smcgannon / gcs-resource

Concourse resource for interacting with Google Cloud Storage

GCS Resource

Versions objects in a Google Cloud Storage (GCS) bucket, by pattern-matching filenames to identify version numbers.

This resource is based on the official S3 resource.

Source Configuration

• bucket (required): the name of the bucket.

• json_key (required): the contents of your GCS Account JSON Key file to use when accessing the bucket. Example:

  json_key: |
    {
      "private_key_id": "...",
      "private_key": "...",
      "client_email": "...",
      "client_id": "...",
      "type": "service_account"
    }
  

File Names

One of the following two options must be specified:

• regexp: the pattern to match filenames against within GCS. The first grouped match is used to extract the version, or if a group is explicitly named version, that group is used.

  The version extracted from this pattern is used to version the resource. Semantic versions, or just numbers, are supported. Accordingly, full regular expressions are supported, to specify the capture groups.

• versioned_file: if you enable versioning for your GCS bucket then you can keep the file name the same and upload new versions of your file without resorting to version numbers. This property is the path to the file in your GCS bucket.

Initial state

If no resource versions exist you can set up this resource to emit an initial version with a specified content. This won't create a real resource in GCS but only create an initial version for Concourse. The resource file will be created as usual when you get a resource with an initial version.

You can define one of the following two options:

• initial_path: Optional. Must be used with the regexp option. You should set this to the file path containing the initial version which would match the given regexp. E.g. if regexp is file/build-(.*).zip, then initial_path might be file/build-0.0.0.zip. The resource version will be 0.0.0 in this case.

• initial_version: Optional. Must be used with the versioned_file option. This will be the resource version.

By default the resource file will be created with no content when get runs. You can set the content by using one of the following options:

• initial_content_text: Optional. Initial content as a string.

• initial_content_binary: Optional. You can pass binary content as a base64-encoded string.

Behavior

check: Extract versions from the bucket.

Objects will be found via the pattern configured by regexp or versioned_file. The versions will be used to order them (using semver). Each object's filename is the resulting version.

in: Fetch an object from the bucket.

Places the following files in the destination:

• (filename): the file fetched from the bucket.

• url: a file containing the URL of the object.

• version: the version identified in the file name (only if using regexp).

• generation: the object's generation (only if using versioned_file).

Parameters

• skip_download: Optional. If true, skip downloading object from GCS.

  This is useful to trigger a job that does not utilize the file, or to skip the implicit get after uploading a file to GCS using put (using get_params).

• unpack: Optional. If true and the file is an archive (tar, gzipped tar, other gzipped file, or zip), unpack the file. Gzipped tarballs will be both ungzipped and untarred.

out: Upload an object to the bucket.

Given a file specified by file, upload it to the GCS bucket. If regexp is specified, the new file will be uploaded to the directory that the regex searches in. If versioned_file is specified, the new file will be uploaded as a new version of that file.

Parameters

• file (required): path to the file to upload, provided by an output of a task. If multiple files are matched by the glob, an error is raised. The file which matches will be placed into the directory structure on GCS as defined in regexp in the resource definition. The matching syntax is bash glob expansion, so no capture groups, etc.

• predefined_acl (optional): the predefined ACL for the object. Acceptable values are:

  • authenticatedRead: Object owner gets OWNER access, and allAuthenticatedUsers get READER access.
  • bucketOwnerFullControl: Object owner gets OWNER access, and project team owners get OWNER access.
  • bucketOwnerRead: Object owner gets OWNER access, and project team owners get READER access.
  • private: Object owner gets OWNER access.
  • projectPrivate: Object owner gets OWNER access, and project team members get access according to their roles.
  • publicRead: Object owner gets OWNER access, and allUsers get READER access.
  • publicReadWrite: Object owner gets OWNER access, and allUsers get READER and WRITER access.

• content_type (optional): sets the MIME type for the object to be uploaded, eg. application/octet-stream.

• cache_control (optional): sets the Cache-Control directive for the object to be uploaded.

Example Configuration

Resource Type

resource_types:
  - name: gcs-resource
    type: docker-image
    source:
      repository: frodenas/gcs-resource

Resource

resources:
  - name: release
    type: gcs-resource
    source:
      bucket: releases
      json_key: <GCS-ACCOUNT-JSON-KEY-CONTENTS>
      regexp: directory_on_gcs/release-(.*).tgz

Plan

- get: release

- put: release
  params:
    file: path/to/release-*.tgz
    predefined_acl: publicRead
    content_type: application/octet-stream
    cache_control: max-age=3600

Development

• Get the resource: go get github.com/frodenas/gcs-resource
• Run the unit-tests: make
• Run the integration-tests: make integration-tests
• Build the source code using concourse: fly -t ConcourseTarget execute -c ci/tasks/build.yml -i gcs-resource-src=. -o built-resource=.
• Build the Docker image to be use inside your pipeline: docker build -t frodenas/gcs-resource .

Contributing

Refer to the contributing guidelines.

License

Apache License 2.0, see LICENSE.