🥇in-the-fly image resize usura Nginx et LuaJIT (OpenResty)

Nam satis iam dudum, inspirata art Imagines in musca Sedeo imago resize felis usura ngx_http_image_filter_module et omnia operata sicut debet. Una autem quaestio orta est cum procurator imagines recipere opus est ad aliquas rationes ad aliqua officia discenda, quia... haec technica erant. Exempli gratia, si originalis magnitudinis imaginem habemus 1200 × 1200et cum resiendo scribimus aliquid simile ? Resize = DC CDtunc imaginem proportionaliter reductam in minimo ore, magnitudine 400 × 400. Impossibile est etiam imaginem obtinere cum proposito superiore (upscale). Illae. ? Resize = DC CD et imago eadem revertetur 1200 × 1200

Hoc articulum ad liberandum OpenResty: conversus NGINX in plenam applicationem servo flexae intelligere quomodo Nginx cum Lua et ipsa bibliotheca Luae operatur isage / lua-imaginatio — Luae pura-c ligaturae ad ImageMagick. Quare haec solutio eligenda est, et non in Pythone aliquid, quia celere et opportunum est. Etiam non necesse est ut quaslibet limas creas, omnia in Nginx config (libitum).

Quid ergo opus est?

Exempla ex Debian dabuntur.

Installing nginx et nginx-extras

apt-get update
apt-get install nginx-extras

installing LuaJIT

apt-get -y install lua5.1 luajit-5.1 libluajit-5.1-dev

Installing imagemagick

apt-get -y install imagemagick

et bibliothecas magicwand ad illud, in mea causa pro versione 6

apt-cache search libmagickwand
apt-get -y install libmagickwand-6.q16-3 libmagickwand-6.q16-dev

lua-imaginatio Building

Reconditorium clone (seu zip et EXPEDIO accipere)

cd ~
git clone https://github.com/isage/lua-imagick.git
cd lua-imagick
mkdir build
cd build
cmake ..
make
make install

Si bene omnia sunt, configurare Nginx potes.

Exemplum dabo Mandi hostiae backendi, quae re vera est resipiscendi. Imitatur a fronte servo, etiam cum Nginx, ubi caching certum tempus (dierum) et alia occurrit.

nginx backend config

# Backend image server
server {
    listen       8082;
    listen [::]:8082;
    set $files_root /var/www/example.lh/frontend/web;
    root $files_root;
    access_log off;
    expires 1d;

    location /files {
        # дефолтные значения ресайза
        set $w 700;
        set $h 700;
        set $q 89;

        #1-89 allowed
        if ($arg_q ~ "^([1-9]|[1-8][0-9])$") {
            set $q $arg_q;
        }

        if ($arg_resize ~ "([d-]+)x([d+!^]+)") {  
            set $w $1;
            set $h $2;
            rewrite  ^(.*)$   /resize/$w/$h/$q$uri     last;
        }

        rewrite  ^(.*)$   /resize/$w/$h/$q$uri     last;
    }

    location ~* ^/resize/([d]+)/([d+!^]+)/([d]+)/files/(.+)$ {
        default_type 'text/plain';

        set $w $1;
        set $h $2;
        set $q $3;
        set $fname $4;

        # Есть возможность вынести весь Lua код в отдельный файл
        # content_by_lua_file /var/www/some.lua;
        # lua_code_cache off; #dev
        content_by_lua '
        local magick = require "imagick"
        local img = magick.open(ngx.var.files_root .. "/files/" .. ngx.var.fname)
        if not img then ngx.exit(ngx.HTTP_NOT_FOUND) end
        img:set_gravity(magick.gravity["CenterGravity"])

        if string.match(ngx.var.h, "%d+%+") then
            local h = string.gsub(ngx.var.h, "(%+)", "")
            resize = ngx.var.w .. "x" .. h
            -- для png с альфа каналом
            img:set_bg_color(img:has_alphachannel() and "none" or img:get_bg_color())
            img:smart_resize(resize)
            img:extent(ngx.var.w, h)
        else
                img:smart_resize(ngx.var.w .. "x" .. ngx.var.h)
        end

        if ngx.var.arg_q then img:set_quality(ngx.var.q) end

        ngx.say(img:blob())
        ';
    }
}

# Upstream
upstream imageserver {
    server localhost:8082;
}

server {
    listen 80;
    server_name examaple.lh;

    # отправляем все jpg и png картинки на imageserver
    location ~* ^/files/.+.(jpg|png) {
        proxy_buffers 8 2m;
        proxy_buffer_size 10m;
        proxy_busy_buffers_size 10m;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        proxy_pass     http://imageserver;  # Backend image server
    }
}

Quod erat faciendum (expansus imaginem circa margines) accidit utens img:extent() et definitur per modulum resize cum signo + in termino.

Optiones sequentes praesto sunt:

WxH.
WxH^ (Rationem aspectum custodi, dimensio inferioris usus))
WxH! (Ignorare aspect-ratio)
WxH+.

Summarium mensam cum resize proventuum

Request uri parametri
Output Image Location

? Resize = DC CD
200 × 200

?resize=400×200^
400 × 400

?resize=400×200!
400×200 (non proportionales)

?resize=400×200+
400×200 (Proportional)

exitum

Considerans hanc vim ac simplicitatem aditus, res efficere potes cum logica admodum multiplici, exempli gratia, additis notis vel auctoritati limitatis accessu exsequendo. Ut facultates API investigandi cum imaginibus operandi, ad documentum bibliothecae referre potes isage / lua-imaginatio

Source: www.habr.com

Imagines in musca uti Nginx et LuaJIT (OpenResty)