Import Weather in Insulae

What you need

• A postgresql database
• the schemas "foundation" and "world"
• g++, make, curl, libcurl4-openssl-dev libpq-dev libpqxx-dev
• an OpenWeathermap.org api key

Dependencies

• Tencent/rapidjson
• jpbarrette/curlpp
• gabime/spdlog

Creating relevant subfolders

mkdir bin
mkdir log
mkdir coverage

Creating the relevant tables

ReadWeatherSources needs two tables. One in which is the definition about the places to watch for the weather and the other is for holding the current weather. The table definitions can be found in: db/createTables.sql Have in mind that are to schemas, foundation and world, are a requirement.

Use your favored psql tool to create both tables. On the bash it can be something like this:

psql -U {user_name} -d {database_name} -f db/createTables.sql -h {host_name}

If everything is right there should now both tables in your database.

Getting an OpenWeatherMap api key

To read data from the openweathermap.org api, we need to create an account and request an api key. Please refer to https://home.openweathermap.org/users/sign_up for the details.

Adjust the config file

In the file "insulae.cfg" the central config is stored

dbname=[INSERT DATABASE NAME]
user=[INSERT DATABASE USER]
password=[INSERT DATABASE PASSWORD]
hostaddr=[INSERT THE HOST IP ADDRESS]
port=5432
logdir=log/
batchlogfile=batch.log
weatherjobname=ReadWeatherSource
appid=[INSERT YOUR OpenWeathermap API KEY]

Insert your values and your're set.

Install OS dependencies

In order to run, we need some software components. On modern debian systems you can install them via apt. For other destribution please refer to the designated repostories.

apt-get install g++ make curl libcurl4-openssl-dev libpq-dev libpqxx-dev

Intialise the submodules

We need the submodules before we can compile or even run the programm.

git submodue update --init

Please refer to the separate README files if and how to build the submodules.

Compile the programm

Now we can compile everything. Simply run:

make

You should see the following output

export GLIBCXX_FORCE_NEW=true                                                                                                                                                                                                                                                                                                                                                               
g++ -std=c++17 -flto -pthread -D_FORTIFY_SOURCE=2 -pie -fPIE -ftrapv -Wl,-z,relro,-z,now -fpic -fvisibility=hidden -fstack-check -fstack-protector-all --param ssp-buffer-size=1 -fmessage-length=0 -O3 src/Batch.cpp src/Weather.cpp src/WeatherFactory.cpp src/ReadWeatherSource.cpp -lpqxx -lpq -Llib -lcurlpp -lcurl -Isrc -I/usr/include/postgresql -I frameworks/rapidjson/include/ -I
 frameworks/spdlog/include/ -I/usr/include -Iinclude -includelibpq-fe.h -o bin/ReadWeatherSource                                                                                                                                                                                                                                                                                            
export GLIBCXX_FORCE_NEW=false                                                                                                                                                                                                                                                                                                                                                              

The output is in the subfolder bin, named "ReadWeatherSource"

Add a weathersource to watch

Now we are, theoretically, able to read current weather data and import it for further useage. But we need a definition what places we want to want. So we insert a new place in the table foundation.weathersource

INSERT INTO weathersource (id, locationname, active) VALUES ('3413829', 'Reykjavik', '1');

Running the program

Everythig is up, we can now run the programm for the first time.

bin/ReadWeatherSource

That's it. You now should have an entry in the table world.weather with the current data.

Important warning

The error handling in this sample is reduced because my regular used routines from https://git.janhkrueger.de/insulae/insulae-private are still not open for the public. So no fancy error handling. Nonetheless, there should be no nard errors or atomar explosions.