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.
Previously this code used a run-time map lookup keyed by
runtime.GOOS/GOARCH. This version uses conditional compilation to make
this choice at compile time, giving immediate feedback for unsupported
platforms.
/proc/self/ns/net gives the main thread's namespace, not necessarily
the namespace of the thread that's running the testcases. This causes
sporadic failures of the tests.
For example, with a testcase reading inodes after switching netns:
/proc/27686/task/27689/ns/net 4026532565
/proc/self/ns/net 4026531969
/proc/27686/task/27689/ns/net 4026532565
See also:
008d17ae00
Running Suite: pkg/ns Suite
===========================
Random Seed: 1459953577
Will run 6 of 6 specs
• Failure [0.028 seconds]
Linux namespace operations
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:167
WithNetNS
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:166
executes the callback within the target network namespace [It]
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:97
Expected
<uint64>: 4026531969
to equal
<uint64>: 4026532565
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:96
------------------------------
•••••
Summarizing 1 Failure:
[Fail] Linux namespace operations WithNetNS [It] executes the callback within the target network namespace
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:96
Ran 6 of 6 Specs in 0.564 seconds
FAIL! -- 5 Passed | 1 Failed | 0 Pending | 0 Skipped --- FAIL: TestNs (0.56s)
FAIL
/proc/self/ns/net gives the main thread's namespace, not necessarily
the namespace of the thread that's running the testcases. This causes
sporadic failures of the tests.
For example, with a testcase reading inodes after switching netns:
/proc/27686/task/27689/ns/net 4026532565
/proc/self/ns/net 4026531969
/proc/27686/task/27689/ns/net 4026532565
See also:
008d17ae00
Running Suite: pkg/ns Suite
===========================
Random Seed: 1459953577
Will run 6 of 6 specs
• Failure [0.028 seconds]
Linux namespace operations
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:167
WithNetNS
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:166
executes the callback within the target network namespace [It]
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:97
Expected
<uint64>: 4026531969
to equal
<uint64>: 4026532565
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:96
------------------------------
•••••
Summarizing 1 Failure:
[Fail] Linux namespace operations WithNetNS [It] executes the callback within the target network namespace
/cni/gopath/src/github.com/appc/cni/pkg/ns/ns_test.go:96
Ran 6 of 6 Specs in 0.564 seconds
FAIL! -- 5 Passed | 1 Failed | 0 Pending | 0 Skipped --- FAIL: TestNs (0.56s)
FAIL
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 is an attempt to testing the PluginMain() function of the skel pkg.
We should be able to do better by using a mockable interface for the
plugins, but this is a start.
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.
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.
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.
