Backup docker container using shell script

j# Backup docker container using shell script

Backup

Using following shell script to backup docker container with date tag

#!/bin/bash
# backup-docker.sh <container_name> <registry_path>

container=$1            # <container_name>
repo_prefix=$2          # <registry>/<prefix>
registry=${repo_prefix//\/*/}

repo_name=$repo_prefix/`hostname`/$container
repo_path=$repo_name:`date +%Y%m%d`

docker commit $container $repo_path
docker login $registry
docker push $repo_path

Note: If following certification error occurred, follow the page below to install ceritficate.

Configure trust self generated ca certificate of docker registry

List repo

Using following shell command to list repo list in docker registry

curl https://bianxi:$PASSWORD@${registry}/v2/_catalog

Sample output

{"repositories":["bianxi/dnsmasq","bianxi/heart/dnsmasq"]}

List tags

Using follwing shell command to list tags for one repo in docker registry

echo curl https://bianxi:$PASSWORD@${registry}/v2/${repo}/tags/list

Sample output

{"name":"bianxi/heart/dnsmasq","tags":["20210620","20210621","20210622","20210623","20210624","20210625","20210626","20210627"]}

Get digest for tag

Get digest by pull image

docker pull registry.bx.net/bianxi/heart/dnsmasq:20210624

Sample output

20210624: Pulling from bianxi/heart/dnsmasq
...
22b5d63ad977: Already exists
8e2e66517d7e: Pull complete
Digest: sha256:7535af1f65524f9200b901fc31b9c779819e45c0502ef99605666842a319908f

Verify digest

curl https://bianxi:$PASSWORD@registry.bx.net/v2/bianxi/heart/dnsmasq/manifests/sha256:xxxxxxxxxxxxxxxx

curl -v --silent -H "Accept: application/vnd.docker.distribution.manifest.v2+json" -X GET https://bianxi:$PASSWORD@registry.bx.net/v2/bianxi/heart/dnsmasq/manifests/20210624 2>&1 | grep Docker-Content-Digest | awk '{print ($3)}'

Delete local repo

docker rmi registry.bx.net/bianxi/heart/dnsmasq:<tag>

Delete tag

curl -X DELETE https://bianxi:$PASSWORD@registry.bx.net/v2/bianxi/heart/dnsmasq/manifests/sha256:xxxxxxxxxxxxxxxx

Run garbage-collect

docker exec registry bin/registry garbage-collect --delete-untagged /etc/docker/registry/config.yml

Restart registry if necessary

docker restart registry