Nginx cache api delete
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The document describes how to implement an API in Nginx to delete a specific cached file by URI. It explains that Nginx caches files based on an MD5 hash of the request URI. A Lua script is used to take the URI as input, calculate the hashed file path, and delete it using the OS remove command. The script returns a JSON response indicating if the file was successfully deleted. While this approach works, the author later found a simpler existing solution for purging cached items in Nginx using Lua.
Nginx cache api delete
- 1. Nginx Cache Delete API I want to use Nginx cache delete api. Yuki Iwamoto 02/12/2019
- 2. Who am I? ? Yuki Iwamoto ? Freelance Engineer ? Quitting smoking (40days)
- 3. I¨m searching for a Nginx function ? Delete cache function ? Only one uri (Not all cache)
- 4. Example ? I want to delete only this uri cache.? http://localhost/entry/11/112233 ? Sending request like this, ? then delete ＾/entry/11/112233￣ cache? http://localhost:8080/cache_clear_uri/entry/11/112233
- 5. About nginx cache ? File name is md5 hashed from proxy_cache_key ? The ?rst folder would be the last (n) character? from levels in proxy_cache_path ? ?nd and delete the ?le
- 6. proxy_cache_path /data/nginx/cache/yi levels=1:1:2 keys_zone=yi:256m max_size=100g inactive=7d; proxy_cache_key ＾$uri"; server { listen 8080 default_server; server_name localhost; location ~ /cache_clear_uri/(.*) { set $cache_uri $1; content_by_lua ' local cjson = require ＾cjson" local cache_base_path = "/data/nginx/cache/yi" local cache_uri = "/" .. ngx.var.cache_uri local uri_md5 = ngx.md5( cache_uri ) local ?rst_path = string.sub( uri_md5, -1, -1 ) local second_path = string.sub( uri_md5, -2,-2 ) local third_path = string.sub( uri_md5, -4, -3 ) local cache_?le = cache_base_path .. "/" .. ?rst_path .. "/" .. second_path .. "/" .. third_path .. "/" .. uri_md5 local code = os.execute( "/bin/rm " .. cache_?le ) ngx.say(cjson.encode({ code = code , cache_?le = cache_?le })) ngx.header.content_type = "application/json; charset=utf-8" '; } }
- 7. ? (.*) = ($1) setting to cache_uri? ? set $cache_uri $1;
- 8. ? When proxy_cache_key is uri, ? this case is only uri? ? proxy_cache_key ＾$uri";
- 9. ? Convert uri to md5? ? local uri_md5 = ngx.md5( cache_uri )
- 10. ? The ?rst folder would be the last (1) character (from -1 to -1)? from levels in proxy_cache_path? ? local ?rst_path = string.sub( uri_md5, -1, -1 ) ? The second folder would be the last (2) character(from -2 to -2)? from levels in proxy_cache_path? ? local second_path = string.sub( uri_md5, -2,-2 ) ? The third folder would be the last (3) character (from -3 to -4)? from levels in proxy_cache_path? local third_path = string.sub( uri_md5, -4, -3 )
- 11. ? Delete by os.execute ( rm command )? ? local code = os.execute( "/bin/rm " .. cache_?le )? ? ? ?
- 12. ? Return json (delete or not , and which ?le)? ? ngx.say(cjson.encode({ code = code , cache_?le = cache_?le })) ngx.header.content_type = "application/json; charset=utf-8" { ＾code￣:0, ＾cache_?le￣:￣ /data/nginx/cache/yi/ab/0/1/123ab456cd789ef￣ } ? Json result example
- 13. I found a better solution ? https://scene-si.org/2016/11/02/purging-cached- items-from-nginx-with-lua/
- 14. Conclusion ? We can do something by Lua ? Sometimes, dif?cult to ?nd a good solution