[lxc-devel] [PATCH V2] lxcapi: Add new get_ips() call
Serge Hallyn
serge.hallyn at ubuntu.com
Tue May 21 15:04:04 UTC 2013
Quoting Stéphane Graber (stgraber at ubuntu.com):
> 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>
Acked-by: Serge E. Hallyn <serge.hallyn at ubuntu.com>
> ---
> src/lxc/lxccontainer.c | 116 ++++++++++++++++++++++++++++++++++++
> 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, 186 insertions(+), 62 deletions(-)
>
> diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
> index 23db6f2..4a6f774 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 +772,117 @@ 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);
> +
> + /* 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);
> +
> + /* Append NULL to the array */
> + if (count) {
> + count++;
> + temp = realloc(addresses, count * sizeof(*addresses));
> + if (!temp) {
> + for (int i = 0; i < count-1; i++)
> + free(addresses[i]);
> + free(addresses);
> + return NULL;
> + }
> + addresses = temp;
> + addresses[count - 1] = NULL;
> + }
> +
> + return addresses;
> +}
> +
> static int lxcapi_get_config_item(struct lxc_container *c, const char *key, char *retv, int inlen)
> {
> int ret;
> @@ -1642,6 +1757,7 @@ 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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