func GetArtifactContent(ctx context.Context, r render.Render, req *http.Request, res http.ResponseWriter, db database.Database, s3bucket *s3.Bucket, artifact *model.Artifact) {
if artifact == nil {
LogAndRespondWithErrorf(ctx, r, http.StatusBadRequest, "No artifact specified")
return
}
switch artifact.State {
case model.UPLOADED:
// Fetch from S3
url := s3bucket.SignedURL(artifact.S3URL, time.Now().Add(30*time.Minute))
rq, err := http.NewRequest("GET", url, nil)
if byteRanges := req.Header.Get("Range"); byteRanges != "" {
// If request contains Range: headers, pass them right through to S3.
// TODO(anupc): Validation? We're sending user input through to the data store.
rq.Header.Add("Range", byteRanges)
}
resp, err := http.DefaultClient.Do(rq)
if err != nil {
LogAndRespondWithError(ctx, r, http.StatusInternalServerError, err)
return
}
if resp.StatusCode != http.StatusPartialContent && resp.StatusCode != http.StatusOK {
LogAndRespondWithErrorf(ctx, r, http.StatusInternalServerError, fmt.Sprintf("Bad status code %d recieved from S3", resp.StatusCode))
return
}
contentdisposition.SetFilename(res, filepath.Base(artifact.RelativePath))
res.Header().Add("Content-Length", strconv.Itoa(int(artifact.Size)))
if n, err := io.CopyN(res, resp.Body, artifact.Size); err != nil {
sentry.ReportError(ctx, fmt.Errorf("Error transferring artifact (for artifact %s/%s, bytes (%d/%d) read): %s", artifact.BucketId, artifact.Name, n, artifact.Size, err))
return
}
return
case model.UPLOADING:
// Not done uploading to S3 yet. Error.
LogAndRespondWithErrorf(ctx, r, http.StatusNotFound, "Waiting for content to complete uploading")
return
case model.APPENDING:
fallthrough
case model.APPEND_COMPLETE:
// Pick from log chunks
contentdisposition.SetFilename(res, filepath.Base(artifact.RelativePath))
// All written bytes are immutable. So, unless size changes, all previously read contents can be cached.
res.Header().Add("ETag", strconv.Itoa(int(artifact.Size)))
http.ServeContent(res, req, filepath.Base(artifact.RelativePath), time.Time{}, newLogChunkReaderWithReadahead(artifact, db))
return
case model.WAITING_FOR_UPLOAD:
// Not started yet. Error
LogAndRespondWithErrorf(ctx, r, http.StatusNotFound, "Waiting for content to get uploaded")
return
}
}
func GetArtifactContent(r render.Render, req *http.Request, res http.ResponseWriter, db database.Database, params martini.Params, s3bucket *s3.Bucket, artifact *model.Artifact) {
if artifact == nil {
JsonErrorf(r, http.StatusBadRequest, "Error: no artifact specified")
return
}
switch artifact.State {
case model.UPLOADED:
// Fetch from S3
reader, err := s3bucket.GetReader(artifact.S3URL)
if err != nil {
JsonErrorf(r, http.StatusInternalServerError, err.Error())
return
}
// Ideally, we'll use a Hijacker to take over the conn so that we can employ an io.Writer
// instead of loading the entire file into memory before writing it back out. But, for now, we
// will run the risk of OOM if large files need to be served.
var buf bytes.Buffer
_, err = buf.ReadFrom(reader)
if err != nil {
JsonErrorf(r, http.StatusInternalServerError, "Error reading upload buffer: %s", err.Error())
return
}
res.Write(buf.Bytes())
return
case model.UPLOADING:
// Not done uploading to S3 yet. Error.
