PiPS Configuration

Any global PiPS configuration file should be stored at the default path of /etc/system/config/pips.cfg on the target, or the path specified in the PIPS_CONFIG environment variable. At a minimum, this file should load all required providers by naming their library files, and specify the default provider. For example, the following configuration loads only the QNX Neutrino Message Passing (QNMP) provider, and sets it as the default:

{
    "providers":[ "pips-qnmp-provider.so" ],
    "default-provider":"QNMP",
}

In addition to loading the providers, the global file is meant to configure the elements of PiPS that are common to all provider implementations. The file can therefore have these fields:

The PiPS framework fails to initialize if the configuration file is malformed, and issues a warning when any of the following less serious issues occurs (but it continues to parse the file):

• A filename in the providers array is malformed.
• A provider's library file couldn't be opened.
• The provider indicated in default-provider isn't listed in providers (and hence, isn't loaded and registered).

The following is an example of a well-formed global configuration file:

{
    "verbosity":4,
    "domain-id":123,
    "providers":["pips-qnmp-provider.so","pips-fastrtps-provider.so"],
    "default-provider":"QNMP",
    "default-separator":".",
    "typedefs":{
        "QNMP":["NavMgr-plugin-qnmp.so","gal-plugin-qnmp.so","cp-plugin-qnmp.so"],
        "FASTRTPS":["NavMgr-plugin-fastrtps.so","gal-plugin-fastrtps.so","cp-plugin-fastrtps.so"],
    },
    "topics":[
        {"name":"example.quantity",   "type":"Number"},
        {"name":"example.toggle",     "type":"Boolean"},
        {"name":"example.text",       "type":"String"},
        {"name":"example.structured", "type":"JSON"},
        {"name":"example.opaque",     "type":"BLOB"},
        {"name":"example.mixed",      "type":"MultiMap"},
    ],
}

A provider configuration file defines parameters for the underlying middleware service (i.e., settings specific to the provider). Some of the supported fields are the same as those in the global file. When a field is defined in both places, the union of the settings is used for that provider only. You can define the following fields at either the global or provider level:

• domain-id
• topics
• typedefs (for Fast RTPS only)

For the QNMP provider, you can configure each publish-subscribe domain by setting the following fields within a domain-id object:

The following is an example of a QNMP provider configuration file:

{
    "domain-id:123":{
        "randomize-ids": false,
        "resource-limits":{
            "max-participants":256,
            "max-publications":256,
        }
    }
}

Within a topics array entry, in addition to the mandatory name and type fields, you can specify the resource limits and QoS settings in a hierarchy of JSON objects, as follows:

You can configure the transport layer used by the Fast RTPS provider by defining the transport object at the top level in the configuration file. This object can contain the following fields:

The following is an example of a Fast RTPS provider configuration file:

{
    "domain-id":0,
    "transport":{
        "port":{
            "base":7400,
            "gain":{
                "domain-id":250,
                "participant-id":2,
            },
            "offsets":{
                "d0": 0,
                "d1": 10,
                "d2": 1,
                "d3": 11,
            },
        },
        "locators":[
            {"type":"multicast", "protocol":"UDPv4", "address":"10.122.41.111"},
            {"type":"multicast", "protocol":"UDPv4", "address":"192.168.0.1"},
            {"type":"multicast", "protocol":"UDPv4", "address":"127.0.0.1"},
        ],
        "peers":[
            {"protocol":"UDPv4", "address":"192.168.0.2"},
        ],
    },
    "typedefs":[],
    "topics":[
        {
            "name":"qnxcar.drivetrain.propulsion_mode",
            "type":"String",
            "qos":{
                "history":{
                    "depth":1,
                    "policy":"last"
                },
                "reader":{
                    "durability":"volatile",
                    "reliability":"best-effort"
                },
                "writer":{
                    "durability":"local",
                    "reliability":"reliable"
                }
            },
        },
        {
            "name":"qnxcar.drivetrain.transmission.temperature",
            "type":"Number",
            "qos":{
                "history":{
                    "depth":3,
                    "policy":"last"
                }
            },
            "resource-limits":{
                "max-samples": 50,
                "max-instances": 2,
                "max-samples-per-instance": 50,
                "allocated-samples": 20
            },
        },
    ],
}