15599: Support IAM role credentials in keepstore.
authorTom Clegg <tclegg@veritasgenetics.com>
Fri, 27 Sep 2019 20:39:51 +0000 (16:39 -0400)
committerTom Clegg <tclegg@veritasgenetics.com>
Mon, 30 Sep 2019 23:03:02 +0000 (19:03 -0400)
Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tclegg@veritasgenetics.com>

doc/install/configure-s3-object-storage.html.textile.liquid
lib/config/config.default.yml
lib/config/generated_config.go
services/keepstore/s3_volume.go
services/keepstore/s3_volume_test.go

index 6e725b34490915bc14542ee6f4355fb14ba94c0f..4007e6d221784368093cb91dc5ff41a1152be73f 100644 (file)
@@ -32,7 +32,13 @@ Volumes are configured in the @Volumes@ section of the cluster configuration fil
 
         Driver: S3
         DriverParameters:
-          # The credentials to use to access the bucket.
+          # If an IAM role name is given here, credentials to access
+          # the bucket will be retrieved at runtime from instance
+          # metadata.
+          IAMRole: s3access
+
+          # The credentials to use to access the bucket. Omit or leave
+          # blank if IAMRole is configured.
           AccessKey: aaaaa
           SecretKey: aaaaa
 
index 572a2558eda3c291463e56515c0e1583c2a4adc7..7c22233178fde187a0423f18d0fcabcdc5f21861 100644 (file)
@@ -815,6 +815,7 @@ Clusters:
 
           # for s3 driver -- see
           # https://doc.arvados.org/install/configure-s3-object-storage.html
+          IAMRole: aaaaa
           AccessKey: aaaaa
           SecretKey: aaaaa
           Endpoint: ""
index 32c101a5a080836aa84a3f2a5d0fc7d244813dda..d18251b27f59e4e23a0f033dd098ed082a0c5e74 100644 (file)
@@ -821,6 +821,7 @@ Clusters:
 
           # for s3 driver -- see
           # https://doc.arvados.org/install/configure-s3-object-storage.html
+          IAMRole: aaaaa
           AccessKey: aaaaa
           SecretKey: aaaaa
           Endpoint: ""
index 9fc87045e0c29a471cb13c5953b299851d648195..ad04a2e2229036fc945b218968cbbdae26e73aa7 100644 (file)
@@ -45,8 +45,11 @@ func newS3Volume(cluster *arvados.Cluster, volume arvados.Volume, logger logrus.
 }
 
 func (v *S3Volume) check() error {
-       if v.Bucket == "" || v.AccessKey == "" || v.SecretKey == "" {
-               return errors.New("DriverParameters: Bucket, AccessKey, and SecretKey must be provided")
+       if v.Bucket == "" {
+               return errors.New("DriverParameters: Bucket must be provided")
+       }
+       if v.IAMRole == "" && (v.AccessKey == "" || v.SecretKey == "") {
+               return errors.New("DriverParameters: either IAMRole or literal credentials (AccessKey and SecretKey) must be provided")
        }
        if v.IndexPageSize == 0 {
                v.IndexPageSize = 1000
@@ -55,7 +58,8 @@ func (v *S3Volume) check() error {
                return errors.New("DriverParameters: RaceWindow must not be negative")
        }
 
-       region, ok := aws.Regions[v.Region]
+       var ok bool
+       v.region, ok = aws.Regions[v.Region]
        if v.Endpoint == "" {
                if !ok {
                        return fmt.Errorf("unrecognized region %+q; try specifying endpoint instead", v.Region)
@@ -64,18 +68,13 @@ func (v *S3Volume) check() error {
                return fmt.Errorf("refusing to use AWS region name %+q with endpoint %+q; "+
                        "specify empty endpoint or use a different region name", v.Region, v.Endpoint)
        } else {
-               region = aws.Region{
+               v.region = aws.Region{
                        Name:                 v.Region,
                        S3Endpoint:           v.Endpoint,
                        S3LocationConstraint: v.LocationConstraint,
                }
        }
 
-       auth := aws.Auth{
-               AccessKey: v.AccessKey,
-               SecretKey: v.SecretKey,
-       }
-
        // Zero timeouts mean "wait forever", which is a bad
        // default. Default to long timeouts instead.
        if v.ConnectTimeout == 0 {
@@ -85,16 +84,9 @@ func (v *S3Volume) check() error {
                v.ReadTimeout = s3DefaultReadTimeout
        }
 
