73 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			73 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| ---
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| title: Docker Network
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| ---
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| 
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| By design containers are isolated from the host and other running containers. The virtual networking of Docker containers allows them to talk to services inside other containers or on the host.
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| 
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| By default, every container gets a virtual Ethernet interface that gets connected via a bridge on the host.
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| 
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| ## List all Docker networks
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| 
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| `docker network ls` lists all current Docker networks. 
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| 
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| When installing Docker it creates three default networks:
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| 
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| - *bridge*:  
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| Default for containers that are run without a network specified
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| - *host*:  
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| Allows a container to directly use the network stack of the host
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| - *none*:  
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| No networking to other containers is possible
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| 
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| You can use these, but when you plan on running your service containers in production it is advised to create special networks.
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| 
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| ## Inspect a Docker Network
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| 
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| `docker network inspect NAMEOFNETWORK` outputs details on the configuration of the network in JSON format. For example, the containers that are part of the network, or their private IPv4-adresses.
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| 
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| ```json
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| "Containers": {
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|             "156693991b505f5c17ae524ee31fe18775e62011db816cce5313cd2f22576a9c": {
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|                 "Name": "app",
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|                 "EndpointID": "ac4d2dff6f2191fa22749d6c00a2005f400ee74771e0e9186ffa35c94f9b9994",
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|                 "MacAddress": "02:42:ac:18:00:02",
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|                 "IPv4Address": "172.24.0.2/16",
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|                 "IPv6Address": ""
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|             },
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|             "64b4328f46a7c4f26e925b66cd6783dc024a93210e958b768292427e52b35bf3": {
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|                 "Name": "database",
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|                 "EndpointID": "b7dcf87f8a8501eab01c6e7fe58aa9454ae81c84c3bc41d9490bcd92e2ab531a",
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|                 "MacAddress": "02:42:ac:18:00:03",
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|                 "IPv4Address": "172.24.0.3/16",
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|                 "IPv6Address": ""
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|             }
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| ```
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| 
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| ## Create a Docker network
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| 
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| To create a network simply run: 
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| 
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| `docker network create my_app_network`
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| 
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| ## Attach Containers to a network
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| 
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| To directly attach a new container to the newly created network run:
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| 
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| `docker run --name my_new_webapp --network="my_app_network" -d httpd:2.4-alpine`
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| 
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| To attach an already running container to a network run:
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| `docker network connect my_app_network my_running_webapp`
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| 
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| They can now talk to each other. 
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| 
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| ## Networking with Docker Compose
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| 
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| When running your containers with Docker Compose it by default creates a network of all service containers in the `docker-compose.yml` file.
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| 
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| #### For More Information:
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| - [Docker Networking: Overview](https://docs.docker.com/network/)
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| - [Docker Networking: Tutorial for standalone containers](https://docs.docker.com/network/network-tutorial-standalone/)
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| - [Docker Compose: Networking in Compose](https://docs.docker.com/compose/networking/)
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| 
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