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authorLennart Poettering <lennart@poettering.net>2016-05-06 21:00:27 +0200
committerLennart Poettering <lennart@poettering.net>2016-05-09 15:45:31 +0200
commit22b28dfdc78680a5c03e6af3b0ce6bc96f8174a1 (patch)
treede1324b7d10f1a27d73d5823187d4bcbf981a5ae
parentef76dff225a00008fe0edd1f528c9096f1a91179 (diff)
nspawn: add new --network-zone= switch for automatically managed bridge devices
This adds a new concept of network "zones", which are little more than bridge devices that are automatically managed by nspawn: when the first container referencing a bridge is started, the bridge device is created, when the last container referencing it is removed the bridge device is removed again. Besides this logic --network-zone= is pretty much identical to --network-bridge=. The usecase for this is to make it easy to run multiple related containers (think MySQL in one and Apache in another) in a common, named virtual Ethernet broadcast zone, that only exists as long as one of them is running, and fully automatically managed otherwise.
-rw-r--r--src/nspawn/nspawn-gperf.gperf1
-rw-r--r--src/nspawn/nspawn-network.c181
-rw-r--r--src/nspawn/nspawn-network.h3
-rw-r--r--src/nspawn/nspawn-settings.c40
-rw-r--r--src/nspawn/nspawn-settings.h2
-rw-r--r--src/nspawn/nspawn.c51
6 files changed, 235 insertions, 43 deletions
diff --git a/src/nspawn/nspawn-gperf.gperf b/src/nspawn/nspawn-gperf.gperf
index 34e1310e29..1d3f0b40bf 100644
--- a/src/nspawn/nspawn-gperf.gperf
+++ b/src/nspawn/nspawn-gperf.gperf
@@ -40,4 +40,5 @@ Network.IPVLAN, config_parse_strv, 0, offsetof(Settings,
Network.VirtualEthernet, config_parse_tristate, 0, offsetof(Settings, network_veth)
Network.VirtualEthernetExtra, config_parse_veth_extra, 0, 0
Network.Bridge, config_parse_string, 0, offsetof(Settings, network_bridge)
+Network.Zone, config_parse_network_zone, 0, 0
Network.Port, config_parse_expose_port, 0, 0
diff --git a/src/nspawn/nspawn-network.c b/src/nspawn/nspawn-network.c
index 9938fce503..8da47a2ca6 100644
--- a/src/nspawn/nspawn-network.c
+++ b/src/nspawn/nspawn-network.c
@@ -26,6 +26,7 @@
#include "alloc-util.h"
#include "ether-addr-util.h"
+#include "lockfile-util.h"
#include "netlink-util.h"
#include "nspawn-network.h"
#include "siphash24.h"
@@ -41,6 +42,30 @@
#define VETH_EXTRA_CONTAINER_HASH_KEY SD_ID128_MAKE(af,50,17,61,ce,f9,4d,35,84,0d,2b,20,54,be,ce,59)
#define MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f)
+static int remove_one_link(sd_netlink *rtnl, const char *name) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ if (isempty(name))
+ return 0;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_DELLINK, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, name);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r == -ENODEV) /* Already gone */
+ return 0;
+ if (r < 0)
+ return log_error_errno(r, "Failed to remove interface %s: %m", name);
+
+ return 1;
+}
+
static int generate_mac(
const char *machine_name,
struct ether_addr *mac,
@@ -240,45 +265,149 @@ int setup_veth_extra(
return 0;
}
-int setup_bridge(const char *veth_name, const char *bridge_name) {
+static int join_bridge(sd_netlink *rtnl, const char *veth_name, const char *bridge_name) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
- _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
int r, bridge_ifi;
+ assert(rtnl);
assert(veth_name);
assert(bridge_name);
bridge_ifi = (int) if_nametoindex(bridge_name);
if (bridge_ifi <= 0)
- return log_error_errno(errno, "Failed to resolve interface %s: %m", bridge_name);
-
- r = sd_netlink_open(&rtnl);
- if (r < 0)
- return log_error_errno(r, "Failed to connect to netlink: %m");
+ return -errno;
r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0);
if (r < 0)
- return log_error_errno(r, "Failed to allocate netlink message: %m");
+ return r;
r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP);
