Tutorial

This tutorial explains how to configure the timeseries interface of the EDR plugin when using Docker.

The timeseries interface is optional: it is served only if the timeseries_url attribute is defined in the EDR plugin configuration file. The query syntax is described on the Using the Timeseries API page.

Prereqs

Docker software has been installed on some Linux server where you have access to and the smartmetserver docker container is up and running. The EDR plugin and the configuration file it uses have been defined in the main configuration file smartmet.conf already.

File edr.conf

The purpose of the file "edr.conf" is to define configuration attributes so that the EDR plugin can fetch the meteorological time series information over the Web using the HTTP protocol for a specific time or time interval chosen by the user. HTTP request contains the parameters needed to obtain the information in response to a query. It contains also the parameters needed for processing the results and formatting the output.

If you followed the “SmartMet Server Tutorial (Docker)” you have your configuration folders and files in the host machine at $HOME/docker-smartmetserver/smartmetconf but inside Docker they show up under /etc/smartmet.

1. Go to the correct directory and enter command below to review the file:

$ less edr.conf

2. Use Nano or some other editor to enable/disable configuration attributes or to change their values if needed.

Configuration attributes

timeseries_url

This attribute enables the timeseries interface and defines the URL path (or an array of URL paths) it is served at. If the attribute is not defined, only the EDR API is served.

url            = "/edr";
timeseries_url = "/timeseries";

language

This attribute defines the default language used in the response of a request (e.g. "fi", "sv", "en").

language             = "en";

locale

This attribute defines the default locale value (e.g. "fi_FI", "en_US.utf8") of the names and abbreviations used for week days (Sunday, monday / Sun, Mon, etc.) and months (January, February / Jan, Feb, etc.).

locale               = "en_US.utf8";

observation_disabled

This attribute can be used to enable/disable the usage of the Observation-engine. It can have values "true" or "false". The Grid-engine and the Avi-engine are disabled in the same way with the attributes gridengine_disabled and aviengine_disabled.

observation_disabled = true;

geometry_tables

The PostGIS shapes used for areas and paths are configured in the geometry_tables section. Leave the section out if PostGIS shapes are not used. Note that the standalone TimeSeries plugin used a postgis section for the same purpose.

geometry_tables:
{
        server  = "";           // default server of the gis-engine
        schema  = "fminames";
        table   = "kunnat";
        field   = "kuntanimi";
};

precision

This attribute is used to define a list of precision names that can be used with the "precision" parameter when requesting the data. Typically the following precision names are defined:

• normal
• double
• full

In addition to this, the meaning of these attributes is also defined on the parameter level later in this configuration file. In other words, the "normal" precision for the parameter X might be 2 decimals while the "normal" precision for the parameter Z might be 5 decimals. All the precision attributes are defined in the configuration file.

The optional enabled_timeseries list is used for timeseries requests only. It makes it possible to use a different default precision (the first name of the list) for the timeseries interface than for the EDR API. If it is not defined, enabled is used for both.

precision:
{
        // default is the first one listed

        enabled            = ["auto","normal","double","full"];
        enabled_timeseries = ["normal","double","full","auto"];

    // normal output mode for meteograms & tables

    normal:
    {
                default                 = 0;
                Precipitation1h        = 1;
        SigWaveHeight        = 1;
        CorrectedReflectivity    = 1;
        TotalPrecipitationF0    = 1;
        TotalPrecipitationF10    = 1;
        TotalPrecipitationF25    = 1;
        TotalPrecipitationF50    = 1;
        TotalPrecipitationF75    = 1;
etc...

    // double precision for graphs

    double:
    {
        default            = 1;

        PrecipitationForm    = 0;
        PrecipitationType    = 0;
        WeatherSymbol1        = 0;
        WeatherSymbol3        = 0;

        CorrectedReflectivity    = 2;
        TotalPrecipitationF0    = 2;
        TotalPrecipitationF10    = 2;
etc...

    // full precision for math etc

    full:
    {
        default            = 16;

        PrecipitationForm    = 0;
        PrecipitationType    = 0;
        WeatherSymbol1        = 0;
        WeatherSymbol3        = 0;
    };

Note: You can review the attributes table for more details about the attributes that affect timeseries requests, and the EDR Plugin Configuration Guide for the EDR specific ones.

3. Test the plugin. The URL of the HTTP request contains parameters that have to be delivered to the plugin. For example, the following request fetches the temperature forecasted for the city of Helsinki:

http://hostname:8080/timeseries?format=debug&place=Helsinki&param=name,time,temperature

Note: Replace hostname with your host machine name, by localhost or by host-ip. This depends on where you have the container you are using.