network: print deprecaton warning for networks

Specifying networks without an index is deprecated.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index 6f752f29ed3f69050f9dd1c3d82fdd2aeb66e067..7e30c0162d461b64e107c356488ca5989cc369af 100644 (file)
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -696,10 +696,13 @@ static int set_config_network_type(const char *key, const char *value,
                return clr_config_network_type(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.type\" without an index "
+                    "(e.g.\"lxc.network.0.type\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -915,10 +918,13 @@ static int set_config_network_flags(const char *key, const char *value,
                return clr_config_network_flags(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.flags\" without an index "
+                    "(e.g.\"lxc.network.0.flags\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -997,10 +1003,13 @@ static int set_config_network_link(const char *key, const char *value,
                return clr_config_network_link(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.link\" without an index "
+                    "(e.g.\"lxc.network.0.link\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1021,10 +1030,13 @@ static int set_config_network_name(const char *key, const char *value,
                return clr_config_network_name(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.name\" without an index "
+                    "(e.g.\"lxc.network.0.name\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1040,10 +1052,13 @@ static int set_config_network_veth_pair(const char *key, const char *value,
                return clr_config_network_veth_pair(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.veth.pair\" without an "
+                    "index (e.g. \"lxc.network.0.veth.pair\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1060,10 +1075,14 @@ static int set_config_network_macvlan_mode(const char *key, const char *value,
                return clr_config_network_macvlan_mode(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.macvlan.mode\" without an "
+                    "index (e.g. \"lxc.network.0.macvlan.mode\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1079,6 +1098,17 @@ static int set_config_network_hwaddr(const char *key, const char *value,
        if (lxc_config_value_empty(value))
                return clr_config_network_hwaddr(key, lxc_conf, data);
 
+       /* lxc.network.* without an index */
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.hwaddr\" without an index "
+                    "(e.g. \"lxc.network.0.hwaddr\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
+       } else {
+               netdev = data;
+       }
+       if (!netdev)
+               return -1;
+
        new_value = strdup(value);
        if (!new_value) {
                SYSERROR("failed to strdup \"%s\"", value);
@@ -1086,16 +1116,6 @@ static int set_config_network_hwaddr(const char *key, const char *value,
        }
        rand_complete_hwaddr(new_value);
 
-       /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
-               netdev = data;
-       if (!netdev) {
-               free(new_value);
-               return -1;
-       }
-
        if (lxc_config_value_empty(new_value)) {
                free(new_value);
                netdev->hwaddr = NULL;
@@ -1115,10 +1135,13 @@ static int set_config_network_vlan_id(const char *key, const char *value,
                return clr_config_network_vlan_id(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.vlan.id\" without an index "
+                    "(e.g. \"lxc.network.0.vlan.id\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1137,10 +1160,13 @@ static int set_config_network_mtu(const char *key, const char *value,
                return clr_config_network_mtu(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.mtu\" without an index "
+                    "(e.g. \"lxc.network.0.mtu\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1160,10 +1186,13 @@ static int set_config_network_ipv4(const char *key, const char *value,
                return clr_config_network_ipv4(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv4\" without an index "
+                    "(e.g. \"lxc.network.0.ipv4\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1253,10 +1282,14 @@ static int set_config_network_ipv4_gateway(const char *key, const char *value,
                return clr_config_network_ipv4_gateway(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv4.gateway\" without an "
+                    "index (e.g. \"lxc.network.0.ipv4.gateway\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1301,10 +1334,13 @@ static int set_config_network_ipv6(const char *key, const char *value,
                return clr_config_network_ipv6(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv6\" without an index "
+                    "(e.g. \"lxc.network.0.ipv6\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1366,10 +1402,14 @@ static int set_config_network_ipv6_gateway(const char *key, const char *value,
                return clr_config_network_ipv6_gateway(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv6.gateway\" without an "
+                    "index (e.g. \"lxc.network.0.ipv6.gateway\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1411,10 +1451,14 @@ static int set_config_network_script_up(const char *key, const char *value,
                return clr_config_network_script_up(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.script.up\" without an "
+                    "index (e.g. \"lxc.network.0.script.up\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -1430,10 +1474,14 @@ static int set_config_network_script_down(const char *key, const char *value,
                return clr_config_network_script_down(key, lxc_conf, data);
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.script.down\" without an "
+                    "index (e.g. \"lxc.network.0.script.down\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4232,6 +4280,7 @@ get_network_config_ops(const char *key, struct lxc_conf *lxc_conf, ssize_t *idx)
        if (!copy)
                return NULL;
 
+       /* lxc.network.<n> */
        if (isdigit(*(key + 12))) {
                int ret;
                unsigned int tmpidx;
@@ -4348,7 +4397,7 @@ static int clr_config_network_nic(const char *key, struct lxc_conf *lxc_conf,
        if (!config || idx < 0)
                return -1;
 
-       netdev = lxc_get_netdev_by_idx(lxc_conf, (unsigned int)idx);
+       netdev = lxc_find_netdev_by_idx(lxc_conf, (unsigned int)idx);
        if (!netdev)
                return -1;
 
