Merge pull request #1575 from moxiegirl/fix-yaml-code

Updating from three ticks to code block

docs/yml.md

@@ -24,11 +24,9 @@ specify them again in `docker-compose.yml`.
 Tag or partial image ID. Can be local or remote - Compose will attempt to
 pull if it doesn't exist locally.
 
-```
-image: ubuntu
-image: orchardup/postgresql
-image: a4bc65fd
-```
+    image: ubuntu
+    image: orchardup/postgresql
+    image: a4bc65fd
 
 ### build
 
@@ -38,9 +36,7 @@ itself. This directory is also the build context that is sent to the Docker daem
 
 Compose will build and tag it with a generated name, and use that image thereafter.
 
-```
-build: /path/to/build/dir
-```
+    build: /path/to/build/dir
 
 ### dockerfile
 
@@ -48,17 +44,13 @@ Alternate Dockerfile.
 
 Compose will use an alternate file to build with.
 
-```
-dockerfile: Dockerfile-alternate
-```
+    dockerfile: Dockerfile-alternate
 
 ### command
 
 Override the default command.
 
-```
-command: bundle exec thin -p 3000
-```
+    command: bundle exec thin -p 3000
 
 <a name="links"></a>
 ### links
@@ -67,21 +59,17 @@ Link to containers in another service. Either specify both the service name and
 the link alias (`SERVICE:ALIAS`), or just the service name (which will also be
 used for the alias).
 
-```
-links:
- - db
- - db:database
- - redis
-```
+    links:
+     - db
+     - db:database
+     - redis
 
 An entry with the alias' name will be created in `/etc/hosts` inside containers
 for this service, e.g:
 
-```
-172.17.2.186  db
-172.17.2.186  database
-172.17.2.187  redis
-```
+    172.17.2.186  db
+    172.17.2.186  database
+    172.17.2.187  redis
 
 Environment variables will also be created - see the [environment variable
 reference](env.md) for details.
@@ -93,29 +81,23 @@ of Compose, especially for containers that provide shared or common services.
 `external_links` follow semantics similar to `links` when specifying both the
 container name and the link alias (`CONTAINER:ALIAS`).
 
-```
-external_links:
- - redis_1
- - project_db_1:mysql
- - project_db_1:postgresql
-```
+    external_links:
+     - redis_1
+     - project_db_1:mysql
+     - project_db_1:postgresql
 
 ### extra_hosts
 
 Add hostname mappings. Use the same values as the docker client `--add-host` parameter.
 
-```
-extra_hosts:
- - "somehost:162.242.195.82"
- - "otherhost:50.31.209.229"
-```
+    extra_hosts:
+     - "somehost:162.242.195.82"
+     - "otherhost:50.31.209.229"
 
 An entry with the ip address and hostname will be created in `/etc/hosts` inside containers for this service, e.g:
 
-```
-162.242.195.82  somehost
-50.31.209.229   otherhost
-```
+    162.242.195.82  somehost
+    50.31.209.229   otherhost
 
 ### ports
 
@@ -127,46 +109,38 @@ port (a random host port will be chosen).
 > parse numbers in the format `xx:yy` as sexagesimal (base 60). For this reason,
 > we recommend always explicitly specifying your port mappings as strings.
 
-```
-ports:
- - "3000"
- - "8000:8000"
- - "49100:22"
- - "127.0.0.1:8001:8001"
-```
+    ports:
+     - "3000"
+     - "8000:8000"
+     - "49100:22"
+     - "127.0.0.1:8001:8001"
 
 ### expose
 
 Expose ports without publishing them to the host machine - they'll only be
 accessible to linked services. Only the internal port can be specified.
 
-```
-expose:
- - "3000"
- - "8000"
-```
+    expose:
+     - "3000"
+     - "8000"
 
 ### volumes
 
 Mount paths as volumes, optionally specifying a path on the host machine
 (`HOST:CONTAINER`), or an access mode (`HOST:CONTAINER:ro`).
 
-```
-volumes:
- - /var/lib/mysql
- - cache/:/tmp/cache
- - ~/configs:/etc/configs/:ro
-```
+    volumes:
+     - /var/lib/mysql
+     - cache/:/tmp/cache
+     - ~/configs:/etc/configs/:ro
 
 ### volumes_from
 
 Mount all of the volumes from another service or container.
 
-```
-volumes_from:
- - service_name
- - container_name
-```
+    volumes_from:
+     - service_name
+     - container_name
 
 ### environment
 
@@ -175,15 +149,13 @@ Add environment variables. You can use either an array or a dictionary.
 Environment variables with only a key are resolved to their values on the
 machine Compose is running on, which can be helpful for secret or host-specific values.
 
-```
-environment:
-  RACK_ENV: development
-  SESSION_SECRET:
+    environment:
+      RACK_ENV: development
+      SESSION_SECRET:
 
-environment:
-  - RACK_ENV=development
-  - SESSION_SECRET
-```
+    environment:
+      - RACK_ENV=development
+      - SESSION_SECRET
 
 ### env_file
 
@@ -194,22 +166,18 @@ If you have specified a Compose file with `docker-compose -f FILE`, paths in
 
 Environment variables specified in `environment` override these values.
 
-```
-env_file: .env
+    env_file: .env
 
-env_file:
-  - ./common.env
-  - ./apps/web.env
-  - /opt/secrets.env
-```
+    env_file:
+      - ./common.env
+      - ./apps/web.env
+      - /opt/secrets.env
 
 Compose expects each line in an env file to be in `VAR=VAL` format. Lines
 beginning with `#` (i.e. comments) are ignored, as are blank lines.
 
