Tag: networking

Access a docker container in docker multi-host network

I have created a Docker multi-host network using Docker Overlay network with 4 nodes: node0, node1, node2, and node3. Node0 act as key-value store which shares the information of nodes while node1, node2, and node3 are bound to the key-value store. Here are node1 networks: user@node1$ docker network ls NETWORK ID NAME DRIVER 04adb1ab4833 RED […]

Prevent Docker Compose from creating separate network

I discovered that Docker Compose places containers in a separate network when using version 2 of their YAML syntax. This makes linking with existing containers difficult. Is there a way to prevent this, and revert to the behavior of version 1, without actually reverting?

Cannot run nuttcp inside Docker

I am trying to run nuttcp inside a Docker container to measure it’s UDP throughput. However, whenever I am starting the client instance, the server instance crashes with the following error message: Segmentation fault (core dumped). I found this bug report for Debian which says that nuttcp crashes because the file /proc/sys/net/ipv4/tcp_adv_win_scale does not exist. […]

How to create an overlay network with Docker?

When I try to create an overlay network with Docker I get the following error: docker@boot2docker:/vagrant$ docker network create –driver overlay somenetwork Error response from daemon: failed to parse pool request for address space “GlobalDefault” pool “” subpool “”: cannot find address space GlobalDefault (most likely the backing datastore is not configured)` I found this […]

internal infrastructure with docker

i’ve a small company-network with following services/servers: jenkins stash (atlassian) confluence (atlassian) ldap owncloud zabbix (monitoring) puppet and some java-web-apps all running in separate kvm(libvirt)-vms in separate virtual-subnets on 2 machines (1 internal, 1 hetzner-rootserver) with shorewall inbetween. i’m thinking about switching to docker. but there are 2 questions to me: how can i achieve […]

Adding a new NIC to a Docker container in a specific order

I’m trying to have a CentOS container with two network interfaces. After going through the Docker docs and “googleing” a bit, I found this GitHub issue comment that specifies how to achieve this. Following it, I created a new network (default type: bridge) docker network create my-network Inspecting the new network, I can see that […]

Assign different public IPs to different Docker container

I need to run two containers each containing a script binding on a specific (public) IP ( and The docker host itself is on I wrote this docker-compose.yml version: ‘2’ services: nginx-0: image: nginx:1.10 networks: app_net: ipv4_address: nginx-1: image: nginx:1.10 networks: app_net: ipv4_address: networks: app_net: driver: bridge ipam: driver: default config: […]

Can Docker automatically add IP addresses to the host upon running container

I’ve got a server on hetzner.de with around 16 public IPv4 addresses. Right now I’m running containers like this: sudo docker run -d –name test6 -it -p sunebeck/apache-php This will initially yield this error: Error starting userland proxy: listen tcp bind: cannot assign requested address. Which is fixed by adding the ip address […]

Docker and inconsistent IP addresses from host

I am trying to setup some containers to manage my personal emails on my VPS. I’ve set up TLS encryption for the postfix server. While setting up SPF to detect forged emails, I discovered that the reported IP is not the same depending if encryption is used: When receiving email from some senders: Received: from […]

Using rc.local to start network dependent services

Is it safe to use /etc/rc.local to initialize services that depend on the network? I’m using it to start a service that makes some requests to the network during its startup process. Happens that occasionally the service startup is failing (not all the times). This is the error I’m getting: 2016-06-07T12:01:48.724+0000 W NETWORK [ReplicationExecutor] getaddrinfo(“my_machine_local_dns”) […]

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