support for libvirt—1.1 naming scheme
Thierry Parmentelat [Fri, 10 Jan 2014 13:25:29 +0000 (14:25 +0100)]
lxcsu

diff --git a/lxcsu b/lxcsu
index 3c63f74..078d275 100755 (executable)
--- a/lxcsu
+++ b/lxcsu
@@ -11,6 +11,129 @@ drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'
 # can set to True here, but also use the -d option
 debug = False
 
+#################### should go into a separate libvirtsystemd.py
+# but we want to keep packaging simple for now
+
+# reproducing libvirt's systemd-oriented escaping mechanism
+# http://code.metager.de/source/xref/lib/virt/src/util/virsystemd.c
+# (see original code at the end of this file)
+
+def virSystemdEscapeName (name):
+    result=''
+    def ESCAPE(c,s):
+        # replace hex's output '0x..' into '\x..' 
+        return s+hex(ord(c)).replace('0','\\',1)
+    VALID_CHARS = \
+        "0123456789" + \
+        "abcdefghijklmnopqrstuvwxyz" + \
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + \
+        ":-_.\\"
+    for c in name:
+        if c=='/': 
+            result += '-'
+        elif c in '-\\' or c not in VALID_CHARS:
+            result=ESCAPE(c,result)
+        else:
+            result += c
+    return result
+
+#35static void virSystemdEscapeName(virBufferPtr buf,
+#36                                 const char *name)
+#37{
+#38    static const char hextable[16] = "0123456789abcdef";
+#39
+#40#define ESCAPE(c)                                                       \
+#41    do {                                                                \
+#42        virBufferAddChar(buf, '\\');                                    \
+#43        virBufferAddChar(buf, 'x');                                     \
+#44        virBufferAddChar(buf, hextable[(c >> 4) & 15]);                 \
+#45        virBufferAddChar(buf, hextable[c & 15]);                        \
+#46    } while (0)
+#47
+#48#define VALID_CHARS                             \
+#49        "0123456789"                            \
+#50        "abcdefghijklmnopqrstuvwxyz"            \
+#51        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"            \
+#52        ":-_.\\"
+#53
+#54    if (*name == '.') {
+#55        ESCAPE(*name);
+#56        name++;
+#57    }
+#58
+#59    while (*name) {
+#60        if (*name == '/')
+#61            virBufferAddChar(buf, '-');
+#62        else if (*name == '-' ||
+#63                 *name == '\\' ||
+#64                 !strchr(VALID_CHARS, *name))
+#65            ESCAPE(*name);
+#66        else
+#67            virBufferAddChar(buf, *name);
+#68        name++;
+#69    }
+#70
+#71#undef ESCAPE
+#72#undef VALID_CHARS
+#73}
+
+def virSystemdMakeScopeName (name, drivername, partition):
+    result=''
+    result += virSystemdEscapeName (partition)
+    result += '-'
+    result += virSystemdEscapeName (drivername)
+    result += '\\x2d'
+    result += virSystemdEscapeName (name)
+    result += '.scope'
+    return result
+
+#76char *virSystemdMakeScopeName(const char *name,
+#77                              const char *drivername,
+#78                              const char *partition)
+#79{
+#80    virBuffer buf = VIR_BUFFER_INITIALIZER;
+#81
+#82    if (*partition == '/')
+#83        partition++;
+#84
+#85    virSystemdEscapeName(&buf, partition);
+#86    virBufferAddChar(&buf, '-');
+#87    virSystemdEscapeName(&buf, drivername);
+#88    virBufferAddLit(&buf, "\\x2d");
+#89    virSystemdEscapeName(&buf, name);
+#90    virBufferAddLit(&buf, ".scope");
+#91
+#92    if (virBufferError(&buf)) {
+#93        virReportOOMError();
+#94        return NULL;
+#95    }
+#96
+#97    return virBufferContentAndReset(&buf);
+#98}
+
+### our own additions
+import os.path
+def find_first_dir (candidates):
+    for candidate in candidates:
+        if os.path.isdir(candidate): return candidate
+    raise Exception,"Cannot find valid dir among %s"%'\n'.join(candidates)
+
+def find_sysfs_scope (subsystem, slice_name):
+    subsystem1=subsystem
+    subsystem2=subsystem
+    if subsystem=='cpuacct':
+        subsystem2='cpu,cpuacct'
+    candidates = [ 
+        # for f16 and our locally brewed libvirt 1.0.4
+        "/sys/fs/cgroup/%s/libvirt/lxc/%s"%(subsystem1, slice_name),
+        # f20 and libvirt 1.1.3
+        "/sys/fs/cgroup/%s/machine.slice/%s"%(subsystem2, 
+                                              virSystemdMakeScopeName(slice_name,'lxc','machine')),
+        ]
+    return find_first_dir (candidates)
+
+#################### end of libvirtsystemd.py
+
 def getarch(f):
     output = os.popen('readelf -h %s 2>&1'%f).readlines()
     classlines = [x for x in output if ('Class' in x.split(':')[0])]
@@ -118,7 +241,7 @@ def main ():
     # Enter cgroups
     try:
        for subsystem in ['cpuset','memory','blkio']:
-           open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid()))
+            open( find_sysfs_scope (subsystem, slice_name)+"/tasks", 'w').write(str(os.getpid()))
 
     except Exception,e:
        if debug: print e 
@@ -126,7 +249,7 @@ def main ():
        exit(1)
 
     try:
-        open('/sys/fs/cgroup/cpuacct/system/libvirtd.service/libvirt/lxc/%s/tasks'%slice_name,'w').write(str(os.getpid()))
+        open ( find_sysfs_scope ('cpuacct', slice_name)+"/tasks", 'w').write(str(os.getpid()))
     except Exception,e:
        if debug: print e 
        print "Error assigning cpuacct: %s" % slice_name
@@ -137,7 +260,7 @@ def main ():
     # in this case to error out the shell. (an alternative would be to un-freeze it,
     # add the task, and re-freeze it)
     try:
-       f=open('/sys/fs/cgroup/freezer/libvirt/lxc/%s/tasks'%(slice_name),'w')
+       f=open( find_sysfs_scope ('freezer', slice_name)+"/tasks", 'w')
        f.write(str(os.getpid()))
        # note: we need to call f.close() explicitly, or we'll get an exception in
        # the object destructor, which will not be caught