Use modern apt invocation

Author: vmcj

docker-contributor/Dockerfile

@@ -14,8 +14,8 @@ ENV DEBIAN_FRONTEND=noninteractive \
   DJ_DB_INSTALL_BARE=0
 
 # Install required packages and clean up afterwards to make this image layer smaller
-RUN apt-get update \
-    && apt-get install --no-install-recommends --no-install-suggests -y \
+RUN apt update \
+    && apt install --no-install-recommends --no-install-suggests -y \
     dumb-init autoconf automake git acl \
     gcc g++ make zip unzip mariadb-client \
     nginx php7.4 php7.4-cli php7.4-fpm php7.4-zip \
@@ -50,8 +50,8 @@ RUN useradd -m domjudge \
   && for id in `seq 0 4`; do useradd -d /nonexistent -g nogroup -s /bin/false domjudge-run-$id; done
 
 # Install composer
-RUN apt-get update && \
-    apt-get install --no-install-recommends --no-install-suggests -y ca-certificates \
+RUN apt update && \
+    apt install --no-install-recommends --no-install-suggests -y ca-certificates \
 	&& rm -rf /var/lib/apt/lists/* \
     && php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" && php composer-setup.php \
     && mv /composer.phar /usr/local/bin/composer

docker-gitlabci/Dockerfile

@@ -1,6 +1,6 @@
 FROM ubuntu:20.04
 ENV DEBIAN_FRONTEND=noninteractive
-RUN apt-get update && apt-get install -y \
+RUN apt update && apt install -y \
   acl make zip unzip apache2-utils bsdmainutils libcurl4-gnutls-dev \
   libjsoncpp-dev libmagic-dev autoconf automake bats sudo debootstrap procps \
   gcc g++ default-jre-headless default-jdk ghc fp-compiler libcgroup-dev \
@@ -33,8 +33,8 @@ RUN apt-get update && apt-get install -y \
   && rm -rf /var/lib/apt/lists/*
 
 # Install composer
-RUN apt-get update && \
-    apt-get install --no-install-recommends --no-install-suggests -y ca-certificates \
+RUN apt update && \
+    apt install --no-install-recommends --no-install-suggests -y ca-certificates \
 	&& rm -rf /var/lib/apt/lists/* \
     && php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" && php composer-setup.php \
     && mv /composer.phar /usr/local/bin/composer

docker/domserver/Dockerfile

@@ -4,8 +4,8 @@ LABEL org.opencontainers.image.authors="DOMjudge team <[email protected]>"
 ENV DEBIAN_FRONTEND=noninteractive
 
 # Install required packages for build of domserver
-RUN apt-get update \
-	&& apt-get install --no-install-recommends --no-install-suggests -y \
+RUN apt update \
+	&& apt install --no-install-recommends --no-install-suggests -y \
 	autoconf automake git \
 	gcc g++ make acl zip unzip \
 	php-cli php-zip \
@@ -52,8 +52,8 @@ ENV DEBIAN_FRONTEND=noninteractive \
 	DJ_DB_INSTALL_BARE=0
 
 # Install required packages for running of domserver
-RUN apt-get update \
-	&& apt-get install --no-install-recommends --no-install-suggests -y \
+RUN apt update \
+	&& apt install --no-install-recommends --no-install-suggests -y \
 	acl curl zip unzip supervisor mariadb-client apache2-utils \
 	nginx php-cli php-fpm php-zip \
 	php-gd php-curl php-mysql php-json php-intl \

docker/judgehost/Dockerfile

@@ -11,8 +11,8 @@ ENV DEBIAN_FRONTEND=noninteractive \
 	RUN_USER_UID_GID=62860
 
 # Install required packages for running of judgehost
-RUN apt-get update \
-	&& apt-get install --no-install-recommends --no-install-suggests -y \
+RUN apt update \
+	&& apt install --no-install-recommends --no-install-suggests -y \
 	dumb-init \
 	acl zip unzip supervisor sudo procps libcgroup1 \
 	php-cli php-zip php-gd php-curl php-mysql php-json \

docker/judgehost/Dockerfile.build

@@ -4,8 +4,8 @@ LABEL org.opencontainers.image.authors="DOMjudge team <[email protected]>"
 ENV DEBIAN_FRONTEND=noninteractive
 
 # Install required packages for build of judgehost
-RUN apt-get update \
-	&& apt-get install --no-install-recommends --no-install-suggests -y \
+RUN apt update \
+	&& apt install --no-install-recommends --no-install-suggests -y \
 	autoconf automake git \
 	gcc g++ make zip unzip \
 	php-cli php-zip lsb-release debootstrap \

docker/judgehost/Dockerfile.chroot

@@ -1,6 +1,6 @@
 FROM ubuntu:20.04
 ENV DEBIAN_FRONTEND=noninteractive
-RUN apt-get update && apt-get -y install \
+RUN apt update && apt -y install \
   ca-certificates default-jre-headless pypy3 locales \
   && rm -rf /var/lib/apt/lists/*