To support this, a new netlabel is added: `com.docker.network.endpoint.ifname`.
It gives the ability to specify the interface name to be set by
netdrivers when the interface is added / moved into the container's
network namespace.
All builtin netdrivers support it.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
Since commit 933fcc9 (Re-remove the SetKey OCI prestart hook),
the network namespace will be set up before endpoints are
created in most cases, apart from build containers.
So, when possible, create the veth with one end in that netns
to save moving it in later. On my host, that saves about 20ms
for each bridge network a container is connected to.
Signed-off-by: Rob Murray <rob.murray@docker.com>
The default is to send 3 messages at 1s intervals.
That can be overridden in "docker network create" using:
-o com.docker.network.advertise_addr_nmsgs=3
-o com.docker.network.advertise_addr_ms=1000
Or, in daemon.json for each driver:
"default-network-opts": {
"bridge": {
"com.docker.network.advertise_addr_nmsgs": "3",
"com.docker.network.advertise_addr_ms": "1000"
}
}
The allowed range is 0-3 for the number of messages, and
100-2000ms for the interval. Setting nmsgs to 0 disables the
gratuitous ARP/NA messages.
The default bridge will always use the built-in defaults,
it cannot be configured.
Signed-off-by: Rob Murray <rob.murray@docker.com>
On live-restore, the Sandbox tries to restore state in the osSbox
by telling it about interface, routes, and gateways that would
have been set up by the previous incarnation of the daemon.
Restoring gateways has been broken since commit 18327745c0 (Allow
separate IPv4/IPv6 gateway endpoints.) ... which didn't properly
deal with searching for the "dstName" of an interface based on its
IPv6 address.
This commit fixes that, and splits the osSbox restore into three
parts:
- Restore the interfaces, including finding the "dstName".
- Restore routes, unchanged, they're just a copy of the sandbox's
StaticRoutes
- Restore gateway info - if the Sandbox's gateway endpoint has an
IP address (v4 or v6, depending on which addr family/families it's
acting as the gateway for), store that. If not, the default route
is bound to the interface, so store that.
Signed-off-by: Rob Murray <rob.murray@docker.com>
In L3 modes, the ipvlan driver can't set up a default gateway with
a next hop address, because there's no L2 for it to resolve the
gateway IP into a MAC address.
Instead, it sets up a route to 0.0.0.0 or [::] that's connected to
the network's interface. The end result is the same - the container
has a default route.
So, don't set up routes to 0.0.0.0/:: when applying routes when an
endpoint joins a sandbox, set them up when the endpoint is selected
as the container's gateway. And, drop those routes when another
endpoint becomes the gateway.
Signed-off-by: Rob Murray <rob.murray@docker.com>
A dual-stack endpoint still has priority when selecting a gateway
Endpoint for a Sandbox. But, now there are IPv6-only networks, it
is possible to have a Sandbox with only IPv4-only and IPv6-only
endpoints. This change means they are both gateway endpoints.
Tell the network driver it mustn't proxy host-IPv6 to endpoint-IPv4
when there's an IPv6 gateway endpoint (which may belong to a different
net driver). Update that when networks are connected/disconnected.
Signed-off-by: Rob Murray <rob.murray@docker.com>
When a container doesn't support IPv6 and it's joined to an IPv6
network, don't allocate an IPv6 address for it.
Update the DNS resolver to understand that it can have an 'ipv6miss'
(meaning an IPv4 address exists, but no IPv6) when a network is
IPv6 enabled.
Signed-off-by: Rob Murray <rob.murray@docker.com>
If config for legacy links needs to be added to a libnetwork.Sandbox,
add it when constructing the Endpoint that needs it - removing the
constraint on ordering of Endpoint construction, and the dependency
between Endpoint and Sandbox construction.
So, now a Sandbox can be constructed in one place, before the first
Endpoint.
Signed-off-by: Rob Murray <rob.murray@docker.com>
Second attempt to stop using the OCI prestart hook to call SetKey
to set up the OS Sandbox's key and perform network config in the
new network namespace.
The first attempt was reverted because it made it impossible to
use --sysctl to set per-interface sysctls on an interface that had
not yet been moved into the new network namespace.
Now, per-interface sysctls can be used to do that (with less
ambiguity because the setting is not tied to the interface using
an unpredictably assigned name).
Signed-off-by: Rob Murray <rob.murray@docker.com>
Until now it's been possible to set per-interface sysctls using, for
example, '--sysctl net.ipv6.conf.eth0.accept_ra=2'. But, the index in
the interface name is allocated serially, and the numbering in a container
with more than one interface may change when a container is restarted.
The change to make it possible to connect a container to more than one
network when it's created increased the ambiguity.
This change adds label "com.docker.network.endpoint.sysctls" to the
DriverOpts in EndpointSettings. This option is explicitly associated
with the interface.
Settings in "--sysctl" for "eth0" are migrated to DriverOpts.
Because using "--sysctl" with any interface apart from "eth0" would have
unpredictable results, it is now an error to use any other interface name
in the top level "--sysctl" option. The error message includes a hint at
how to use the new per-interface setting.
The per-endpoint sysctl name has the interface name replaced by
"IFNAME". For example:
net.ipv6.conf.eth0.accept_ra=2
becomes:
net.ipv6.conf.IFNAME.accept_ra=2
The value of DriverOpts["com.docker.network.endpoint.sysctls"] is a
comma separated list.
