existing ETCDCTL_API env var causes e2e to fail some of its tests. ETCDCTL_API should not be set before e2e tests start.
the tests themselves should set ETCDCTL_API properly.
Add the bin-dir option to the command line, so the e2e tests can
run with an exist binary. For example(run the command under e2e
directory):
go test -v -timeout 10m -bin-dir /usr/bin -cpu 1,2,4
Signed-off-by: Yiqiao Pu <ypu@redhat.com>