Building our own images with a Dockerfile, I use Docker build command to build a new image from Dockerfile. How to Docker build image from Dockerfile. Let’s go!
The first Docker build images
To create a directory and a Dockerfile, the sample as below:
$ mkdir project $ cd project $ touch Dockerfile
The example Docker build the image from Dockerfile
$ vim Dockerfile
The content a Dockerfile as below:
# CentOS 7 Dockerfile # Docker build: # sudo docker build -t devopsroles/centos:latest . # Docker create: # sudo docker create -it --name centos -h centos devopsroles/centos # Docker start: # sudo docker start centos # Connect with bash # sudo docker exec -it centos bash FROM centos:latest MAINTAINER PHAN VAN HUU <pvhuu90@gmail.com> My blogs: devopsroles.com #Update centos RUN yum update -y && yum upgrade -y RUN yum -y install git curl net-tools wget vim # Install EPEL Repository RUN yum install -y epel-release # Clean CentOS 7 RUN yum clean all # Set the environment variables ENV HOME /root # Working directory WORKDIR /root # Default command CMD ["bash"]
Docker build image from Dockerfile
Running the Dockerfile use Docker build commands
$ cd project $ sudo docker build -t . $ sudo docker build -t devopsroles/centos:latest . $ sudo docker create -it --name centos -h centos devopsroles/centos
The result, Docker images devopsroles/centos as below:
$ sudo docker images
The output, docker images as below:
REPOSITORY TAG IMAGE ID CREATED SIZE devopsroles/centos latest c9ef43af9836 2 minutes ago 428.7 MB
The docker start container centos
$ sudo docker start centos $ sudo docker ps
The output below:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 2d1a8e53668f devopsroles/centos "bash" 43 seconds ago Up 4 seconds centos
The connect container bash
$ sudo docker exec -it centos bash
The output below:
[root@centos ~]# ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 172.17.0.2 netmask 255.255.0.0 broadcast 0.0.0.0 inet6 fe80::42:acff:fe11:2 prefixlen 64 scopeid 0x20<link> ether 02:42:ac:11:00:02 txqueuelen 0 (Ethernet) RX packets 8 bytes 648 (648.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 8 bytes 648 (648.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1 (Local Loopback) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 [root@centos ~]# ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. 64 bytes from 8.8.8.8: icmp_seq=1 ttl=127 time=68.7 ms 64 bytes from 8.8.8.8: icmp_seq=2 ttl=127 time=69.1 ms ^C --- 8.8.8.8 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1001ms rtt min/avg/max/mdev = 68.720/68.945/69.170/0.225 ms
Or test ping 8.8.8.8 from docker run command as below
$ sudo docker run centos ping 8.8.8.8 -c4
The output below:
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. 64 bytes from 8.8.8.8: icmp_seq=1 ttl=127 time=40.6 ms 64 bytes from 8.8.8.8: icmp_seq=2 ttl=127 time=41.7 ms 64 bytes from 8.8.8.8: icmp_seq=3 ttl=127 time=42.1 ms 64 bytes from 8.8.8.8: icmp_seq=4 ttl=127 time=40.1 ms --- 8.8.8.8 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3005ms rtt min/avg/max/mdev = 40.124/41.184/42.196/0.832 ms
Conclusion
Docker build image from Dockerfile. You can update and edit package from Dockerfile file. For example to install Nginx, PHP, MySQL package in Dockerfile file. Thank you for reading the DevopsRoles page!
