[lxc-devel] [PATCH] lxcapi: Add new get_ips() call
Stéphane Graber
stgraber at ubuntu.com
Mon May 20 21:57:05 UTC 2013
This adds a new get_ips call which takes a family (inet, inet6 or NULL),
a network interface (or NULL for all) and a scope (0 for global) and returns
a char** of all the IPs in the container.
This also adds a matching python3 binding (function result is a tuple) and
deprecates the previous pure-python get_ips() implementation.
WARNING: The python get_ips() call is quite different from the previous
implementation. The timeout argument has been removed, the family names are
slightly different (inet/inet6 vs ipv4/ipv6) and an extra scope parameter
has been added.
Signed-off-by: Stéphane Graber <stgraber at ubuntu.com>
---
src/lxc/lxccontainer.c | 113 ++++++++++++++++++++++++++++++++++++
src/lxc/lxccontainer.h | 1 +
src/python-lxc/examples/api_test.py | 9 ++-
src/python-lxc/lxc.c | 61 +++++++++++++++++++
src/python-lxc/lxc/__init__.py | 61 -------------------
5 files changed, 183 insertions(+), 62 deletions(-)
diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 23db6f2..0e0c029 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -37,6 +37,10 @@
#include "bdev.h"
#include <lxc/utils.h>
#include <lxc/monitor.h>
+#include <sched.h>
+#include <fcntl.h>
+#include <arpa/inet.h>
+#include <ifaddrs.h>
static pthread_mutex_t thread_mutex = PTHREAD_MUTEX_INITIALIZER;
@@ -768,6 +772,114 @@ static bool lxcapi_clear_config_item(struct lxc_container *c, const char *key)
return ret == 0;
}
+char** lxcapi_get_ips(struct lxc_container *c, char* interface, char* family, int scope)
+{
+ int count = 0;
+ struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
+ char addressOutputBuffer[INET6_ADDRSTRLEN];
+ void *tempAddrPtr = NULL;
+ char **addresses = NULL, **temp;
+ char *address = NULL;
+ char new_netns_path[MAXPATHLEN];
+ int old_netns = -1, new_netns = -1, ret = 0;
+
+ if (!c->is_running(c))
+ goto out;
+
+ /* Save reference to old netns */
+ old_netns = open("/proc/self/ns/net", O_RDONLY);
+ if (old_netns < 0) {
+ SYSERROR("failed to open /proc/self/ns/net");
+ goto out;
+ }
+
+ /* Switch to new netns */
+ ret = snprintf(new_netns_path, MAXPATHLEN, "/proc/%d/ns/net", c->init_pid(c));
+ if (ret < 0 || ret >= MAXPATHLEN)
+ goto out;
+
+ new_netns = open(new_netns_path, O_RDONLY);
+ if (new_netns < 0) {
+ SYSERROR("failed to open %s", new_netns_path);
+ goto out;
+ }
+
+ if (setns(new_netns, CLONE_NEWNET)) {
+ SYSERROR("failed to setns");
+ goto out;
+ }
+
+ /* Grab the list of interfaces */
+ if (getifaddrs(&interfaceArray)) {
+ SYSERROR("failed to get interfaces list");
+ goto out;
+ }
+
+ /* Iterate through the interfaces */
+ for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
+ if(tempIfAddr->ifa_addr->sa_family == AF_INET) {
+ if (family && strcmp(family, "inet"))
+ continue;
+ tempAddrPtr = &((struct sockaddr_in *)tempIfAddr->ifa_addr)->sin_addr;
+ }
+ else {
+ if (family && strcmp(family, "inet6"))
+ continue;
+
+ if (((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_scope_id != scope)
+ continue;
+
+ tempAddrPtr = &((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_addr;
+ }
+
+ if (interface && strcmp(interface, tempIfAddr->ifa_name))
+ continue;
