LASP HAPI Server

A HAPI server built on LaTiS. This project is based on LaTiS v3, which is currently under development.

HAPI (Heliophysics API) is an interoperable, REST-style interface to timeseries data. We implement version 3.0 of the specification.

LaTiS is a library for describing and manipulating scientific data. By building a HAPI server on LaTiS, we can reuse existing LaTiS capabilities to make datasets in a wide variety of formats available through a HAPI interface.

Getting Started

First, download the latest release of the latis-hapi script.

By default, running this script will start a HAPI server running on port 8080. It will look for FDML files in a directory called datasets in its working directory.

Visit http://localhost:8080/hapi/catalog to verify that your datasets are visible to the server.

Configuring Datasets

See Configuring Datasets for an example of creating and validating FDML files.

Configuring the /about Endpoint

The /about endpoint provides metadata to describe this server. The endpoint will fail to load if values are not set for its three required parameters id, title, and contact. You can optionally set values for description, contactId, and citation as well. See the HAPI spec for details about these parameters.

They are namespaced with latis.hapi.about.<param>, so to set a value for id, for example, configure the latis.hapi.about.id variable. There are three main ways to configure variables:

• configuration file
• environment variables
• Java properties

To configure them with a file, create a latis.conf file and start the server with the -J-Dconfig.file=<path to latis.conf> flag.

Here is an example latis.conf:

# latis.conf

latis {
  # Set /about endpoint values:
  hapi {
    about {
      id = "SERVER"
      title = "Your Server"
      contact = "[email protected]"
    }
  }

  # Enable the HAPI endpoint:
  services = [
    {type: "class", mapping: "/hapi", class: "latis.service.hapi.HapiService"}
  ]
}

Other Configuration

This server will run on port 8080 and serve datasets out of ./datasets by default. You can change the port, location of FDML files, or enable additional endpoints with configuration options.

Again, to configure the server, create a latis.conf file and start the server with the -J-Dconfig.file=<path to latis.conf> flag.

Here is another example latis.conf:

# latis.conf

latis {
  # Set the port:
  port = 8090

  # Set the directory containing FDML files:
  fdml.dir = <path to FDML files>
  
  # Set /about endpoint values:
  hapi {
    about {
      id = "SERVER"
      title = "Your Server"
      contact = "[email protected]"
    }
  }

  # Enable the DAP2 endpoint:
  services = [
    {type: "class", mapping: "/hapi", class: "latis.service.hapi.HapiService"},
    {type: "class", mapping: "/dap", class: "latis.service.dap2.Dap2Service"}
  ]
}