Docs

Download Resources from Component Versions

This guide shows how to view and download the resources of a component version. You will also learn how to download a complete component version as well as OCI artifacts.

Prerequisites

List the Resources of a Component Version

To list the resources found in a component version tree, use the command ocm get resources:

ocm get resources ghcr.io/open-component-model/ocm//ocm.software/toi/demo/helmdemo:0.12.0 --recursive -o tree
  COMPONENT                                       NAME           VERSION IDENTITY TYPE        RELATION
  └─ ocm.software/toi/demo/helmdemo                              0.12.0
     ├─                                           chart          0.12.0           helmChart   local
     ├─                                           config-example 0.12.0           yaml        local
     ├─                                           creds-example  0.12.0           yaml        local
     ├─                                           image          1.0              ociImage    external
     ├─                                           package        0.12.0           toiPackage  local
     └─ ocm.software/toi/installers/helminstaller installer      0.12.0
        ├─                                        toiexecutor    0.12.0           toiExecutor local
        └─                                        toiimage       0.12.0           ociImage    local

Download the Resources of a Component Version

Use the ocm download command to download resources such as component versions, individual resources or artifacts:

ocm download resource ghcr.io/open-component-model/ocm//ocm.software/toi/demo/helmdemo:0.12.0 chart -O helmchart.tgz
  helmchart.tgz: 4707 byte(s) written

Because it is stored as OCI artifact in an OCI registry, the filesystem format used for OCI artifacts is the blob format.

What happened?

The file helmchart.tgz was downloaded.

tar xvf helmchart.tgz
  x index.json
  x oci-layout
  x blobs
  x blobs/sha256.a9dd654eed17e786b5c5445e8bc48f3a47371c2efe392a53a3fbecd9e942b696
  x blobs/sha256.c8017985866ceb44c2426a4ad9a429d6aec1f6818cb6dccbf964623139c1d1d5
  x blobs/sha256.ea8e5b44cd1aff1f3d9377d169ad795be20fbfcd58475a62341ed8fb74d4788c
jq . index.json
{
  "schemaVersion": 2,
  "mediaType": "application/vnd.oci.image.index.v1+json",
  "manifests": [
    {
      "mediaType": "application/vnd.oci.image.manifest.v1+json",
      "digest": "sha256:c8017985866ceb44c2426a4ad9a429d6aec1f6818cb6dccbf964623139c1d1d5",
      "size": 410,
      "annotations": {
        "org.opencontainers.image.ref.name": "0.1.0",
        "software.ocm/tags": "0.1.0"
      }
    }
  ],
  "annotations": {
    "software.ocm/main": "sha256:c8017985866ceb44c2426a4ad9a429d6aec1f6818cb6dccbf964623139c1d1d5"
  }
}

Download with Download Handlers

To use a format more suitable for the content technology, enable the usage of download handlers.

If a download handler is available for the artifact type and the blob media type used to store the blob in the OCM repository, it will convert the blob format into a more suitable format:

ocm download resource -d ghcr.io/open-component-model/ocm//ocm.software/toi/demo/helmdemo:0.12.0 chart -O helmchart.tgz
  helmchart.tgz: 3763 byte(s) written
What happened?

The downloaded archive is now a regular Helm Chart archive:

tar tvf helmchart.tgz
  -rw-r--r--  0 0      0         136 Jul 19 16:32 echoserver/Chart.yaml
  -rw-r--r--  0 0      0        1842 Jul 19 16:32 echoserver/values.yaml
  -rw-r--r--  0 0      0        1755 Jul 19 16:32 echoserver/templates/NOTES.txt
  -rw-r--r--  0 0      0        1802 Jul 19 16:32 echoserver/templates/_helpers.tpl
  -rw-r--r--  0 0      0        1848 Jul 19 16:32 echoserver/templates/deployment.yaml
  -rw-r--r--  0 0      0         922 Jul 19 16:32 echoserver/templates/hpa.yaml
  -rw-r--r--  0 0      0        2083 Jul 19 16:32 echoserver/templates/ingress.yaml
  -rw-r--r--  0 0      0         367 Jul 19 16:32 echoserver/templates/service.yaml
  -rw-r--r--  0 0      0         324 Jul 19 16:32 echoserver/templates/serviceaccount.yaml
  -rw-r--r--  0 0      0         385 Jul 19 16:32 echoserver/templates/tests/test-connection.yaml
  -rw-r--r--  0 0      0         349 Jul 19 16:32 echoserver/.helmignore

