Hai semuanya, di materi kali ini kita akan membahas tentang Labeling pada suatu image yang kita build yaitu sebagai berikut:

The LABEL instruction adds metadata to an image. A LABEL is a key-value pair. To include spaces within a LABEL value, use quotes and backslashes as you would in command-line parsing. A few usage examples:

LABEL "com.example.vendor"="ACME Incorporated"
LABEL com.example.label-with-value="foo"
LABEL version="1.0"
LABEL description="This text illustrates \
that label-values can span multiple lines."

The MAINTAINER instruction sets the Author field of the generated images. The LABEL instruction is a much more flexible version of this and you should use it instead, as it enables setting any metadata you require, and can be viewed easily, for example with docker inspect. To set a label corresponding to the MAINTAINER field you could use:

MAINTAINER "someone@something.com" # deprecated
LABEL maintainer="someone@something.com"

For Example:

Jika di jalankan maka hasilnya seperti berikut:

➜ bootcamp docker build -t dimmaryanto93/centos:0.5 .                               
[+] Building 0.2s (8/8) FINISHED
 => [internal] load build definition from Dockerfile                                 0.0s 
 => => transferring dockerfile: 371B                                                 0.0s 
 => [internal] load .dockerignore                                                    0.0s 
 => => transferring context: 34B                                                     0.0s 
 => [internal] load metadata for docker.io/library/centos:7                          0.0s 
 => [internal] load build context                                                    0.0s 
 => => transferring context: 494B                                                    0.0s 
 => [1/3] FROM docker.io/library/centos:7                                            0.0s 
 => CACHED [2/3] RUN mkdir -p /usr/share/nginx/html                                  0.0s 
 => [3/3] ADD . /usr/share/nginx/html                                                0.0s 
 => exporting to image                                                               0.0s 
 => => exporting layers                                                              0.0s 
 => => writing image sha256:6ca624eebf09de934c436767d7ba8c5b58b6449f7543f74b7aca089  0.0s 
 => => naming to docker.io/dimmaryanto93/centos:0.5

➜ bootcamp docker images
REPOSITORY             TAG       IMAGE ID       CREATED         SIZE
dimmaryanto93/centos   0.5       6ca624eebf09   2 minutes ago   204MB
dimmaryanto93/centos   0.4       7109257718d3   4 hours ago     204MB
dimmaryanto93/centos   0.3       e4e14fbbd628   5 hours ago     204MB
dimmaryanto93/centos   0.2       22b22460babc   7 hours ago     204MB
dimmaryanto93/centos   0.1       53126b30ada3   19 hours ago    204MB

➜ bootcamp docker image inspect dimmaryanto93/centos:0.5 -f '{{json .Config.Labels}}'
{
   "com.maryanto.dimas.image.authors":"software.dimas_m@icloud.com",
   "com.maryanto.dimas.vendor":"PT. Tabeldata Informatika",
   "maintaniner":"software.dimas_m@icloud.com",
   "org.label-schema.build-date":"20201113",
   "org.label-schema.license":"GPLv2",
   "org.label-schema.name":"CentOS Base Image",
   "org.label-schema.schema-version":"1.0",
   "org.label-schema.vendor":"CentOS",
   "org.opencontainers.image.created":"2020-11-13 00:00:00+00:00",
   "org.opencontainers.image.licenses":"GPL-2.0-only",
   "org.opencontainers.image.title":"CentOS Base Image",
   "org.opencontainers.image.vendor":"CentOS",
   "version":"0.5"
}

Cleanup

Seperti biasa, setelah kita mencoba praktikan kita bersih-bersih dulu ya. berikut perintahnya: