docker container run --detach --rm --publish 80:80 --name webserver nginx
docker container run --detach --publish 80:80 --name webserver nginx
docker container rm <container_Name|container_Id_First3Digit_SHA>
Use -- flags, its a good practice in docker
docker image ls
docker container logs webserver
docker container top ContainerID|containerName
docker run -d --name mongo mongo
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$ docker run -it --rm --privileged --pid=host justincormack/nsenter1
/ #
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ps aux | { head -1; grep -E 'mysql|mongo' ; }
ps -ef | { head -1; grep bash; }
ps aux | { head -1; grep 999 ; }
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Docker proces is running on host
docker top mongo
//mongo is name of container and this command tells us processes running as a part of mongo docker container - top 10 Processes
ps aux | grep mongod
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docs.docker.com
--help
Our friends
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docker container run -d -p 3306:3306 --name db --env MYSQL_RANDOM_ROOT_PASSWORD=yes mysql
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Analyse Outside container
docker container top Container_Name
docker container inspect [OPTIONS] Container_Name
docker container stats [OPTIONS] [CONTAINER...] //if no container_Name , it means all
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Analyse Inside container - To know about whats happening in container
docker container start -ai Container_Name //a means attach , i means interactive
docker container exec -it Container_Name //t means tty , i means interactive
docker container run -it ImageName //t means tty , i means interactive
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apt-get update
apt-get install -y procps //Install "ps" in mysql - Its having debian
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docker container port nginx
virtual network ----is having a container's port
host port
only host port is mapped to only 1 Container...mapped
A container can talk to other container if they are on same virtual networks
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• Each Container is by default connected to - private virtual network "Bridge"
• Each PVN routes through NAT Firewall on host IP
• All containers on a virtual network can talk to each other without -p
For example :
A network has 2 Containers :-> Mysql and httpd
httpd has 8080:80
While Mysql has nothing
Mysql can talk to httpd
• 2 Different networks cannot talk to each other they have to go via NAT
• 1 host level port is mapped to 1 container only
• Make new virtual networks
• Attach containers to more than 1 virtual network
• Use docker network Drivers.
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ifconfig en0 // Linux based Actual Host machine
ipconfig // Windows based Actual Host machine
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docker container port ContainerID
docker container inspect ContainerID
docker container inspect --format "{{ .NetworkSettings.IPAddress}}" nginx
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Why its called a bridge network ?
Its a type of "Driver"
because this vpn connects our container to outside physical network through NAT firewall
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:::::docker network commands :::::
• docker network ls // Shows list of all private virtual networks with type of Drivers they possess
//bridge is called "bridge" or "docker0"
• docker network inspect bridge //shows containers attached to this network
Each Container has its own IP Address , although they are attached to same Network SHAid
• Network Type has a Subnet": "172.17.0.0/16" in IPAM Config
has many containers attached to it , Each having its own Ip Addresses
"IPv4Address": "172.17.0.6/16"
"IPv4Address": "172.17.0.3/16"
"IPv4Address": "172.17.0.2/16"
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172.17.0.0 ---- Default IP Address of Bridge Network
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another network is "host", gives up docker security
attaches directly to host interface
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docker network inspect bridge
docker network inspect host
docker network inspect none
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:::: Create a new network
docker network create my_app_net
docker network inspect my_app_net
"Subnet": "172.18.0.0/16",
"Gateway": "172.18.0.1"
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docker network create my_app_net
docker container run --name new_nginx --network my_app_net nginx:alpine //New Container
docker network inspect my_app_net // it has new_nginx attached to it
// --network network flag on "run" command Connect a container to a network
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//docker network
// docker network connect [OPTIONS] NETWORK CONTAINER
docker network connect --help
docker network connect my_app_net nginx //Attach network to container
docker container inspect nginx //Inspect container --- It shows connection to 2 networks, now
"Networks": {
"bridge": {
"IPAMConfig": null,
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.6",
},
"my_app_net": {
"IPAMConfig": {},
"Gateway": "172.18.0.1",
"IPAddress": "172.18.0.3",
}
}
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docker network disconnect my_app_net nginx // Disconnect custom network from ContainerName
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if apps are on same host, then you should connect both apps to same network
Explicit -p is very safe because all other ports are blocked!!!! so its very safe.
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docker network create --driver bridge my_app_net
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Containers should not rely on IP addresses for communication. DNS Should be used.
Custom Network have DNS Server built into them
default "bridge" network does not has DNS, use --link as workaround.
docker container exec -it my_nginx ping new_nginx
Container Names can be used as - DNS Hostnames , So, if there are 2 containes on same custom Network
They can ping each other using just "Container Names" which are DNS Names
