atlasplatformdocker/rta-influxdatasvc repository overview

⁠RTA Influx Data Service

This service is part of the RTA Toolkit Services suite.

It provides a data adapter for InfluxDB, to be exposed to users via the Gateway Service.

This service is intended to be used alongside the Session Service, Config Service, Stream Service (if live updates are required) and Gateway Service as a reverse proxy to bring the capabilties together. The Schema Mapping Service is also required as a support service, to describe the mapping between the InfluxDB domain model (measurements, fields) and the RTA domain model.

It is available as a binary for Windows and Linux, and as a Docker image.

This version only supports InfluxQL, not Flux.

⁠Schema

⁠Data Identity and Filter Expressions

The data identity is passed to the service in the URI:

http://myhost:2670/rta/v2/data/<identity>/timestamped/-

For this service, the data identity is an InfluxDB filter expression, in InfluxQL:

This expression is merged into the data retrieval query and must therefore come from a trusted source. Do not compose this filter expression directly from user data.

The expression is automatically wrapped in brackets in the query. You can use complex boolean expressions with relational comparisons.

⁠Publishing Schema Mappings

You must publish a Schema Mapping to the Schema Mapping Service.

You must define:

The field_mappings enable the service to select fields matching the incoming RTA channel-based request.

Each FieldMapping looks like this:

⁠Sample

In JSON format:

{
  "dataSource": "mydata",
  "dataIdentity": "someData='50835ebe-a7f6-453b-9efd-c956e6da09f4'",
  "schemaMapping": {
    "properties": {
      "dialect": "influxql",
      "database": "mydb",
      "measurement": "mydata"
    },
    "fieldMappings": [
      {
        "sourceField": "aaa",
        "targetChannel": 0
      },
      {
        "sourceField": "bbb",
        "targetChannel": 1
      },
      {
        "sourceField": "ccc",
        "targetChannel": 2
      }
    ],
    "eventMappings": []
  }
}

In this example, an RTA request for channels 1,2 would translate to an InfluxQL query like this:

SELECT "bbb", "ccc" FROM "mydb"."autogen"."mydata" WHERE (someData='50835ebe-a7f6-453b-9efd-c956e6da09f4')

⁠Usage

⁠Docker

InfluxDB 1.8+:

docker run --rm \
  -e RTA_DataSource=mydata \
  -e RTA_SchemaMappingGrpcUri=http://myhost:2682/ \
  -e RTA_InfluxUri=http://myhost:8086/ \
  -e RTA_MaxFrequency=100 \
  -p 2690:2690 -p 2691:2691 \
  mclarenapplied/rta-influxdatasvc

Earlier versions:

docker run --rm \
  -e RTA_DataSource=mydata \
  -e RTA_SchemaMappingGrpcUri=http://myhost:2682/ \
  -e RTA_InfluxUri=http://myhost:8086/ \
  -e RTA_InfluxHealthCheckPath=/ping \
  -e RTA_MaxFrequency=100 \
  -p 2690:2690 -p 2691:2691 \
  mclarenapplied/rta-influxdatasvc

⁠Command Line

rta-influxdatasvc --DataSource mydata --SchemaMappingGrpcUri "http://myhost:2682/" --InfluxUri "http://myhost:8086/" --MaxFrequency 100

⁠Ports

There is no GRPC interface, and you cannot write data using this service.

⁠Monitoring

HTTP GET / : Returns 200 OK and reports the software version. In Kubernetes, use this for liveness probes.

HTTP GET /health : Returns 200 OK if the service is up and both InfluxDB and the Schema Mapping Service are reachable and healthy.
In Kubernetes, use this for readiness probes.

HTTP GET /metrics : Prometheus⁠ metrics, including the health check status.

⁠Configuration

The service must be configured with URIs to InfluxDB and the Schema Mapping Service.

Options can be set using both environment variables and command line arguments, or by the provided appsettings.config JSON configuration file.

Environment variables are all prefixed with RTA_, and can be written in ALLCAPS or MixedCase.
For example, DataSource is RTA_DATASOURCE or RTA_DataSource.

For Linux and on Kubernetes, also replace : with __.
For example, Category:Item is RTA_CATEGORY__ITEM.

⁠Authentication and Authorization

These options enable OAuth 2.0 support.

Bearer tokens are forwarded to the configured services.

⁠Schema Mapping Defaults

These options specify default Schema Mapping properties if not specified via the Schema Mapping Service.