Settings from '--sysctl' are applied by the runtime lib during task
creation. So, task creation fails if the endpoint does not exist.
Applying per-endpoint settings during interface configuration means the
endpoint can be created later, which paves the way for removal of the
SetKey OCI prestart hook.
Unlike other DriverOpts, the sysctl label itself is not driver-specific,
but each driver has a chance to check settings/values and raise an error
if a setting would cause it a problem - no such checks have been added
in this initial version. As a future extension, if required, it would be
possible for the driver to echo back valid/extended/modified settings to
libnetwork for it to apply to the interface. (At that point, the syntax
for the options could become driver specific to allow, for example, a
driver to create more than one interface).
Signed-off-by: Rob Murray <rob.murray@docker.com>
Make the internal DNS resolver for Windows containers forward requests
to upsteam DNS servers when it cannot respond itself, rather than
returning SERVFAIL.
Windows containers are normally configured with the internal resolver
first for service discovery (container name lookup), then external
resolvers from '--dns' or the host's networking configuration.
When a tool like ping gets a SERVFAIL from the internal resolver, it
tries the other nameservers. But, nslookup does not, and with this
change it does not need to.
The internal resolver learns external server addresses from the
container's HNSEndpoint configuration, so it will use the same DNS
servers as processes in the container.
The internal resolver for Windows containers listens on the network's
gateway address, and each container may have a different set of external
DNS servers. So, the resolver uses the source address of the DNS request
to select external resolvers.
On Windows, daemon.json feature option 'windows-no-dns-proxy' can be used
to prevent the internal resolver from forwarding requests (restoring the
old behaviour).
Signed-off-by: Rob Murray <rob.murray@docker.com>
Partially reverts 0046b16 "daemon: set libnetwork sandbox key w/o OCI hook"
Running SetKey to store the OCI Sandbox key after task creation, rather
than from the OCI prestart hook, meant it happened after sysctl settings
were applied by the runtime - which was the intention, we wanted to
complete Sandbox configuration after IPv6 had been disabled by a sysctl
if that was going to happen.
But, it meant '--sysctl' options for a specfic network interface caused
container task creation to fail, because the interface is only moved into
the network namespace during SetKey.
This change restores the SetKey prestart hook, and regenerates config
files that depend on the container's support for IPv6 after the task has
been created. It also adds a regression test that makes sure it's possible
to set an interface-specfic sysctl.
Signed-off-by: Rob Murray <rob.murray@docker.com>
When IPv6 is disabled in a container by, for example, using the --sysctl
option - an IPv6 address/gateway is still allocated. Don't attempt to
apply that config because doing so enables IPv6 on the interface.
Signed-off-by: Rob Murray <rob.murray@docker.com>
Some configuration in a container depends on whether it has support for
IPv6 (including default entries for '::1' etc in '/etc/hosts').
Before this change, the container's support for IPv6 was determined by
whether it was connected to any IPv6-enabled networks. But, that can
change over time, it isn't a property of the container itself.
So, instead, detect IPv6 support by looking for '::1' on the container's
loopback interface. It will not be present if the kernel does not have
IPv6 support, or the user has disabled it in new namespaces by other
means.
Once IPv6 support has been determined for the container, its '/etc/hosts'
is re-generated accordingly.
The daemon no longer disables IPv6 on all interfaces during initialisation.
It now disables IPv6 only for interfaces that have not been assigned an
IPv6 address. (But, even if IPv6 is disabled for the container using the
sysctl 'net.ipv6.conf.all.disable_ipv6=1', interfaces connected to IPv6
networks still get IPv6 addresses that appear in the internal DNS. There's
more to-do!)
Signed-off-by: Rob Murray <rob.murray@docker.com>
The github.com/containerd/containerd/log package was moved to a separate
module, which will also be used by upcoming (patch) releases of containerd.
This patch moves our own uses of the package to use the new module.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
InterfaceOptions() returned an IfaceOptionSetter interface, which contained
"methods" that returned functional options. Such a construct could have made
sense if the functional options returned would (e.g.) be pre-propagated with
information from the Sandbox (network namespace), but none of that was the case.
There was only one implementation of IfaceOptionSetter (networkNamespace),
which happened to be the same as the only implementation of Sandbox, so remove
the interface as well, to help networkNamespace with its multi-personality
disorder.
This patch:
- removes Sandbox.Bridge() and makes it a regular function (WithIsBridge)
- removes Sandbox.Master() and makes it a regular function (WithMaster)
- removes Sandbox.MacAddress() and makes it a regular function (WithMACAddress)
- removes Sandbox.Address() and makes it a regular function (WithIPv4Address)
- removes Sandbox.AddressIPv6() and makes it a regular function (WithIPv6Address)
- removes Sandbox.LinkLocalAddresses() and makes it a regular function (WithLinkLocalAddresses)
- removes Sandbox.Routes() and makes it a regular function (WithRoutes)
- removes Sandbox.InterfaceOptions().
- removes the IfaceOptionSetter interface.
Note that the IfaceOption signature was changes as well to allow returning
an error. This is not currently used, but will be used for some options
in the near future, so adding that in preparation.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
osl.NewSandbox() always returns a nil interface on Windows (and other non-Linux
platforms). This means that any code that these fields are always nil, and
any code using these fields must be considered Linux-only.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