Download an Image

For example, for OCI images, the OCI format is more suitable:

ocm download resource ghcr.io/open-component-model/ocm//ocm.software/toi/demo/helmdemo:0.12.0 image -O image.tgz
  image.tgz: 46181313 byte(s) written
What happened?

The file image.tgz was downloaded.

tar xvf image.tgz
  x index.json
  x oci-layout
  x blobs
  x blobs/sha256.06679f57dba70a6875e4ae5843ba2483ecab6ec48182ca8720ddc5b1863bad52
  x blobs/sha256.28c6282d04f63710146ace6c7be14a40c7ee6a71a2f91316928469e4aafe0d92
  x blobs/sha256.2d3e25b9e93ad26878862abee5ed02683206f6f6d57e311cdd1dedf3662b61c8
  x blobs/sha256.365ec60129c5426b4cf160257c06f6ad062c709e0576c8b3d9a5dcc488f5252d
  x blobs/sha256.4b12f3ef8e65aaf1fd77201670deb98728a8925236d8f1f0473afa5abe9de119
  x blobs/sha256.76d46396145f805d716dcd1607832e6a1257aa17c0c2646a2a4916e47059dd54
  x blobs/sha256.7fd34bf149707ca78b3bb90e4ba68fe9a013465e5d03179fb8d3a3b1cac8be27
  x blobs/sha256.b0e3c31807a2330c86f07d45a6d80923d947a8a66745a2fd68eb3994be879db6
  x blobs/sha256.bc391bffe5907b0eaa04e96fd638784f77d39f1feb7fbe438a1dae0af2675205
  x blobs/sha256.cb5c1bddd1b5665e1867a7fa1b5fa843a47ee433bbb75d4293888b71def53229
  x blobs/sha256.d5157969118932d522396fe278eb722551751c7aa7473e6d3f03e821a74ee8ec
  x blobs/sha256.e0962580d8254d0b1ef35006d7e2319eb4870e63dc1f9573d2406c7c47d442d2
jq . index.json
{
  "schemaVersion": 2,
  "mediaType": "application/vnd.oci.image.index.v1+json",
  "manifests": [
    {
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "digest": "sha256:cb5c1bddd1b5665e1867a7fa1b5fa843a47ee433bbb75d4293888b71def53229",
      "size": 2400,
      "annotations": {
        "org.opencontainers.image.ref.name": "1.10",
        "software.ocm/tags": "1.10"
      }
    }
  ],
  "annotations": {
    "software.ocm/main": "sha256:cb5c1bddd1b5665e1867a7fa1b5fa843a47ee433bbb75d4293888b71def53229"
  }
}

Download an Executable

The Open Component Model allows to publish platform-specific executables. In this case, the platform specification is used by convention as extra identity for the artifacts that are contained in the component version.

Example:

ocm get componentversion ghcr.io/open-component-model/ocm//ocm.software/ocmcli:0.1.0-dev -o yaml
...
    resources:
    - name: ocmcli
      extraIdentity:
        architecture: amd64
        os: linux
      relation: local
      type: executable
      version: 0.1.0-dev
      access:
        localReference: sha256:1a8827761f0aaa897d1d4330c845121c157e905d1ff300ba5488f8c423bc7cd9
        mediaType: application/octet-stream
        type: localBlob
    - name: ocmcli
      extraIdentity:
        architecture: arm64
        os: darwin
      relation: local
      type: executable
      version: 0.1.0-dev
      access:
        localReference: sha256:9976b18dc16ae2b2b3fc56686f18f4896d44859f1ea6221f70e83517f697e289
        mediaType: application/octet-stream
        type: localBlob
...

