dim

Docker Image Manager

DIM is a Docker Image Management utility. It's the perfect companion for your self-hosted private registry and provides useful commands to manage your docker images :

• Search and advanced search
• Image labels add / removal
• Image deletion (both locally and on your private registry)
• Show image details

Moreover, it brings to your private registries :

• Authentication and access controls
• Hooks on push / delete event

DIM works in two ways that are complementary :

• server mode : provides search feature for both the docker command line and dim client mode. Server mode also allows you to secure access to your private registry and provides an advanced hook configurations
• client mode : to manage images locally and on your private registry and to run advanced searches (only with dim server enabled)

Finally, dim server mode is totally compatible with docker command line so you can docker login, docker pull, docker push, and even docker search against your private registry

Installation

DIM is written in go so it is easy to install. Moreover a docker image is available to easily setup the server mode.

Client installation

To run dim in client mode, simply download the latest binary from the release page and give it execution permission.

curl -L https://github.com/nhurel/dim/releases/download/<version>/dim-linux-x64 -o dim
chmod a+x dim
./dim help

Server installation

The easiest way to deploy dim in server mode is to use the docker image as documented in SERVER.md in the doc directory. Otherwise, it's obviously possible to install the same binary as for client installation and run it with dim server command.

Configuration (client and server mode)

All dim commands may need to access a private registry, so the global command line flags are available :

• --registry-url : hostname or full URL to the docker registry
• --registry-user : username to authenticate on the registry
• --registry-password : password to authenticate on the registry

As it may be cumbersome to always provide these flags, those values can be given through the following environment variables :

• REGISTRY_URL
• REGISTRY_USER
• REGISTRY_PASSWORD

Finally, dim will also search for those settings in the dim.yml config file that can be located :

• in current directory
• in $HOME/.dim/ directory

Managing images using dim

Pretty print an image details :

Dim show command can print image details of docker images :

$ dim show redis:latest
Name :  redis:latest
Id :  sha256:a858478874d144f6bfc03ae2d4598e2942fc9994159f2872e39fae88d45bd847
Labels:

Tags:
redis:latest

Ports :
6379/tcp = {}

Volumes:
/data = {}

Env :
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
 GOSU_VERSION=1.7
 REDIS_VERSION=3.2.9
 REDIS_DOWNLOAD_URL=http://download.redis.io/releases/redis-3.2.9.tar.gz
 REDIS_DOWNLOAD_SHA=6eaacfa983b287e440d0839ead20c2231749d5d6b78bbe0e0ffa3a890c59ff26

Entrypoint : [docker-entrypoint.sh]
Command : [redis-server]

Using -r flag you can even print details of an image hosted on your private registry without pulling it first

Adding / Editing labels on an image :

Dim lets you add or edit your image labels with the dim label command.

Update image labels locally

Using -o flag, dim will override the current image with the labeled one :

dim label add -o ubuntu:vivid my_label=value my_other_label=another.value

To make sure the image you're editing is up to date, you can use the -p flag to force dim to download the image before applying labels :

dim label add -o -p ubuntu:vivid my_label=value my_other_label=another.value

Save the labeled image under a different tag

To leave the original image untouched and apply the label in a dedicated image, use the -t flag. For example this will create a new image ubuntu:vivid_with_label leaving ubuntu:vivid untouched :

dim label add ubuntu:vivid my_label=value my_other_label=another.value -t ubuntu:vivid_with_label

Label an image and push it to your registry

Finally, dim can automatically push the labeled image to a registry with the -r flag :

# Add a label on an officiel docker hub image and save the result on your registry
dim label add ubuntu:vivid my_label=value my_other_label=another.value -t private-registry/ubuntu:vivid_with_label -r

# Add a label on your custom image and push the result in your registry
dim label add private-registry/my_image:latest my_label=value -p -o -r

Removing labels on an image

Label removal is done with the same dim label command using the -d flag. Keep in mind that removing a label from on image is not possible with docker, so dim will simply put the label value to an empty value. Nevertheless, when dim server will index the image, it won't index empty labels so the image won't match query based on this label.

dim label -d private-registry/my_image:latest my_label_to_delete -p -o -r

Searching an image

Whether you want to search images with docker command or dim command, you will need to deploy dim in server mode first.

Running simple searches with docker command

Once you have your private registry and dim service up and running, you can search your private registry with :

docker search private-registry/my_query

This will search in all your images names and tags

Running simple and advanced queries with dim

Simple searches

Assuming you've configured the registry info for your dim client, dim search command let you search your images by name or tag with the simple syntax :

dim search image_name

Like all other dim command, you can specify only the registry-url setting and dim will ask you your username and password interactively :

dim search --registry-url=private-registry image_name

Advanced searches

Using the -a flag, you can run advanced searches against your private registry.

Search all images with a given label

You can find all images having a specific label key with the Labels: prefix :

dim search -a Labels:label_key

This supports also fuzzy searches, using the following syntax :

dim search -a Labels:label_*
dim search -a Labels:/.*bel_.*/

Finally, you can find all images with a specific label value using the Label. prefix :

dim search -a Label.label_key:value

This also support fuzzy searches on values :

dim search -a Label.label_key:/val.*/

Search all images with given environment variable

You can find all images having a specific environment variable with the Envs: prefix :

dim search -a Envs:JAVA_VERSION

Like labels searches, you can run fuzzy searches on envrionments variable names.

Also, you can search on a specific environment variable value with the Env. prefix :

dim search -a Env.JAVA_VERSION:/1.8.*/

Search images by tag or by name

Use the Tag: or Name: prefix to search for images by tag or name

dim search -a Tag:vivid
dim search -a Name:ubuntu

Search image by creation date

Use the Created field to search image created between dates.

dim search -a '+Created:>"2016-01-01" +Created:<"2016-02-01"'

Combining search criteria

You can run more advanced queries by using + and - operators like :

# Find all images with java 1.8 except ones with the label REJECTED=true
dim search -a "+Env.JAVA_VERSION:/1.8.*/ -Label.REJECTED:true"