docker-networking

What is the use of Docker ‘host’ and ‘none’ Networks?

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Docker by default supports 3 networks: 1) None: This mode will not configure any IP for the container and doesn’t have any access to the external network as well as for other containers. It does have the loopback address and can be used for running batch jobs. # docker run -it –network=none ubuntu:14.04 /bin/bash root@66308c6686be:/# … Read more

Connect to SQL Server in local machine (host) from docker using host.docker.internal

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If anyone have similar problem, here’s how I solve it Open SQL Server Configuration Manager Enable TCP/IP in Server Network Configuration Restart SQL Service Service If it’s still not working, there are a few more things to check Firewall (open port 1433) Enable remote connections to your sql server

What is the equivalent of –add-host=host.docker.internal:host-gateway in a Compose file

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The actual Docker Compose equivalent is achieved by appending the same string to the extra_hosts parameters (#Doc) as: version: ‘3.9’ services: postgres: image: postgres:14.1-bullseye environment: POSTGRES_PASSWORD: **** ports: – “5433:5432” extra_hosts: – “host.docker.internal:host-gateway” You can see it has been successfully mapped to the IP of the docker0 interface, here 172.17.0.1, from inside your container, e.g.: … Read more

Docker 1.10 access a container by its hostname from a host machine

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As answered here there is a software solution for this, called DNS Proxy Server. $ sudo ./dns-proxy-server $ docker run –rm –hostname nginx.dev nginx $ ping nginx.dev PING nginx.dev (172.17.0.4) 56(84) bytes of data. 64 bytes from 172.17.0.4 (172.17.0.4): icmp_seq=1 ttl=64 time=0.043 ms 64 bytes from 172.17.0.4 (172.17.0.4): icmp_seq=2 ttl=64 time=0.022 ms

no internet inside docker-compose service

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Check /etc/default/docker to ensure it doesn’t have the following line: DOCKER_OPTS=”–iptables=false” Also check /etc/docker/daemon.json to ensure it doesn’t have the following key: { “iptables”:false } We added this on one server to get UFW working with docker. We then changed to an external firewall. Spent ages looking for the reason external networking wasn’t working because … Read more

Docker Networking – nginx: [emerg] host not found in upstream

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This can be solved with the mentioned depends_on directive since it’s implemented now (2016): version: ‘2’ services: nginx: image: nginx ports: – “42080:80” volumes: – ./config/docker/nginx/default.conf:/etc/nginx/conf.d/default.conf:ro depends_on: – php php: build: config/docker/php ports: – “42022:22” volumes: – .:/var/www/html env_file: config/docker/php/.env.development depends_on: – mongo mongo: image: mongo ports: – “42017:27017” volumes: – /var/mongodata/wa-api:/data/db command: –smallfiles Successfully … Read more

How can I forward a port from one docker container to another?

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Install socat in your container and at startup run socat TCP-LISTEN:3306,fork TCP:B-IP:3306 & This will listen locally on your 3306 and pass any traffic bidirectionally to B-IP:3306. socat is available in package named socat. So you will run any of the below commands to install it $ yum install -y socat $ apt install -y … Read more