anchor.diff:  # gpg: key 5072E1F5: public key "MySQL Release Engineering <mysql-build@oss.oracle.com>" imported
   	key='A4A9406876FCBD3C456770C88C718D3B5072E1F5'; \
   	export GNUPGHOME="$(mktemp -d)"; \
  -	gpg --keyserver ha.pool.sks-keyservers.net --recv-keys "$key"; \
  +	gpg --keyserver hkp://pool.sks-keyservers.net:80 --recv-keys "$key" || \
  +        gpg --keyserver pgp.mit.edu --recv-keys "$key" || \
  +        gpg --keyserver keyserver.pgp.com --recv-keys "$key" ; \
   	gpg --export "$key" > /etc/apt/trusted.gpg.d/mysql.gpg; \
   	rm -rf "$GNUPGHOME"; \
   	apt-key list > /dev/null
   
   ENV MYSQL_MAJOR 5.7
  -ENV MYSQL_VERSION 5.7.21-1debian9
  +ENV MYSQL_VERSION 5.7.22-1debian9
   
   RUN echo "deb http://repo.mysql.com/apt/debian/ stretch mysql-${MYSQL_MAJOR}" > /etc/apt/sources.list.d/mysql.list
   
  
positive.code: FROM debian:stretch-slim
  
  # add our user and group first to make sure their IDs get assigned consistently, regardless of whatever dependencies get added
  RUN groupadd -r mysql && useradd -m -g mysql mysql
  
  RUN apt-get update && apt-get install -y --no-install-recommends gnupg dirmngr && rm -rf /var/lib/apt/lists/*
  
  # add gosu for easy step-down from root
  ENV GOSU_VERSION 1.7
  
negative.code: 	&& wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture)" \
  	&& wget -O /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture).asc" \
  	&& export GNUPGHOME="$(mktemp -d)" \
  	&& gpg --keyserver hkp://pool.sks-keyservers.net:80 --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 || \
          gpg --keyserver pgp.mit.edu --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 || \
          gpg --keyserver keyserver.pgp.com --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 || \
          curl https://keybase.io/tianon/pgp_keys.asc?fingerprint=b42f6819007f00f88e364fd4036a9c25bf357dd4 | gpg --import ; \
  	gpg --batch --verify /usr/local/bin/gosu.asc /usr/local/bin/gosu \
  	&& rm -rf "$GNUPGHOME" /usr/local/bin/gosu.asc \
  	&& chmod +x /usr/local/bin/gosu \
  	&& gosu nobody true \
  