launch a redis container if we can connect to the host docker

When the redis connection parameters are not specified, the image
will try to spin up a redis container if it is able to communicate with
the host docker.

This is only possible if the following two options are specified in the
docker run command:
  `-v /var/run/docker.sock:/run/docker.sock`
  `-v $(which docker):/bin/docker`

This is primarily added to get the quick start guide to work without
much of a hassel.

Makefile

@@ -16,8 +16,10 @@ build:
 start:
 	@echo "Starting gitlab..."
 	@docker run --name='gitlab-demo' -d \
-		-p 10022:22 -p 10080:80 \
 		-e 'GITLAB_PORT=10080' -e 'GITLAB_SSH_PORT=10022' \
+		-p 10022:22 -p 10080:80 \
+		-v /var/run/docker.sock:/run/docker.sock \
+		-v $(shell which docker):/bin/docker \
 		${USER}/gitlab:latest >/dev/null
 	@echo "GitLab instance is booting up..."
 	@echo "Please be patient. This could take a while..."

README.md

@@ -153,8 +153,10 @@ Run the gitlab image
 
 ```bash
 docker run --name='gitlab' -it --rm \
--p 10022:22 -p 10080:80 \
 -e 'GITLAB_PORT=10080' -e 'GITLAB_SSH_PORT=10022' \
+-p 10022:22 -p 10080:80 \
+-v /var/run/docker.sock:/run/docker.sock \
+-v $(which docker):/bin/docker \
 sameersbn/gitlab:7.2.2
 ```
 

assets/init

@@ -135,6 +135,33 @@ case "${DB_TYPE}" in
   *) echo "Unsupported database adapter. Available adapters are mysql and postgres." && exit 1 ;;
 esac
 
+##
+## For the sake of getting the quick start guide to work,
+## we attempt to spin up a redis container if possible.
+##
+## NOTE: this is only meant for getting the quick start guide to work .
+##
+if [ -z "${REDIS_HOST}" -a -n "$(which docker)" -a -S /var/run/docker.sock ]; then
+  echo "Redis connection details not specified."
+  echo "Will try to spin up a new redis image with the name redis-gitlab."
+  echo "Please manually configure the redis connection in production."
+  case "$(docker inspect --format {{.State.Running}} redis-gitlab 2>/dev/null)" in
+    true)
+      echo "Using existing redis container..."
+      ;;
+    false)
+      echo "Starting up existing redis container..."
+      docker start redis-gitlab >/dev/null 2>/dev/null
+      ;;
+    *)
+      echo "Starting up a new redis container..."
+      docker run --name='redis-gitlab' -d sameersbn/redis:latest >/dev/null 2>/dev/null
+      ;;
+  esac
+  REDIS_HOST=$(docker inspect --format {{.NetworkSettings.IPAddress}} redis-gitlab 2>/dev/null)
+  REDIS_PORT=6379
+fi
+
 if [ -z "${REDIS_HOST}" ]; then
   echo "ERROR: "
   echo "  Please configure the redis connection."