-       client := s3.New(auth, region)
-       if region.EC2Endpoint.Signer == aws.V4Signature {
-               // Currently affects only eu-central-1
-               client.Signature = aws.V4Signature
-       }
-       client.ConnectTimeout = time.Duration(v.ConnectTimeout)
-       client.ReadTimeout = time.Duration(v.ReadTimeout)
        v.bucket = &s3bucket{
-               Bucket: &s3.Bucket{
-                       S3:   client,
+               bucket: &s3.Bucket{
+                       S3:   v.newS3Client(),
                        Name: v.Bucket,
                },
        }
@@ -102,6 +94,11 @@ func (v *S3Volume) check() error {
        lbls := prometheus.Labels{"device_id": v.GetDeviceID()}
        v.bucket.stats.opsCounters, v.bucket.stats.errCounters, v.bucket.stats.ioBytes = v.metrics.getCounterVecsFor(lbls)
 
+       err := v.bootstrapIAMCredentials()
+       if err != nil {
+               return fmt.Errorf("error getting IAM credentials: %s", err)
+       }
+
        return nil
 }
 
@@ -136,6 +133,9 @@ func s3regions() (okList []string) {
 type S3Volume struct {
        AccessKey          string
        SecretKey          string
+       AuthToken          string    // populated automatically when IAMRole is used
+       AuthExpiration     time.Time // populated automatically when IAMRole is used
+       IAMRole            string
        Endpoint           string
        Region             string
        Bucket             string
@@ -151,6 +151,7 @@ type S3Volume struct {
        logger    logrus.FieldLogger
        metrics   *volumeMetricsVecs
        bucket    *s3bucket
+       region    aws.Region
        startOnce sync.Once
 }
 
@@ -159,6 +160,107 @@ func (v *S3Volume) GetDeviceID() string {
        return "s3://" + v.Endpoint + "/" + v.Bucket
 }
 
