Can someone help me how to configure bridge connection in linux and what are the command that being use.
I do really appreciate your help!
I am new Debian Linux user. I want to setup Bridge for virtualised environments (KVM) running on Debian Linux.
By default, a private network bridge created when using Kernel-based Virtual Machine(KVM). You need to set up interfaces manually, avoiding conflicts with, network manager.If you want to assign IP addresses to your virtual machines and make them accessible from your LAN you need to setup network bridge.
The procedure to configure network bridge on Debian Linux is as follows:
Just use the ip command:
$ ip -f inet a s
$ cat /etc/network/interfaces
$ sudo vi /etc/network/interfaces.d/br0
$ sudo systemctl restart network-manager
$ ip a s
$ ip r
$ ping -c 2 cyberciti.biz
$ brctl show
$ bridge link
Related
In my local setup, I can run ...
docker run --name myapp -e HOST=$(docker-machine ip default) --user root myapp
... and then use $HOST to connect to any other container (e.g. one running mongodb).
However, in Travis, docker-machine does not exist. Thus, I cannot simply put that line in my .travis.yml.
How do I get the network IP?
The flag --link adds an entry to /etc/hosts with the ip address of the specified running container
docker run --name myapp --link mongodb:mongodb myapp
However please note that:
The default docker0 bridge network supports the use of port mapping
and docker run --link to allow communications between containers in
the docker0 network. These techniques are cumbersome to set up and
prone to error. While they are still available to you as techniques,
it is better to avoid them and define your own bridge networks
instead.
Another option is using the flag --add-host if you want to add a known ip address
docker run --name myapp --add-host mongodb:10.10.10.1 myapp
Option 2
Create a network
docker network create --subnet=172.18.0.0/16 mynet123
Run mongodb container assigning an static ip
docker run --network mynet123 --ip 172.18.0.22 -d mongodb
Add that ip to the other container
docker run --network mynet123 --add-host mongodb:172.18.0.22 -d myapp
I'm following Digital Ocean's tutorial on how to start a nginx docker container (Currently on Step 4). Currently this is their output:
$ docker run --name docker-nginx -p 80:80 -d nginx
d3ccb73a91985651ec61231bca9f9c716f0dec807e354a29eeef2144f883a01c
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b91f3ce26553 nginx "nginx -g 'daemon off" About a minute ago Up About a minute 0.0.0.0:80->80/tcp, 443/tcp docker-nginx
But when I run it, this is my output (noticed the different IP of the container):
C:\>docker run --name docker-nginx -p 80:80 -d nginx
d3ccb73a91985651ec61231bca9f9c716f0dec807e354a29eeef2144f883a01c
C:\>docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
d3ccb73a9198 nginx "nginx -g 'daemon off" 14 hours ago Up 2 seconds 10.0.75.2:80->80/tcp, 443/tcp docker-nginx
Why does this happen? And how can I get the same results as Digital Ocean's? (Getting the server to start on localhost)
Edit: I'm using Docker for windows (recently released) which apparently runs native using Hyper-V. My output for docker-machine ls is this:
C:\>docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
C:\>
But when I run it, this is my output (noticed the different IP of the
container)
Since this a Windows machine, I assume that you're using Docker Toolbox Docker for Windows. 10.0.75.2 is the IP of the boot2docker virtual machine.
If you are using Windows or Mac OS, you will need some form of virtualization in
order to run Docker. The IP you just saw is the IP of that lightweight virtual machine.
And how can I get the same results as Digital Ocean's? (Getting the
server to start on localhost)
Use a Linux distribution! Also you can enable Expose container ports on localhost in Docker For Windows Settings:
Despite you created the containers in your local machine. These are actually running on a different machine (a virtual machine)
First, check what is the IP of your docker machine (the virtual machine)
$docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM
default * virtualbox Running tcp://192.168.99.100
Then run curl command (or open a browser) to view the default web site on your nginx web server inside the container
curl http://192.168.99.100:80
if you are using a virtual machine on windows:
docker-machine ip default
https://docs.docker.com/machine/concepts/
When I ran this command for the first time: docker run -d -p 80:80 --name docker-tutorial docker101tutorial
I got this error:
docker: Error response from daemon: Conflict. The container name
"/docker-tutorial" is already in use by container "LONG_CONTAINER_ID".
You have to remove (or rename) that container to be able to reuse that
name.
so, I tried to remove this container using: docker rm -f LONG_CONTAINER_ID
then I did: docker run -d -p 3080:80 --name docker-tutorial docker101tutorial
note 3080:80 instead of 80:80... Had I run this from the docker desktop, I would see this default option below:
We have a dockerized server application that is doing auto-discovery of physical appliances on the network by listening for multicast packets on port 6969. So we need our docker container to be able to receive these packets from devices outside the host, through the host, and in to the container. I've seen some similar issues and done a lot of reading but I'm still unable to get the server to respond to these multicast packets.
I'm sitting on Wireshark watching network traffic, but I'm not a specialist. I know Docker creates a MASQUERADE address to make the traffic all look like it's coming from the Docker gateway, so when I watch veth I see mostly talk between 172.17.0.1 and 172.17.0.2 although my server is unable to retrieve any information about the devices on the network. (If I run outside of docker, I have no issues of course.)
