consul/vendor/github.com/gophercloud/gophercloud/util.go

103 lines
2.7 KiB
Go

package gophercloud
import (
"fmt"
"net/url"
"path/filepath"
"strings"
"time"
)
// WaitFor polls a predicate function, once per second, up to a timeout limit.
// This is useful to wait for a resource to transition to a certain state.
// To handle situations when the predicate might hang indefinitely, the
// predicate will be prematurely cancelled after the timeout.
// Resource packages will wrap this in a more convenient function that's
// specific to a certain resource, but it can also be useful on its own.
func WaitFor(timeout int, predicate func() (bool, error)) error {
type WaitForResult struct {
Success bool
Error error
}
start := time.Now().Unix()
for {
// If a timeout is set, and that's been exceeded, shut it down.
if timeout >= 0 && time.Now().Unix()-start >= int64(timeout) {
return fmt.Errorf("A timeout occurred")
}
time.Sleep(1 * time.Second)
var result WaitForResult
ch := make(chan bool, 1)
go func() {
defer close(ch)
satisfied, err := predicate()
result.Success = satisfied
result.Error = err
}()
select {
case <-ch:
if result.Error != nil {
return result.Error
}
if result.Success {
return nil
}
// If the predicate has not finished by the timeout, cancel it.
case <-time.After(time.Duration(timeout) * time.Second):
return fmt.Errorf("A timeout occurred")
}
}
}
// NormalizeURL is an internal function to be used by provider clients.
//
// It ensures that each endpoint URL has a closing `/`, as expected by
// ServiceClient's methods.
func NormalizeURL(url string) string {
if !strings.HasSuffix(url, "/") {
return url + "/"
}
return url
}
// NormalizePathURL is used to convert rawPath to a fqdn, using basePath as
// a reference in the filesystem, if necessary. basePath is assumed to contain
// either '.' when first used, or the file:// type fqdn of the parent resource.
// e.g. myFavScript.yaml => file://opt/lib/myFavScript.yaml
func NormalizePathURL(basePath, rawPath string) (string, error) {
u, err := url.Parse(rawPath)
if err != nil {
return "", err
}
// if a scheme is defined, it must be a fqdn already
if u.Scheme != "" {
return u.String(), nil
}
// if basePath is a url, then child resources are assumed to be relative to it
bu, err := url.Parse(basePath)
if err != nil {
return "", err
}
var basePathSys, absPathSys string
if bu.Scheme != "" {
basePathSys = filepath.FromSlash(bu.Path)
absPathSys = filepath.Join(basePathSys, rawPath)
bu.Path = filepath.ToSlash(absPathSys)
return bu.String(), nil
}
absPathSys = filepath.Join(basePath, rawPath)
u.Path = filepath.ToSlash(absPathSys)
if err != nil {
return "", err
}
u.Scheme = "file"
return u.String(), nil
}