+func (v *S3Volume) bootstrapIAMCredentials() error {
+       if v.IAMRole == "" {
+               return nil
+       }
+       ttl, err := v.updateIAMCredentials()
+       if err != nil {
+               return err
+       }
+       go func() {
+               for {
+                       time.Sleep(ttl)
+                       ttl, err = v.updateIAMCredentials()
+                       if err != nil {
+                               v.logger.WithError(err).Warnf("failed to update credentials for IAM role %q", v.IAMRole)
+                               ttl = time.Second
+                       } else if ttl < time.Second {
+                               v.logger.WithField("TTL", ttl).Warnf("received stale credentials for IAM role %q", v.IAMRole)
+                               ttl = time.Second
+                       }
+               }
+       }()
+       return nil
+}
+
+func (v *S3Volume) newS3Client() *s3.S3 {
+       auth := aws.NewAuth(v.AccessKey, v.SecretKey, v.AuthToken, v.AuthExpiration)
+       client := s3.New(*auth, v.region)
+       if v.region.EC2Endpoint.Signer == aws.V4Signature {
+               // Currently affects only eu-central-1
+               client.Signature = aws.V4Signature
+       }
+       client.ConnectTimeout = time.Duration(v.ConnectTimeout)
+       client.ReadTimeout = time.Duration(v.ReadTimeout)
+       return client
+}
+
+// returned by AWS metadata endpoint .../security-credentials/${rolename}
+type iamCredentials struct {
+       Code            string
+       LastUpdated     time.Time
+       Type            string
+       AccessKeyID     string
+       SecretAccessKey string
+       Token           string
+       Expiration      time.Time
+}
+
+// Returns TTL of updated credentials, i.e., time to sleep until next
+// update.
+func (v *S3Volume) updateIAMCredentials() (time.Duration, error) {
+       ctx, cancel := context.WithDeadline(context.Background(), time.Now().Add(time.Minute))
+       defer cancel()
+
+       var url string
+       if strings.Contains(v.IAMRole, "://") {
+               // Configuration provides complete URL (used by tests)
+               url = v.IAMRole
+       } else {
+               // Configuration provides IAM role name and we use the
+               // AWS metadata endpoint
+               url = "http://169.254.169.254/latest/meta-data/iam/security-credentials/" + v.IAMRole
+       }
+       v.logger.WithField("URL", url).Debug("getting credentials")
+       req, err := http.NewRequest("GET", url, nil)
+       if err != nil {
+               return 0, fmt.Errorf("error setting up request %s: %s", url, err)
+       }
+       resp, err := http.DefaultClient.Do(req.WithContext(ctx))
+       if err != nil {
+               return 0, fmt.Errorf("error getting %s: %s", url, err)
+       }
+       defer resp.Body.Close()
+       if resp.StatusCode != http.StatusOK {
+               return 0, fmt.Errorf("error getting %s: HTTP status %s", url, resp.Status)
+       }
+       var cred iamCredentials
+       err = json.NewDecoder(resp.Body).Decode(&cred)
+       if err != nil {
+               return 0, fmt.Errorf("error decoding credentials from %s: %s", url, err)
+       }
+       v.AccessKey, v.SecretKey, v.AuthToken, v.AuthExpiration = cred.AccessKeyID, cred.SecretAccessKey, cred.Token, cred.Expiration
+       v.bucket.SetBucket(&s3.Bucket{
+               S3:   v.newS3Client(),
+               Name: v.Bucket,
+       })
+       // TTL is time from now to expiration, minus 5m.  "We make new
+       // credentials available at least five minutes before the
+       // expiration of the old credentials."  --
+       // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html#instance-metadata-security-credentials
+       // (If that's not true, the returned ttl might be zero or
+       // negative, which the caller can handle.)
+       ttl := cred.Expiration.Sub(time.Now()) - 5*time.Minute
+       v.logger.WithFields(logrus.Fields{
+               "AccessKeyID": cred.AccessKeyID,
+               "LastUpdated": cred.LastUpdated,
+               "Expiration":  cred.Expiration,
+               "TTL":         arvados.Duration(ttl),
+       }).Debug("updated credentials")
+       return ttl, nil
+}
+
 func (v *S3Volume) getReaderWithContext(ctx context.Context, loc string) (rdr io.ReadCloser, err error) {
        ready := make(chan bool)
        go func() {
@@ -410,13 +512,13 @@ func (v *S3Volume) Mtime(loc string) (time.Time, error) {
 func (v *S3Volume) IndexTo(prefix string, writer io.Writer) error {
        // Use a merge sort to find matching sets of X and recent/X.
        dataL := s3Lister{
-               Bucket:   v.bucket.Bucket,
+               Bucket:   v.bucket.Bucket(),
                Prefix:   prefix,
                PageSize: v.IndexPageSize,
                Stats:    &v.bucket.stats,
        }
        recentL := s3Lister{
-               Bucket:   v.bucket.Bucket,
+               Bucket:   v.bucket.Bucket(),
                Prefix:   "recent/" + prefix,
                PageSize: v.IndexPageSize,
                Stats:    &v.bucket.stats,
@@ -531,15 +633,15 @@ func (v *S3Volume) checkRaceWindow(loc string) error {
 // (PutCopy returns 200 OK if the request was received, even if the
 // copy failed).
 func (v *S3Volume) safeCopy(dst, src string) error {
-       resp, err := v.bucket.PutCopy(dst, s3ACL, s3.CopyOptions{
+       resp, err := v.bucket.Bucket().PutCopy(dst, s3ACL, s3.CopyOptions{
                ContentType:       "application/octet-stream",
                MetadataDirective: "REPLACE",
-       }, v.bucket.Name+"/"+src)
+       }, v.bucket.Bucket().Name+"/"+src)
        err = v.translateError(err)
        if os.IsNotExist(err) {
                return err
        } else if err != nil {
-               return fmt.Errorf("PutCopy(%q ← %q): %s", dst, v.bucket.Name+"/"+src, err)
+               return fmt.Errorf("PutCopy(%q ← %q): %s", dst, v.bucket.Bucket().Name+"/"+src, err)
        }
        if t, err := time.Parse(time.RFC3339Nano, resp.LastModified); err != nil {
                return fmt.Errorf("PutCopy succeeded but did not return a timestamp: %q: %s", resp.LastModified, err)
@@ -769,7 +871,7 @@ func (v *S3Volume) EmptyTrash() {
        }
 
        trashL := s3Lister{
-               Bucket:   v.bucket.Bucket,
+               Bucket:   v.bucket.Bucket(),
                Prefix:   "trash/",
                PageSize: v.IndexPageSize,
                Stats:    &v.bucket.stats,
@@ -848,14 +950,29 @@ func (lister *s3Lister) pop() (k *s3.Key) {
        return
 }
 
