@koopjs/provider-s3-select

Koop provider for fetching data stored S3 with S3 Select. Files can be JSON, JSON lines, or CSVs. Note that CSV source files currently result in features with empty geometries.

Usage

Install

npm install @koopjs/provider-s3-select

Register

// initialize Koop
const Koop = require('koop')
const koop = new Koop()

// register
const s3SelectProvider = require('@koopjs/provider-s3-select')
koop.register(s3SelectProvider)

Configuration

The S3 Select provider uses the config module to store configuration settings in an object scoped to the koopProviderS3Select key. The following JSON provides an example configuration:

{
  "koopProviderS3Select": {
    "s3Path": "my-default-bucket", // default path
    "ttl": 300, // The TTL option is measured in seconds, it will be used to set the cache expiration entry
    "stores": {
      "my-store-key": {
        "s3Path": "my-other-bucket/a-folder", // specific path for this store
        "serialization": {
          "JSON": {
            "Type": "LINES"
          }  
        }
      }
    }
  }
}

key	type	description	required
`s3Path`	String	Default path-prefix that will be prepended to all requested files. Begins with the S3 bucket name and may include any sub-directory path.	No
`ttl`	Integer	Number of seconds to cache the data	No
`stores`	Object	key-value lookup used by the provider to fetch specific configuration information for a request. Each key in `stores` defines a valid value of the `:host` route parameter	Yes
`stores[<key>].s3Path`	String	Path-prefix that will be prepended to all file requests when `:host` is equal to `<key>`	No
`stores[<key>].serialization`	Object	S3 input serialization object. Informs S3 how files requested with a give `:host` value should be deserialized. See S3 documentation.	No

As noted above, s3Path is always optional, but if set,it should begin with the S3 bucket name and include any sub-directory path along which you want to restrict requests for fetching files. If s3Path is not set, the full S3 path to the file, including the bucket name, needs to be included in the request's :id parameter.

AWS Credentials

In order to use the provider (and its S3 sdk), you will need to set your AWS credentials as environment variables. See the AWS docs for details.

Request Parameters

Once the provider is registered with Koop, it will be available for all output services and will include the :host and :id route parameters.

parameter	type	desription
`:host`	String	Points the provider to an entry in the `koopProviderS3Select.stores` config object.
`:id`	String	The S3 path to a S3 file, with adjustments for any path prefix set in configuration with `s3Path`. Any forward slashes in the path should be replaced with `::` to avoid routing errors.

The Koop output service provides an example of the usage of these parameters. The pattern for the query service is:

/s3/:host/:id/FeatureServer/:layer/:method

An example request using this pattern is below:

/s3/json-lines/path::to::json::file.json/FeatureServer/0/query

In the above request, json-lines is the :host parameter and refers to a key in the configurations stores object. path::to::json::file.json is the :id parameter and is a partial path to an S3 file with all / replaced with ::. Using the s3Path from the json-lines entry of the configuration object, the noted request would fetch the file with the following path /my-other-bucket/a-folder/path/to/json/file.json.

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