if (r < 0)
- return log_error_errno(r, "Failed to set IFF_UP flag: %m");
+ return r;
r = sd_netlink_message_append_string(m, IFLA_IFNAME, veth_name);
if (r < 0)
- return log_error_errno(r, "Failed to add netlink interface name field: %m");
+ return r;
r = sd_netlink_message_append_u32(m, IFLA_MASTER, bridge_ifi);
if (r < 0)
- return log_error_errno(r, "Failed to add netlink master field: %m");
+ return r;
r = sd_netlink_call(rtnl, m, 0, NULL);
if (r < 0)
- return log_error_errno(r, "Failed to add veth interface to bridge: %m");
+ return r;
return bridge_ifi;
}
+static int create_bridge(sd_netlink *rtnl, const char *bridge_name) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, bridge_name);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "bridge");
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+int setup_bridge(const char *veth_name, const char *bridge_name, bool create) {
+ _cleanup_release_lock_file_ LockFile bridge_lock = LOCK_FILE_INIT;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ int r, bridge_ifi;
+ unsigned n = 0;
+
+ assert(veth_name);
+ assert(bridge_name);
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ if (create) {
+ /* We take a system-wide lock here, so that we can safely check whether there's still a member in the
+ * bridge before removing it, without risking interferance from other nspawn instances. */
+
+ r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+ if (r < 0)
+ return log_error_errno(r, "Failed to take network zone lock: %m");
+ }
+
+ for (;;) {
+ bridge_ifi = join_bridge(rtnl, veth_name, bridge_name);
+ if (bridge_ifi >= 0)
+ return bridge_ifi;
+ if (bridge_ifi != -ENODEV || !create || n > 10)
+ return log_error_errno(bridge_ifi, "Failed to add interface %s to bridge %s: %m", veth_name, bridge_name);
+
+ /* Count attempts, so that we don't enter an endless loop here. */
+ n++;
+
+ /* The bridge doesn't exist yet. Let's create it */
+ r = create_bridge(rtnl, bridge_name);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create bridge interface %s: %m", bridge_name);
+
+ /* Try again, now that the bridge exists */
+ }
+}
+
+int remove_bridge(const char *bridge_name) {
+ _cleanup_release_lock_file_ LockFile bridge_lock = LOCK_FILE_INIT;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ const char *path;
+ int r;
+
+ /* Removes the specified bridge, but only if it is currently empty */
+
+ if (isempty(bridge_name))
+ return 0;
+
+ r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+ if (r < 0)
+ return log_error_errno(r, "Failed to take network zone lock: %m");
+
+ path = strjoina("/sys/class/net/", bridge_name, "/brif");
+
+ r = dir_is_empty(path);
+ if (r == -ENOENT) /* Already gone? */
+ return 0;
+ if (r < 0)
+ return log_error_errno(r, "Can't detect if bridge %s is empty: %m", bridge_name);
+ if (r == 0) /* Still populated, leave it around */
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ return remove_one_link(rtnl, bridge_name);
+}
+
static int parse_interface(struct udev *udev, const char *name) {
_cleanup_udev_device_unref_ struct udev_device *d = NULL;
char ifi_str[2 + DECIMAL_STR_MAX(int)];
@@ -541,30 +670,6 @@ int veth_extra_parse(char ***l, const char *p) {
return 0;
}
-static int remove_one_veth_link(sd_netlink *rtnl, const char *name) {
- _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
- int r;
-
- if (isempty(name))
- return 0;
-
- r = sd_rtnl_message_new_link(rtnl, &m, RTM_DELLINK, 0);
- if (r < 0)
- return log_error_errno(r, "Failed to allocate netlink message: %m");
-
- r = sd_netlink_message_append_string(m, IFLA_IFNAME, name);
- if (r < 0)
- return log_error_errno(r, "Failed to add netlink interface name: %m");
-
- r = sd_netlink_call(rtnl, m, 0, NULL);
- if (r == -ENODEV) /* Already gone */
- return 0;
- if (r < 0)
- return log_error_errno(r, "Failed to remove veth interface %s: %m", name);
-
- return 1;
-}
-
int remove_veth_links(const char *primary, char **pairs) {
_cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
char **a, **b;
@@ -580,10 +685,10 @@ int remove_veth_links(const char *primary, char **pairs) {
if (r < 0)
return log_error_errno(r, "Failed to connect to netlink: %m");
- remove_one_veth_link(rtnl, primary);
+ remove_one_link(rtnl, primary);
STRV_FOREACH_PAIR(a, b, pairs)
- remove_one_veth_link(rtnl, *a);
+ remove_one_link(rtnl, *a);
return 0;
}
diff --git a/src/nspawn/nspawn-network.h b/src/nspawn/nspawn-network.h
index c5036ab470..3d8861e1e5 100644
--- a/src/nspawn/nspawn-network.h
+++ b/src/nspawn/nspawn-network.h
@@ -26,7 +26,8 @@
int setup_veth(const char *machine_name, pid_t pid, char iface_name[IFNAMSIZ], bool bridge);
int setup_veth_extra(const char *machine_name, pid_t pid, char **pairs);
-int setup_bridge(const char *veth_name, const char *bridge_name);
+int setup_bridge(const char *veth_name, const char *bridge_name, bool create);
+int remove_bridge(const char *bridge_name);
int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces);
int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces);
diff --git a/src/nspawn/nspawn-settings.c b/src/nspawn/nspawn-settings.c
index b98a79fd09..5f1522cfb6 100644
--- a/src/nspawn/nspawn-settings.c
+++ b/src/nspawn/nspawn-settings.c
@@ -24,10 +24,11 @@
#include "nspawn-settings.h"
#include "parse-util.h"
#include "process-util.h"
+#include "socket-util.h"
+#include "string-util.h"
#include "strv.h"
#include "user-util.h"
#include "util.h"
-#include "string-util.h"
int settings_load(FILE *f, const char *path, Settings **ret) {
_cleanup_(settings_freep) Settings *s = NULL;
@@ -96,6 +97,7 @@ Settings* settings_free(Settings *s) {
strv_free(s->network_ipvlan);
strv_free(s->network_veth_extra);
free(s->network_bridge);
+ free(s->network_zone);
expose_port_free_all(s->expose_ports);
custom_mount_free_all(s->custom_mounts, s->n_custom_mounts);
@@ -111,6 +113,7 @@ bool settings_private_network(Settings *s) {
s->private_network > 0 ||
s->network_veth > 0 ||
s->network_bridge ||
+ s->network_zone ||
s->network_interfaces ||
s->network_macvlan ||
s->network_ipvlan ||
@@ -122,7 +125,8 @@ bool settings_network_veth(Settings *s) {
return
s->network_veth > 0 ||
- s->network_bridge;
+ s->network_bridge ||
+ s->network_zone;
}
DEFINE_CONFIG_PARSE_ENUM(config_parse_volatile_mode, volatile_mode, VolatileMode, "Failed to parse volatile mode");
@@ -319,6 +323,38 @@ int config_parse_veth_extra(
return 0;
}
+int config_parse_network_zone(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ Settings *settings = data;
+ _cleanup_free_ char *j = NULL;
+
+ assert(filename);
+ assert(lvalue);
+ assert(rvalue);
+
+ j = strappend("vz-", rvalue);
+ if (!ifname_valid(j)) {
+ log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid network zone name %s, ignoring: %m", rvalue);
+ return 0;
+ }
+
+ free(settings->network_zone);
+ settings->network_zone = j;
+ j = NULL;
+
+ return 0;
+}
+
int config_parse_boot(
const char *unit,
const char *filename,
diff --git a/src/nspawn/nspawn-settings.h b/src/nspawn/nspawn-settings.h
index e12e91b886..1c47e37912 100644
--- a/src/nspawn/nspawn-settings.h
+++ b/src/nspawn/nspawn-settings.h
@@ -85,6 +85,7 @@ typedef struct Settings {
int private_network;
int network_veth;
char *network_bridge;
+ char *network_zone;
char **network_interfaces;
char **network_macvlan;
char **network_ipvlan;
@@ -109,6 +110,7 @@ int config_parse_volatile_mode(const char *unit, const char *filename, unsigned
int config_parse_bind(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_tmpfs(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_veth_extra(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_network_zone(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_boot(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_pid2(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_private_users(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 643f459851..efda7d66d7 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -176,6 +176,7 @@ static char **arg_network_ipvlan = NULL;