-// s3bucket wraps s3.bucket and counts I/O and API usage stats.
+// s3bucket wraps s3.bucket and counts I/O and API usage stats. The
+// wrapped bucket can be replaced atomically with SetBucket in order
+// to update credentials.
 type s3bucket struct {
-       *s3.Bucket
-       stats s3bucketStats
+       bucket *s3.Bucket
+       stats  s3bucketStats
+       mu     sync.Mutex
+}
+
+func (b *s3bucket) Bucket() *s3.Bucket {
+       b.mu.Lock()
+       defer b.mu.Unlock()
+       return b.bucket
+}
+
+func (b *s3bucket) SetBucket(bucket *s3.Bucket) {
+       b.mu.Lock()
+       defer b.mu.Unlock()
+       b.bucket = bucket
 }
 
 func (b *s3bucket) GetReader(path string) (io.ReadCloser, error) {
-       rdr, err := b.Bucket.GetReader(path)
+       rdr, err := b.Bucket().GetReader(path)
        b.stats.TickOps("get")
        b.stats.Tick(&b.stats.Ops, &b.stats.GetOps)
        b.stats.TickErr(err)
@@ -863,7 +980,7 @@ func (b *s3bucket) GetReader(path string) (io.ReadCloser, error) {
 }
 
 func (b *s3bucket) Head(path string, headers map[string][]string) (*http.Response, error) {
-       resp, err := b.Bucket.Head(path, headers)
+       resp, err := b.Bucket().Head(path, headers)
        b.stats.TickOps("head")
        b.stats.Tick(&b.stats.Ops, &b.stats.HeadOps)
        b.stats.TickErr(err)
@@ -882,7 +999,7 @@ func (b *s3bucket) PutReader(path string, r io.Reader, length int64, contType st
        } else {
                r = NewCountingReader(r, b.stats.TickOutBytes)
        }
-       err := b.Bucket.PutReader(path, r, length, contType, perm, options)
+       err := b.Bucket().PutReader(path, r, length, contType, perm, options)
        b.stats.TickOps("put")
        b.stats.Tick(&b.stats.Ops, &b.stats.PutOps)
        b.stats.TickErr(err)
@@ -890,7 +1007,7 @@ func (b *s3bucket) PutReader(path string, r io.Reader, length int64, contType st
 }
 
 func (b *s3bucket) Del(path string) error {
-       err := b.Bucket.Del(path)
+       err := b.Bucket().Del(path)
        b.stats.TickOps("delete")
        b.stats.Tick(&b.stats.Ops, &b.stats.DelOps)
        b.stats.TickErr(err)
index 5c639d62952c06f63b69ad3274e5c7b9b9fa404b..49ea24aa03b8cee1903a2de01010b061085b4528 100644 (file)
@@ -10,6 +10,7 @@ import (
        "crypto/md5"
        "encoding/json"
        "fmt"
+       "io"
        "log"
        "net/http"
        "net/http/httptest"
@@ -45,6 +46,7 @@ var _ = check.Suite(&StubbedS3Suite{})
 
 type StubbedS3Suite struct {
        s3server *httptest.Server
+       metadata *httptest.Server
        cluster  *arvados.Cluster
        handler  *handler
        volumes  []*TestableS3Volume
@@ -52,6 +54,7 @@ type StubbedS3Suite struct {
 
 func (s *StubbedS3Suite) SetUpTest(c *check.C) {
        s.s3server = nil
+       s.metadata = nil
        s.cluster = testCluster(c)
        s.cluster.Volumes = map[string]arvados.Volume{
                "zzzzz-nyw5e-000000000000000": {Driver: "S3"},
@@ -99,6 +102,40 @@ func (s *StubbedS3Suite) TestIndex(c *check.C) {
        }
 }
 
