seaweedfs/docs/usecases.rst

Use cases
===================

Saving image with different sizes
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Each image usually store one file key in database. However, one image can have several versions, e.g., thumbnail, small, medium, large, original. And each version of the same image will have a file key. It's not ideal to store all the keys.

One way to resolve this is here.

Reserve a set of file keys, for example, 5

.. code-block:: bash

	curl http://<host>:<port>/dir/assign?count=5
	{"fid":"3,01637037d6","url":"127.0.0.1:8080","publicUrl":"localhost:8080","count":5}

Save the 5 versions of the image to the volume server. The urls for each image can be:

.. code-block:: bash

	http://<url>:<port>/3,01637037d6
	http://<url>:<port>/3,01637037d6_1
	http://<url>:<port>/3,01637037d6_2
	http://<url>:<port>/3,01637037d6_3
	http://<url>:<port>/3,01637037d6_4

Overwriting mime types
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The correct way to send mime type:


.. code-block:: bash

	curl -F "file=@myImage.png;type=image/png" http://127.0.0.1:8081/5,2730a7f18b44

The wrong way to send it:

.. code-block:: bash

	curl -H "Content-Type:image/png" -F file=@myImage.png http://127.0.0.1:8080/5,2730a7f18b44
	
Securing Seaweed-FS
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The simple way is to front all master and volume servers with firewall.

However, if blocking servicing port is not feasible or trivial, a white list option can be used. Only traffic from the white list IP addresses have write permission.

.. code-block:: bash

	weed master -whiteList="::1,127.0.0.1"
	weed volume -whiteList="::1,127.0.0.1"
	# "::1" is for IP v6 localhost.