Issue #3404256 by dimitriskr, andypost: MySQL/MariaDB containers do not use...

Issue #3404256 by dimitriskr, andypost: MySQL/MariaDB containers do not use the provided configuration

cherry-pick of cf2c835c without Mysql 5.6 as unsupported

db/mariadb-10.3.22/Dockerfile

@@ -7,7 +7,7 @@ RUN apt-get -y update || true; \
     apt-get -y install netcat psmisc --no-install-recommends && \
     rm -rf /var/lib/apt/lists/*
 
-COPY ./conf/my.cnf /etc/mysql/conf.d/drupalci.cnf
+COPY --chmod=644 ./conf/my.cnf /etc/mysql/conf.d/drupalci.cnf
 
 USER root
 

db/mysql-5.5/Dockerfile

@@ -7,7 +7,7 @@ RUN apt-get -y update && \
 
 RUN apt-get clean && apt-get autoclean && apt-get -y autoremove
 
-COPY ./conf/my.cnf /etc/mysql/my.cnf
+COPY --chmod=644 ./conf/my.cnf /etc/mysql/my.cnf
 
 RUN rm -rf /var/lib/mysql/*
 

db/mysql-5.7/Dockerfile

@@ -5,7 +5,7 @@ MAINTAINER drupalci
 RUN yum install -y --setopt=skip_missing_names_on_install=False \
     netcat psmisc; yum clean all
 
-COPY ./conf/my.cnf /etc/mysql/my.cnf
+COPY --chmod=644 ./conf/my.cnf /etc/mysql/my.cnf
 
 USER root
 

db/mysql-8/Dockerfile

@@ -6,7 +6,7 @@ RUN apt-get -y update && \
     apt-get -y install netcat psmisc --no-install-recommends && \
     rm -rf /var/lib/apt/lists/*
 
-COPY ./conf/my.cnf /etc/mysql/conf.d/drupalci.cnf
+COPY --chmod=644 ./conf/my.cnf /etc/mysql/conf.d/drupalci.cnf
 
 USER root