App store is a place where you can take piece of code that solves specific problem. App store also provides a central repository and its contents are curated, tested and maintained and it represent years of condensed experience and trial and error.
Brick is the something that is in app_store and that you are going to use. This is a working title and it is likely to change but what we try to convey with the name is that it is something that should be part of bigger whole that plays along. In your ETL there are usually many problems but many of those repeat and thanks to us seeing many implementations we can see what is a recurring thing. Brick is something that should solve one problem particularly well. It should be tested, parametrizable, promote the right way to do it and to some extent flexible but mainly it should play well within the larger system.
While all our bricks are currently written in Ruby this is not mandatory. Brick can be in any language as long as it is supported within GoodData platform. Since majority of the bricks are currently dealing with APIs imperative language is the most flexible way to go.
You can find bricks in the apps directory. Each folder there represent one brick. You can deploy by cloning the app store and using a web interface in "Administration console" or you can use Automation SDK. You can both deploy and redeploy with it.
While deployment is tool agnostic. Scheduling has to be performed using Automation SDK at this point. The reason for this is that gooddata platform currently does not support nested (JSON like) parameters which are necessary for concisely parametrize majority of the bricks. Automation SDK takes care of the details for you. The caveat is that in the Administration console you will see the data encoded (though still readable) the advantage is that configuration is much more readable.
You can read about various ways how to schedule processes in our cookbook
As stated before we are trying to minimize the amount of glue code that is necessary to make things work. Since generally you do not know where your data would come from we want to give you power to consume wider number of sources (web, ADS, staging (aka WebDAV)) so you do not have to change any code just configuration. What is considered a source you can recognize by the name of the parameter in the documentation of specific brick. The name of the parameter will be "*_input_source" or just "input_source". If it is named according to this convention then you can treat is as a datasource.
Staging is an ephemeral storage that is part of gooddata platform. It supports couple of protocols most useful of which is WebDAV so sometimes it is internally referred to as WebDAV. You can specify a data source to consume a file from staging like this.
The file is consumed as is. Majority of the bricks are expecting CSV that is parsed using a csv library.
"input_source": {
"type": "staging",
"path": "filename"
}
Since staging is most common there is also a shorthand
"input_source": "folder/filename/"
Which is equivalent to the previous. Filename is expected to be relative to the root of the project specific staging (ie relative to the "https://secure-di.gooddata.com/project-uploads/{PROJECT_ID}/"). Please note that there is not slash as the first character.
ADS is a database service. You can specify a query to ADS as a data source.
You have to specify how to connect to ads. This is configured using ads_client structure.
"ads_client": { "username": "username@example.com", "password": "secret", "ads_id": "123898qajldna97ad8" },
"input_source": {
"type": "ads",
"query": "SELECT * FROM my_table"
}
You can also omit username and password. In such case the defaults "GDC_USERNAME" and "GDC_PASSWORD" would be used. This is useful if you want different user than the one that is executing the rest of the task for example upload to webdav.
"GDC_USERNAME": "username@example.com",
"GDC_PASSWORD": "secret",
"ads_client": { "ads_id": "123898qajldna97ad8" },
"input_source": {
"type": "ads",
"query": "SELECT * FROM my_table"
}
The query is consumed using our JDBC driver. And it is accessible in the code as an Array of Hashes. The keys of each hash is equivalent to the name of the column from the query.
You can consume a file on the web directly.
"input_source": {
"type": "web",
"url": "https://gist.githubusercontent.com/fluke777/4005f6d99e9a8c6a9c90/raw/d7c5eb5794dfe543de16a44ecd4b2495591df057/domain_users.csv"
}
The file is consumed as is. Majority of the bricks are expecting CSV that is parsed using a csv library.
It would make sense to do something similar for the outputs and that is planned. Currently this is not implemented.