtualization",
+        },
+    )
+    if result.returncode != 0:
+        pytest.fail(f"Incus image build failed: {result.stderr}")
+
+
 @pytest.fixture(scope="module")
-def incus_qemu(request):
-    """Boot a QEMU VM with incus and return the pexpect session."""
+def incus_qemu(request, incus_image):
+    """Build incus image, boot a QEMU VM, and return the pexpect session."""
     machine = request.config.getoption("--machine", default="qemux86-64")
     boot_timeout = int(request.config.getoption("--boot-timeout", default="120"))
     no_kvm = request.config.getoption("--no-kvm", default=False)
 
-    builddir = os.environ.get("BUILDDIR", os.path.expanduser("~/poky/build"))
+    poky_dir = Path(request.config.getoption("--poky-dir"))
+    bd = request.config.getoption("--build-dir")
+    builddir = str(Path(bd) if bd else poky_dir / "build")
 
     kvm_opt = "" if no_kvm else "kvm"
-    cmd = f"runqemu {machine} nographic slirp {kvm_opt} qemuparams=\"-m 4096\""
+    cmd = f"runqemu {machine} container-image-host ext4 nographic slirp {kvm_opt} qemuparams=\"-m 4096\""
 
-    child = pexpect.spawn(f"bash -c 'source {builddir}/oe-init-build-env {builddir} >/dev/null 2>&1 && {cmd}'",
+    child = pexpect.spawn(f"bash -c 'cd {poky_dir} && source oe-init-build-env {builddir} >/dev/null 2>&1 && {cmd}'",
                           timeout=boot_timeout, encoding="utf-8", logfile=None)
 
     # Wait for login prompt
diff --git a/tests/test_k3s_runtime.py b/tests/test_k3s_runtime.py
index aa0d443f..662bdf4c 100644
--- a/tests/test_k3s_runtime.py
+++ b/tests/test_k3s_runtime.py
@@ -8,22 +8,18 @@ Single-node tests verify k3s server start, node readiness, and basic pod
 deployment. Multi-node tests use QEMU socket networking to connect two VMs
 on a shared L2 segment and verify agent join + multi-node scheduling.
 
-Build prerequisites (in local.conf):
-    require conf/distro/include/meta-virt-host.conf
-    require conf/distro/include/container-host-k3s.conf
-    MACHINE = "qemux86-64"  # or qemuarm64
-
-    bitbake container-image-host
+The tests automatically build container-image-host with CONTAINER_PROFILE=k3s-host
+before booting. No local.conf changes needed.
 
 Run:
     # Single-node only
-    pytest tests/test_k3s_runtime.py -v -k "not multinode" --machine qemux86-64
+    pytest tests/test_k3s_runtime.py -v -k "not multinode" --poky-dir /opt/bruce/poky
 
     # Multi-node only
-    pytest tests/test_k3s_runtime.py -v -k "multinode" --machine qemux86-64
+    pytest tests/test_k3s_runtime.py -v -k "multinode" --poky-dir /opt/bruce/poky
 
     # All tests
-    pytest tests/test_k3s_runtime.py -v --machine qemux86-64
+    pytest tests/test_k3s_runtime.py -v --poky-dir /opt/bruce/poky
 
 Options:
     --k3s-timeout       Overall k3s readiness timeout (default: 300s)
@@ -43,6 +39,8 @@ Notes:
 import os
 import re
 import shutil
+import subprocess
+import tempfile
 import time
 import pytest
 from pathlib import Path
@@ -290,6 +288,39 @@ class K3sRunner:
 # Fixtures
 # ============================================================================
 
+def run_bitbake(build_dir, recipe, extra_vars=None, timeout=3600):
+    """Run a bitbake command within the Yocto environment."""
+    import tempfile
+
+    bb_cmd = "bitbake"
+
+    conf_file = None
+    if extra_vars:
+        conf_file = tempfile.NamedTemporaryFile(
+            mode='w', suffix='.conf', prefix='pytest-k3s-',
+            dir=str(build_dir / "conf"), delete=False)
+        for var, val in extra_vars.items():
+            conf_file.write(f'{var} = "{val}"\n')
+        conf_file.close()
+        bb_cmd += f" -R {conf_file.name}"
+
+    bb_cmd += f" {recipe}"
+
+    poky_dir = build_dir.parent
+    full_cmd = f"bash -c 'cd {poky_dir} && source oe-init-build-env {build_dir} >/dev/null 2>&1 && {bb_cmd}'"
+
+    try:
+        result = subprocess.run(
+            full_cmd, shell=True, cwd=build_dir,
+            timeout=timeout, capture_output=True, text=True,
+        )
+    finally:
+        if conf_file:
+            os.unlink(conf_file.name)
+
+    return result
+
+
 @pytest.fixture(scope="module")
 def poky_dir(request):
     """Path to poky directory."""
@@ -325,20 +356,28 @@ def k3s_timeout(request):
 
 
 @pytest.fixture(scope="module")
-def k3s_session(request, poky_dir, build_dir, machine):
+def k3s_image(build_dir):
+    """Build container-image-host with k3s profile."""
+    result = run_bitbake(
+        build_dir, "container-image-host",
+        extra_vars={
+            "CONTAINER_PROFILE": "k3s-host",
+            "DISTRO_FEATURES:append": " k3s virtualization",
+        },
+    )
+    if result.returncode != 0:
+        pytest.fail(f"K3s image build failed: {result.stderr}")
+
+
+@pytest.fixture(scope="module")
+def k3s_session(request, poky_dir, build_dir, machine, k3s_image):
     """
-    Module-scoped fixture that boots container-image-host once for all
-    single-node k3s tests. Uses runqemu for single-node tests.
+    Module-scoped fixture that builds container-image-host with k3s profile,
+    boots it, and provides a session for all single-node k3s tests.
     """
     if not PEXPECT_AVAILABLE:
         pytest.skip("pexpect not installed. Run: pip install pexpect")
 