Note that the resources shown above have the same name and type executable but a different extra-identity. If a component version complies to this convention, executables can directly be downloaded for the specified platform with the use of the -x option. If only one executable is contained in the component version, the resource name can be omitted. Example:

ocm download resource -x --latest ghcr.io/open-component-model/ocm//ocm.software/ocmcli
  ocm: 83369938 byte(s) written
What happened?
file ocm

With the option --latest, the latest matching component version is used for download. With the option --constraints, version constraints can be configured. For example: --constraints 0.1.x will select all patch versions of 0.1. Together with --latest, the latest patch version is selected.

The option -x enables the executable download handler, which provides the x-bit of the downloaded files. Additionally, it filters all matching resources for executables and the correct platform.

Download a Full Component Version

Download entire component versions using the ocm download componentversion command:

ocm download componentversions ghcr.io/open-component-model/ocm//ocm.software/toi/demo/helmdemo:0.12.0 -O helloworld
  helloworld: downloaded

The result is a CTF archive. This can then be modified using the ocm add ... commands shown earlier.

What happened?

The component version was downloaded.

tree helloworld
  helloworld/
  ├── blobs
  │   ├── sha256.87cef1e2233bf5591030ac854e2556fbe6a00a28bb5640e25a9cb69ece519c5a
  │   ├── sha256.8a2fe6af4ce56249094622c9d618e24b4cfb461a7dfa6a42cce31749189bc499
  │   └── sha256.e790920a11de2016de64225280efcf062e14b767955f7508de64fd5192e3fb3a
  └── component-descriptor.yaml

Download OCI Artifacts

Download OCI artifacts from an OCI registry, such as OCI images, with the ocm download artifacts command:

ocm download artifact ghcr.io/open-component-model/ocm-controller:v0.24.0 -O ocm-controller
  ocm-controller: downloaded
What happened?

The OCI image echoserver was downloaded.

tree echoserver
  ocm-controller/
  ├── blobs
  │   ├── sha256.05d57e68048827c243cd477025f96064df9f4d83b8639ed04306f0647c9cfe78
  │   ├── sha256.0f8b424aa0b96c1c388a5fd4d90735604459256336853082afb61733438872b5
  │   ├── sha256.1069fc2daed1aceff7232f4b8ab21200dd3d8b04f61be9da86977a34a105dfdc
  │   ├── sha256.286c61c9a31ace5fa0b8832c8e8e30d66bf32138f2f787463235aa0071f714ea
  │   ├── sha256.2bdf44d7aa71bf3a0da2de0563ad0e3882948d699b4991edf8c0ab44e7f26ae3
  │   ├── sha256.35fddc32f468fc8d276fa1b6a72cac27f35a0080233c2ddc6a03fab224024dbc
  │   ├── sha256.3f4e2c5863480125882d92060440a5250766bce764fee10acdbac18c872e4dc7
  │   ├── sha256.452e9eed7ecfd0c2b44ac6fda20cee66ab98aec38ba30aa868e02445be7c8bb0
  │   ├── sha256.80a8c047508ae5cd6a591060fc43422cb8e3aea1bd908d913e8f0146e2297fea
  │   ├── sha256.9375d0c4fac611287075434624a464af5b6bb026947698a06577ad348f607d56
  │   ├── sha256.b40161cd83fc5d470d6abe50e87aa288481b6b89137012881d74187cfbf9f502
  │   ├── sha256.c8022d07192eddbb2a548ba83be5e412f7ba863bbba158d133c9653bb8a47768
  │   ├── sha256.d557676654e572af3e3173c90e7874644207fda32cd87e9d3d66b5d7b98a7b21
  │   └── sha256.d858cbc252ade14879807ff8dbc3043a26bbdb92087da98cda831ee040b172b3
  ├── index.json
  └── oci-layout
Prev
Create Component Versions
Next
Sign Component Versions