Current progress of Helm 3 changes related to working with registries

helm-3-chart-command.md

Helm 3 chart command

Note: this is a work in progress, and is subject to change soon.

Chart Subcommands

save

save a chart directory

$ helm chart save mychart/ localhost:5000/myrepo/mychart:latest
Saving localhost:5000/myrepo/mychart:latest

list

list all saved charts

$ helm chart list
REF                                                     NAME                    VERSION DIGEST  SIZE            CREATED
localhost:5000/myrepo/mychart:latest                    mychart                 2.7.1   84059d7 454 B           27 seconds
localhost:5000/stable/acs-engine-autoscaler:latest      acs-engine-autoscaler   2.2.2   d8d6762 4.3 KiB         2 hours
localhost:5000/stable/aerospike:latest                  aerospike               0.2.1   4aff638 3.7 KiB         2 hours
localhost:5000/stable/airflow:latest                    airflow                 0.13.0  c46cc43 28.1 KiB        2 hours
localhost:5000/stable/anchore-engine:latest             anchore-engine          0.10.0  3f3dcd7 34.3 KiB        2 hours
...

export

export a chart to directory

$ helm chart export localhost:5000/myrepo/mychart:latest
Exported to mychart/

push

push a chart to remote

$ helm chart push localhost:5000/myrepo/mychart:latest
Pushing localhost:5000/myrepo/mychart:latest

pull

pull a chart from remote

$ helm chart pull localhost:5000/stable/wordpress:latest
Pulling localhost:5000/stable/wordpress:latest

remove

$ helm chart remove localhost:5000/myrepo/mychart:latest
Deleting localhost:5000/myrepo/mychart:latest

Chart Manifest

This is the manifest of a Helm chart as stored in a registry:

$ curl -s -H 'Accept: application/vnd.oci.image.manifest.v1+json' http://localhost:5000/v2/myrepo/mychart/manifests/latest | jq
{
  "schemaVersion": 2,
  "config": {
    "mediaType": "application/vnd.oci.image.config.v1+json",
    "digest": "sha256:44136fa355b3678a1146ad16f7e8649e94fb4fc21fe77e8310c060f61caaff8a",
    "size": 2
  },
  "layers": [
    {
      "mediaType": "application/vnd.cncf.helm.chart.meta.v1+json",
      "digest": "sha256:c356ec641a696eb5f3320bed9e8ceeb505fcc84b7ee072a85a8098fc362e13b7",
      "size": 210,
      "annotations": {
        "org.opencontainers.image.title": "chart-meta.json"
      }
    },
    {
      "mediaType": "application/vnd.cncf.helm.chart.content.v1+tar",
      "digest": "sha256:84059d7403f496a1c63caf97fdc5e939ea39e561adbd98d0aa864d1b9fc9653f",
      "size": 454,
      "annotations": {
        "sh.helm.chart.name": "mychart",
        "sh.helm.chart.version": "2.7.1",
        "org.opencontainers.image.title": "chart-content.tgz"
      }
    }
  ]
}

The manifest is built using deislabs/oras.

Here is an example of how Helm is using oras as a library for push/pull: https://github.com/jdolitsky/oras-helm-demo

Chart Storage

Chart content is currently stored locally in $HELM_HOME/registry:

$ tree ~/.helm/registry
/Users/me/.helm/registry
├── blobs
│   ├── content
│   │   └── sha256
│   │       └── 84
│   │           └── 059d7403f496a1c63caf97fdc5e939ea39e561adbd98d0aa864d1b9fc9653f
│   └── meta
│       └── sha256
│           └── c3
│               └── 56ec641a696eb5f3320bed9e8ceeb505fcc84b7ee072a85a8098fc362e13b7
├── charts
│   └── mychart
│       └── versions
│           └── 2.7.1
└── refs
    └── localhost:5000
        └── myrepo
            └── mychart
                └── tags
                    └── latest
                        ├── chart -> /Users/me/.helm/registry/charts/mychart/versions/2.7.1
                        ├── content -> /Users/me/.helm/registry/blobs/content/sha256/84/059d7403f496a1c63caf97fdc5e939ea39e561adbd98d0aa864d1b9fc9653f
                        └── meta -> /Users/me/.helm/registry/blobs/meta/sha256/c3/56ec641a696eb5f3320bed9e8ceeb505fcc84b7ee072a85a8098fc362e13b7

Note: This is using a simple filesystem layout, but this is subject to change. We will potentially use something like bbolt.