engine/examples: fix up some markdown

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

engine/examples/apt-cacher-ng.md

@@ -16,6 +16,7 @@ the second download of any package almost instant.
 
 Use the following Dockerfile:
 
+```dockerfile
 #
 # Build: docker build -t apt-cacher .
 # Run: docker run -d -p 3142:3142 --name apt-cacher-run apt-cacher
@@ -32,19 +33,26 @@ Use the following Dockerfile:
 
 EXPOSE 3142
 CMD    chmod 777 /var/cache/apt-cacher-ng && /etc/init.d/apt-cacher-ng start && tail -f /var/log/apt-cacher-ng/*
+```
 
 To build the image using:
 
+```bash
 $ docker build -t eg_apt_cacher_ng .
+```
 
 Then run it, mapping the exposed port to one on the host
 
+```bash
 $ docker run -d -p 3142:3142 --name test_apt_cacher_ng eg_apt_cacher_ng
+```
 
 To see the logfiles that are `tailed` in the default command, you can
 use:
 
+```bash
 $ docker logs -f test_apt_cacher_ng
+```
 
 To get your Debian-based containers to use the proxy, you have
 following options. Replace `dockerhost` with the
@@ -63,34 +71,43 @@ container.
 **Option 1** injects the settings safely into your apt configuration in
 a local version of a common base:
 
+```dockerfile
 FROM ubuntu
 RUN echo 'Acquire::http { Proxy "http://dockerhost:3142"; };' >> /etc/apt/apt.conf.d/01proxy
 RUN apt-get update && apt-get install -y vim git
 
 # docker build -t my_ubuntu .
+```
 
 **Option 2** is good for testing, but breaks other HTTP clients
 which obey `http_proxy`, such as `curl`, `wget` and others:
 
+```bash
 $ docker run --rm -t -i -e http_proxy=http://dockerhost:3142/ debian bash
+```
 
 **Option 3** is the least portable, but you might need to do it and you can do it
 from your `Dockerfile` too.
 
 **Option 4** links Debian-containers to the proxy server using following command:
 
+```bash
 $ docker run -i -t --link test_apt_cacher_ng:apt_proxy -e http_proxy=http://apt_proxy:3142/ debian bash
+```
 
 **Option 5** creates a custom network of APT proxy server and Debian-based containers:
 
+```bash
 $ docker network create mynetwork
 $ docker run -d -p 3142:3142 --network=mynetwork --name test_apt_cacher_ng eg_apt_cacher_ng
 $ docker run --rm -it --network=mynetwork -e http_proxy=http://test_apt_cacher_ng:3142/ debian bash
+```
 
 Apt-cacher-ng has some tools that allow you to manage the repository,
 and they can be used by leveraging the `VOLUME`
 instruction, and the image we built to run the service:
 
+```bash
 $ docker run --rm -t -i --volumes-from test_apt_cacher_ng eg_apt_cacher_ng bash
 
 root@f38c87f2a42d:/# /usr/lib/apt-cacher-ng/distkill.pl
@@ -111,10 +128,13 @@ instruction, and the image we built to run the service:
          index files. Select d to see detailed list.
 
 (Number nn: tag distribution or architecture nn; 0: exit; d: show details; r: remove tagged; q: quit): q
+```
 
 Finally, clean up after your test by stopping and removing the
 container, and then removing the image.
 
+```bash
 $ docker container stop test_apt_cacher_ng
 $ docker container rm test_apt_cacher_ng
 $ docker image rm eg_apt_cacher_ng
+```

engine/examples/couchdb_data_volumes.md

@@ -4,8 +4,9 @@ keywords: docker, example, package installation, networking, couchdb,  data volu
 title: Dockerize a CouchDB service
 ---
 
-> **Note**:
-> - **If you don't like sudo** then see [*Giving non-root access*](../install/linux-postinstall.md#manage-docker-as-a-non-root-user)
+> **Note**
+>
+> **If you don't like sudo** then see [*Giving non-root access*](../install/linux-postinstall.md#manage-docker-as-a-non-root-user)
 
 Here's an example of using data volumes to share the same data between
 two CouchDB containers. This could be used for hot upgrades, testing
@@ -15,28 +16,36 @@ different versions of CouchDB on the same data, etc.
 
 We're marking `/var/lib/couchdb` as a data volume.
 