+ else if (!interface && strcmp("lo", tempIfAddr->ifa_name) == 0)
+ continue;
+
+ address = (char *)inet_ntop(tempIfAddr->ifa_addr->sa_family,
+ tempAddrPtr,
+ addressOutputBuffer,
+ sizeof(addressOutputBuffer));
+ if (!address)
+ continue;
+
+ count += 1;
+ temp = realloc(addresses, count * sizeof(*addresses));
+ if (!temp) {
+ count--;
+ goto out;
+ }
+ addresses = temp;
+ addresses[count - 1] = strdup(address);
+ }
+
+out:
+ if(interfaceArray)
+ freeifaddrs(interfaceArray);
+
+ /* Append NULL to the array */
+ if (count) {
+ count++;
+ temp = realloc(addresses, count * sizeof(*addresses));
+ if (!temp) {
+ return NULL;
+ }
+ addresses = temp;
+ addresses[count - 1] = NULL;
+ }
+
+ /* Switch back to original netns */
+ if (old_netns >= 0 && setns(old_netns, CLONE_NEWNET))
+ SYSERROR("failed to setns");
+ if (new_netns >= 0)
+ close(new_netns);
+ if (old_netns >= 0)
+ close(old_netns);
+
+ return addresses;
+}
+
static int lxcapi_get_config_item(struct lxc_container *c, const char *key, char *retv, int inlen)
{
int ret;
@@ -1642,6 +1754,7 @@ struct lxc_container *lxc_container_new(const char *name, const char *configpath
c->get_config_path = lxcapi_get_config_path;
c->set_config_path = lxcapi_set_config_path;
c->clone = lxcapi_clone;
+ c->get_ips = lxcapi_get_ips;
/* we'll allow the caller to update these later */
if (lxc_log_init(NULL, "none", NULL, "lxc_container", 0, c->config_path)) {
diff --git a/src/lxc/lxccontainer.h b/src/lxc/lxccontainer.h
index 67fbed4..bf3168c 100644
--- a/src/lxc/lxccontainer.h
+++ b/src/lxc/lxccontainer.h
@@ -58,6 +58,7 @@ struct lxc_container {
* the length which was our would be printed. */
int (*get_config_item)(struct lxc_container *c, const char *key, char *retv, int inlen);
int (*get_keys)(struct lxc_container *c, const char *key, char *retv, int inlen);
+ char** (*get_ips)(struct lxc_container *c, char* interface, char* family, int scope);
/*
* get_cgroup_item returns the number of bytes read, or an error (<0).
* If retv NULL or inlen 0 is passed in, then the length of the cgroup
diff --git a/src/python-lxc/examples/api_test.py b/src/python-lxc/examples/api_test.py
index 367bb7a..45a1150 100644
--- a/src/python-lxc/examples/api_test.py
+++ b/src/python-lxc/examples/api_test.py
@@ -28,6 +28,7 @@ warnings.filterwarnings("ignore", "The python-lxc API isn't yet stable")
import lxc
import uuid
import sys
+import time
# Some constants
LXC_TEMPLATE = "ubuntu"
@@ -90,7 +91,13 @@ assert(container.state == "RUNNING")
## Checking IP address
print("Getting the IP addresses")
-ips = container.get_ips(timeout=10)
+
+count = 0
+ips = []
+while not ips or count == 10:
+ ips = container.get_ips()
+ time.sleep(1)
+ count += 1
container.attach("NETWORK|UTSNAME", "/sbin/ifconfig", "eth0")
# A few basic checks of the current state
diff --git a/src/python-lxc/lxc.c b/src/python-lxc/lxc.c
index 4e9fde7..cdc1e8b 100644
--- a/src/python-lxc/lxc.c
+++ b/src/python-lxc/lxc.c
@@ -400,6 +400,61 @@ Container_get_keys(Container *self, PyObject *args, PyObject *kwds)
}
static PyObject *
+Container_get_ips(Container *self, PyObject *args, PyObject *kwds)
+{
+ static char *kwlist[] = {"interface", "family", "scope", NULL};
+ char* interface = NULL;
+ char* family = NULL;
+ int scope = 0;
+
+ int i = 0;
+ char** ips = NULL;
+
