func (v *vm) Run(command string, attempts attempt.Strategy, out io.Writer, stderr io.Writer) error {
var sc *ssh.Client
err := attempts.Run(func() (err error) {
fmt.Fprintf(stderr, "Attempting to ssh to %s:22...\n", v.IP())
sc, err = v.DialSSH()
return
})
if err != nil {
return err
}
defer sc.Close()
sess, err := sc.NewSession()
sess.Stdin = bytes.NewBufferString(command)
sess.Stdout = out
sess.Stderr = stderr
if err := sess.Run("bash"); err != nil {
return fmt.Errorf("failed to run command on %s: %s", v.IP(), err)
}
return nil
}
func (S) TestAttemptTiming(c *C) {
testAttempt := attempt.Strategy{
Total: 0.25e9,
Delay: 0.1e9,
}
want := []time.Duration{0, 0.1e9, 0.2e9, 0.2e9}
got := make([]time.Duration, 0, len(want)) // avoid allocation when testing timing
t0 := time.Now()
for a := testAttempt.Start(); a.Next(); {
got = append(got, time.Now().Sub(t0))
}
got = append(got, time.Now().Sub(t0))
c.Assert(got, HasLen, len(want))
const margin = 0.01e9
for i, got := range want {
lo := want[i] - margin
hi := want[i] + margin
if got < lo || got > hi {
c.Errorf("attempt %d want %g got %g", i, want[i].Seconds(), got.Seconds())
}
}
}
func (S) TestAttemptNextHasNext(c *C) {
a := attempt.Strategy{}.Start()
c.Assert(a.Next(), Equals, true)
c.Assert(a.Next(), Equals, false)
a = attempt.Strategy{}.Start()
c.Assert(a.Next(), Equals, true)
c.Assert(a.HasNext(), Equals, false)
c.Assert(a.Next(), Equals, false)
a = attempt.Strategy{Total: 2e8}.Start()
c.Assert(a.Next(), Equals, true)
c.Assert(a.HasNext(), Equals, true)
time.Sleep(2e8)
c.Assert(a.HasNext(), Equals, true)
c.Assert(a.Next(), Equals, true)
c.Assert(a.Next(), Equals, false)
a = attempt.Strategy{Total: 1e8, Min: 2}.Start()
time.Sleep(1e8)
c.Assert(a.Next(), Equals, true)
c.Assert(a.HasNext(), Equals, true)
c.Assert(a.Next(), Equals, true)
c.Assert(a.HasNext(), Equals, false)
c.Assert(a.Next(), Equals, false)
}