-```
-# Set Rails/Rack environment
-RACK_ENV=development
-```
+    # Set Rails/Rack environment
+    RACK_ENV=development
 
 ### extends
 
@@ -222,30 +190,26 @@ Here's a simple example. Suppose we have 2 files - **common.yml** and
 
 **common.yml**
 
-```
-webapp:
-  build: ./webapp
-  environment:
-    - DEBUG=false
-    - SEND_EMAILS=false
-```
+    webapp:
+      build: ./webapp
+      environment:
+        - DEBUG=false
+        - SEND_EMAILS=false
 
 **development.yml**
 
-```
-web:
-  extends:
-    file: common.yml
-    service: webapp
-  ports:
-    - "8000:8000"
-  links:
-    - db
-  environment:
-    - DEBUG=true
-db:
-  image: postgres
-```
+    web:
+      extends:
+        file: common.yml
+        service: webapp
+      ports:
+        - "8000:8000"
+      links:
+        - db
+      environment:
+        - DEBUG=true
+    db:
+      image: postgres
 
 Here, the `web` service in **development.yml** inherits the configuration of
 the `webapp` service in **common.yml** - the `build` and `environment` keys -
@@ -262,17 +226,15 @@ Add metadata to containers using [Docker labels](http://docs.docker.com/userguid
 
 It's recommended that you use reverse-DNS notation to prevent your labels from conflicting with those used by other software.
 
-```
-labels:
-  com.example.description: "Accounting webapp"
-  com.example.department: "Finance"
-  com.example.label-with-empty-value: ""
+    labels:
+      com.example.description: "Accounting webapp"
+      com.example.department: "Finance"
+      com.example.label-with-empty-value: ""
 
-labels:
-  - "com.example.description=Accounting webapp"
-  - "com.example.department=Finance"
-  - "com.example.label-with-empty-value"
-```
+    labels:
+      - "com.example.description=Accounting webapp"
+      - "com.example.department=Finance"
+      - "com.example.label-with-empty-value"
 
 ### log driver
 
@@ -282,27 +244,22 @@ Allowed values are currently ``json-file``, ``syslog`` and ``none``. The list wi
 
 The default value is json-file.
 
-```
-log_driver: "json-file"
-log_driver: "syslog"
-log_driver: "none"
-```
+    log_driver: "json-file"
+    log_driver: "syslog"
+    log_driver: "none"
 
 ### net
 
 Networking mode. Use the same values as the docker client `--net` parameter.
 
-```
-net: "bridge"
-net: "none"
-net: "container:[name or id]"
-net: "host"
-```
+    net: "bridge"
+    net: "none"
+    net: "container:[name or id]"
+    net: "host"
+
 ### pid
 
-```
-pid: "host"
-```
+    pid: "host"
 
 Sets the PID mode to the host PID mode.  This turns on sharing between
 container and the host operating system the PID address space.  Containers
@@ -313,86 +270,74 @@ containers in the bare-metal machine's namespace and vise-versa.
 
 Custom DNS servers. Can be a single value or a list.
 
-```
-dns: 8.8.8.8
-dns:
-  - 8.8.8.8
-  - 9.9.9.9
-```
+    dns: 8.8.8.8
+    dns:
+      - 8.8.8.8
+      - 9.9.9.9
 
 ### cap_add, cap_drop
 
 Add or drop container capabilities.
 See `man 7 capabilities` for a full list.
 
-```
-cap_add:
-  - ALL
+    cap_add:
+      - ALL
 
-cap_drop:
-  - NET_ADMIN
-  - SYS_ADMIN
-```
+    cap_drop:
+      - NET_ADMIN
+      - SYS_ADMIN
 
 ### dns_search
 
 Custom DNS search domains. Can be a single value or a list.
 
-```
-dns_search: example.com
-dns_search:
-  - dc1.example.com
-  - dc2.example.com
-```
+    dns_search: example.com
+    dns_search:
+      - dc1.example.com
+      - dc2.example.com
 
 ### devices
 
 List of device mappings.  Uses the same format as the `--device` docker 
 client create option.
 
-```
-devices:
-  - "/dev/ttyUSB0:/dev/ttyUSB0"
-```
+    devices:
+      - "/dev/ttyUSB0:/dev/ttyUSB0"
 
 ### security_opt
 
 Override the default labeling scheme for each container.
 
-```
-security_opt:
-  - label:user:USER
-  - label:role:ROLE
-```
+      security_opt:
+        - label:user:USER
+        - label:role:ROLE
 
 ### working\_dir, entrypoint, user, hostname, domainname, mac\_address, mem\_limit, privileged, restart, stdin\_open, tty, cpu\_shares, cpuset, read\_only 
 
 Each of these is a single value, analogous to its
 [docker run](https://docs.docker.com/reference/run/) counterpart.
 
-```
-cpu_shares: 73
-cpuset: 0,1
+    cpu_shares: 73
+    cpuset: 0,1
 
-working_dir: /code
-entrypoint: /code/entrypoint.sh
-user: postgresql
+    working_dir: /code
+    entrypoint: /code/entrypoint.sh
+    user: postgresql
 
-hostname: foo
-domainname: foo.com
+    hostname: foo
+    domainname: foo.com
 
-mac_address: 02:42:ac:11:65:43
+    mac_address: 02:42:ac:11:65:43
 
-mem_limit: 1000000000
-privileged: true
+    mem_limit: 1000000000
+    privileged: true
 
-restart: always
+    restart: always
 
-stdin_open: true
-tty: true
-read_only: true
+    stdin_open: true
+    tty: true
+    read_only: true
 
-```
 
 ## Compose documentation