What is it
This is ready-to-use docker microservice for file and image uploading. Upload takes all care about preserving and distributing files and images.
Lets take deeper look, how it works.
Files
Consider, you have to upload some files and then show download links at some place.
Uploading can be done via next HTTP request:
POST https://upload.example.com/file
This can be done even from client-side code. After successful uploading server returns json with special digest parameter (among other parameters such as file name, extension, size, etc):
{
...
"digest": "qwertyuiop",
...
}
This digest is actually an internal identificator of uploaded file. If you need to place somewhere a link for file downloading, you can write html link as following:
<a href="https://upload.example.com/file/qwertyuiop" target="_blank">Download my file</a>
And that’s it.
Images
Uploading images is as simple as file.
POST https://upload.example.com/image
Upload server already returns all needed CORS-headers, so this request can be done right from javascript-code.
Again, in response there will be digest, which you can then send in AJAX request to your server and save to the database for respective resource.
If you want to show an image somewhere, you can place html “img” tag as following:
<img src="https://upload.example.com/image/qwertyuiop?w=400&h=300&m=c">
Notice special parameters we placed to the end of the link: w, h, m. They are width, height and resize mode parameters respectively. “w=400&h=300&m=c” query string means, that upload server will resize image to “400x300” dimension with crop-typed mode. Crop means that image will be returned exactly as “400x300” (extra dimensions will be cut off). Another option is “m=r” (which is default behaviour). It means that image will be resized till it can be placed entirely to rectangle “400x300”.
So, when you call “https://upload.example.com/image/qwertyuiop?w=400&h=300&m=c” uploader resizes image on-the-fly and returns smaller image to reduce bandwidth traffic. Resize is done just once, and then resized image is placed to cache. On repetitive requests this image will be returned right by bundled nginx web-server making this operation fast. Original image is not deleted after resize, and is preserved all the time. Resized image is a smaller copy of that image.
Audio and videos
Uploader also supports video and audio upload, this is made just like as a file upload. The only difference is that Uploader converts videos to smaller format after upload to reduce hard drive space consumption.