func (*trySuite) TestMaxParallel(c *gc.C) {
try := parallel.NewTry(3, nil)
var (
mu sync.Mutex
count int
max int
)
for i := 0; i < 10; i++ {
try.Start(func(<-chan struct{}) (io.Closer, error) {
mu.Lock()
if count++; count > max {
max = count
}
c.Check(count, gc.Not(jc.GreaterThan), 3)
mu.Unlock()
time.Sleep(20 * time.Millisecond)
mu.Lock()
count--
mu.Unlock()
return result("hello"), nil
})
}
r, err := try.Result()
c.Assert(err, gc.IsNil)
c.Assert(r, gc.Equals, result("hello"))
mu.Lock()
defer mu.Unlock()
c.Assert(max, gc.Equals, 3)
}
func (*trySuite) TestOneSuccess(c *gc.C) {
try := parallel.NewTry(0, nil)
try.Start(tryFunc(0, result("hello"), nil))
val, err := try.Result()
c.Assert(err, gc.IsNil)
c.Assert(val, gc.Equals, result("hello"))
}
func (*trySuite) TestExtraResultsAreClosed(c *gc.C) {
try := parallel.NewTry(0, nil)
begin := make([]chan struct{}, 4)
results := make([]*closeResult, len(begin))
for i := range begin {
begin[i] = make(chan struct{})
results[i] = &closeResult{make(chan struct{})}
i := i
try.Start(func(<-chan struct{}) (io.Closer, error) {
<-begin[i]
return results[i], nil
})
}
begin[0] <- struct{}{}
val, err := try.Result()
c.Assert(err, gc.IsNil)
c.Assert(val, gc.Equals, results[0])
timeout := time.After(shortWait)
for i, r := range results[1:] {
begin[i+1] <- struct{}{}
select {
case <-r.closed:
case <-timeout:
c.Fatalf("timed out waiting for close")
}
}
select {
case <-results[0].closed:
c.Fatalf("result was inappropriately closed")
case <-time.After(shortWait):
}
}
func (*trySuite) TestOutOfOrderResults(c *gc.C) {
try := parallel.NewTry(0, nil)
try.Start(tryFunc(50*time.Millisecond, result("first"), nil))
try.Start(tryFunc(10*time.Millisecond, result("second"), nil))
r, err := try.Result()
c.Assert(err, gc.IsNil)
c.Assert(r, gc.Equals, result("second"))
}
func (*trySuite) TestCloseTwice(c *gc.C) {
try := parallel.NewTry(0, nil)
try.Close()
try.Close()
val, err := try.Result()
c.Assert(val, gc.IsNil)
c.Assert(err, gc.IsNil)
}
// waitSSH waits for the instance to be assigned a routable
// address, then waits until we can connect to it via SSH.
//
// waitSSH attempts on all addresses returned by the instance
// in parallel; the first succeeding one wins. We ensure that
// private addresses are for the correct machine by checking
// the presence of a file on the machine that contains the
// machine's nonce. The "checkHostScript" is a bash script
// that performs this file check.
func waitSSH(ctx environs.BootstrapContext, interrupted <-chan os.Signal, client ssh.Client, checkHostScript string, inst addresser, timeout config.SSHTimeoutOpts) (addr string, err error) {
globalTimeout := time.After(timeout.Timeout)
pollAddresses := time.NewTimer(0)
// checker checks each address in a loop, in parallel,
// until one succeeds, the global timeout is reached,
// or the tomb is killed.
checker := parallelHostChecker{
Try: parallel.NewTry(0, nil),
client: client,
stderr: ctx.GetStderr(),
active: make(map[instance.Address]chan struct{}),
checkDelay: timeout.RetryDelay,
checkHostScript: checkHostScript,
}
defer checker.Kill()
fmt.Fprintln(ctx.GetStderr(), "Waiting for address")
for {
select {
case <-pollAddresses.C:
pollAddresses.Reset(timeout.AddressesDelay)
if err := inst.Refresh(); err != nil {
return "", fmt.Errorf("refreshing addresses: %v", err)
}
addresses, err := inst.Addresses()
if err != nil {
return "", fmt.Errorf("getting addresses: %v", err)
}
checker.UpdateAddresses(addresses)
case <-globalTimeout:
checker.Close()
lastErr := checker.Wait()
format := "waited for %v "
args := []interface{}{timeout.Timeout}
if len(checker.active) == 0 {
format += "without getting any addresses"
} else {
format += "without being able to connect"
}
if lastErr != nil && lastErr != parallel.ErrStopped {
format += ": %v"
args = append(args, lastErr)
}
return "", fmt.Errorf(format, args...)