+func (s *StubbedS3Suite) TestIAMRoleCredentials(c *check.C) {
+       s.metadata = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+               upd := time.Now().UTC().Add(-time.Hour).Format(time.RFC3339)
+               exp := time.Now().UTC().Add(time.Hour).Format(time.RFC3339)
+               // Literal example from
+               // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html#instance-metadata-security-credentials
+               // but with updated timestamps
+               io.WriteString(w, `{"Code":"Success","LastUpdated":"`+upd+`","Type":"AWS-HMAC","AccessKeyId":"ASIAIOSFODNN7EXAMPLE","SecretAccessKey":"wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY","Token":"token","Expiration":"`+exp+`"}`)
+       }))
+       defer s.metadata.Close()
+
+       v := s.newTestableVolume(c, s.cluster, arvados.Volume{Replication: 2}, newVolumeMetricsVecs(prometheus.NewRegistry()), 5*time.Minute)
+       c.Check(v.AccessKey, check.Equals, "ASIAIOSFODNN7EXAMPLE")
+       c.Check(v.SecretKey, check.Equals, "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY")
+       c.Check(v.bucket.bucket.S3.Auth.AccessKey, check.Equals, "ASIAIOSFODNN7EXAMPLE")
+       c.Check(v.bucket.bucket.S3.Auth.SecretKey, check.Equals, "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY")
+
+       s.metadata = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+               w.WriteHeader(http.StatusNotFound)
+       }))
+       deadv := &S3Volume{
+               IAMRole:  s.metadata.URL + "/fake-metadata/test-role",
+               Endpoint: "http://localhost:12345",
+               Region:   "test-region-1",
+               Bucket:   "test-bucket-name",
+               cluster:  s.cluster,
+               logger:   ctxlog.TestLogger(c),
+               metrics:  newVolumeMetricsVecs(prometheus.NewRegistry()),
+       }
+       err := deadv.check()
+       c.Check(err, check.ErrorMatches, `.*/fake-metadata/test-role.*`)
+       c.Check(err, check.ErrorMatches, `.*404.*`)
+}
+
 func (s *StubbedS3Suite) TestStats(c *check.C) {
        v := s.newTestableVolume(c, s.cluster, arvados.Volume{Replication: 2}, newVolumeMetricsVecs(prometheus.NewRegistry()), 5*time.Minute)
        stats := func() string {
@@ -229,7 +266,7 @@ func (s *StubbedS3Suite) TestBackendStates(c *check.C) {
                        return
                }
                v.serverClock.now = &t
-               v.bucket.Put(key, data, "application/octet-stream", s3ACL, s3.Options{})
+               v.bucket.Bucket().Put(key, data, "application/octet-stream", s3ACL, s3.Options{})
        }
 
        t0 := time.Now()
@@ -425,10 +462,16 @@ func (s *StubbedS3Suite) newTestableVolume(c *check.C, cluster *arvados.Cluster,
                endpoint = s.s3server.URL
        }
 
+       iamRole, accessKey, secretKey := "", "xxx", "xxx"
+       if s.metadata != nil {
+               iamRole, accessKey, secretKey = s.metadata.URL+"/fake-metadata/test-role", "", ""
+       }
+
        v := &TestableS3Volume{
                S3Volume: &S3Volume{
-                       AccessKey:          "xxx",
-                       SecretKey:          "xxx",
+                       AccessKey:          accessKey,
+                       SecretKey:          secretKey,
+                       IAMRole:            iamRole,
                        Bucket:             TestBucketName,
                        Endpoint:           endpoint,
                        Region:             "test-region-1",
@@ -445,7 +488,7 @@ func (s *StubbedS3Suite) newTestableVolume(c *check.C, cluster *arvados.Cluster,
                serverClock: clock,
        }
        c.Assert(v.S3Volume.check(), check.IsNil)
-       c.Assert(v.bucket.PutBucket(s3.ACL("private")), check.IsNil)
+       c.Assert(v.bucket.Bucket().PutBucket(s3.ACL("private")), check.IsNil)
        // We couldn't set RaceWindow until now because check()
        // rejects negative values.
        v.S3Volume.RaceWindow = arvados.Duration(raceWindow)
@@ -454,11 +497,11 @@ func (s *StubbedS3Suite) newTestableVolume(c *check.C, cluster *arvados.Cluster,
 
 // PutRaw skips the ContentMD5 test
 func (v *TestableS3Volume) PutRaw(loc string, block []byte) {
-       err := v.bucket.Put(loc, block, "application/octet-stream", s3ACL, s3.Options{})
+       err := v.bucket.Bucket().Put(loc, block, "application/octet-stream", s3ACL, s3.Options{})
        if err != nil {
                log.Printf("PutRaw: %s: %+v", loc, err)
        }
-       err = v.bucket.Put("recent/"+loc, nil, "application/octet-stream", s3ACL, s3.Options{})
+       err = v.bucket.Bucket().Put("recent/"+loc, nil, "application/octet-stream", s3ACL, s3.Options{})
        if err != nil {
                log.Printf("PutRaw: recent/%s: %+v", loc, err)
        }
@@ -469,7 +512,7 @@ func (v *TestableS3Volume) PutRaw(loc string, block []byte) {
 // while we do this.
 func (v *TestableS3Volume) TouchWithDate(locator string, lastPut time.Time) {
        v.serverClock.now = &lastPut
-       err := v.bucket.Put("recent/"+locator, nil, "application/octet-stream", s3ACL, s3.Options{})
+       err := v.bucket.Bucket().Put("recent/"+locator, nil, "application/octet-stream", s3ACL, s3.Options{})
        if err != nil {
                panic(err)
        }