I can't use --net=host as, like others, we make use of the --link feature. I've tried the following variations...
docker run --name app -p 6969:6969 -d me/app:latest
docker run --name app -p 0.0.0.0:6969:6969 -d me/app:latest (This one I could have sworn worked once but now doesn't?)
docker run --name app -p 0.0.0.0:6969:6969/udp -d me/app:latest
docker run --name app -p 255.255.255.255:6969:6969 -d me/app:latest
Any help or insight you could provide would be greatly appreciated.
Try to enable multicast on your nics:
ip link set eth0 multicast on
echo 1 >/proc/sys/net/ipv4/ip_forward to turn on IP forwarding
You need to explicitly set or at least check that it is enabled on relevant interfaces.
net.ipv4.conf.all.mc_forwarding = 1
net.ipv4.conf.eth0.rp_filter=0
Allow the multicast traffic:
iptables -I INPUT -d 224.0.0.0/4 -j ACCEPT
iptables -I FORWARD -d 224.0.0.0/4 -j ACCEPT
Also you might need to add the route for multicast traffic:
route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0
Change the TTL of the multicast sender:
iptables -t mangle -A OUTPUT -d <group> -j TTL --ttl-set 128
Where group is the multicast group address of the stream you want to change the TTL of.
Also you can start multicast proxy
PS:
You should try (if above doesn't help) to start docker container with --net=none option and use pipework with follow command:
pipework docker0 -i eth0 CONTAINER_ID IP_ADDRESS/IP_MASK#DEFAULT_ROUTE_IP
which creates eth0 interface inside container with IFF_MULTICAST flag and defined IP address.
How can I integrate OpenStack instances in my local network? I have Devstack Kilo running on a single Ubuntu VM that has its own IP different than the physical host. I assigned as floating IPs a set of IPs from the local network. But I cannot ping neither the external network, nor the local network from the instances.
You need to set up the network on the devstack host to do ip and arp forwarding. This ususally works:
sudo bash
echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
This is for an Ubuntu host running devstack - your distro may be a little different, but the ideas are the same.
I wrote a post about doing this a while back. It's for Havana, but the principles are the same:
https://barakme.wordpress.com/2013/12/23/openstack-in-a-box-setting-up-devstack-havana-on-your/
I'm trying to set up a docker dnsmasq container so that I can have all my docker containers look up the domain names rather than having hard-coded IPs (if they are on the same host). This fixes an issue with the fact that one cannot alter the /etc/hosts file in docker containers, and this allows me to easily update all my containers in one go, by altering a single file that the dnsmasq container references.
It looks like someone has already done the hard work for me and created a dnsmasq container. Unfortunately, it is not "working" for me. I wrote a bash script to start the container as shown below:
name="dnsmasq_"
timenow=$(date +%s)
name="$name$timenow"
sudo docker run \
-v="$(pwd)/dnsmasq.hosts:/dnsmasq.hosts" \
--name=$name \
-p='127.0.0.1:53:5353/udp' \
-d sroegner/dnsmasq
Before running that, I created the dnsmasq.hosts directory and inserted a single file within it called hosts.txt with the following contents:
192.168.1.3 database.mydomain.com
Unfortunately whenever I try to ping that domain from within:
the host
The dnsmasq container
another container on the same host
I always receive the ping: unknown host error message.
I tried starting the dnsmasq container without daemon mode so I could debug its output, which is below:
dnsmasq: started, version 2.59 cachesize 150
dnsmasq: compile time options: IPv6 GNU-getopt DBus i18n DHCP TFTP conntrack IDN
dnsmasq: reading /etc/resolv.dnsmasq.conf
dnsmasq: using nameserver 8.8.8.8#53
dnsmasq: read /etc/hosts - 7 addresses
dnsmasq: read /dnsmasq.hosts//hosts.txt - 1 addresses
I am guessing that I have not specified the -p parameter correctly when starting the container. Can somebody tell me what it should be for other docker containers to lookup the DNS, or whether what I am trying to do is actually impossible?
The build script for the docker dnsmasq service needs to be changed in order to bind to your server's public IP, which in this case is 192.168.1.12 on my eth0 interface
#!/bin/bash
NIC="eth0"
name="dnsmasq_"
timenow=$(date +%s)
name="$name$timenow"
MY_IP=$(ifconfig $NIC | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}')
sudo docker run \
-v="$(pwd)/dnsmasq.hosts:/dnsmasq.hosts" \
--name=$name \
-p=$MY_IP:53:5353/udp \
-d sroegner/dnsmasq
On the host (in this case ubuntu 12), you need to update the resolv.conf or /etc/network/interfaces file so that you have registered your public IP (eth0 or eth1 device) as the nameserver.
You may want to set a secondary nameserver to be google for whenever the container is not running, by changing the line to be dns-nameservers xxx.xxx.xxx.xxx 8.8.8.8 E.g. there is no comma or another line.
You then need to restart your networking service sudo /etc/init.d/networking restart if you updated the /etc/network/interfaces file so that this auto updates the /etc/resolve.conf file that docker will copy to the container during the build.
Now restart all of your containers
sudo docker stop $CONTAINER_ID
sudo docker start $CONTAINER_ID
This causes their /etc/resolv.conf files update so they point to the new nameserver settings.
DNS lookups in all your docker containers (that you built since making the changes) should now work using your dnsmasq container!
As a side note, this means that docker containers on other hosts can also take advantage of your dnsmasq service on this host as long as their host's nameserver settings is set to using this server's public IP.