The `--userland-proxy` daemon flag makes it possible to rely on hairpin
NAT and additional iptables routes instead of userland proxy for port
publishing and inter-container communication.
Usage of the userland proxy remains the default as hairpin NAT is
unsupported by older kernels.
Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
When firewalld (or iptables service) restarts/reloads,
all previously added docker firewall rules are flushed.
With firewalld we can react to its Reloaded() [1]
D-Bus signal and recreate the firewall rules.
Also when firewalld gets restarted (stopped & started)
we can catch the NameOwnerChanged signal [2].
To specify which signals we want to react to we use AddMatch [3].
Libvirt has been doing this for quite a long time now.
Docker changes firewall rules on basically 3 places.
1) daemon/networkdriver/portmapper/mapper.go - port mappings
Portmapper fortunatelly keeps list of mapped ports,
so we can easily recreate firewall rules on firewalld restart/reload
New ReMapAll() function does that
2) daemon/networkdriver/bridge/driver.go
When setting a bridge, basic firewall rules are created.
This is done at once during start, it's parametrized and nowhere
tracked so how can one know what and how to set it again when
there's been firewalld restart/reload ?
The only solution that came to my mind is using of closures [4],
i.e. I keep list of references to closures (anonymous functions
together with a referencing environment) and when there's firewalld
restart/reload I re-call them in the same order.
3) links/links.go - linking containers
Link is added in Enable() and removed in Disable().
In Enable() we add a callback function, which creates the link,
that's OK so far.
It'd be ideal if we could remove the same function from
the list in Disable(). Unfortunatelly that's not possible AFAICT,
because we don't know the reference to that function
at that moment, so we can only add a reference to function,
which removes the link. That means that after creating and
removing a link there are 2 functions in the list,
one adding and one removing the link and after
firewalld restart/reload both are called.
It works, but it's far from ideal.
[1] https://jpopelka.fedorapeople.org/firewalld/doc/firewalld.dbus.html#FirewallD1.Signals.Reloaded
[2] http://dbus.freedesktop.org/doc/dbus-specification.html#bus-messages-name-owner-changed
[3] http://dbus.freedesktop.org/doc/dbus-specification.html#message-bus-routing-match-rules
[4] https://en.wikipedia.org/wiki/Closure_%28computer_programming%29
Signed-off-by: Jiri Popelka <jpopelka@redhat.com>
Firewalld [1] is a firewall managing daemon with D-Bus interface.
What sort of problem are we trying to solve with this ?
Firewalld internally also executes iptables/ip6tables to change firewall settings.
It might happen on systems where both docker and firewalld are running
concurrently, that both of them try to call iptables at the same time.
The result is that the second one fails because the first one is holding a xtables lock.
One workaround is to use --wait/-w option in both
docker & firewalld when calling iptables.
It's already been done in both upstreams:
b315c380f4b3b451d6f8
But it'd still be better if docker used firewalld when it's running.
Other problem the firewalld support would solve is that
iptables/firewalld service's restart flushes all firewall rules
previously added by docker.
See next patch for possible solution.
This patch utilizes firewalld's D-Bus interface.
If firewalld is running, we call direct.passthrough() [2] method instead
of executing iptables directly.
direct.passthrough() takes the same arguments as iptables tool itself
and passes them through to iptables tool.
It might be better to use other methods, like direct.addChain and
direct.addRule [3] so it'd be more intergrated with firewalld, but
that'd make the patch much bigger.
If firewalld is not running, everything works as before.
[1] http://www.firewalld.org/
[2] https://jpopelka.fedorapeople.org/firewalld/doc/firewalld.dbus.html#FirewallD1.direct.Methods.passthrough
[3] https://jpopelka.fedorapeople.org/firewalld/doc/firewalld.dbus.html#FirewallD1.direct.Methods.addChainhttps://jpopelka.fedorapeople.org/firewalld/doc/firewalld.dbus.html#FirewallD1.direct.Methods.addRule
Signed-off-by: Jiri Popelka <jpopelka@redhat.com>
Api requesting port for daemon before init_networkdriver called.
Problem is that now initialization of api depends on initialization of
daemon and their intializations runs in parallel. Proper fix will be
just do it sequentially. For now I don't want refactor it, because it
can bring additional problems in 1.6.0.
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
This has a few hacks in it but it ensures that the bridge driver does
not use global state in the mappers, atleast as much as possible at this
point without further refactoring. Some of the exported fields are
hacks to handle the daemon port mapping but this results in a much
cleaner approach and completely remove the global state from the mapper
and allocator.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This modifies iptables.Exists so that it must be called with an explicit
table and chain. This allows us (a) to generate an appropriate command
line for "iptables -C", which was not previously possible, and (b) it
allows us to limit our strings.Contains() search to just the table and
chain in question, preventing erroneous matches against unrelated rules.
Resolves#10781
Signed-off-by: Lars Kellogg-Stedman <lars@redhat.com>
This fixes the daemon's failure to start when setting --ipv6=true for
the first time without deleting `docker0` bridge from a prior use with
only IPv4 addressing.
The addition of the IPv6 bridge address is factored out into a separate
initialization routine which is called even if the bridge exists but no
IPv6 addresses are found.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Sometimes other programs can bind on ports from our range, so we just
skip this ports on allocation.
Fixes#9293
Probably fixes#8714
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
Gianluca Borello
Arnaud Porterie
Alexander Morozov
John Howard
Tibor Vass
Gosuke Miyashita
Sylvain Baubeau
Jiri Popelka
Antonio Murdaca
Jessica Frazelle
Evan Hazlett
Lei Jitang
John Gossman
Tibor Vass
José Tomás Albornoz
Alexander Morozov
Michael Crosby
Brian Goff
Peter Choi
David Calavera
bobby abbott
Jessie Frazelle
Michael Crosby
Lars Kellogg-Stedman
Michal Minar
Sven Dowideit
Zen Lin(Zhinan Lin)
Erik Hollensbe
Phil Estes
Jonathan Rudenberg
Malte Janduda
Ian Bishop
Porjo
Vincent Batts
Sami Wagiaalla
Srini Brahmaroutu