@@ -4361,10 +4410,13 @@ static int clr_config_network_type(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.type\" without an index "
+                    "(e.g. \"lxc.network.0.type\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4379,10 +4431,13 @@ static int clr_config_network_name(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.name\" without an index "
+                    "(e.g. \"lxc.network.0.name\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4399,10 +4454,13 @@ static int clr_config_network_flags(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.flags\" without an index "
+                    "(e.g. \"lxc.network.0.flags\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4417,10 +4475,13 @@ static int clr_config_network_link(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.link\" without an index "
+                    "(e.g. \"lxc.network.0.link\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4437,10 +4498,14 @@ static int clr_config_network_macvlan_mode(const char *key,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.macvlan.mode\" without an "
+                    "index (e.g. \"lxc.network.0.macvlan.mode\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4458,10 +4523,14 @@ static int clr_config_network_veth_pair(const char *key,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.veth.pair\" without an "
+                    "index (e.g. \"lxc.network.0.veth.pair\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4477,10 +4546,14 @@ static int clr_config_network_script_up(const char *key,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.script.up\" without an "
+                    "index (e.g. \"lxc.network.0.script.up\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4496,10 +4569,14 @@ static int clr_config_network_script_down(const char *key,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.script.down\" without an "
+                    "index (e.g. \"lxc.network.0.script.down\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4515,10 +4592,13 @@ static int clr_config_network_hwaddr(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.hwaddr\" without an index "
+                    "(e.g. \"lxc.network.0.hwaddr\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4534,10 +4614,13 @@ static int clr_config_network_mtu(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.mtu\" without an index "
+                    "(e.g. \"lxc.network.0.mtu\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4553,10 +4636,13 @@ static int clr_config_network_vlan_id(const char *key,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.vlan.id\" without an index "
+                    "(e.g. \"lxc.network.0.vlan.id\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4572,10 +4658,14 @@ static int clr_config_network_ipv4_gateway(const char *key,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv4.gateway\" without an "
+                    "index (e.g. \"lxc.network.0.ipv4.gateway\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4592,10 +4682,15 @@ static int clr_config_network_ipv4(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_list *cur, *next;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv4\" without an index "
+                    "(e.g. \"lxc.network.0.ipv4\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
+       if (!netdev)
+               return -1;
 
        lxc_list_for_each_safe(cur, &netdev->ipv4, next) {
                lxc_list_del(cur);
@@ -4613,10 +4708,14 @@ static int clr_config_network_ipv6_gateway(const char *key,
        struct lxc_netdev *netdev;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv6.gateway\" without an "
+                    "index (e.g. \"lxc.network.0.ipv6.gateway\" is "
+                    "DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4633,10 +4732,15 @@ static int clr_config_network_ipv6(const char *key, struct lxc_conf *lxc_conf,
        struct lxc_list *cur, *next;
 
        /* lxc.network.* without an index */
-       if (!data)
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv6\" without an index "
+                    "(e.g. \"lxc.network.0.ipv6\") is DEPRECATED.");
                netdev = lxc_get_netdev_by_idx(lxc_conf, 0);
-       else
+       } else {
                netdev = data;
+       }
+       if (!netdev)
+               return -1;
 
        lxc_list_for_each_safe(cur, &netdev->ipv6, next) {
                lxc_list_del(cur);
@@ -4677,10 +4781,13 @@ static int get_config_network_type(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.type\" without an index "
+                    "(e.g. \"lxc.network.0.type\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4701,10 +4808,13 @@ static int get_config_network_flags(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.flags\" without an index "
+                    "(e.g. \"lxc.network.0.flags\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4726,10 +4836,13 @@ static int get_config_network_link(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.link\" without an index "
+                    "(e.g. \"lxc.network.0.link\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4751,10 +4864,13 @@ static int get_config_network_name(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.name\" without an index "
+                    "(e.g. \"lxc.network.0.name\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4778,10 +4894,14 @@ static int get_config_network_macvlan_mode(const char *key, char *retv,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.macvlan.mode\" without an "
+                    "index (e.g. \"lxc.network.0.macvlan.mode\" is "
+                    "DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4823,10 +4943,14 @@ static int get_config_network_veth_pair(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.veth.pair\" without an "
+                    "index (e.g. \"lxc.network.0.veth.pair\" is "
+                    "DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4852,10 +4976,14 @@ static int get_config_network_script_up(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.script.up\" without an "
+                    "index (e.g. \"lxc.network.0.script.up\" is "
+                    "DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4878,10 +5006,14 @@ static int get_config_network_script_down(const char *key, char *retv,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.script.down\" without an "
+                    "index (e.g. \"lxc.network.0.script.down\" is "
+                    "DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4903,10 +5035,13 @@ static int get_config_network_hwaddr(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.hwaddr\" without an index "
+                    "(e.g. \"lxc.network.0.hwaddr\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4928,10 +5063,13 @@ static int get_config_network_mtu(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.mtu\" without an index "
+                    "(e.g. \"lxc.network.0.mtu\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4953,10 +5091,13 @@ static int get_config_network_vlan_id(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.vlan.id\" without an index "
+                    "(e.g. \"lxc.network.0.vlan.id\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -4982,10 +5123,14 @@ static int get_config_network_ipv4_gateway(const char *key, char *retv,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv4.gateway\" without an "
+                    "index (e.g. \"lxc.network.0.ipv4.gateway\" is "
+                    "DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -5014,10 +5159,13 @@ static int get_config_network_ipv4(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv4\" without an index "
+                    "(e.g. \"lxc.network.0.ipv4\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -5046,10 +5194,14 @@ static int get_config_network_ipv6_gateway(const char *key, char *retv,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv6.gateway\" without an "
+                    "index (e.g. \"lxc.network.0.ipv6.gateway\" is "
+                    "DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;
 
@@ -5078,10 +5230,13 @@ static int get_config_network_ipv6(const char *key, char *retv, int inlen,
                memset(retv, 0, inlen);
 
        /* lxc.network.* without an index */
-       if (!data)
-               netdev = lxc_find_netdev_by_idx(c, 0);
-       else
+       if (!data) {
+               WARN("WARNING: using \"lxc.network.ipv6\" without an index "
+                    "(e.g. \"lxc.network.0.ipv6\") is DEPRECATED.");
+               netdev = lxc_get_netdev_by_idx(c, 0);
+       } else {
                netdev = data;
+       }
        if (!netdev)
                return -1;