+```bash
 $ COUCH1=$(docker run -d -p 5984 -v /var/lib/couchdb shykes/couchdb:2013-05-03)
+```
 
 ## Add data to the first database
 
 We're assuming your Docker host is reachable at `localhost`. If not,
 replace `localhost` with the public IP of your Docker host.
 
+```bash
 $ HOST=localhost
 $ URL="http://$HOST:$(docker port $COUCH1 5984 | grep -o '[1-9][0-9]*$')/_utils/"
 $ echo "Navigate to $URL in your browser, and use the couch interface to add data"
+```
 
 ## Create second database
 
 This time, we're requesting shared access to `$COUCH1`'s volumes.
 
+```bash
 $ COUCH2=$(docker run -d -p 5984 --volumes-from $COUCH1 shykes/couchdb:2013-05-03)
+```
 
 ## Browse data on the second database
 
+```bash
 $ HOST=localhost
 $ URL="http://$HOST:$(docker port $COUCH2 5984 | grep -o '[1-9][0-9]*$')/_utils/"
 $ echo "Navigate to $URL in your browser. You should see the same data as in the first database"'!'
+```
 
 Congratulations, you are now running two Couchdb containers, completely
 isolated from each other *except* for their data.

engine/examples/running_riak_service.md

@@ -11,34 +11,39 @@ Riak pre-installed.
 
 Create an empty file called `Dockerfile`:
 
+```bash
 $ touch Dockerfile
+```
 
 Next, define the parent image you want to use to build your image on top
 of. We use [Ubuntu](https://hub.docker.com/_/ubuntu/) (tag:
 `trusty`), which is available on [Docker Hub](https://hub.docker.com):
 
+```dockerfile
 # Riak
 #
 # VERSION       0.1.1
 
 # Use the Ubuntu parent image provided by dotCloud
 FROM ubuntu:trusty
+```
 
 After that, we install the curl which is used to download the repository setup
 script and we download the setup script and run it.
 
+```dockerfile
 # Install Riak repository before we do apt-get update, so that update happens
 # in a single step
 RUN apt-get install -q -y curl && \
     curl -fsSL https://packagecloud.io/install/repositories/basho/riak/script.deb | sudo bash
+```
 
 Then we install and setup a few dependencies:
 
  - `supervisor` is used manage the Riak processes
  - `riak=2.0.5-1` is the Riak package coded to version 2.0.5
 
-<!-- -->
-
+```dockerfile
 # Install and setup project dependencies
 RUN apt-get update && \
     apt-get install -y supervisor riak=2.0.5-1
@@ -48,31 +53,41 @@ Then we install and setup a few dependencies:
 RUN locale-gen en_US en_US.UTF-8
 
 COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
+```
 
 After that, we modify Riak's configuration:
 
+```dockerfile
 # Configure Riak to accept connections from any host
 RUN sed -i "s|listener.http.internal = 127.0.0.1:8098|listener.http.internal = 0.0.0.0:8098|" /etc/riak/riak.conf
 RUN sed -i "s|listener.protobuf.internal = 127.0.0.1:8087|listener.protobuf.internal = 0.0.0.0:8087|" /etc/riak/riak.conf
+```
 
 Then, we expose the Riak Protocol Buffers and HTTP interfaces:
 
+```dockerfile
 # Expose Riak Protocol Buffers and HTTP interfaces
 EXPOSE 8087 8098
+```
 
 Finally, run `supervisord` so that Riak is started:
 
+```dockerfile
 CMD ["/usr/bin/supervisord"]
+```
 
 ## Create a supervisord configuration file
 
 Create an empty file called `supervisord.conf`. Make
 sure it's at the same directory level as your `Dockerfile`:
 
+```bash
 touch supervisord.conf
+```
 
 Populate it with the following program definitions:
 
+```ini
 [supervisord]
 nodaemon=true
 
@@ -85,12 +100,15 @@ Populate it with the following program definitions:
 environment=HOME="/var/lib/riak"
 stdout_logfile=/var/log/supervisor/%(program_name)s.log
 stderr_logfile=/var/log/supervisor/%(program_name)s.log
+```
 
 ## Build the Docker image for Riak
 
 Now you can build a Docker image for Riak:
 
+```bash
 $ docker build -t "<yourname>/riak" .
+```
 
 ## Next steps