r.JSON(http.StatusNotFound, map[string]string{"error": "Waiting for content to complete uploading"})
return
case model.APPENDING:
fallthrough
case model.APPEND_COMPLETE:
// Pick from log chunks
logChunks, err := db.ListLogChunksInArtifact(artifact.Id)
if err != nil {
JsonErrorf(r, http.StatusInternalServerError, err.Error())
return
}
var buf bytes.Buffer
for _, logChunk := range logChunks {
buf.WriteString(logChunk.Content)
}
res.Write(buf.Bytes())
return
case model.WAITING_FOR_UPLOAD:
// Not started yet. Error
JsonErrorf(r, http.StatusNotFound, "Waiting for content to get uploaded")
return
}
}
func killBucket(b *s3.Bucket) {
var err error
for attempt := attempts.Start(); attempt.Next(); {
err = b.DelBucket()
if err == nil {
return
}
if _, ok := err.(*net.DNSError); ok {
return
}
e, ok := err.(*s3.Error)
if ok && e.Code == "NoSuchBucket" {
return
}
if ok && e.Code == "BucketNotEmpty" {
// Errors are ignored here. Just retry.
resp, err := b.List("", "", "", 1000)
if err == nil {
for _, key := range resp.Contents {
_ = b.Del(key.Key)
}
}
multis, _, _ := b.ListMulti("", "")
for _, m := range multis {
_ = m.Abort()
}
}
}
message := "cannot delete test bucket"
if err != nil {
message += ": " + err.Error()
}
panic(message)
}
func uploadArtifactToS3(bucket *s3.Bucket, artifactName string, artifactSize int64, contentReader io.ReadSeeker) error {
attempts := 0
for {
attempts++
// Rewind Seeker to beginning, required if we had already read a few bytes from it before.
if _, err := contentReader.Seek(0, os.SEEK_SET); err != nil {
return err
}
if err := bucket.PutReader(artifactName, contentReader, artifactSize, "binary/octet-stream", s3.PublicRead); err != nil {
if attempts < MaxUploadAttempts {
log.Printf("[Attempt %d/%d] Error uploading to S3: %s", attempts, MaxUploadAttempts, err)
continue
}
return fmt.Errorf("Error uploading to S3: %s", err)
}
bytesUploadedCounter.Add(artifactSize)
return nil
}
return nil // This should never happen - only here to satisfy the compiler
}
// GetArtifactContentChunks lists artifact contents in a chunked form. Useful to poll for updates to
// chunked artifacts. All artifact types are supported and chunks can be requested from arbitrary
// locations within artifacts.
//
// This is primarily meant for Changes UI for log following. If you need to fetch byte ranges from the
// store, it should be available directly at /content
//
// URL query parameters offset and limit can be used to control range of chunks to be fetched.
// offset -> byte offset of the start of the range to be fetched (defaults to beginning of artifact)
// limit -> number of bytes to be fetched (defaults to 100KB)
//
// Negative values for any query parameter will cause it to be set to 0 (default)
func GetArtifactContentChunks(ctx context.Context, r render.Render, req *http.Request, res http.ResponseWriter, db database.Database, s3bucket *s3.Bucket, artifact *model.Artifact) {
if artifact == nil {
LogAndRespondWithErrorf(ctx, r, http.StatusBadRequest, "No artifact specified")
return
}
type Chunk struct {
ID int64 `json:"id"`
Offset int64 `json:"offset"`
Size int64 `json:"size"`
Text string `json:"text"`
}
type Result struct {
Chunks []Chunk `json:"chunks"`
EOF bool `json:"eof"`
NextOffset int64 `json:"nextOffset"`
}
byteRangeBegin, byteRangeEnd, err := getByteRangeFromRequest(req, artifact)
if err != nil {
// If given range is not valid, steer client to a valid range.
r.JSON(http.StatusOK, &Result{Chunks: []Chunk{}, EOF: err == errReadBeyondEOF && artifact.State == model.UPLOADED, NextOffset: byteRangeEnd})
return
}
switch artifact.State {
case model.UPLOADING:
// No data to report right now. Wait till upload to S3 completes.
