EnsureBridge used to skip creation and initialization of the weave
bridge and friends if such existed. This caused problems when
EnsureBridge failed before completing all init steps and so, subsequent
weaver could not work without "weave reset".
This change makes EnsureBridge idempotent.
"docker.sock" is used to access Docker API which is required to:
1. subscribe to Docker events to configure-arp,
2. query Docker network info to detect whether multicast should be
enabled.
3. get list of Swarm peers before starting the plugin.
(1) is currently not implemented.
(2) is replaced by WEAVE_MULTICAST env var which
can enable multicast for all Weave networks created by
the plugin (not ideal, but better than nothing).
(3) is fixed by not removing "restart.sentinel".
Docker Plugin V2 does not expose a plugin name to the plugin, so we
check for "net-plugin" within driver name of a network to detect
whether network is ours.
- "noDNS" controls whether upon ContainerStarted event a container
should be registered within the Weave DNS.
- "isPluginV2" will be used to determine a path to host's /proc.
NetworkAllocate is called on Swarm master node which creates a network.
The return option map is used to describe the network, and is passed
to CreateNetwork which is called on all nodes when a service is
created.
Returning nil instead the actual options made Docker to omit
the "works.weave.multicast" flag, thus no multicast could be used
in Swarm.
When running in the AWSVPC mode, we need to do the following:
- Keep the HW TX offloading on.
- Check that the allocated address belongs to the default subnet,
because only one subnet is allowed and it should be the default one.
If it is not possible to determine whether AWSVPC is on, we ignore
all the steps, because the attachment routines have to work
regardless whether the router is running and the AWSVPC detection
is done by querying the /ipinfo/tracker endpoint served by
the router.
Now it's off by default, and there is an option to enable the
multicast route per-network.
We turn it on for the `weave` network created when we start the plugin.
Consistency, consistency, consistency:
- prefix all log messages with "[net]" - important since the same
process acts as both a network and ipam driver
- include the API function name in all log messages
- log request and response details at debug level
- log request summary at info level
- log ContainerStarted as a pseudo API function, but only at debug
level (since it can be quite high volume)
And eliminate some dot imports.
It is a library function, so logging of any errors should be left to
the caller.
We also get rid of a logged warning which contained the complete data
structure returned by netlink.LinkByName.
So this function now does no logging at all. Which is how it should be.
Martynas Pumputis