First, let’s discuss the common commands for Docker images.
Search for Images
You can use the docker search command to search for images stored in Docker Hub.
Command format:
docker search [OPTIONS] TERM
Parameters:
| Name, shorthand | Default | Description |
|---|---|---|
--automated |
false |
Only list automated build images |
--filter, -f |
Filter results based on specified criteria | |
--limit |
25 |
Maximum number of search results |
--no-trunc |
false |
Do not truncate output, display full output |
--stars, -s |
0 |
Only show results with stars not less than this value |
Example 1:
docker search java
After executing this command, Docker will search for image repositories containing the keyword “java” in Docker Hub. You will see a table similar to the following:
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
java Java is a concurrent, ... 1281 [OK]
anapsix/alpine-java Oracle Java 8 (and 7) ... 190 [OK]
isuper/java-oracle This repository conta ... 48 [OK]
lwieske/java-8 Oracle Java 8 Contain ... 32 [OK]
nimmis/java-centos This is docker images ... 23 [OK]
...
This table contains five columns with the following meanings:
1. NAME: Image repository name.
2. DESCRIPTION: Image repository description.
3. STARS: Number of stars for the image repository, indicating its popularity, similar to GitHub stars.
4. OFFICIAL: Indicates whether it is an official repository; images marked with [OK] are created and maintained by the official project teams of each software. From the results, we can see that the java image repository is an official repository, while others are not.
5. AUTOMATED: Indicates whether it is an automated build image repository.
Example 2:
docker search -s 10 java
Download Images [Important]
Use the docker pull command to download images from Docker Registry.
Command format:
docker pull [OPTIONS] NAME[:TAG|@DIGEST]
Parameters:
| Name, shorthand | Default | Description |
|---|---|---|
--all-tags, -a |
false |
Download all tags of the image |
--disable-content-trust |
true |
Ignore image verification |
Example 1:
docker pull java
After executing this command, Docker will download the latest version of the Java image from the java repository in Docker Hub.
Example 2:
This command can also specify the desired image tag and Docker Registry address, for example:
docker pull reg.itmuch.com/java:7
This allows you to download the Java image with tag 7 from the specified Docker Registry.
List Images [Important]
Use the docker images command to list the downloaded images.
After executing this command, you will see a table similar to the following:
REPOSITORY TAG IMAGE ID CREATED SIZE
java latest 861e95c114d6 4 weeks ago 643.1 MB
hello-world latest c54a2cc56cbb 5 months ago 1.848 kB
This table contains five columns with the following meanings:
1. REPOSITORY: Name of the image’s repository.
2. TAG: Image tag. The default is latest, indicating the most recent version.
3. IMAGE ID: Image ID, indicating the unique identifier of the image.
4. CREATED: Time the image was created.
5. SIZE: Size of the image.
Command format:
docker images [OPTIONS] [REPOSITORY[:TAG]]
Parameters:
| Name, shorthand | Default | Description |
|---|---|---|
--all, -a |
false |
List all images locally (including intermediate image layers, which are filtered out by default) |
--digests |
false |
Display digest information |
--filter, -f |
Display images that meet the conditions | |
--format |
Display images using a Go template file | |
--no-trunc |
false |
Do not truncate output, display complete image information |
--quiet, -q |
false |
Only display image IDs |
Example:
docker images
docker images java
docker images java:8
docker images --digests
docker images --filter "dangling=true" # Display dangling images
Delete Local Images [Important]
Use the docker rmi command to delete specified images.
Command format:
docker rmi [OPTIONS] IMAGE [IMAGE...]
Parameters:
| Name, shorthand | Default | Description |
|---|---|---|
--force, -f |
false |
Force delete |
--no-prune |
false |
Do not remove the process images of the image, by default remove |
Example 1: Delete the specified image by name.
docker rmi hello-world
This means deleting the hello-world image.
Example 2: Delete all images.
docker rmi -f $(docker images)
The -f parameter means to force deletion.
Save Images
Use the docker save command to save images.
Command format:
docker save [OPTIONS] IMAGE [IMAGE...]
Parameters:
| Name, shorthand | Default | Description |
|---|---|---|
--output, -o |
Write to a file, instead of STDOUT |
Example 1:
docker save busybox > busybox.tar
docker save --output busybox.tar busybox
Load Images
Use the docker load command to load images.
Command format:
docker load [OPTIONS]
Parameters:
| Name, shorthand | Default | Description |
|---|---|---|
--input, -i |
Load from file instead of STDIN | |
--quiet, -q |
false |
Load silently |
Example 1:
docker load < busybox.tar.gz
docker load --input fedora.tar
Build Images [Important]
Build images using a Dockerfile.
Command format:
docker build [OPTIONS] PATH | URL | -
Parameters:
| Name, shorthand | Default | Description |
|---|---|---|
--add-host |
Add custom host-to-IP mappings, format is (host:ip) | |
--build-arg |
Set build-time variables | |
--cache-from |
Images to use as cache sources | |
--cgroup-parent |
Optional parent cgroup for the container | |
--compress |
false |
Use gzip to compress build context |
--cpu-period |
0 |
Limit CPU CFS (Completely Fair Scheduler) period |
--cpu-quota |
0 |
Limit CPU CFS (Completely Fair Scheduler) quota |
--cpu-shares, -c |
0 |
CPU weight (relative weight) |
--cpuset-cpus |
Specify allowed CPUs to execute | |
--cpuset-mems |
Specify allowed memory to execute | |
--disable-content-trust |
true |
Ignore verification |
--file, -f |
Specify the name of the Dockerfile, default is ‘PATH/Dockerfile’ | |
--force-rm |
false |
Remove intermediate containers |
--iidfile |
Write the image ID to a file | |
--isolation |
Container isolation technology | |
--label |
Set metadata used by the image | |
--memory, -m |
0 |
Set memory limit |
--memory-swap |
0 |
Set the maximum value of swap to memory + swap; if set to -1 means unlimited swap |
--network |
default |
Set the network mode for RUN instructions during build |
--no-cache |
false |
Do not use cache during image build |
--pull |
false |
Always try to update to the new version of the image |
--quiet, -q |
false |
Silent mode, only output image ID after successful build |
--rm |
true |
Immediately remove intermediate containers after successful build |
--security-opt |
Security options | |
--shm-size |
0 |
Specify the size of the /dev/shm directory |
--squash |
false |
Compress the built layers into a new layer |
--tag, -t |
Set tag, format: name:tag, tag is optional | |
--target |
Set the target build stage during build | |
--ulimit |
Ulimit options |
Further Reading
Docker commands: https://docs.docker.com/engine/reference/commandline/docker/