use more modern syntax, upgrade to php 8.3, setup dependabot

Dockerfile

@@ -1,47 +1,51 @@
-# syntax=docker/dockerfile:1
+# syntax=docker/dockerfile:1.9@sha256:5510f694edfe648d961b59dcf217026485e560d2663c73e45067b8c8d7a6d247
 
 ### Stage 1: build client
-FROM node:20 as client-builder
+FROM node:20 AS client-builder
 WORKDIR /client-builder
 
 # Install node packages
-COPY package.json .
-COPY client/package.json client/
-COPY client/package-lock.json client/
-RUN npm run install-dependencies:client
+RUN --mount=type=bind,source=package.json,target=package.json \
+  --mount=type=bind,source=client/package.json,target=client/package.json \
+  --mount=type=bind,source=client/package-lock.json,target=client/package-lock.json \
+  --mount=type=cache,sharing=locked,id=npmcache,mode=0777,target=/root/.npm \
+  npm run install-dependencies-ci:client
 
 # Build client
 COPY client/ client/
-RUN npm run build
+RUN --mount=type=bind,source=package.json,target=package.json \
+  --mount=type=bind,source=client/package.json,target=client/package.json \
+  --mount=type=bind,source=client/package-lock.json,target=client/package-lock.json \
+  --mount=type=cache,sharing=locked,id=npmcache,mode=0777,target=/root/.npm \
+  npm run build
 
 
 ### Stage 2: final container
-FROM php:8.2-apache
+FROM php:8.3-apache
 # Install runtime & development package dependencies & php extensions
 # then clean-up dev package dependencies
 RUN export DEBIAN_FRONTEND=noninteractive \
-    && apt update \
-    && apt install -y --no-install-recommends \
-      unzip \
-      libjpeg62-turbo libpng16-16 libpq5 libonig5 libtidy5deb1 \
-      libjpeg62-turbo-dev libpng-dev libpq-dev libonig-dev libtidy-dev \
-    && update-ca-certificates --fresh \
-    && docker-php-ext-configure gd --with-jpeg \
-    && docker-php-ext-install gd mbstring pdo_pgsql pdo_mysql tidy \
-    && apt remove -y libjpeg62-turbo-dev libpng-dev libpq-dev libonig-dev libtidy-dev \
-    && apt autoremove -y \
-    && apt clean \
-    && rm -rf /var/lib/apt/lists/*
+  && apt update \
+  && apt install -y --no-install-recommends \
+  unzip \
+  libjpeg62-turbo libpng16-16 libpq5 libonig5 libtidy5deb1 \
+  libjpeg62-turbo-dev libpng-dev libpq-dev libonig-dev libtidy-dev \
+  && update-ca-certificates --fresh \
+  && docker-php-ext-configure gd --with-jpeg \
+  && docker-php-ext-install -j$(nproc) gd mbstring pdo_pgsql pdo_mysql tidy \
+  && apt remove -y libjpeg62-turbo-dev libpng-dev libpq-dev libonig-dev libtidy-dev \
+  && apt autoremove -y \
+  && apt clean \
+  && rm -rf /var/lib/apt/lists/*
 
 # Install Apache modules
 RUN a2enmod headers rewrite
 
 # Install Selfoss PHP dependencies
-COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
-COPY composer.json .
-COPY composer.lock .
-RUN COMPOSER_ALLOW_SUPERUSER=1 composer install --optimize-autoloader --no-dev
-RUN rm /usr/bin/composer
+RUN --mount=type=bind,source=composer.json,target=composer.json \
+  --mount=type=bind,source=composer.lock,target=composer.lock \
+  --mount=type=bind,from=composer:2,source=/usr/bin/composer,target=/usr/bin/composer \
+  COMPOSER_ALLOW_SUPERUSER=1 composer install --optimize-autoloader --no-dev
 
 # Install Selfoss and copy frontend from the first stage
 WORKDIR /var/www/html

dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "daily"

package.json

@@ -32,6 +32,7 @@
     "fix:helpers:cs": "black utils/ tests/",
     "install-dependencies": "npm run install-dependencies:client && npm run install-dependencies:server",
     "install-dependencies:client": "npm install --production=false --prefix client/",
+    "install-dependencies-ci:client": "npm ci --production=false --prefix client/",
     "install-dependencies:server": "composer install --dev",
     "test:server": "composer run-script test",
     "test:integration": "python3 tests/integration/run.py",