Controlling the mac address of the interface (veth peer) in the
container is useful for functionalities that depend on the mac address.
Examples range from dynamic IP allocations based on an identifier (the
mac) and up to firewall rules (e.g. no-mac-spoofing).
Enforcing a mac address at an early stage and not through a chained
plugin assures the configuration does not have wrong intermediate
configuration. This is especially critical when a dynamic IP may be
provided already in this period.
But it also has implications for future abilities that may land on the
bridge plugin, e.g. supporting no-mac-spoofing.
The field name used (`mac`) fits with other plugins which control the
mac address of the container interface.
The mac address may be specified through the following methods:
- CNI_ARGS
- Args
- RuntimeConfig [1]
The list is ordered by priority, from lowest to higher. The higher
priority method overrides any previous settings.
(e.g. if the mac is specified in RuntimeConfig, it will override any
specifications of the mac mentioned in CNI_ARGS or Args)
[1] To use RuntimeConfig, the network configuration should include the
`capabilities` field with `mac` specified (`"capabilities": {"mac": true}`).
Signed-off-by: Edward Haas <edwardh@redhat.com>
Previously, if an IPAM plugin provided DNS settings in the result to the PTP
plugin, those settings were always lost because the PTP plugin would always
provide its own DNS settings in the result even if the PTP plugin was not
configured with any DNS settings.
This was especially problematic when trying to use, for example, the host-local
IPAM plugin's support for retrieving DNS settings from a resolv.conf file on
the host. Before this change, those DNS settings were always lost when using the
PTP plugin and couldn't be specified as part of PTP instead because PTP does not
support parsing a resolv.conf file.
This change checks to see if any fields were actually set in the PTP plugin's
DNS settings and only overrides any previous DNS results from an IPAM plugin in
the case that settings actually were provided to PTP. In the case where no
DNS settings are provided to PTP, the DNS results of the IPAM plugin (if any)
are used instead.
Signed-off-by: Erik Sipsma <sipsma@amazon.com>
Now that libcni has the ability to print a version message, plumb it
through correctly.
While we're at it,
- fix import paths
- run gofmt
- add some more comments to sample
- add container runtime swappability for release
host-local and static ipam plugins
tuning, bandwidth and portmap meta plugins
Utility functions created for common PrevResult checking
Fix windows build
* Wait for addresses to leave tentative state before setting routes
* Enable forwarding correctly
* Set up masquerading according to the active protocol
Updates the spec and plugins to return an array of interfaces and IP details
to the runtime including:
- interface names and MAC addresses configured by the plugin
- whether the interfaces are sandboxed (container/VM) or host (bridge, veth, etc)
- multiple IP addresses configured by IPAM and which interface they
have been assigned to
Returning interface details is useful for runtimes, as well as allowing
more flexible chaining of CNI plugins themselves. For example, some
meta plugins may need to know the host-side interface to be able to
apply firewall or traffic shaping rules to the container.
This will give deterministic MAC addresses for all interfaces CNI
creates and manages the IP for:
* bridge: container veth and host bridge
* macvlan: container veth
* ptp: container veth and host veth
Add a namespace object interface for somewhat cleaner code when
creating and switching between network namespaces. All created
namespaces are now mounted in /var/run/netns to ensure they
have persistent inodes and paths that can be passed around
between plugin components without relying on the current namespace
being correct.
Also remove the thread-locking arguments from the ns package
per https://github.com/appc/cni/issues/183 by doing all the namespace
changes in a separate goroutine that locks/unlocks itself, instead of
the caller having to track OS thread locking.
appc/cni#76 added a "dns" field in the result JSON. But before this
patch, the plugins had no way of knowing which name server to return.
There could be two ways of knowing which name server to return:
1. add it as an extra argument ("CNI_ARGS")
2. add it in the network configuration as a convenience (received via
stdin)
I chose the second way because it is easier. In the case of rkt, it
means the user could just add the DNS name servers in
/etc/rkt/net.d/mynetwork.conf.
In some cases the route deletion would fail due to wrong
scope. It should be NOWHERE when deleting (per iproute2).
This also adds more verbose error messages.
Instead of allocating a /31 for each container,
use the same IP on the host side for all veths.
This is very similar how real point-to-point
devices work (using donor IPs).
This takes some of the machinery from CNI and from the rkt networking
code, and turns it into a library that can be linked into go apps.
Included is an example command-line application that uses the library,
called `cnitool`.
Other headline changes:
* Plugin exec'ing is factored out
The motivation here is to factor out the protocol for invoking
plugins. To that end, a generalisation of the code from api.go and
pkg/plugin/ipam.go goes into pkg/invoke/exec.go.
* Move argument-handling and conf-loading into public API
The fact that the arguments get turned into an environment for the
plugin is incidental to the API; so, provide a way of supplying them
as a struct or saying "just use the same arguments as I got" (the
latter is for IPAM plugins).