fallthrough
case model.WAITING_FOR_UPLOAD:
// Upload hasn't started. No data to report. Try again later.
r.JSON(http.StatusOK, &Result{Chunks: []Chunk{}, NextOffset: byteRangeBegin})
return
case model.UPLOADED:
// Fetch from S3
url := s3bucket.SignedURL(artifact.S3URL, time.Now().Add(30*time.Minute))
rq, err := http.NewRequest("GET", url, nil)
if err != nil {
LogAndRespondWithError(ctx, r, http.StatusInternalServerError, err)
return
}
rq.Header.Add("Range", fmt.Sprintf("bytes=%d-%d", byteRangeBegin, byteRangeEnd))
resp, err := http.DefaultClient.Do(rq)
if err != nil {
LogAndRespondWithError(ctx, r, http.StatusInternalServerError, err)
return
}
if resp.StatusCode != http.StatusPartialContent && resp.StatusCode != http.StatusOK {
LogAndRespondWithErrorf(ctx, r, http.StatusBadRequest, fmt.Sprintf("Bad status code %d", resp.StatusCode))
return
}
var buf bytes.Buffer
n, err := buf.ReadFrom(resp.Body)
if err != nil {
LogAndRespondWithError(ctx, r, http.StatusInternalServerError, err)
return
}
nextOffset := byteRangeBegin + int64(n)
r.JSON(http.StatusOK, &Result{
Chunks: []Chunk{Chunk{Offset: byteRangeBegin, Size: int64(n), Text: buf.String()}},
EOF: nextOffset == artifact.Size,
NextOffset: nextOffset,
})
return
case model.APPENDING:
fallthrough
case model.APPEND_COMPLETE:
// Pick from log chunks
rd := newLogChunkReader(artifact, db)
rd.Seek(byteRangeBegin, os.SEEK_SET)
bts := make([]byte, byteRangeEnd-byteRangeBegin+1)
n, err := runeLimitedRead(rd, bts)
if err != nil && err != io.EOF {
LogAndRespondWithError(ctx, r, http.StatusInternalServerError, err)
return
}
if n > 0 {
r.JSON(http.StatusOK, &Result{
Chunks: []Chunk{Chunk{Offset: byteRangeBegin, Size: int64(n), Text: string(bts[:n])}},
NextOffset: byteRangeBegin + int64(n),
})
} else {
r.JSON(http.StatusOK, &Result{Chunks: []Chunk{}, NextOffset: byteRangeBegin})
}
return
}
}
func PutArtifact(artifact *model.Artifact, db database.Database, bucket *s3.Bucket, req PutArtifactReq) error {
if artifact.State != model.WAITING_FOR_UPLOAD {
return fmt.Errorf("Expected artifact to be in state WAITING_FOR_UPLOAD: %s", artifact.State)
}
// New file being inserted into DB.
// Mark status change to UPLOADING and start uploading to S3.
//
// First, verify that the size of the content being uploaded matches our expected size.
var fileSize int64
var err error
if req.ContentLength != "" {
fileSize, err = strconv.ParseInt(req.ContentLength, 10, 64) // string, base, bits
// This should never happen if a sane HTTP client is used. Nonetheless ...
if err != nil {
return fmt.Errorf("Invalid Content-Length specified")
}
} else {
// This too should never happen if a sane HTTP client is used. Nonetheless ...
return fmt.Errorf("Content-Length not specified")
}
if fileSize != artifact.Size {
return fmt.Errorf("Content length %d does not match expected file size %d", fileSize, artifact.Size)
}
// XXX Do we need to commit here or is this handled transparently?
artifact.State = model.UPLOADING
if err := db.UpdateArtifact(artifact); err != nil {
return err
}
cleanupAndReturn := func(err error) error {
// TODO: Is there a better way to detect and handle errors?
