forked from cerc-io/ipld-eth-server
58 lines
2.3 KiB
Markdown
58 lines
2.3 KiB
Markdown
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## Plugins
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This directory is for Exporter plugins (.go and .so files) generated by, output from, and linked to from the composeAndExecute command
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These plugins are generated using information provided in a .toml config file
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The config file requires, at a minimum, the below fields:
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```toml
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[database]
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name = "vulcanize_public"
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hostname = "localhost"
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user = "vulcanize"
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password = "vulcanize"
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port = 5432
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[client]
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ipcPath = "http://kovan0.vulcanize.io:8545"
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[exporter]
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filePath = "$GOPATH/src/github.com/vulcanize/vulcanizedb/plugins/"
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fileName = "exporter"
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[exporter.transformers]
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transformer1 = "github.com/path/to/transformer1"
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transformer2 = "github.com/path/to/transformer2"
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transformer3 = "github.com/path/to/transformer3"
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```
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In the above, the exporter.transformers are mappings of import aliases to their import paths
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If the individual transformers require additional configuration variables be sure to include them in the .toml file
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The general structure of a plugin .go file, and what we would see with the above config is below
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Note that `shared_transformer` is a reserved alias needed for the generic TransformerInitializer type:
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```go
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package main
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import (
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shared_transformer "github.com/vulcanize/vulcanizedb/libraries/shared/transformer"
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transformer1 "github.com/path/to/transformer1"
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transformer2 "github.com/path/to/transformer2"
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transformer3 "github.com/path/to/transformer3"
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)
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type exporter string
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var Exporter exporter
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func (e exporter) Export() []shared_transformer.TransformerInitializer {
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return []shared_transformer.TransformerInitializer{
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transformer1.TransformerInitializer,
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transformer2.TransformerInitializer,
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transformer3.TransformerInitializer,
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}
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}
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```
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As such, to plug in an external transformer all we need to do is create a [package](https://github.com/vulcanize/maker-vulcanizedb/blob/compose_and_execute/pkg/autogen/test_helpers/bite/initializer.go) that exports a variable `TransformerInitializer` that is of type [TransformerInitializer](https://github.com/vulcanize/maker-vulcanizedb/blob/compose_and_execute/libraries/shared/transformer/transformer.go#L19)
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As long as the imported transformers abide by the required interfaces, we can execute over any arbitrary set of them
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