package main import ( "crypto/rand" "errors" "fmt" "git.curoverse.com/arvados.git/sdk/go/keepclient" "io" "io/ioutil" "log" "time" ) // RunPullWorker is used by Keepstore to initiate pull worker channel goroutine. // The channel will process pull list. // For each (next) pull request: // For each locator listed, execute Pull on the server(s) listed // Skip the rest of the servers if no errors // Repeat // func RunPullWorker(pullq *WorkQueue, keepClient *keepclient.KeepClient) { nextItem := pullq.NextItem for item := range nextItem { pullRequest := item.(PullRequest) err := PullItemAndProcess(item.(PullRequest), GenerateRandomAPIToken(), keepClient) pullq.DoneItem <- struct{}{} if err == nil { log.Printf("Pull %s success", pullRequest) } else { log.Printf("Pull %s error: %s", pullRequest, err) } } } // PullItemAndProcess pulls items from PullQueue and processes them. // For each Pull request: // Generate a random API token. // Generate a permission signature using this token, timestamp ~60 seconds in the future, and desired block hash. // Using this token & signature, retrieve the given block. // Write to storage // func PullItemAndProcess(pullRequest PullRequest, token string, keepClient *keepclient.KeepClient) (err error) { keepClient.Arvados.ApiToken = token serviceRoots := make(map[string]string) for _, addr := range pullRequest.Servers { serviceRoots[addr] = addr } keepClient.SetServiceRoots(serviceRoots, nil, nil) // Generate signature with a random token expiresAt := time.Now().Add(60 * time.Second) signedLocator := SignLocator(pullRequest.Locator, token, expiresAt) reader, contentLen, _, err := GetContent(signedLocator, keepClient) if err != nil { return } if reader == nil { return errors.New(fmt.Sprintf("No reader found for : %s", signedLocator)) } defer reader.Close() readContent, err := ioutil.ReadAll(reader) if err != nil { return err } if (readContent == nil) || (int64(len(readContent)) != contentLen) { return errors.New(fmt.Sprintf("Content not found for: %s", signedLocator)) } err = PutContent(readContent, pullRequest.Locator) return } // Fetch the content for the given locator using keepclient. var GetContent = func(signedLocator string, keepClient *keepclient.KeepClient) ( reader io.ReadCloser, contentLength int64, url string, err error) { reader, blocklen, url, err := keepClient.Get(signedLocator) return reader, blocklen, url, err } const alphaNumeric = "0123456789abcdefghijklmnopqrstuvwxyz" // GenerateRandomAPIToken generates a random api token func GenerateRandomAPIToken() string { var bytes = make([]byte, 36) rand.Read(bytes) for i, b := range bytes { bytes[i] = alphaNumeric[b%byte(len(alphaNumeric))] } return (string(bytes)) } // Put block var PutContent = func(content []byte, locator string) (err error) { _, err = PutBlock(content, locator) return }