uppsala-makerspace / image-cache

A minimal set of php scripts that caches and resizes images for the tool web.

image-cache

A minimal set of php scripts that caches and resizes images for the tool web of Uppsala Makerspace. A standalone version of the tool web is available at: Tool web.

Prerequisities

1. Have php running as CGI scripts in nginx
2. Have imagemagick and libcurl installed
3. Php libraries for running imagemagick and libcurl

Nginx configuration

Since we do not have extensions on the images we cache we provide a default media type to be image.

When loading a cached file we try to load it directly, e.g. from:

https://uppsalamakerspace.se/toolimages/cache/1/34

If it cannot be found, we try to fetch it via the generate.php script.

location /toolimages {
       default_type image;
       try_files $uri /toolimages/scripts/generate.php;
}

The generate.php script

The script does the following:

1. Extract the two numbers at the end of the URL, e.g. 1 (context) and 34 (entry) in the example above.
2. Fetch the file (with help of curl) from the EntryScape API, e.g: https://data.uppsalamakerspace.se/store/1/resource/34.
3. Save the image in the folder original/1/34
4. Resize the image (unsing imagemagic) to the preferred size (currently hardcoded in the script to be max width 100px)
5. Save the image in the cache folder, i.e. cache/1/34