Nginx-caching-config.md

start by creating the needed directorys and changing the permission to the nginx proccess (www-data on ubuntu)

mkdir -p /var/cache/nginx/sks /var/cache/nginx/temp
chown -R www-data:www-data /var/cache/nginx

Below is my config.

http {

...

    proxy_ignore_headers        Expires Cache-Control;
    proxy_cache_use_stale       error timeout updating http_500 http_502 http_503 http_504;
    proxy_cache_path            /var/cache/nginx/sks levels=1:2 keys_zone=keyserver:10m max_size=10g inactive=6h;
    proxy_temp_path             /var/cache/nginx/temp;
    
 ...
 
 }

Then in the Server secion, I have

        location /pks {
           proxy_cache                 keyserver;
           proxy_cache_use_stale       error timeout updating http_500 http_502 http_503 http_504;
           proxy_cache_valid           200 301 302 6h;
           proxy_cache_valid           404 502 503 504 1m;
           proxy_pass                  http://127.0.0.1:11371;
           add_header                  Via "1.1 keyserver.mattrude.com:11371 (nginx)";
           proxy_ignore_client_abort   on;
           client_max_body_size        8m;
       }
       

rrd-updater.sh

#!/bin/bash

if [ ! -f /var/lib/sks/cache.rrd ]; then
    mkdir -p /var/lib/sks
    rrdtool create /var/lib/sks/cache.rrd \
        --start now \
        --step 300 \
        DS:cache:GAUGE:95040:U:U \
        DS:hit:GAUGE:120:0:U \
        DS:mis:GAUGE:120:0:U \
        RRA:AVERAGE:0.5:1:8640 \
        RRA:AVERAGE:0.5:12:9480 \
        RRA:MIN:0.5:12:8640 \
        RRA:MAX:0.5:12:8640
fi

CACHE=`du -bc /var/cache/nginx/sks/* |grep 'total' |awk '{ print $1 }'`
HIT=`grep "HIT$" /var/log/nginx/keyserver.log |wc -l`
MIS=`grep "MISS$" /var/log/nginx/keyserver.log |grep -v ' 404 1075 ' |wc -l`
TOT=`echo $(( $HIT + $MIS ))`

HITL=`awk -vn=$HIT "BEGIN{print(n/$TOT)}" |sed 's/0\.//g'`
MISL=`awk -vn=$MIS "BEGIN{print(n/$TOT)}" |sed 's/0\.//g'`
HITS=`echo ${HITL:0:2}`
MISS=`echo ${MISL:0:2}`

rrdtool update /var/lib/sks/cache.rrd N:${CACHE}:${HITS}:${MISS}

time_readible=$(echo $(date) | sed 's/\:/\\:/g')
hostname=`hostname -f`
mkdir -p /var/www/keyserver.mattrude.com/graphs/
for period in day week month year
do
        rrdtool graph /var/www/keyserver.mattrude.com/graphs/cache-$period.png -s -1$period \
        -t "Nginx Reverse Proxy Cache Size in MBytes for the last $period" -z \
        -c "BACK#FFFFFF" -c "SHADEA#FFFFFF" -c "SHADEB#FFFFFF" \
        -c "MGRID#AAAAAA" -c "GRID#CCCCCC" -c "ARROW#333333" \
        -c "FONT#333333" -c "AXIS#333333" -c "FRAME#333333" \
        -h 250 -w 700 -l 0 -a PNG -v "MegaBytes" \
        DEF:cache=/var/lib/sks/cache.rrd:cache:LAST \
        VDEF:mincache=cache,MINIMUM \
        VDEF:maxcache=cache,MAXIMUM \
        VDEF:avgcache=cache,AVERAGE \
        VDEF:lstcache=cache,LAST \
        VDEF:totcache=cache,TOTAL \
        "COMMENT: \l" \
        "COMMENT:               " \
        "COMMENT:Minimum      " \
        "COMMENT:Maximum      " \
        "COMMENT:Average      " \
        "COMMENT:Current      \l" \
        "COMMENT:   " \
        "AREA:cache#204d74:Cache  " \
        "LINE1:cache#337ab7" \
        "GPRINT:mincache:%5.1lf %sB     " \
        "GPRINT:maxcache:%5.1lf %sB     " \
        "GPRINT:avgcache:%5.1lf %sB     " \
        "GPRINT:lstcache:%5.1lf %sB   \l" \
        "COMMENT:Server\: $hostname\u" \
        "COMMENT:Built\: $time_readible\r" > /dev/null
done