-    deploy_dir = build_dir / "tmp" / "deploy" / "images" / machine
-    ext4_files = list(deploy_dir.glob("container-image-host-*.rootfs.ext4"))
-    if not ext4_files:
-        pytest.skip(
-            f"container-image-host ext4 image not found in {deploy_dir}")
-
     timeout = request.config.getoption("--boot-timeout")
     use_kvm = not request.config.getoption("--no-kvm")
 
@@ -356,10 +395,10 @@ def k3s_session(request, poky_dir, build_dir, machine):
 
 
 @pytest.fixture(scope="module")
-def k3s_multinode(request, poky_dir, build_dir, machine):
+def k3s_multinode(request, poky_dir, build_dir, machine, k3s_image):
     """
-    Module-scoped fixture that boots two VMs connected via QEMU socket
-    networking for multi-node k3s testing.
+    Module-scoped fixture that builds with k3s profile, then boots two VMs
+    connected via QEMU socket networking for multi-node k3s testing.
 
     Uses direct QEMU launch (not runqemu) since runqemu can only run
     one VM at a time. Creates a copy of the rootfs for the agent VM.
diff --git a/tests/test_xen_runtime.py b/tests/test_xen_runtime.py
index 697c57ee..790a25bf 100644
--- a/tests/test_xen_runtime.py
+++ b/tests/test_xen_runtime.py
@@ -7,21 +7,11 @@ Xen runtime boot tests - boot xen-image-minimal and verify hypervisor.
 These tests boot an actual Xen Dom0 image via runqemu, verify the
 hypervisor is functional, check guest bundling, and exercise vxn/containerd.
 
-Build prerequisites (minimum for Dom0 boot tests):
-    DISTRO_FEATURES:append = " xen systemd"
-    MACHINE = "qemux86-64"  # or qemuarm64
-    bitbake xen-image-minimal
-
-For guest bundling tests:
-    IMAGE_INSTALL:append:pn-xen-image-minimal = " alpine-xen-guest-bundle"
-
-For vxn/containerd tests:
-    DISTRO_FEATURES:append = " virtualization vcontainer vxn"
-    IMAGE_INSTALL:append:pn-xen-image-minimal = " vxn"
-    BBMULTICONFIG = "vruntime-aarch64 vruntime-x86-64"
+The tests automatically build xen-image-minimal with the required
+DISTRO_FEATURES before booting. No local.conf changes needed.
 
 Run with:
-    pytest tests/test_xen_runtime.py -v --machine qemux86-64
+    pytest tests/test_xen_runtime.py -v --poky-dir /opt/bruce/poky
 
 Skip network-dependent tests:
     pytest tests/test_xen_runtime.py -v -m "boot and not network"
@@ -33,7 +23,10 @@ Custom paths and longer timeout:
         --boot-timeout 180
 """
 
+import os
 import re
+import subprocess
+import tempfile
 import time
 import pytest
 from pathlib import Path
@@ -50,6 +43,29 @@ except ImportError:
 # are defined in conftest.py to avoid conflicts with other test files.
 
 
+def _run_bitbake(build_dir, recipe, extra_vars=None, timeout=3600):
+    """Run bitbake with optional variable overrides via -R conf file."""
+    bb_cmd = "bitbake"
+    conf_file = None
+    if extra_vars:
+        conf_file = tempfile.NamedTemporaryFile(
+            mode='w', suffix='.conf', prefix='pytest-xen-',
+            dir=str(build_dir / "conf"), delete=False)
+        for var, val in extra_vars.items():
+            conf_file.write(f'{var} = "{val}"\n')
+        conf_file.close()
+        bb_cmd += f" -R {conf_file.name}"
+    bb_cmd += f" {recipe}"
+    poky_dir = build_dir.parent
+    full_cmd = f"bash -c 'cd {poky_dir} && source oe-init-build-env {build_dir} >/dev/null 2>&1 && {bb_cmd}'"
+    try:
+        return subprocess.run(full_cmd, shell=True, cwd=build_dir,
+                              timeout=timeout, capture_output=True, text=True)
+    finally:
+        if conf_file:
+            os.unlink(conf_file.name)
+
+
 class XenRunner:
     """
     Manages a runqemu session for Xen boot testing.
@@ -218,11 +234,25 @@ def machine(request):
 
 
 @pytest.fixture(scope="module")
-def xen_session(request, poky_dir, build_dir, machine):
+def xen_image(build_dir):
+    """Build xen-image-minimal with required distro features."""
+    result = _run_bitbake(
+        build_dir, "xen-image-minimal",
+        extra_vars={
+            "DISTRO_FEATURES:append": " xen vxn virtualization vcontainer systemd",
+        },
+    )
+    if result.returncode != 0:
+        pytest.fail(f"Xen image build failed: {result.stderr}")
+
+
+@pytest.fixture(scope="module")
+def xen_session(request, poky_dir, build_dir, machine, xen_image):
     """
-    Module-scoped fixture that boots xen-image-minimal once for all tests.
+    Module-scoped fixture that builds xen-image-minimal and boots it
+    once for all tests.
 
-    Skips if pexpect is not available, image is not found, or boot fails.
+    Skips if pexpect is not available or boot fails.
     """
     if not PEXPECT_AVAILABLE:
         pytest.skip("pexpect not installed. Run: pip install pexpect")