Attempt to use alpine php image

.gitlab-ci.yml

@@ -13,7 +13,7 @@ test:7:
       - bash build/docker_install.sh > /dev/null
       - curl -sS https://getcomposer.org/installer | php
       - php composer.phar install --no-dev
-    image: php:7
+    image: php:7-alpine
     script:
       - phpunit -c build --coverage-text --colors=never
       
@@ -22,7 +22,7 @@ test:7.1:
       - bash build/docker_install.sh > /dev/null
       - curl -sS https://getcomposer.org/installer | php
       - php composer.phar install --no-dev
-    image: php:7.1
+    image: php:7.1-alpine
     script:
       - phpunit -c build --coverage-text --colors=never
 

build/docker_install.sh

@@ -9,14 +9,13 @@ DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 set -xe
 
 # Install git (the php image doesn't have it) which is required by composer
-apt-get update -yqq
+apk upgrade --update && apk add \
-apt-get install \
+	curl \
 	git \
 	libxslt1-dev \
 	libxslt1.1 \
 	zlib1g-dev \
-	unzip \
+	unzip
-	-yqq
 
 # Install phpunit, the tool that we will use for testing
 curl -Lo /usr/local/bin/phpunit https://phar.phpunit.de/phpunit.phar