Add troubleshooting section to the docker documentation.

docker/Dockerfile

@@ -4,7 +4,6 @@
 # sudo docker build --tag gitlab_image docker/
 # sudo docker run --name gitlab_data gitlab_image /bin/true
 # sudo docker run --detach --name gitlab --publish 8080:80 --publish 2222:22 --volumes-from gitlab_data gitlab_image
-# sudo docker run -t --rm --volumes-from gitlab_data ubuntu tail -f /var/log/gitlab/reconfigure.log
 
 FROM ubuntu:14.04
 MAINTAINER Vincent Robert <vincent.robert@genezys.net>
@@ -14,6 +13,7 @@ RUN apt-get update -q \
     && DEBIAN_FRONTEND=noninteractive apt-get install -qy \
       openssh-server \
       wget \
+      vim \
     && apt-get clean
 
 # Download & Install GitLab

docker/README.md

@@ -8,7 +8,7 @@ GitLab offers git repository management, code reviews, issue tracking, activity
 ![GitLab Logo](https://gitlab.com/uploads/appearance/logo/1/brand_logo-c37eb221b456bb4b472cc1084480991f.png)
 
 
-How to use this image.
+How to use this image
 ======================
 
 I recommend creating a data volume container first, this will simplify migrations and backups:
@@ -28,7 +28,7 @@ Then run GitLab:
 You can then go to `http://localhost:8080/` (or most likely `http://192.168.59.103:8080/` if you use boot2docker). Next time, you can just use `docker start gitlab` and `docker stop gitlab`.
 
 
-How to configure GitLab.
+How to configure GitLab
 ========================
 
 This container uses the official Omnibus GitLab distribution, so all configuration is done in the unique configuration file `/etc/gitlab/gitlab.rb`.
@@ -40,3 +40,7 @@ To access GitLab configuration, you can start a new container using the shared d
 **Note** that GitLab will reconfigure itself **at each container start.** You will need to restart the container to reconfigure your GitLab.
 
 You can find all available options in [GitLab documentation](https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/README.md#configuration).
+
+Troubleshooting
+=========================
+Please see the [troubleshooting](troubleshooting.md) file in this directory.

docker/troubleshooting.md

+# Troubleshooting
+
+This is to troubleshoot https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/245
+But it might contain useful commands for other cases as well.
+
+The configuration to add the postgres log in vim is:
+postgresql['log_directory'] = '/var/log/gitlab/postgresql.log'
+
+# Commands
+
+sudo docker rm -f gitlab
+sudo docker rm -f gitlab_data
+
+sudo docker build --tag gitlab_image docker/
+sudo docker run --name gitlab_data gitlab_image /bin/true
+
+sudo docker run -ti --rm --volumes-from gitlab_data ubuntu apt-get install -y vim; sudo vi /etc/gitlab/gitlab.rb
+
+sudo docker run --detach --name gitlab --publish 8080:80 --publish 2222:22 --volumes-from gitlab_data gitlab_image
+
+sudo docker run -t --rm --volumes-from gitlab_data ubuntu tail -f /var/log/gitlab/reconfigure.log
+
+sudo docker run -t --rm --volumes-from gitlab_data ubuntu cat /var/log/gitlab/postgresql.log