#2: Add support for DB creds in the ENV because its 2016

1/apache/Dockerfile

@@ -20,3 +20,9 @@ RUN curl -fSL "https://github.com/backdrop/backdrop/archive/${BACKDROP_VERSION}.
   && tar -xz --strip-components=1 -f backdrop.tar.gz \
   && rm backdrop.tar.gz \
   && chown -R www-data:www-data sites
+
+# Add custom entrypoint to set BACKDROP_SETTINGS correctly
+COPY docker-entrypoint.sh /entrypoint.sh
+
+ENTRYPOINT ["/entrypoint.sh"]
+CMD ["apache2-foreground"]

1/apache/docker-entrypoint.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+set -e
+
+if [[ "$1" == apache2* ]] || [ "$1" == php-fpm ]; then
+  if [ -n "$MYSQL_PORT_3306_TCP" ]; then
+    if [ -z "$BACKDROP_DB_HOST" ]; then
+      BACKDROP_DB_HOST='mysql'
+    else
+      echo >&2 'warning: both BACKDROP_DB_HOST and MYSQL_PORT_3306_TCP found'
+      echo >&2 "  Connecting to BACKDROP_DB_HOST ($BACKDROP_DB_HOST)"
+      echo >&2 '  instead of the linked mysql container'
+    fi
+  fi
+
+  if [ -z "$BACKDROP_DB_HOST" ]; then
+    echo >&2 'error: missing BACKDROP_DB_HOST and MYSQL_PORT_3306_ADDR environment variables'
+    echo >&2 '  Did you forget to --link some_mysql_container:mysql or set an external db'
+    echo >&2 '  with -e BACKDROP_DB_HOST=hostname?'
+    exit 1
+  fi
+
+  # if we're linked to MySQL and thus have credentials already, let's use them
+  : ${BACKDROP_DB_USER:=${MYSQL_ENV_MYSQL_USER:-root}}
+  if [ "$BACKDROP_DB_USER" = 'root' ]; then
+    : ${BACKDROP_DB_PASSWORD:=$MYSQL_ENV_MYSQL_ROOT_PASSWORD}
+  fi
+
+  : ${BACKDROP_DB_PASSWORD:=$MYSQL_ENV_MYSQL_PASSWORD}
+  : ${BACKDROP_DB_NAME:=${MYSQL_ENV_MYSQL_DATABASE:-backdrop}}
+  : ${BACKDROP_DB_PORT:=${MYSQL_ENV_MYSQL_PORT:-3306}}
+  : ${BACKDROP_DB_DRIVER:=${MYSQL_ENV_MYSQL_DRIVER:-mysql}}
+
+  if [ -z "$BACKDROP_DB_PASSWORD" ]; then
+    echo >&2 'error: missing required BACKDROP_DB_PASSWORD environment variable'
+    echo >&2 '  Did you forget to -e BACKDROP_DB_PASSWORD=... ?'
+    echo >&2
+    echo >&2 '  (Also of interest might be BACKDROP_DB_USER and BACKDROP_DB_NAME.)'
+    exit 1
+  fi
+
+  # lets construct our BACKDROP_SETTINGS and pass them into apache or fpm
+  export BACKDROP_SETTINGS="{\"databases\":{\"default\":{\"default\":{\"host\":\"database\",\"port\":$BACKDROP_DB_PORT,\"username\":\"$BACKDROP_DB_USER\",\"password\":\"$BACKDROP_DB_PASSWORD\",\"database\":\"$BACKDROP_DB_NAME\",\"driver\":\"$BACKDROP_DB_DRIVER\"}}}}"
+  if [[ "$1" == apache2* ]]; then
+    echo "PassEnv BACKDROP_SETTINGS" > /etc/apache2/conf-enabled/backdrop.conf
+  elif [[ "$1" == php-fpm* ]]; then
+    POOL_ENV_LINE="env['BACKDROP_SETTINGS'] = $BACKDROP_SETTINGS"
+    POOL_FILE=/usr/local/etc/php-fpm.d/www.conf
+    grep -q "$POOL_ENV_LINE" "$POOL_FILE" || echo "$POOL_ENV_LINE" >> "$POOL_FILE"
+  fi
+
+fi
+
+exec "$@"

