Just a rewrite...

Author: navossoc

Dockerfile

@@ -1,36 +1,34 @@
 FROM alpine:3.12
 
 LABEL description="PostfixAdmin is a web based interface used to manage mailboxes" \
-      maintainer="Hardware <contact@meshup.net>"
+   maintainer="Hardware <contact@meshup.net>"
 
 ARG VERSION=3.2.4
 ARG SHA256_HASH="f61a64b32052c46f40cba466e5e384de0efab8c343c91569bcc5ebfd3694811e"
 
-RUN echo "@community https://nl.alpinelinux.org/alpine/v3.12/community" >> /etc/apk/repositories \
- && apk -U upgrade \
- && apk add -t build-dependencies \
-    ca-certificates \
-    gnupg \
- && apk add \
-    su-exec \
-    dovecot \
-    tini@community \
-    php7@community \
-    php7-phar \
-    php7-fpm@community \
-    php7-imap@community \
-    php7-pgsql@community \
-    php7-mysqli@community \
-    php7-session@community \
-    php7-mbstring@community \
- && cd /tmp \
- && PFA_TARBALL="postfixadmin-${VERSION}.tar.gz" \
- && wget -q https://github.com/postfixadmin/postfixadmin/archive/${PFA_TARBALL} \
- && CHECKSUM=$(sha256sum ${PFA_TARBALL} | awk '{print $1}') \
- && if [ "${CHECKSUM}" != "${SHA256_HASH}" ]; then echo "ERROR: Checksum does not match!" && exit 1; fi \
- && mkdir /postfixadmin && tar xzf ${PFA_TARBALL} -C /postfixadmin && mv /postfixadmin/postfixadmin-postfixadmin-$VERSION/* /postfixadmin \
- && apk del build-dependencies \
- && rm -rf /var/cache/apk/* /tmp/* /root/.gnupg /postfixadmin/postfixadmin-$VERSION*
+RUN set -eux; \
+   apk add --no-cache \
+      su-exec \
+      dovecot \
+      tini \
+      \
+      php7 \
+      php7-fpm \
+      php7-imap \
+      php7-mbstring \
+      php7-mysqli \
+      php7-pgsql \
+      php7-phar \
+      php7-session \
+   ; \
+   \
+   PFA_TARBALL="postfixadmin-${VERSION}.tar.gz"; \
+   wget -q https://github.com/postfixadmin/postfixadmin/archive/${PFA_TARBALL}; \
+   echo "${SHA256_HASH} *${PFA_TARBALL}" | sha256sum -c; \
+   \
+   mkdir /postfixadmin; \
+   tar -xzf ${PFA_TARBALL} --strip-components=1 -C /postfixadmin; \
+   rm -f ${PFA_TARBALL}
 
 COPY bin /usr/local/bin
 RUN chmod +x /usr/local/bin/*