2.3 KiB
Plugins
This directory is for Exporter plugins (.go and .so files) generated by, output from, and linked to from the composeAndExecute command
These plugins are generated using information provided in a .toml config file
The config file requires, at a minimum, the below fields:
[database]
name = "vulcanize_public"
hostname = "localhost"
user = "vulcanize"
password = "vulcanize"
port = 5432
[client]
ipcPath = "http://kovan0.vulcanize.io:8545"
[exporter]
filePath = "$GOPATH/src/github.com/vulcanize/vulcanizedb/plugins/"
fileName = "exporter"
[exporter.transformers]
transformer1 = "github.com/path/to/transformer1"
transformer2 = "github.com/path/to/transformer2"
transformer3 = "github.com/path/to/transformer3"
In the above, the exporter.transformers are mappings of import aliases to their import paths If the individual transformers require additional configuration variables be sure to include them in the .toml file
The general structure of a plugin .go file, and what we would see with the above config is below
Note that shared_transformer is a reserved alias needed for the generic TransformerInitializer type:
package main
import (
shared_transformer "github.com/vulcanize/vulcanizedb/libraries/shared/transformer"
transformer1 "github.com/path/to/transformer1"
transformer2 "github.com/path/to/transformer2"
transformer3 "github.com/path/to/transformer3"
)
type exporter string
var Exporter exporter
func (e exporter) Export() []shared_transformer.TransformerInitializer {
return []shared_transformer.TransformerInitializer{
transformer1.TransformerInitializer,
transformer2.TransformerInitializer,
transformer3.TransformerInitializer,
}
}
As such, to plug in an external transformer all we need to do is create a package that exports a variable TransformerInitializer that is of type TransformerInitializer
As long as the imported transformers abide by the required interfaces, we can execute over any arbitrary set of them