1/fpm/Dockerfile

@@ -18,3 +18,9 @@ RUN curl -fSL "https://github.com/backdrop/backdrop/archive/${BACKDROP_VERSION}.
 	&& tar -xz --strip-components=1 -f backdrop.tar.gz \
 	&& rm backdrop.tar.gz \
 	&& chown -R www-data:www-data sites
+
+# Add custom entrypoint to set BACKDROP_SETTINGS correctly
+COPY docker-entrypoint.sh /entrypoint.sh
+
+ENTRYPOINT ["/entrypoint.sh"]
+CMD ["php-fpm"]

1/fpm/docker-entrypoint.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+set -e
+
+if [[ "$1" == apache2* ]] || [ "$1" == php-fpm ]; then
+  if [ -n "$MYSQL_PORT_3306_TCP" ]; then
+    if [ -z "$BACKDROP_DB_HOST" ]; then
+      BACKDROP_DB_HOST='mysql'
+    else
+      echo >&2 'warning: both BACKDROP_DB_HOST and MYSQL_PORT_3306_TCP found'
+      echo >&2 "  Connecting to BACKDROP_DB_HOST ($BACKDROP_DB_HOST)"
+      echo >&2 '  instead of the linked mysql container'
+    fi
+  fi
+
+  if [ -z "$BACKDROP_DB_HOST" ]; then
+    echo >&2 'error: missing BACKDROP_DB_HOST and MYSQL_PORT_3306_ADDR environment variables'
+    echo >&2 '  Did you forget to --link some_mysql_container:mysql or set an external db'
+    echo >&2 '  with -e BACKDROP_DB_HOST=hostname?'
+    exit 1
+  fi
+
+  # if we're linked to MySQL and thus have credentials already, let's use them
+  : ${BACKDROP_DB_USER:=${MYSQL_ENV_MYSQL_USER:-root}}
+  if [ "$BACKDROP_DB_USER" = 'root' ]; then
+    : ${BACKDROP_DB_PASSWORD:=$MYSQL_ENV_MYSQL_ROOT_PASSWORD}
+  fi
+
+  : ${BACKDROP_DB_PASSWORD:=$MYSQL_ENV_MYSQL_PASSWORD}
+  : ${BACKDROP_DB_NAME:=${MYSQL_ENV_MYSQL_DATABASE:-backdrop}}
+  : ${BACKDROP_DB_PORT:=${MYSQL_ENV_MYSQL_PORT:-3306}}
+  : ${BACKDROP_DB_DRIVER:=${MYSQL_ENV_MYSQL_DRIVER:-mysql}}
+
+  if [ -z "$BACKDROP_DB_PASSWORD" ]; then
+    echo >&2 'error: missing required BACKDROP_DB_PASSWORD environment variable'
+    echo >&2 '  Did you forget to -e BACKDROP_DB_PASSWORD=... ?'
+    echo >&2
+    echo >&2 '  (Also of interest might be BACKDROP_DB_USER and BACKDROP_DB_NAME.)'
+    exit 1
+  fi
+
+  # lets construct our BACKDROP_SETTINGS and pass them into apache or fpm
+  export BACKDROP_SETTINGS="{\"databases\":{\"default\":{\"default\":{\"host\":\"database\",\"port\":$BACKDROP_DB_PORT,\"username\":\"$BACKDROP_DB_USER\",\"password\":\"$BACKDROP_DB_PASSWORD\",\"database\":\"$BACKDROP_DB_NAME\",\"driver\":\"$BACKDROP_DB_DRIVER\"}}}}"
+  if [[ "$1" == apache2* ]]; then
+    echo "PassEnv BACKDROP_SETTINGS" > /etc/apache2/conf-enabled/backdrop.conf
+  elif [[ "$1" == php-fpm* ]]; then
+    POOL_ENV_LINE="env['BACKDROP_SETTINGS'] = $BACKDROP_SETTINGS"
+    POOL_FILE=/usr/local/etc/php-fpm.d/www.conf
+    grep -q "$POOL_ENV_LINE" "$POOL_FILE" || echo "$POOL_ENV_LINE" >> "$POOL_FILE"
+  fi
+
+fi
+
+exec "$@"

README.md

@@ -16,40 +16,62 @@ The comprehensive CMS for small to medium sized businesses and non-profits.
 The basic pattern for starting a `backdrop` instance is:
 
 ```console
-$ docker run --name some-backdrop -d kalabox/backdrop
+$ docker run --name some-backdrop --link some-mysql:mysql -d backdrop/backdrop
 ```
 