case <-interrupted:
return "", fmt.Errorf("interrupted")
case <-checker.Dead():
result, err := checker.Result()
if err != nil {
return "", err
}
return result.(*hostChecker).addr.Value, nil
}
}
}
func (*trySuite) TestStartReturnsErrorAfterClose(c *gc.C) {
try := parallel.NewTry(0, nil)
expectErr := errors.New("foo")
err := try.Start(tryFunc(0, nil, expectErr))
c.Assert(err, gc.IsNil)
try.Close()
err = try.Start(tryFunc(0, result("goodbye"), nil))
c.Assert(err, gc.Equals, parallel.ErrClosed)
// Wait for the first try to deliver its result
time.Sleep(shortWait)
try.Kill()
err = try.Wait()
c.Assert(err, gc.Equals, expectErr)
}
func (*trySuite) TestTriesAreStopped(c *gc.C) {
try := parallel.NewTry(0, nil)
stopped := make(chan struct{})
try.Start(func(stop <-chan struct{}) (io.Closer, error) {
<-stop
stopped <- struct{}{}
return nil, parallel.ErrStopped
})
try.Start(tryFunc(0, result("hello"), nil))
val, err := try.Result()
c.Assert(err, gc.IsNil)
c.Assert(val, gc.Equals, result("hello"))
select {
case <-stopped:
case <-time.After(longWait):
c.Fatalf("timed out waiting for stop")
}
}
func (*trySuite) TestOneFailure(c *gc.C) {
try := parallel.NewTry(0, nil)
expectErr := errors.New("foo")
err := try.Start(tryFunc(0, nil, expectErr))
c.Assert(err, gc.IsNil)
select {
case <-try.Dead():
c.Fatalf("try died before it should")
case <-time.After(shortWait):
}
try.Close()
select {
case <-try.Dead():
case <-time.After(longWait):
c.Fatalf("timed out waiting for Try to complete")
}
val, err := try.Result()
c.Assert(val, gc.IsNil)
c.Assert(err, gc.Equals, expectErr)
}
func (*trySuite) TestAllConcurrent(c *gc.C) {
try := parallel.NewTry(0, nil)
started := make(chan chan struct{})
for i := 0; i < 10; i++ {
try.Start(func(<-chan struct{}) (io.Closer, error) {
reply := make(chan struct{})
started <- reply
<-reply
return result("hello"), nil
})
}
timeout := time.After(longWait)
for i := 0; i < 10; i++ {
select {
case reply := <-started:
reply <- struct{}{}
case <-timeout:
c.Fatalf("timed out")
}
}
}
func (*trySuite) TestEverything(c *gc.C) {
try := parallel.NewTry(5, gradedErrorCombine)
tries := []struct {
startAt time.Duration
wait time.Duration
val result
err error
}{{
wait: 30 * time.Millisecond,
err: gradedError(3),
}, {
startAt: 10 * time.Millisecond,
wait: 20 * time.Millisecond,
val: result("result 1"),
}, {
startAt: 20 * time.Millisecond,
wait: 10 * time.Millisecond,
val: result("result 2"),
}, {
startAt: 20 * time.Millisecond,
wait: 5 * time.Second,
val: "delayed result",
}, {
startAt: 5 * time.Millisecond,
err: gradedError(4),
}}
for _, t := range tries {
t := t
go func() {
time.Sleep(t.startAt)
try.Start(tryFunc(t.wait, t.val, t.err))
}()
}
val, err := try.Result()
if val != result("result 1") && val != result("result 2") {
c.Errorf(`expected "result 1" or "result 2" got %#v`, val)
}
c.Assert(err, gc.IsNil)
}
func (*trySuite) TestErrorCombine(c *gc.C) {
// Use maxParallel=1 to guarantee that all errors are processed sequentially.
try := parallel.NewTry(1, func(err0, err1 error) error {
if err0 == nil {
err0 = &multiError{}
}
err0.(*multiError).errs = append(err0.(*multiError).errs, int(err1.(gradedError)))
return err0
})
errors := []gradedError{3, 2, 4, 0, 5, 5, 3}
for _, err := range errors {
err := err
try.Start(func(<-chan struct{}) (io.Closer, error) {
return nil, err
})
}
try.Close()
val, err := try.Result()
c.Assert(val, gc.IsNil)
grades := err.(*multiError).errs
sort.Ints(grades)
c.Assert(grades, gc.DeepEquals, []int{0, 2, 3, 3, 4, 5, 5})
}
func (*trySuite) TestStartBlocksForMaxParallel(c *gc.C) {
try := parallel.NewTry(3, nil)
started := make(chan struct{})
begin := make(chan struct{})
go func() {
for i := 0; i < 6; i++ {
err := try.Start(func(<-chan struct{}) (io.Closer, error) {
<-begin
return nil, fmt.Errorf("an error")
})
started <- struct{}{}
if i < 5 {
c.Check(err, gc.IsNil)
} else {
c.Check(err, gc.Equals, parallel.ErrClosed)
}
}
close(started)
}()
// Check we can start the first three.