// Use a channel to signify upload completion. In defer, check if the channel is empty. If
// yes, mark error. Else ignore.
if err != nil {
// TODO: s/ERROR/WAITING_FOR_UPLOAD/ ?
log.Printf("Error uploading to S3: %s\n", err)
artifact.State = model.ERROR
err2 := db.UpdateArtifact(artifact)
if err2 != nil {
log.Printf("Error while handling error: %s", err2.Error())
}
return err
}
return nil
}
fileName := artifact.DefaultS3URL()
if err := bucket.PutReader(fileName, req.Body, artifact.Size, "binary/octet-stream", s3.PublicRead); err != nil {
return cleanupAndReturn(fmt.Errorf("Error uploading to S3: %s", err))
}
artifact.State = model.UPLOADED
artifact.S3URL = fileName
if err := db.UpdateArtifact(artifact); err != nil {
return err
}
return nil
}
// Merges all of the individual chunks into a single object and stores it on s3.
// The log chunks are stored in the database, while the object is uploaded to s3.
func MergeLogChunks(artifact *model.Artifact, db database.Database, s3bucket *s3.Bucket) error {
switch artifact.State {
case model.APPEND_COMPLETE:
// TODO: Reimplement using GorpDatabase
// If the file is empty, don't bother creating an object on S3.
if artifact.Size == 0 {
artifact.State = model.CLOSED_WITHOUT_DATA
artifact.S3URL = ""
// Conversion between *DatabaseEror and error is tricky. If we don't do this, a nil
// *DatabaseError can become a non-nil error.
return db.UpdateArtifact(artifact).GetError()
}
// XXX Do we need to commit here or is this handled transparently?
artifact.State = model.UPLOADING
if err := db.UpdateArtifact(artifact); err != nil {
return err
}
logChunks, err := db.ListLogChunksInArtifact(artifact.Id)
if err != nil {
return err
}
r, w := io.Pipe()
errChan := make(chan error)
uploadCompleteChan := make(chan bool)
fileName := artifact.DefaultS3URL()
// Asynchronously upload the object to s3 while reading from the r, w
// pipe. Thus anything written to "w" will be sent to S3.
go func() {
defer close(errChan)
defer close(uploadCompleteChan)
defer r.Close()
if err := s3bucket.PutReader(fileName, r, artifact.Size, "binary/octet-stream", s3.PublicRead); err != nil {
errChan <- fmt.Errorf("Error uploading to S3: %s", err)
return
}
uploadCompleteChan <- true
}()
for _, logChunk := range logChunks {
w.Write([]byte(logChunk.Content))
}
w.Close()
// Wait either for S3 upload to complete or for it to fail with an error.
// XXX This is a long operation and should probably be asynchronous from the
// actual HTTP request, and the client should poll to check when its uploaded.
select {
case _ = <-uploadCompleteChan:
artifact.State = model.UPLOADED
artifact.S3URL = fileName
if err := db.UpdateArtifact(artifact); err != nil {
return err
}
// From this point onwards, we will not send back any errors back to the user. If we are
// unable to delete logchunks, we log it to Sentry instead.
if n, err := db.DeleteLogChunksForArtifact(artifact.Id); err != nil {
// TODO: Send this error to Sentry
log.Printf("Error deleting logchunks for artifact %d: %v\n", artifact.Id, err)
return nil
} else if n != int64(len(logChunks)) {
// TODO: Send this error to Sentry
log.Printf("Mismatch in number of logchunks while deleting logchunks for artifact %d:"+
"Expected: %d Actual: %d\n", artifact.Id, len(logChunks), n)
}
return nil
case err := <-errChan:
return err
}
case model.WAITING_FOR_UPLOAD:
fallthrough
case model.ERROR:
fallthrough
case model.APPENDING:
fallthrough
case model.UPLOADED:
fallthrough
case model.UPLOADING:
return fmt.Errorf("Artifact can only be merged when in APPEND_COMPLETE state, but state is %s", artifact.State)
default:
return fmt.Errorf("Illegal artifact state! State code is %d", artifact.State)
}
}