mandible

A ready-to-deploy uploader that you can run on AWS EC2 or Heroku. It accepts an image via a REST interface and returns information about a file. Also, supports processing steps such as compression and thumbnail generation.

Features:

Supported file types

• JPG
• PNG
• GIF

Pluggable storage layers

• S3
• Local

Pluggable authentication scheme

• Time-grant HMAC

Processing Steps:

• Compression
• Thumbnail generation

Installation

(Optional) Authentication

• Set the following environment variable
  • AUTHENTICATION_HMAC_KEY

S3 Storage Layer

• Set the following environment variables
  • AWS_ACCESS_KEY_ID
  • AWS_SECRET_ACCESS_KEY
  • S3_BUCKET

REST API:

Interfacing with ImgurGo is extremely simple:

Upload an image file:

POST /file

with the following multi-part/form-data

• image - file

Upload an image from a URL:

POST /url

with the following multi-part/form-data

• image - string

Upload an image from base64 data:

POST /base64

with the following multi-part/form-data

• image - image encoded as base64 data

Thumbnail Generation:

To generate thumbnails with the request, pass the following JSON as form-data, keyed under thumbs

{
    "name1": {
        "width": x,
        "height": y,
        "shape": ("square" | "thumb" | "circle")
    },
    "name2": {
        "width": x2,
        "height": y2,
        "shape": ("square" | "thumb" | "circle")
    },

    ...
}

Note: Square thumbnails don't preserve aspect ratio, whereas the 'thumb' type does

Example usage (assuming localhost)

URL Upload with thumbnails:

curl -i http://127.0.0.1:8080/url \
-d 'image=http://i.imgur.com/s9zxmYe.jpg' \
-d 'thumbs={"small": {"width": 20, "height": 20, "shape": "square"}, "profile": {"width": 50, "height": 50, "shape": "circle"}}'

Response:

{
    "data": {
        "width": 380,
        "height": 430,
        "link": "https://s3.amazonaws.com/gophergala/original/CUqU4If",
        "mime": "image/jpeg",
        "name": "",
        "size": 82199,
        "thumbs": {
            "profile":"https://s3.amazonaws.com/gophergala/t/CUqU4If/profile",
            "small": "https://s3.amazonaws.com/gophergala/t/CUqU4If/small"
        }
    },
    "status": 200,
    "success": true
}

File Upload with thumbnails:

curl -i http://127.0.0.1:8080/file \
-F 'image=@/tmp/cat.gif' \
-F 'thumbs={"small": {"width": 20, "height": 20, "shape": "square"}}'

Response:

{
    "data": {
        "width": 354,
        "height": 200,
        "link": "https://s3.amazonaws.com/gophergala/original/L4ASjMX",
        "mime": "image/gif",
        "name": "cat.gif",
        "size": 3511100,
        "thumbs": {
            "small":"https://s3.amazonaws.com/gophergala/t/L4ASjMX/small"
        }
    },
    "status": 200,
    "success": true
}

Authenticated upload

Uses HTTP headers Authentication and X-Authentication-HMAC. Generate HMACs by base64-encoding a JSON blob like below. Example MAC generator. Supplying the client with the Authentication blob and MAC is out of scope for this project. In the future we will support symmetric and asymmetric encryption of the authentication blobs.

Request to my own account with proper authorization:

curl -i http://127.0.0.1:8080/user/1/url \
-d 'image=http://i.imgur.com/s9zxmYe.jpg' \
-H 'Authorization: {"user_id":1,"grant_time":"2010-06-01T00:00:00Z","grant_duration_sec":31536000}' \
-H 'X-Authorization-HMAC: tCtGb04n4nvd/94+Xd6vAx9+pJw51ZmX1vH7E+BlTtc='

Response:

{"data":{"link":"/tmp/original/J/a/Jafq9IH","mime":"image/jpeg","name":"s9zxmYe.jpg","hash":"Jafq9IH","size":81881,"width":380,"height":430,"ocrtext":"change\np.roject .\n\n  \n  \n\n  forg@ot to git p.ull before\n- .-+#~+):,-r,ad)q..,i,ng so/ /","thumbs":{},"user_id":"\u0001"},"status":200,"success":true}

Request to other user's account:

curl -i http://127.0.0.1:8080/user/2/url \
-d 'image=http://i.imgur.com/s9zxmYe.jpg' \
-H 'Authorization: {"user_id":1,"grant_time":"2010-06-01T00:00:00Z","grant_duration_sec":31536000}' \
-H 'X-Authorization-HMAC: tCtGb04n4nvd/94+Xd6vAx9+pJw51ZmX1vH7E+BlTtc='

Response:

HTTP/1.1 401 Unauthorized
Date: Mon, 08 Jun 2015 21:04:41 GMT
Content-Length: 0
Content-Type: text/plain; charset=utf-8

HMAC prevents account forgery

curl -i http://127.0.0.1:8080/user/1/url \
-d 'image=http://i.imgur.com/s9zxmYe.jpg' \
-H 'Authorization: {"user_id":1,"grant_time":"2010-06-01T00:00:00Z","grant_duration_sec":31536000}' \
-H 'X-Authorization-HMAC: foobar'

Response:

HTTP/1.1 401 Unauthorized
Date: Mon, 08 Jun 2015 21:04:41 GMT
Content-Length: 0
Content-Type: text/plain; charset=utf-8