timeout := time.After(longWait)
for i := 0; i < 3; i++ {
select {
case <-started:
case <-timeout:
c.Fatalf("timed out")
}
}
// Check we block when going above maxParallel.
timeout = time.After(shortWait)
select {
case <-started:
c.Fatalf("Start did not block")
case <-timeout:
}
// Unblock two attempts.
begin <- struct{}{}
begin <- struct{}{}
// Check we can start another two.
timeout = time.After(longWait)
for i := 0; i < 2; i++ {
select {
case <-started:
case <-timeout:
c.Fatalf("timed out")
}
}
// Check we block again when going above maxParallel.
timeout = time.After(shortWait)
select {
case <-started:
c.Fatalf("Start did not block")
case <-timeout:
}
// Close the Try - the last request should be discarded,
// unblocking last remaining Start request.
try.Close()
timeout = time.After(longWait)
select {
case <-started:
case <-timeout:
c.Fatalf("Start did not unblock after Close")
}
// Ensure all checks are completed
select {
case _, ok := <-started:
c.Assert(ok, gc.Equals, false)
case <-timeout:
c.Fatalf("Start goroutine did not finish")
}
}
// newAPIFromStore implements the bulk of NewAPIClientFromName
// but is separate for testing purposes.
func newAPIFromStore(envName string, store configstore.Storage, apiOpen apiOpenFunc) (apiState, error) {
// Try to read the default environment configuration file.
// If it doesn't exist, we carry on in case
// there's some environment info for that environment.
// This enables people to copy environment files
// into their .juju/environments directory and have
// them be directly useful with no further configuration changes.
envs, err := environs.ReadEnvirons("")
if err == nil {
if envName == "" {
envName = envs.Default
}
if envName == "" {
return nil, fmt.Errorf("no default environment found")
}
} else if !environs.IsNoEnv(err) {
return nil, err
}
// Try to connect to the API concurrently using two different
// possible sources of truth for the API endpoint. Our
// preference is for the API endpoint cached in the API info,
// because we know that without needing to access any remote
// provider. However, the addresses stored there may no longer
// be current (and the network connection may take a very long
// time to time out) so we also try to connect using information
// found from the provider. We only start to make that
// connection after some suitable delay, so that in the
// hopefully usual case, we will make the connection to the API
// and never hit the provider. By preference we use provider
// attributes from the config store, but for backward
// compatibility reasons, we fall back to information from
// ReadEnvirons if that does not exist.
chooseError := func(err0, err1 error) error {
if err0 == nil {
return err1
}
if errorImportance(err0) < errorImportance(err1) {
err0, err1 = err1, err0
}
logger.Warningf("discarding API open error: %v", err1)
return err0
}
try := parallel.NewTry(0, chooseError)
info, err := store.ReadInfo(envName)
if err != nil && !errors.IsNotFound(err) {
return nil, err
}
var delay time.Duration
if info != nil && len(info.APIEndpoint().Addresses) > 0 {
logger.Debugf("trying cached API connection settings")
try.Start(func(stop <-chan struct{}) (io.Closer, error) {
return apiInfoConnect(store, info, apiOpen, stop)
})
// Delay the config connection until we've spent
// some time trying to connect to the cached info.
delay = providerConnectDelay
} else {
logger.Debugf("no cached API connection settings found")
}
try.Start(func(stop <-chan struct{}) (io.Closer, error) {
cfg, err := getConfig(info, envs, envName)
if err != nil {
return nil, err
}
return apiConfigConnect(cfg, apiOpen, stop, delay)
})
try.Close()
val0, err := try.Result()
if err != nil {
if ierr, ok := err.(*infoConnectError); ok {
// lose error encapsulation:
err = ierr.error
}
return nil, err
}
st := val0.(apiState)
// Even though we are about to update API addresses based on
// APIHostPorts in cacheChangedAPIAddresses, we first cache the
// addresses based on the provider lookup. This is because older API
// servers didn't return their HostPort information on Login, and we
// still want to cache our connection information to them.
if cachedInfo, ok := st.(apiStateCachedInfo); ok {
st = cachedInfo.apiState
if cachedInfo.cachedInfo != nil && info != nil {
// Cache the connection settings only if we used the
// environment config, but any errors are just logged
// as warnings, because they're not fatal.
err = cacheAPIInfo(info, cachedInfo.cachedInfo)
if err != nil {
logger.Warningf("cannot cache API connection settings: %v", err.Error())
} else {
logger.Infof("updated API connection settings cache")
}
}
}
// Update API addresses if they've changed. Error is non-fatal.
if localerr := cacheChangedAPIAddresses(info, st); localerr != nil {
logger.Warningf("cannot failed to cache API addresses: %v", localerr)
}
return st, nil
}