Docker follow-up (#1817)

* Docker follow-up

https://github.com/FreshRSS/FreshRSS/pull/1813

* Readme links

cloud.docker.com does not seem to have a public version of the pages
re-add https://hub.docker.com/r/freshrss/freshrss/

* Link to original GitHub readme

* Docker readme MySQL PostgreSQL

https://github.com/FreshRSS/FreshRSS/pull/1817#issuecomment-370195319

* docker exec username

3 files changed, 37 insertions, 8 deletions

diff --git a/Docker/Dockerfile b/Docker/Dockerfile
index fc753e58d..993dcea31 100644
--- a/Docker/Dockerfile
+++ b/Docker/Dockerfile
@@ -17,6 +17,6 @@ COPY ./Docker/*.Apache.conf /etc/apache2/conf.d/
 
 EXPOSE 80
 CMD php -f ./cli/prepare.php > /dev/null && \
-	chown -R :apache ${FRESHRSS_ROOT} && \
+	chown -R :www-data ${FRESHRSS_ROOT} && \
 	chmod -R g+r ${FRESHRSS_ROOT} && chmod -R g+w ${FRESHRSS_ROOT}/data/ && \
 	exec httpd -D FOREGROUND
diff --git a/Docker/README.md b/Docker/README.md
index d85b9a6f0..ccf4ab3f0 100644
--- a/Docker/README.md
+++ b/Docker/README.md
@@ -1,5 +1,7 @@
 # Deploy FreshRSS with Docker
-* See also https://hub.docker.com/r/freshrss/freshrss/
+* See also:
+	* https://hub.docker.com/r/freshrss/freshrss/
+	* https://cloud.docker.com/app/freshrss/repository/docker/freshrss/freshrss
 
 ## Install Docker
 
@@ -9,7 +11,7 @@ sh get-docker.sh
 ```
 
 ## Optional: Build Docker image of FreshRSS
-Optional, as a *less recent* [online image](https://hub.docker.com/r/freshrss/freshrss/) can be automatically fetched during the next step (run),
+Optional, as a *less recent* online image can be automatically fetched during the next step (run),
 but online images are not available for as many platforms as if you build yourself.
 
 ```sh
@@ -24,7 +26,7 @@ sudo docker build --tag freshrss/freshrss -f Docker/Dockerfile .
 
 ## Run FreshRSS
 
-Example exposing FreshRSS on port 8080. You may have to adapt the network parameters to fit your needs.
+Example using SQLite, and exposing FreshRSS on port 8080. You may have to adapt the network parameters to fit your needs.
 
 ```sh
 # You can optionally run from the directory containing the FreshRSS source code:
@@ -39,6 +41,32 @@ sudo docker run -dit --restart unless-stopped --log-opt max-size=10m \
 	--name freshrss freshrss/freshrss
 ```
 
+### Examples with external databases
+
+You may want to use other link methods such as Docker bridges, and use Docker volumes for the data, but here are some simple examples:
+
+#### MySQL
+See https://hub.docker.com/_/mysql/
+
+```sh
+sudo docker run -d -v /path/to/mysql-data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=rootpass -e MYSQL_DATABASE=freshrss -e MYSQL_USER=freshrss -e MYSQL_PASSWORD=pass --name mysql mysql
+sudo docker run -dit --restart unless-stopped --log-opt max-size=10m \
+	-v $(pwd)/data:/var/www/FreshRSS/data \
+	--link mysql -p 8080:80 \
+	--name freshrss freshrss/freshrss
+```
+
+#### PostgreSQL
+See https://hub.docker.com/_/postgres/
+
+```sh
+sudo docker run -d -v /path/to/pgsql-data:/var/lib/postgresql/data -e POSTGRES_DB=freshrss -e POSTGRES_USER=freshrss -e POSTGRES_PASSWORD=pass --name postgres postgres
+sudo docker run -dit --restart unless-stopped --log-opt max-size=10m \
+	-v $(pwd)/data:/var/www/FreshRSS/data \
+	--link postgres -p 8080:80 \
+	--name freshrss freshrss/freshrss
+```
+
 ## Update
 
 ```sh
@@ -46,17 +74,17 @@ sudo docker run -dit --restart unless-stopped --log-opt max-size=10m \
 sudo docker pull freshrss/freshrss
 # And then 
 sudo docker stop freshrss
-docker rename freshrss freshrss_old
+sudo docker rename freshrss freshrss_old
 # See the run section above for the full command
 sudo docker run ...
 # If everything is working, delete the old container
-docker rm freshrss_old
+sudo docker rm freshrss_old
 ```
 
 ## Command line
 
 ```sh
-sudo docker exec -it freshrss php ./cli/list-users.php
+sudo docker exec --user apache -it freshrss php ./cli/list-users.php
 ```
 
 See the [CLI documentation](../cli/) for all the other commands.
@@ -68,7 +96,7 @@ Set a cron job up on your host machine, calling the `actualize_script.php` insid
 Create `/etc/cron.d/FreshRSS` with:
 
 ```
-7,37 * * * * root docker exec -it freshrss php ./app/actualize_script.php > /tmp/FreshRSS.log 2>&1
+7,37 * * * * root docker exec --user apache -it freshrss php ./app/actualize_script.php > /tmp/FreshRSS.log 2>&1
 ```
 
 ## Debugging
diff --git a/README.md b/README.md
index 8858dd12d..cacf61fa9 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 [![Build Status][travis-badge]][travis-link]
 
+* Read this document on [github.com/FreshRSS/FreshRSS/](https://github.com/FreshRSS/FreshRSS/blob/master/README.md) to get the correct links and pictures.
 * [Version française](README.fr.md)
 
 # FreshRSS