// 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(ctx context.Context, 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
}
fileName := artifact.DefaultS3URL()
r := newLogChunkReaderWithReadahead(artifact, db)
if err := uploadArtifactToS3(s3bucket, fileName, artifact.Size, r); err != nil {
return err
}
// 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.
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 _, err := db.DeleteLogChunksForArtifact(artifact.Id); err != nil {
sentry.ReportError(ctx, err)
return nil
}
return nil
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)
}
}
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
}
}
// LogAndRespondWithError posts a JSON-serialized error and statuscode on the HTTP response object
// (using Martini render).
// Log the error message to Sentry.
func LogAndRespondWithError(ctx context.Context, render render.Render, code int, err error) {
sentry.ReportError(ctx, err)
render.JSON(code, map[string]string{"error": err.Error()})
}
// LogAndRespondWithErrorf posts a JSON-serialized error message and statuscode on the HTTP response
// object (using Martini render).
// Log the error message to Sentry.
func LogAndRespondWithErrorf(ctx context.Context, render render.Render, code int, errStr string, params ...interface{}) {
msg := fmt.Sprintf(errStr, params...)
sentry.ReportError(ctx, errors.New(msg))
render.JSON(code, map[string]string{"error": msg})
}
// PutArtifact writes a streamed artifact to S3. The entire file contents are streamed directly
// through to S3. If S3 is not accessible, we don't make any attempt to buffer on disk and fail
// immediately.
func PutArtifact(ctx context.Context, 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)
}
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/ ?
sentry.ReportError(ctx, 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
}
b := new(bytes.Buffer)
// Note: Storing entire contents of uploaded artifact in memory can cause OOMS.
if n, err := io.CopyN(b, req.Body, artifact.Size); err != nil {
return cleanupAndReturn(fmt.Errorf("Error reading from request body (for artifact %s/%s, bytes (%d/%d) read): %s", artifact.BucketId, artifact.Name, n, artifact.Size, err))
}
fileName := artifact.DefaultS3URL()
if err := uploadArtifactToS3(bucket, fileName, artifact.Size, bytes.NewReader(b.Bytes())); err != nil {
return cleanupAndReturn(err)
}
artifact.State = model.UPLOADED
artifact.S3URL = fileName
if err := db.UpdateArtifact(artifact); err != nil {
return err
}
return nil
}