+The following environment variables are also honored for configuring your Backdrop CMS instance:
+
+- `-e BACKDROP_DB_HOST=...` (defaults to the IP and port of the linked `mysql` container)
+- `-e BACKDROP_DB_USER=...` (defaults to "root")
+- `-e BACKDROP_DB_PASSWORD=...` (defaults to the value of the `MYSQL_ROOT_PASSWORD` environment variable from the linked `mysql` container)
+- `-e BACKDROP_DB_NAME=...` (defaults to "backdrop")
+- `-e BACKDROP_DB_PORT=...` (defaults to 3306)
+- `-e BACKDROP_DB_DRIVER=...` (defaults to "mysql")
+
+The `BACKDROP_DB_NAME` **must already exist** on the given MySQL server. Check out the [official mysql image](https://hub.docker.com/_/mysql/) for more info on spinning up a DB.
+
 If you'd like to be able to access the instance from the host without the container's IP, standard port mappings can be used:
 
 ```console
-$ docker run --name some-backdrop -p 8080:80 kalabox/backdrop
+$ docker run --name some-backdrop --link some-mysql:mysql -p 8080:80 -d backdrop/backdrop
 ```
 
 Then, access it via `http://localhost:8080` or `http://host-ip:8080` in a browser.
 
-There are multiple database types supported by this image, most easily used via standard container linking. In the default configuration, SQLite can be used to avoid a second container and write to flat-files. More detailed instructions for different (more production-ready) database types follow.
-
-When first accessing the webserver provided by this image, it will go through a brief setup process. The details provided below are specifically for the "Set up database" step of that configuration process.
-
-## MySQL
+If you'd like to use an external database instead of a linked `mysql` container, specify the hostname and port with `BACKDROP_DB_HOST`/`BACKDROP_DB_PORT` along with the password in `BACKDROP_DB_PASSWORD` and the username in `BACKDROP_DB_USER` (if it is something other than `root`):
 
 ```console
-$ docker run --name some-backdrop --link some-mysql:mysql -d kalabox/backdrop
+$ docker run --name some-backdrop \
+  -e BACKDROP_DB_HOST=10.1.2.3 \
+  -e BACKDROP_DB_PORT=10432 \
+  -e BACKDROP_DB_USER=... \
+  -e BACKDROP_DB_PASSWORD=... \
+  -d backdrop/backdrop
 ```
 
-- Database type: `MySQL, MariaDB, or equivalent`
-- Database name/username/password: `<details for accessing your MySQL instance>` (`MYSQL_USER`, `MYSQL_PASSWORD`, `MYSQL_DATABASE`; see environment variables in the description for [`mysql`](https://registry.hub.docker.com/_/mysql/))
-- ADVANCED OPTIONS; Database host: `mysql` (for using the `/etc/hosts` entry added by `--link` to access the linked container's MySQL instance)
+## ... via [`docker-compose`](https://github.com/docker/compose)
 
-## PostgreSQL
+Example `docker-compose.yml` for `backdrop`:
+
+```yaml
+backdrop:
+  image: backdrop/backdrop
+  links:
+    - db:mysql
+  ports:
+    - 8080:80
+
+db:
+  image: mysql
+  environment:
+    MYSQL_USER: backdrop
+    MYSQL_PASSWORD: backdrop
+    MYSQL_ALLOW_EMPTY_PASSWORD: 'yes'
+    MYSQL_DATABASE: backdrop
 
-```console
-$ docker run --name some-backdrop --link some-postgres:postgres -d kalabox/backdrop
 ```
 
-- Database type: `PostgreSQL`
-- Database name/username/password: `<details for accessing your PostgreSQL instance>` (`POSTGRES_USER`, `POSTGRES_PASSWORD`; see environment variables in the description for [`postgres`](https://registry.hub.docker.com/_/postgres/))
-- ADVANCED OPTIONS; Database host: `postgres` (for using the `/etc/hosts` entry added by `--link` to access the linked container's PostgreSQL instance)
+Run `docker-compose up`, wait for it to initialize completely, and visit `http://localhost:8080` or `http://host-ip:8080`.
 
 ## Adding additional libraries / extensions