This is another article which is focusing the content about docker. Docker itself is a container platform for running services. In its official website in this link, docker claims to be an only independent container platform that enables organizations to seamlessly build, share and run application, anywhere — from hybrid cloud to the edge. Furthermore, in that link, container is a standardized unit of software. Using docker platform, there can be lots of various software in the local machine. Those software is in the form of docker images. Furthermore, there is a specific command for listing those available docker images in the local machine.
Retrieving docker images is very easy. Just read the following link with the title of ‘How to Pull a Docker Image from Public Docker Registry’ to be able to get or to pull the suitable docker images. After successfully pulling docker images from either public or private docker registry, it will be available in the local machine.
Listing the available docker images in the local machine
The following command is a specific command to list all of them. Just execute the following command pattern :
Using the above command pattern, just execute it in the machine where it has docker installed :
user@hostname:~$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE centos-nginx_web latest 36c49ff2d3bc 2 days ago 457MB apache_image latest 2051d26d51fa 2 days ago 1.61GB mariadb latest 7aca88b09cc5 5 days ago 356MB wordpress latest 42a9bf5a6127 5 days ago 502MB busybox latest 19485c79a9bb 13 days ago 1.22MB php apache aa4bdc74350b 2 weeks ago 414MB php 7.1-apache 1b3f4ce0de58 3 weeks ago 405MB centos 7 67fa590cfc1c 4 weeks ago 202MB centos latest 67fa590cfc1c 4 weeks ago 202MB ubuntu latest a2a15febcdf3 4 weeks ago 64.2MB tomcat latest 6e30b06a90d3 4 weeks ago 506MB mysql 5.7 e1e1680ac726 5 weeks ago 373MB mysql latest 62a9f311b99c 5 weeks ago 445MB mysql/mysql-cluster latest 67fd04af4b8e 7 weeks ago 338MB mysql/mysql-server 5.7 d1469951af27 8 weeks ago 262MB tensorflow/tensorflow latest 7f03c4ff368a 2 months ago 1.17GB centos 9f38484d220f 6 months ago 202MB registry 2 f32a97de94e1 6 months ago 25.8MB hello-world latest fce289e99eb9 8 months ago 1.84kB apache-php5 latest 6bb5b2e462f9 17 months ago 479MB user@hostname:~$
The above command execution of ‘docker images’ will list all of the available docker images in the local machine. What about presenting or displaying only a certain docker image ?. Actually, there is a modification of the command itself just to list certain docker image. Just modify the command by adding certain filter. Actually, the implementation of that filter is very simple. Just add an additional command for filtering the output of the command with certain character pattern as the filter as follows :
user@hostname:~$ docker images | grep mysql mysql 5.7 e1e1680ac726 5 weeks ago 373MB mysql latest 62a9f311b99c 5 weeks ago 445MB mysql/mysql-cluster latest 67fd04af4b8e 7 weeks ago 338MB mysql/mysql-server 5.7 d1469951af27 8 weeks ago 262MB user@hostname:~$
Since there is an additional output filter in the above command execution, the output will be different with the previous one. That filter is printing only the docker image which is match with the character specified in the ‘grep’ command filter.