LXC driver: started implementing connectDomainXMLFromNative

This function aims at converting LXC configuration into a libvirt
domain XML description to help users migrate from LXC to libvirt.

Here is an example of how the lxc configuration works:
virsh -c lxc:/// domxml-from-native lxc-tools /var/lib/lxc/migrate_test/config

It is possible that some parts couldn't be properly mapped into a
domain XML fragment, so users should carefully review the result
before creating the domain.

fstab files in lxc.mount lines will need to be merged into the
configuration file as lxc.mount.entry.

As we can't know the amount of memory of the host, we have to set a
default value for max_balloon that users will probably want to adjust.

tests/Makefile.am

@@ -200,7 +200,7 @@ test_programs += qemuxml2argvtest qemuxml2xmltest qemuxmlnstest \
 endif WITH_QEMU
 
 if WITH_LXC
-test_programs += lxcxml2xmltest
+test_programs += lxcxml2xmltest lxcconf2xmltest
 endif WITH_LXC
 
 if WITH_OPENVZ
@@ -523,6 +523,11 @@ lxcxml2xmltest_SOURCES = \
 	lxcxml2xmltest.c testutilslxc.c testutilslxc.h \
 	testutils.c testutils.h
 lxcxml2xmltest_LDADD = $(lxc_LDADDS)
+
+lxcconf2xmltest_SOURCES = \
+	lxcconf2xmltest.c \
+	testutils.c testutils.h
+lxcconf2xmltest_LDADD = $(lxc_LDADDS)
 else ! WITH_LXC
 EXTRA_DIST += lxcxml2xmltest.c testutilslxc.c testutilslxc.h
 endif ! WITH_LXC

tests/lxcconf2xmldata/lxcconf2xml-simple.config

@@ -0,0 +1,38 @@
+# Template used to create this container: opensuse
+# Template script checksum (SHA-1): 27307e0a95bd81b2c0bd82d6f87fdbe83be075ef
+
+lxc.network.type = veth
+lxc.network.flags = up
+lxc.network.link = virbr0
+lxc.network.hwaddr = 02:00:15:8f:05:c1
+lxc.network.name = eth0
+
+#remove next line if host DNS configuration should not be available to container
+lxc.mount.entry = /etc/resolv.conf etc/resolv.conf none bind,ro 0 0
+lxc.rootfs = /var/lib/lxc/migrate_test/rootfs
+lxc.utsname = migrate_test
+lxc.autodev=1
+lxc.tty = 2
+lxc.pts = 1024
+lxc.mount = /var/lib/lxc/migrate_test/fstab
+lxc.cap.drop = sys_module mac_admin mac_override mknod
+
+# When using LXC with apparmor, uncomment the next line to run unconfined:
+#lxc.aa_profile = unconfined
+
+lxc.cgroup.devices.deny = a
+# /dev/null and zero
+lxc.cgroup.devices.allow = c 1:3 rwm
+lxc.cgroup.devices.allow = c 1:5 rwm
+# consoles
+lxc.cgroup.devices.allow = c 5:1 rwm
+lxc.cgroup.devices.allow = c 5:0 rwm
+lxc.cgroup.devices.allow = c 4:0 rwm
+lxc.cgroup.devices.allow = c 4:1 rwm
+# /dev/{,u}random
+lxc.cgroup.devices.allow = c 1:9 rwm
+lxc.cgroup.devices.allow = c 1:8 rwm
+lxc.cgroup.devices.allow = c 136:* rwm
+lxc.cgroup.devices.allow = c 5:2 rwm
+# rtc
+lxc.cgroup.devices.allow = c 254:0 rwm

tests/lxcconf2xmldata/lxcconf2xml-simple.xml

@@ -0,0 +1,17 @@
+<domain type='lxc'>
+  <name>migrate_test</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>65536</memory>
+  <currentMemory unit='KiB'>0</currentMemory>
+  <vcpu placement='static' current='0'>1</vcpu>
+  <os>
+    <type>exe</type>
+    <init>/sbin/init</init>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>

tests/lxcconf2xmltest.c

@@ -0,0 +1,107 @@
+#include <config.h>
+
+#include "testutils.h"
+
+#ifdef WITH_LXC
+
+# include "lxc/lxc_native.h"
+
+# define VIR_FROM_THIS VIR_FROM_NONE
+
+static int
+blankProblemElements(char *data)
+{
+    if (virtTestClearLineRegex("<uuid>([[:alnum:]]|-)+</uuid>", data) < 0)
+        return -1;
+    return 0;
+}
+
+static int
+testCompareXMLToConfigFiles(const char *xml,
+                            const char *configfile)
+{
+    int ret = -1;
+    char *config = NULL;
+    char *expectxml = NULL;
+    char *actualxml = NULL;
+    virDomainDefPtr vmdef = NULL;
+
+    if (virtTestLoadFile(configfile, &config) < 0)
+        goto fail;
+    if (virtTestLoadFile(xml, &expectxml) < 0)
+        goto fail;
+
+    if (!(vmdef = lxcParseConfigString(config)))
+        goto fail;
+
+    if (!(actualxml = virDomainDefFormat(vmdef, 0)))
+        goto fail;
+
+    if (blankProblemElements(expectxml) < 0 ||
+        blankProblemElements(actualxml) < 0)
+        goto fail;
+
+    if (STRNEQ(expectxml, actualxml)) {
+        virtTestDifference(stderr, expectxml, actualxml);
+        goto fail;
+    }
+
+    ret = 0;
+
+fail:
+    VIR_FREE(expectxml);
+    VIR_FREE(actualxml);
+    VIR_FREE(config);
+    virDomainDefFree(vmdef);
+    return ret;
+}
+
+static int
+testCompareXMLToConfigHelper(const void *data)
+{
+    int result = -1;
+    const char *name = data;
+    char *xml = NULL;
+    char *config = NULL;
+
+    if (virAsprintf(&xml, "%s/lxcconf2xmldata/lxcconf2xml-%s.xml",
+                    abs_srcdir, name) < 0 ||
+        virAsprintf(&config, "%s/lxcconf2xmldata/lxcconf2xml-%s.config",
+                    abs_srcdir, name) < 0)
+        goto cleanup;
+
+    result = testCompareXMLToConfigFiles(xml, config);
+
+cleanup:
+    VIR_FREE(xml);
+    VIR_FREE(config);
+    return result;
+}
+
+static int
+mymain(void)
+{
+    int ret = EXIT_SUCCESS;
+
+# define DO_TEST(name)                                  \
+    if (virtTestRun("LXC Native-2-XML " name,           \
+                    testCompareXMLToConfigHelper,       \
+                    name) < 0)                          \
+        ret = EXIT_FAILURE
+
+    DO_TEST("simple");
+
+    return ret;
+}
+
+VIRT_TEST_MAIN(mymain)
+
+#else
+
+int
+main(void)
+{
+    return EXIT_AM_SKIP;
+}
+
+#endif /* WITH_LXC */