A CNI network configuration file contains the plugin's executable file name.
Some platforms like Windows require a file name extension for executables.
This causes unnecessary burden on admins as they now have to maintain two
versions of each type of netconfig file, which differ only by the ".exe"
extension. A much simpler design is for invoke package to also look for
well-known extensions on platforms that require it. Existing tests are
improved and new tests are added to cover the new behavior.
Fixes #360
Hardcoding the list separator character as ":" causes CNI to fail when parsing
CNI_PATH on other operating systems. For example, Windows uses ";" as list
separator because ":" can legally appear in paths such as "C:\path\to\file".
This change replaces use of ":" with OS-agnostic APIs or os.PathListSeparator.
Fixes #358
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.
highlights:
- NetConf struct finally includes cniVersion field
- improve test coverage of current version report behavior
- godoc a few key functions
- allow tests to control version list reported by no-op plugin
The 'flannel' meta plugin delegates to other plugins to do the actual
OS-level work. It used the ipam.Exec{Add,Del} procedures for this
delegation, since those do precisely what's needed.
However this is a bit misleading, since the flannel plugin _isn't_
doing this for IPAM, and the ipam.Exec* procedures aren't doing
something specific to IPAM plugins.
So: anticipating that there may be more meta plugins that want to
delegate in the same way, this commit moves generic delegation
procedures to `pkg/invoke`, and makes the `pkg/ipam` procedures (still
used, accurately, in the non-meta plugins) shims.
When plugin is executed with a DEL command, it does not
print result to stdout unless there is an error. Therefore
it stdout bytes should not be passed to json.Unmarshal.
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).
