Docker Search, Pull, and Vet an Image

arazzo: 1.0.1
info:
  title: Docker Search, Pull, and Vet an Image
  summary: Search the registry for an official image, pull it, then inspect its metadata and layer history before use.
  description: >-
    A supply-chain-aware discovery flow. Rather than pulling a name someone typed,
    this workflow searches the registry filtered to official images, pulls the top
    match, and then vets what actually arrived by inspecting the image metadata and
    walking its layer history. The history walk is what lets a reviewer or an agent
    see how the image was assembled before anything is run from it. Every step
    spells out its request inline so the flow can be read and executed without
    opening the underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: dockerEngineApi
  url: ../openapi/docker-openapi.yml
  type: openapi
workflows:
- workflowId: search-and-pull-image
  summary: Search for an image, pull the best match, and vet its metadata and layers.
  description: >-
    Validates registry credentials, searches for images matching a term with a
    star and official filter, pulls the requested image and tag, then inspects the
    image and its layer history so the caller can vet it before running it.
  inputs:
    type: object
    required:
    - term
    - image
    - tag
    properties:
      term:
        type: string
        description: Term to search the registry for (e.g. "postgres").
      image:
        type: string
        description: Name of the image to pull once the search has been reviewed.
      tag:
        type: string
        description: Tag of the image to pull (e.g. "16-alpine").
      searchLimit:
        type: integer
        description: Maximum number of search results to return.
      searchFilters:
        type: string
        description: 'JSON-encoded search filters, e.g. {"is-official":["true"],"stars":["100"]}.'
      username:
        type: string
        description: Registry username, when vetting against a private registry.
      password:
        type: string
        description: Registry password or token.
      serveraddress:
        type: string
        description: Registry address (e.g. "https://index.docker.io/v1/").
      registryAuth:
        type: string
        description: Base64url-encoded auth configuration used for the pull.
  steps:
  - stepId: checkCredentials
    description: >-
      Validate credentials against the registry before pulling. Returns 200 with
      an identity token or 204 when the credentials are good.
    operationId: SystemAuth
    requestBody:
      contentType: application/json
      payload:
        username: $inputs.username
        password: $inputs.password
        serveraddress: $inputs.serveraddress
    successCriteria:
    - condition: $statusCode == 200 || $statusCode == 204
    outputs:
      status: $response.body#/Status
  - stepId: searchImages
    description: >-
      Search the registry for the term, filtered so that only well-starred or
      official repositories come back. This is the step that turns a guessed image
      name into a vetted candidate.
    operationId: ImageSearch
    parameters:
    - name: term
      in: query
      value: $inputs.term
    - name: limit
      in: query
      value: $inputs.searchLimit
    - name: filters
      in: query
      value: $inputs.searchFilters
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.length > 0
      type: jsonpath
    outputs:
      topMatch: $response.body#/0/name
      topMatchStars: $response.body#/0/star_count
      topMatchOfficial: $response.body#/0/is_official
      results: $response.body
  - stepId: pullImage
    description: >-
      Pull the chosen image and tag into the local image store. Note that omitting
      a tag pulls every tag for the repository, so the tag is always supplied here.
    operationId: ImageCreate
    parameters:
    - name: fromImage
      in: query
      value: $inputs.image
    - name: tag
      in: query
      value: $inputs.tag
    - name: X-Registry-Auth
      in: header
      value: $inputs.registryAuth
    successCriteria:
    - condition: $statusCode == 200
  - stepId: inspectImage
    description: >-
      Inspect what actually arrived — the image id, repo digests, architecture,
      and the config the image will run with by default.
    operationId: ImageInspect
    parameters:
    - name: name
      in: path
      value: $inputs.image
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      imageId: $response.body#/Id
      repoDigests: $response.body#/RepoDigests
      architecture: $response.body#/Architecture
      os: $response.body#/Os
      config: $response.body#/Config
  - stepId: readHistory
    description: >-
      Walk the image's parent layers to see how it was assembled. This is the
      supply-chain check: each entry carries the command that created the layer and
      its size.
    operationId: ImageHistory
    parameters:
    - name: name
      in: path
      value: $inputs.image
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      layers: $response.body
  outputs:
    topMatch: $steps.searchImages.outputs.topMatch
    imageId: $steps.inspectImage.outputs.imageId
    repoDigests: $steps.inspectImage.outputs.repoDigests
    layers: $steps.readHistory.outputs.layers