store the DOCKER_USER variable inside the .env file

prepare.sh now needs to be sourced only once (when bootstrapping
the containers)

.gitignore

@@ -6,3 +6,4 @@ docker/cover.copy
 __pycache__
 .coverage
 /toolbox/openssh-*.deb
+/.env

README.md

@@ -81,7 +81,9 @@ it is tricky to use a relative path with the allgo/docker image).
 For convenience, all containers not running as root (rails, mysql, registry)
 have their user overridden to the UID:GID of the developer running
 docker-compose. This is managed with the `DOCKER_USER` environment variable set
-by `prepare.sh`.
+[in the `.env`
+file](https://docs.docker.com/compose/environment-variables/#the-env-file) by
+`prepare.sh`.
 
 For convenience (again), there is an extra external volumes for `dev-rails`,
 `dev-controller` and `dev-ssh` so that the source directory of the app is mounted
@@ -112,12 +114,7 @@ To set up the development environment, run:
 	sudo chown USER: /data/dev
 	</pre>
 
- 3. source the `prepare.sh` script (to be run every time before you start working)
- 	<pre>
-	. ./prepare.sh
-	</pre>
-
- 4. bootstrap the environment
+ 3. bootstrap the environment
  	<pre>
 	./bootstrap
 	</pre>
@@ -134,7 +131,7 @@ To set up the development environment, run:
 		./bootstrap dev-mysql dev-rails
 	</pre>
 
- 5. for convenience, you may want to alias `docker-compose` as `fig` (because
+ 4. for convenience, you may want to alias `docker-compose` as `fig` (because
      `fig` is much faster to type than `docker-compose` and you will have to
      type it a lot). Somewhere in your `.bashrc` you should add:
 	<pre>

bootstrap

@@ -2,7 +2,6 @@
 
 set -e
 
-old_du="$DOCKER_USER"
 . prepare.sh
 
 # build base image (if not present)
@@ -56,8 +55,3 @@ do
 	fi
 done
 
-
-if [ -z "$old_du" ]
-then
-	echo 'NOTE: the env variable DOCKER_USER is not set. You should run ". prepare.sh" before working'
-fi

prepare.sh

-export DOCKER_USER="`id -u`:`id -g`"
 
-for ctr in registry rails controller ssh mysql smtpsink nginx
-do
-	mkdir -p "./data/$ctr"
-done
+if [ ! -f "prepare.sh" ] ; then
+	echo "error: prepare.sh must be run from the same directory"
+	false
+else
+	# make directories for the external volumes, and with the right
+	# ownership (the current user)
+	for ctr in registry rails controller ssh mysql smtpsink nginx
+	do
+		mkdir -p "./data/$ctr"
+	done
+
+
+	# generate a .env file for docker-compose
+	cat >".env.tmp" <<EOF
+DOCKER_USER="`id -u`:`id -g`"
+EOF
+	if [ ! -e .env ] ; then
+		mv .env.tmp .env
+	else
+		if cmp --quiet .env .env.tmp ; then
+			rm .env.tmp
+		else
+			echo "error: config file '.env' already exists and is different from the generate config. Remove it if you want it to be overwritten."
+			diff -u .env .env.tmp
+			false
+		fi
+	fi
+
+fi
+

shell

@@ -7,8 +7,6 @@ if [ -z "$CTR" ] ; then
 	exit 1
 fi
 
-. prepare.sh
-
 set -ex
 fig up -d "$CTR"
 docker exec -t -i -- "$CTR" /bin/bash