container-entrypoint.sh

#!/bin/bash
set -e
set -a

INIT_SCRIPT_PATH=${INIT_SCRIPT_PATH}
SETUP_SCRIPT_PATH=${SETUP_SCRIPT_PATH}
SETUP_LOCK_PATH=~/.container-configured.lock
# ...
# Here put all the variables that will be marked for export
# and that will be available from all commands.
# If command modifies the variables, the modifications will never be
# seen in the present script!
set +a

echo "Entrypoint..."

# If lock file don't exists, setup script exists
if [[ ! -f ${SETUP_LOCK_PATH} && -f ${SETUP_SCRIPT_PATH} ]]; then
    # Run setup
	echo 'Running one-time setup...'
	source ${SETUP_SCRIPT_PATH} "$@"

	# Create lock file
    touch ${SETUP_LOCK_PATH}
fi

# If init script exists
if [[ -f ${INIT_SCRIPT_PATH} ]]; then
    # Run init
	echo 'Running init...'
	source ${INIT_SCRIPT_PATH} "$@"
fi

# Run docker command
exec "$@"

Dockerfile

FROM php:7.1-fpm-alpine

###
# -----------------------------------------------------------
# Configure system
# -----------------------------------------------------------
###

# Update and install dependencies
RUN apk add --update --quiet --no-cache    bash                \
                                           busybox-suid        \
                                           bzip2-dev           \
                                           coreutils           \
                                           curl                \
                                           freetype-dev        \
                                           git                 \
                                           libjpeg-turbo-dev   \
                                           libltdl             \
                                           libmcrypt-dev       \
                                           libpng-dev          \
                                           mysql-client        \
                                           openssh-client      \
                                           rsync               \
                                           yarn                \
    # Configure needed php extensions
    && docker-php-ext-configure mcrypt                         \
    # Install needed php extensions
    && docker-php-ext-install mcrypt pdo_mysql zip gd          \
    # Install Composer
    && curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer \
    # Improve Composer performance with Prestissimo
    && composer global require hirak/prestissimo

###
# -----------------------------------------------------------
# Define envinronments
# -----------------------------------------------------------
###

# App arguments with default values
ARG CRM_USER=crmsmuser
ARG CRM_WWW=/home/${CRM_USER}/www

# App arguments as an envinronments
ENV CRM_USER ${CRM_USER}
ENV CRM_WWW ${CRM_WWW}

# Define build envinronments
ENV BIN /usr/local/bin/
ENV INIT_SCRIPT_PATH ${CRM_WWW}/ci-cd/crm/init.sh
ENV SETUP_SCRIPT_PATH ${CRM_WWW}/ci-cd/crm/setup.sh


###
# -----------------------------------------------------------
# Configure build
# -----------------------------------------------------------
###

# Copy and set entrypoint script
COPY /ci-cd/container-entrypoint.sh ${BIN}/container-entrypoint
RUN chmod +x ${BIN}/container-entrypoint
ENTRYPOINT ["container-entrypoint"]

# Set default command
CMD ["php-fpm"]

###
# -----------------------------------------------------------
# Configure system for app
# -----------------------------------------------------------
###

# Add user and group
RUN addgroup -g 1000 -S ${CRM_USER} && adduser -u 1000 -S ${CRM_USER} -G ${CRM_USER}

# Change user
USER ${CRM_USER}

# Attach project files
VOLUME /* ${CRM_WWW}

# Change work dir to project dir
WORKDIR ${CRM_WWW}

###
# -----------------------------------------------------------
# Configure app
# -----------------------------------------------------------
###

# ...