ns: fix reading net namespace in multi-threaded processes

/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 is contained in:
Dan Williams
2016-04-06 11:03:31 -05:00
parent 616702bcf3
commit 07a993dc7d
2 changed files with 18 additions and 18 deletions

View File

@ -27,6 +27,16 @@ import (
. "github.com/onsi/gomega"
)
func getCurrentThreadNetNSPath() string {
pid := unix.Getpid()
tid := unix.Gettid()
return fmt.Sprintf("/proc/%d/task/%d/ns/net", pid, tid)
}
func GetInodeCurNetNS() (uint64, error) {
return GetInode(getCurrentThreadNetNSPath())
}
func GetInode(path string) (uint64, error) {
file, err := os.Open(path)
if err != nil {
@ -68,9 +78,7 @@ func MakeNetworkNS(containerID string) string {
defer GinkgoRecover()
// capture current thread's original netns
pid := unix.Getpid()
tid := unix.Gettid()
currentThreadNetNSPath := fmt.Sprintf("/proc/%d/task/%d/ns/net", pid, tid)
currentThreadNetNSPath := getCurrentThreadNetNSPath()
originalNetNS, err := unix.Open(currentThreadNetNSPath, unix.O_RDONLY, 0)
Expect(err).NotTo(HaveOccurred())
defer unix.Close(originalNetNS)