Egress does not work in the legacy netpol mode, so in the legacy case
we don't have to create the egress traffic steering rules. Otherwise,
some traffic will be blocked.
First check whether the chain exists with the required rules, and
if not - create it.
If we flush each time we start weave-npc then we create a (short)
time window during which all egress traffic is allowed.
The following rules are provisioned by weave-npc:
-A WEAVE-NPC-EGRESS -m state --state RELATED,ESTABLISHED -j RETURN
-A WEAVE-NPC-EGRESS -m set ! --match-set weave-local-pods src -j RETURN
-A WEAVE-NPC-EGRESS -d 224.0.0.0/4 -j RETURN
-A WEAVE-NPC-EGRESS -m state --state NEW -j WEAVE-NPC-EGRESS-DEFAULT
-A WEAVE-NPC-EGRESS -m state --state NEW -m mark ! --mark 0x40000/0x40000 -j WEAVE-NPC-EGRESS-CUSTOM
-A WEAVE-NPC-EGRESS -m state --state NEW -m mark ! --mark 0x40000/0x40000 -j NFLOG --nflog-group 86
-A WEAVE-NPC-EGRESS -m mark ! --mark 0x40000/0x40000 -j DROP
-A WEAVE-NPC-EGRESS-CUSTOM <rulespec> -j MARK --set-xmark 0x40000/0x40000
-A WEAVE-NPC-EGRESS-CUSTOM <rulespec> -j RETURN
-A WEAVE-NPC-EGRESS-DEFAULT <rulespec> -j MARK --set-xmark 0x40000/0x40000
-A WEAVE-NPC-EGRESS-DEFAULT <rulespec> -j RETURN
For each rule we create two (mark and return). We cannot just accept
a packet if it matches any rule, as a packet might need to traverse
the ingress npc as well which happens later in the chain (in some cases
we cannot detect whether packet is ingress or egress, so we need to
check both chains).
Some logs from users show an entry of X with annotation X, which
suggests we have gone down the path of removing ourselves. This change
avoids that possibility.
- Track only local changes.
- Add comment to the iptables rule which prevents SNAT'ing.
- Rename the ipset to weaver-no-masq-local to prevent NPC from destroying it.
- Fix comment about create/flush WEAVE-EXPOSE.
- Add comment about reexpose being no-op if bridge hasn't been exposed.
- Add comment that the feature is not only for Kubernetes.
- Reuse the ipset instance.
Otherwise test 150 would fail - Gorilla mux was not handling a newline
in the format parameter. This way you also get a better error if you
have an error in the parameter - instead of a 404.
"weave attach $CIDR $CONTAINER_ID" is no longer possible w/o
running weaver. This feature was undocumented and complicated
the weave script, as "weave attach" required to call "create_bridge".
Removing the feature allows us to eliminate the bridge creation
from the script.
Running "weave attach" w/o weaver results in the following err:
bridge "weave" not present; did you launch weave?
Also, this commit simplifies the "attach-container" cmd from
weaveutil by removing "mtu" as a param. The cmd is used
only by "weave attach", and a mtu is value for an attached
container interface is exactly the same as one of the weave bridge.
Martynas Pumputis