static bool arg_network_veth = false;
static char **arg_network_veth_extra = NULL;
static char *arg_network_bridge = NULL;
+static char *arg_network_zone = NULL;
static unsigned long arg_personality = PERSONALITY_INVALID;
static char *arg_image = NULL;
static VolatileMode arg_volatile_mode = VOLATILE_NO;
@@ -234,6 +235,8 @@ static void help(void) {
" Add a virtual Ethernet connection between host\n"
" and container and add it to an existing bridge on\n"
" the host\n"
+ " --network-zone=NAME Add a virtual Ethernet connection to the container,\n"
+ " and add it to an automatically managed bridge interface\n"
" -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n"
" Expose a container IP port on the host\n"
" -Z --selinux-context=SECLABEL\n"
@@ -357,6 +360,7 @@ static int parse_argv(int argc, char *argv[]) {
ARG_NETWORK_MACVLAN,
ARG_NETWORK_IPVLAN,
ARG_NETWORK_BRIDGE,
+ ARG_NETWORK_ZONE,
ARG_NETWORK_VETH_EXTRA,
ARG_PERSONALITY,
ARG_VOLATILE,
@@ -404,6 +408,7 @@ static int parse_argv(int argc, char *argv[]) {
{ "network-veth", no_argument, NULL, 'n' },
{ "network-veth-extra", required_argument, NULL, ARG_NETWORK_VETH_EXTRA},
{ "network-bridge", required_argument, NULL, ARG_NETWORK_BRIDGE },
+ { "network-zone", required_argument, NULL, ARG_NETWORK_ZONE },
{ "personality", required_argument, NULL, ARG_PERSONALITY },
{ "image", required_argument, NULL, 'i' },
{ "volatile", optional_argument, NULL, ARG_VOLATILE },
@@ -466,6 +471,28 @@ static int parse_argv(int argc, char *argv[]) {
arg_settings_mask |= SETTING_USER;
break;
+ case ARG_NETWORK_ZONE: {
+ char *j;
+
+ j = strappend("vz-", optarg);
+ if (!j)
+ return log_oom();
+
+ if (!ifname_valid(j)) {
+ log_error("Network zone name not valid: %s", j);
+ free(j);
+ return -EINVAL;
+ }
+
+ free(arg_network_zone);
+ arg_network_zone = j;
+
+ arg_network_veth = true;
+ arg_private_network = true;
+ arg_settings_mask |= SETTING_NETWORK;
+ break;
+ }
+
case ARG_NETWORK_BRIDGE:
if (!ifname_valid(optarg)) {
@@ -1027,6 +1054,11 @@ static int parse_argv(int argc, char *argv[]) {
return -EINVAL;
}
+ if (arg_network_bridge && arg_network_zone) {
+ log_error("--network-bridge= and --network-zone= may not be combined.");
+ return -EINVAL;
+ }
+
if (argc > optind) {
arg_parameters = strv_copy(argv + optind);
if (!arg_parameters)
@@ -3295,6 +3327,7 @@ static int load_settings(void) {
(settings->private_network >= 0 ||
settings->network_veth >= 0 ||
settings->network_bridge ||
+ settings->network_zone ||
settings->network_interfaces ||
settings->network_macvlan ||
settings->network_ipvlan ||
@@ -3325,6 +3358,10 @@ static int load_settings(void) {
free(arg_network_bridge);
arg_network_bridge = settings->network_bridge;
settings->network_bridge = NULL;
+
+ free(arg_network_zone);
+ arg_network_zone = settings->network_zone;
+ settings->network_zone = NULL;
}
}
@@ -3824,14 +3861,23 @@ int main(int argc, char *argv[]) {
goto finish;
if (arg_network_veth) {
- r = setup_veth(arg_machine, pid, veth_name, !!arg_network_bridge);
+ r = setup_veth(arg_machine, pid, veth_name,
+ arg_network_bridge || arg_network_zone);
if (r < 0)
goto finish;
else if (r > 0)
ifi = r;
if (arg_network_bridge) {
- r = setup_bridge(veth_name, arg_network_bridge);
+ /* Add the interface to a bridge */
+ r = setup_bridge(veth_name, arg_network_bridge, false);
+ if (r < 0)
+ goto finish;
+ if (r > 0)
+ ifi = r;
+ } else if (arg_network_zone) {
+ /* Add the interface to a bridge, possibly creating it */
+ r = setup_bridge(veth_name, arg_network_zone, true);
if (r < 0)
goto finish;
if (r > 0)
@@ -4039,6 +4085,7 @@ finish:
expose_port_flush(arg_expose_ports, &exposed);
(void) remove_veth_links(veth_name, arg_network_veth_extra);
+ (void) remove_bridge(arg_network_zone);
free(arg_directory);
free(arg_template);