+ PyObject* ret;
+
+ if (! PyArg_ParseTupleAndKeywords(args, kwds, "|ssi", kwlist,
+ &interface, &family, &scope))
+ return NULL;
+
+ /* Get the IPs */
+ ips = self->container->get_ips(self->container, interface, family, scope);
+ if (!ips)
+ return PyTuple_New(0);
+
+ /* Count the entries */
+ while (ips[i])
+ i++;
+
+ /* Create the new tuple */
+ ret = PyTuple_New(i);
+ if (!ret)
+ return NULL;
+
+ /* Add the entries to the tuple and free the memory */
+ i = 0;
+ while (ips[i]) {
+ PyObject *unicode = PyUnicode_FromString(ips[i]);
+ if (!unicode) {
+ Py_DECREF(ret);
+ ret = NULL;
+ break;
+ }
+ PyTuple_SET_ITEM(ret, i, unicode);
+ i++;
+ }
+
+ /* Free the list of IPs */
+ i = 0;
+ while (ips[i]) {
+ free(ips[i]);
+ i++;
+ }
+ free(ips);
+
+ return ret;
+}
+
+static PyObject *
Container_load_config(Container *self, PyObject *args, PyObject *kwds)
{
static char *kwlist[] = {"path", NULL};
@@ -678,6 +733,12 @@ static PyMethodDef Container_methods[] = {
"\n"
"Get a list of valid sub-keys for a key."
},
+ {"get_ips", (PyCFunction)Container_get_ips,
+ METH_VARARGS|METH_KEYWORDS,
+ "get_ips(interface, family, scope) -> tuple\n"
+ "\n"
+ "Get a tuple of IPs for the container."
+ },
{"load_config", (PyCFunction)Container_load_config,
METH_VARARGS|METH_KEYWORDS,
"load_config(path = DEFAULT) -> boolean\n"
diff --git a/src/python-lxc/lxc/__init__.py b/src/python-lxc/lxc/__init__.py
index c235d18..2fc907c 100644
--- a/src/python-lxc/lxc/__init__.py
+++ b/src/python-lxc/lxc/__init__.py
@@ -26,7 +26,6 @@ import glob
import os
import subprocess
import stat
-import time
import warnings
warnings.warn("The python-lxc API isn't yet stable "
@@ -332,66 +331,6 @@ class Container(_lxc.Container):
else:
return value
- def get_ips(self, timeout=60, interface=None, protocol=None):
- """
- Returns the list of IP addresses for the container.
- """
-
- if not self.running:
- return False
-
- ips = []
-
- count = 0
- while count < timeout:
- if count != 0:
- time.sleep(1)
-
- base_cmd = ["lxc-attach", "-s", "NETWORK",
- "-P", self.get_config_path(), "-n", self.name, "--",
- "ip"]
-
- # Get IPv6
- if protocol in ("ipv6", None):
- ip6_cmd = base_cmd + ["-6", "addr", "show", "scope", "global"]
- if interface:
- ip = subprocess.Popen(ip6_cmd + ["dev", interface],
- stdout=subprocess.PIPE,
- universal_newlines=True)
- else:
- ip = subprocess.Popen(ip6_cmd, stdout=subprocess.PIPE,
- universal_newlines=True)
-
- ip.wait()
- for line in ip.stdout.read().split("\n"):
- fields = line.split()
- if len(fields) > 2 and fields[0] == "inet6":
- ips.append(fields[1].split('/')[0])
-
- # Get IPv4
- if protocol in ("ipv4", None):
- ip4_cmd = base_cmd + ["-4", "addr", "show", "scope", "global"]
- if interface:
- ip = subprocess.Popen(ip4_cmd + ["dev", interface],
- stdout=subprocess.PIPE,
- universal_newlines=True)
- else:
- ip = subprocess.Popen(ip4_cmd, stdout=subprocess.PIPE,
- universal_newlines=True)
-
- ip.wait()
- for line in ip.stdout.read().split("\n"):
- fields = line.split()
- if len(fields) > 2 and fields[0] == "inet":
- ips.append(fields[1].split('/')[0])
-
- if ips:
- break
-
- count += 1
-
- return ips
-
def get_keys(self, key=None):
"""
Returns a list of valid sub-keys.
--
1.8.1.2
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