docker: update to use php8

docker/Dockerfile

@@ -1,14 +1,14 @@
 FROM alpine:3.15
 
-RUN apk add --no-cache gettext curl nginx php7 php7-fpm php7-opcache php7-pdo php7-pdo_sqlite php7-openssl && \
+RUN apk add --no-cache gettext curl nginx php8 php8-fpm php8-opcache php8-pdo php8-pdo_sqlite php8-openssl && \
     mkdir /var/www/html
 
 COPY . /var/www/html
 
 RUN chmod -R 775 /var/www/html && \
     chown -R nginx:nginx /var/www/html
 
-COPY docker/php-fpm.conf /etc/php7/php-fpm.conf
+COPY docker/php-fpm.conf /etc/php8/php-fpm.conf
 COPY docker/nginx.conf /etc/nginx/nginx.conf
 COPY docker/entrypoint.sh /entrypoint.sh
 

docker/entrypoint.sh

@@ -27,7 +27,7 @@ rm -rf /var/www/html/docker
 # Start php-fpm and nginx
 chown -R nginx: /var/www/html/data/
 touch /var/www/html/data/index.php
-php-fpm7
+php-fpm8
 nginx -c /etc/nginx/nginx.conf
 
 # Ready to serve?
@@ -43,4 +43,4 @@ for i in 1 2 3; do
 done
 
 echo "Access logging is disabled for production use. Tailing error logs..."
-tail -f /var/log/nginx/error.log /var/log/php7/error.log
+tail -f /var/log/nginx/error.log /var/log/php8/error.log