X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/6eb3d1fb8fe71623fa63da46c250184cf2e4fbb8..0561bd0c3c07257fd58ded6c7cfa5feeae97af57:/services/keepstore/pull_worker.go

diff --git a/services/keepstore/pull_worker.go b/services/keepstore/pull_worker.go
index 3d67cf2c1e..f821fb5483 100644
--- a/services/keepstore/pull_worker.go
+++ b/services/keepstore/pull_worker.go
@@ -1,99 +1,112 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
 package main
 
 import (
+	"context"
 	"crypto/rand"
-	"errors"
 	"fmt"
-	"git.curoverse.com/arvados.git/sdk/go/keepclient"
 	"io"
 	"io/ioutil"
-	"log"
 	"time"
+
+	"git.curoverse.com/arvados.git/sdk/go/keepclient"
+
+	log "github.com/Sirupsen/logrus"
 )
 
-/*
-	Keepstore initiates 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
-*/
+// RunPullWorker receives PullRequests from pullq, invokes
+// PullItemAndProcess on each one. After each PR, it logs a message
+// indicating whether the pull was successful.
 func RunPullWorker(pullq *WorkQueue, keepClient *keepclient.KeepClient) {
-	nextItem := pullq.NextItem
-	for item := range nextItem {
-		pullRequest := item.(PullRequest)
-		err := PullItemAndProcess(item.(PullRequest), GenerateRandomApiToken(), keepClient)
+	for item := range pullq.NextItem {
+		pr := item.(PullRequest)
+		err := PullItemAndProcess(pr, keepClient)
+		pullq.DoneItem <- struct{}{}
 		if err == nil {
-			log.Printf("Pull %s success", pullRequest)
+			log.Printf("Pull %s success", pr)
 		} else {
-			log.Printf("Pull %s error: %s", pullRequest, err)
+			log.Printf("Pull %s error: %s", pr, err)
 		}
 	}
 }
 
-/*
-	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
-
-	service_roots := make(map[string]string)
+// PullItemAndProcess executes a pull request by retrieving the
+// specified block from one of the specified servers, and storing it
+// on a local volume.
+//
+// If the PR specifies a non-blank mount UUID, PullItemAndProcess will
+// only attempt to write the data to the corresponding
+// volume. Otherwise it writes to any local volume, as a PUT request
+// would.
+func PullItemAndProcess(pullRequest PullRequest, keepClient *keepclient.KeepClient) error {
+	var vol Volume
+	if uuid := pullRequest.MountUUID; uuid != "" {
+		vol = KeepVM.Lookup(pullRequest.MountUUID, true)
+		if vol == nil {
+			return fmt.Errorf("pull req has nonexistent mount: %v", pullRequest)
+		}
+	}
+
+	keepClient.Arvados.ApiToken = randomToken
+
+	serviceRoots := make(map[string]string)
 	for _, addr := range pullRequest.Servers {
-		service_roots[addr] = addr
+		serviceRoots[addr] = addr
 	}
-	keepClient.SetServiceRoots(service_roots, nil, nil)
+	keepClient.SetServiceRoots(serviceRoots, nil, nil)
 
 	// Generate signature with a random token
-	expires_at := time.Now().Add(60 * time.Second)
-	signedLocator := SignLocator(pullRequest.Locator, token, expires_at)
+	expiresAt := time.Now().Add(60 * time.Second)
+	signedLocator := SignLocator(pullRequest.Locator, randomToken, expiresAt)
 
 	reader, contentLen, _, err := GetContent(signedLocator, keepClient)
 	if err != nil {
-		return
+		return err
 	}
 	if reader == nil {
-		return errors.New(fmt.Sprintf("No reader found for : %s", signedLocator))
+		return fmt.Errorf("No reader found for : %s", signedLocator)
 	}
 	defer reader.Close()
 
-	read_content, err := ioutil.ReadAll(reader)
+	readContent, err := ioutil.ReadAll(reader)
 	if err != nil {
 		return err
 	}
 
-	if (read_content == nil) || (int64(len(read_content)) != contentLen) {
-		return errors.New(fmt.Sprintf("Content not found for: %s", signedLocator))
+	if (readContent == nil) || (int64(len(readContent)) != contentLen) {
+		return fmt.Errorf("Content not found for: %s", signedLocator)
 	}
 
-	err = PutContent(read_content, pullRequest.Locator)
-	return
+	writePulledBlock(vol, readContent, pullRequest.Locator)
+	return nil
 }
 
 // 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
+var GetContent = func(signedLocator string, keepClient *keepclient.KeepClient) (io.ReadCloser, int64, string, error) {
+	return keepClient.Get(signedLocator)
 }
 
-const ALPHA_NUMERIC = "0123456789abcdefghijklmnopqrstuvwxyz"
+var writePulledBlock = func(volume Volume, data []byte, locator string) {
+	var err error
+	if volume != nil {
+		err = volume.Put(context.Background(), locator, data)
+	} else {
+		_, err = PutBlock(context.Background(), data, locator)
+	}
+	if err != nil {
+		log.Printf("error writing pulled block %q: %s", locator, err)
+	}
+}
 
-func GenerateRandomApiToken() string {
+var randomToken = func() string {
+	const alphaNumeric = "0123456789abcdefghijklmnopqrstuvwxyz"
 	var bytes = make([]byte, 36)
 	rand.Read(bytes)
 	for i, b := range bytes {
-		bytes[i] = ALPHA_NUMERIC[b%byte(len(ALPHA_NUMERIC))]
+		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
-}
+}()