Writing AIS messages to a Postgres Database¶
As per full release v0.45, there is functionality to write messages to a database (PostgreSQL). The setup is fairly flexible and can be tailored to the particular needs. First create an empty PostgreSQL database, e.g on an Ubuntu distribution (this might be different on your system):
sudo -u postgres createdb ais
sudo -u postgres psql ais < create.sql
create.sql is in the directory DBMS in the AIS-catcher source directory. If you installed via the install script for Ububtu/Debian/Raspberry Pi it can be found in the directory /etc/AIS-catcher/DBMS.
Make sure you build the latest version of AIS-catcher with this dependency:
sudo apt install libpq-dev
For writing to a PSQL database from AIS-catcher, ensure that the user running the program is set up for writing to a PSQL database or specify the user explicitly in the connection string.
Ensure that the Now AIS-catcher can write the received messages to the database:
AIS-catcher -D dbname=ais STATION_ID 17
AIS-catcher -D postgresql://[user[:password]@][netloc][:port][/dbname]
STATION_ID setting is optional but will populate the entries in the database with the specified ID so multiple feeders can write to one database.
There are a few settings for the new -D switch of which the first is the connection string that specifies the database. If you want to use a space in the string use quotation marks around the string. There are other settings that define how tables will be populated:
| Table | Description | Settings | Default |
|---|---|---|---|
| ais_vessel | last received data per MMSI | V on/off | on |
| ais_message | received messages with meta data | MSGS on/off | off |
| ais_nmea | nmea sentences | NMEA on/off | off |
| ais_basestation | basestation messsages from type 4 | BS on/off | off |
| ais_sar_position | sar positions from type 9 | SAR on/off | off |
| ais_aton | aton messages from type 21 | ATON on/off | off |
| ais_vessel_pos | vessel position messages from type 1-3, 18, 19, 27 | VP on/off | off |
| ais_vessel_static | vessel static data from type 5, 19 | VS on/off | off |
| ais_property | specific key/value pairs with link to message | fill with keys specified in the table ais_keys | empty |
From hereon it is fairly straightforward to pick up this data and start analysis. If the connection fails during the decoding, for whatever reason, the program will try to reconnect to the database every 2 seconds. The maximum number of failed connection attempts before the program terminates is set with MAX_FAILS (<1000) and is set on the command line. If MAX_FAILS is 1000 the program will not terminate if the connection fails.
I hope this is sufficient to get you experimenting! Unfortunately, the options cannot yet be set from the JSON configuration file which is work in progress.
Summary Settings¶
| Key | Type | Default | Description |
|---|---|---|---|
| CONN_STR | string | dbname=ais | PostgreSQL connection string |
| STATION_ID | integer | 0 | Station identifier |
| INTERVAL | integer | 10 | Database write interval (5-1800 sec) |
| MAX_FAILS | integer | 10 | Max failed connection attempts |
| Table Options | |||
| V | boolean | true | Enable vessel table logging |
| MSGS | boolean | false | Enable message table logging |
| NMEA | boolean | false | Enable NMEA sentence logging |
| BS | boolean | false | Enable basestation logging |
| SAR | boolean | false | Enable SAR position logging |
| ATON | boolean | false | Enable AtoN logging |
| VP | boolean | false | Enable vessel position logging |
| VS | boolean | false | Enable vessel static data logging |