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 adds the option `resolvConf` to the host-local IPAM configuration.
If specified, the plugin will try to parse the file as a resolv.conf(5)
type file and return it in the DNS response.
It doesn't seem like container IDs should really have whitespace or
newlines in them. As a complete edge-case, manipulating the host-local
store's IP reservations with 'echo' puts a newline at the end, which
caused matching to fail in ReleaseByID(). Don't ask...
Add an e2e host-local plugin testcase, which requires being able
to pass the datadir into the plugin so we can erase it later.
We're not always guaranteed to have access to the default data
dir location, plus it should probably be configurable anyway.
When RangeEnd is given, a.end = RangeEnd+1.
If when getSearchRange() is called and lastReservedIP equals
RangeEnd, a.nextIP() only compares lastReservedIP (which in this
example is RangeEnd) against a.end (which in this example is
RangeEnd+1) and they clearly don't match, so a.nextIP() returns
start=RangeEnd+1 and end=RangeEnd.
Get() happily allocates RangeEnd+1 because it only compares 'cur'
to the end returned by getSearchRange(), not to a.end, and thus
allocates past RangeEnd.
Since a.end is inclusive (eg, host-local will allocate a.end) the
fix is to simply set a.end equal to RangeEnd.
This changes the ip allocation logic to round robin. Before this, host-local IPAM searched for available IPs from start of subnet. Hence it tends to allocate IPs that had been used recently. This is not ideal since it may cause collisions.
This commit adds a struct type CommonArgs that is to be embedded in
every plugin's argument struct. It contains a field named
"IgnoreUnknown" which will be parsed as a boolean and can be provided to
ignore unknown arguments passed to the plugin.
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).
A specific IP can now be requested via the environment variable CNI_ARGS, e.g.
`CNI_ARGS=ip=1.2.3.4`.
The plugin will try to reserve the specified IP.
If this is not successful the execution will fail.
When plugin errors out, it prints out a JSON object to stdout
describing the failure. This object needs to be propagated out
through the plugins and to the container runtime. This change
also adds Print method to both the result and error structs
for easy serialization to stdout.
This adds basic plugins.
"main" types: veth, bridge, macvlan
"ipam" type: host-local
The code has been ported over from github.com/coreos/rkt project
and adapted to fit the CNI spec.
