From 7bbce80ee44a17565e48a1be87ebb7e2b01264db Mon Sep 17 00:00:00 2001
From: Marcello Lamonaca <marcello@lamonaca.eu>
Date: Wed, 21 Sep 2022 15:23:09 +0200
Subject: [PATCH] docker: improve `compose.yml` file notes
---
docs/docker/docker.md | 38 +++++++++++++++++++++-----------------
1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/docs/docker/docker.md b/docs/docker/docker.md
index 77f3d34..594ea65 100644
--- a/docs/docker/docker.md
+++ b/docs/docker/docker.md
@@ -247,7 +247,7 @@ None: Containers are not attached to a network and cannot access other container
```bash
docker network create \
--driver <network_type> \
---subnet <gateway_ip>/<subnet_mask_size>
+--subnet <gateway_ip>/<subnet_mask_size> \
<network_name>
```
@@ -284,13 +284,13 @@ bind mounting: link docker to an exiting folder to be used as a volume.
## Layer Architecture
-
+
All containers created from the same image share the same image layers.
```sh
docker run -v <existing_dir>:<container_dir> <image>:<tag> # older command for bind mounting
-docker run --mount type=bind, source=:<existing_dir>, target=<container_dir> <image>:<tag> # moder command for bind mounting
+docker run --mount type=bind, source=:<existing_dir>, target=<container_dir> <image>:<tag> # modern command for bind mounting
```
---
@@ -301,39 +301,43 @@ Compose is a tool for defining and running multi-container Docker applications.
Using Compose is basically a three-step process:
-1. Define your app’s environment with a `Dockerfile` so it can be reproduced anywhere.
+1. Define the app’s environment with a `Dockerfile` so it can be reproduced anywhere.
2. Define the services that make up your app in `docker-compose.yml` so they can be run together in an isolated environment.
-3. Run `docker-compose up` and Compose starts and runs your entire app.
+3. Run `docker-compose up` and Compose starts and runs the entire app.
```yaml
-# dedicated bridge network for the app (no liks needed, names suffice)
-# support for docker swarm
version: 3.x
services:
- <container_name>:
+ <service_name>:
+ image: <image_name>
+ image: <image_url>
build: <path> # path to folder containing a Dockerfile to build the image
+ build:
+ context: <path>
+ dockerfile: <*.Dockerfile>
+ args: # pass args to dockerfile
+ ARG: <value>
+ - ARG=<value>
ports:
- <host_port>:<container_port>
networks: # attach container to one or more networks
- <network_name>
- - ...
depends_on: # make sure dependencies are running before this container
- <container_name>
- envoroment:
- - ENV_VAR=<value> # declare a env var for this service
+ environment: # declare a env vars for this service
+ ENV_VAR: <value>
+ - ENV_VAR=<value>
env_file:
- - <path/to/env/file> # resuable env file
+ - <path/to/env/file> # reusable env file
volumes:
- "./<rel/path/to/volume>:<in/container/path/to/data>" # service-dedicated volume
- - "<volume_name>:<in/container/path/to/data>" # reuse volume
- ...
+ - "<volume_name>:<in/container/path/to/data>" # reuseable volume
# reusable volume definitions
volumes:
- - <volume_name>: # ?
+ - <volume_name>:
# create networks
networks:
- <network_name>:
- ...
+ <network_name>:
```