com.ebiznext.comet.extractor.ExtractScriptGen.scala Maven / Gradle / Ivy
package com.ebiznext.comet.extractor
import better.files.File
import com.ebiznext.comet.config.{DatasetArea, Settings}
import com.ebiznext.comet.extractor.config.{Settings => ExtractorSettings}
import com.ebiznext.comet.schema.handlers.SchemaHandler
import com.ebiznext.comet.schema.model.Domain
import com.typesafe.config.ConfigFactory
import com.typesafe.scalalogging.StrictLogging
import org.fusesource.scalate._
object ScriptGen extends StrictLogging {
implicit val settings: Settings = Settings(ConfigFactory.load())
val engine: TemplateEngine = new TemplateEngine
/**
* Generate an extraction script payload based on a template and its params
* @param template The extraction script template
* @param templateParams Its params
* @return The produced script payload
*/
def templatize(template: File, templateParams: TemplateParams): String =
engine.layout(
template.pathAsString,
templateParams.paramMap
)
/**
* Generate all extraction scripts based on the given domain
* @param domain The domain extracted from the Excel referential file
* @param scriptTemplateFile The script template
* @param scriptsOutputPath Where the scripts are produced
* @param defaultDeltaColumn Defaut delta column
* @param deltaColumns Mapping table name -> delta column, has precedence over `defaultDeltaColumn`
* @return The list of produced files
*/
def generate(
domain: Domain,
scriptTemplateFile: File,
scriptsOutputPath: File,
defaultDeltaColumn: Option[String],
deltaColumns: Map[String, String]
): List[File] = {
val templateSettings =
TemplateParams.fromDomain(domain, scriptsOutputPath, defaultDeltaColumn, deltaColumns)
templateSettings.map { ts =>
val scriptPayload = templatize(scriptTemplateFile, ts)
val scriptFile =
ts.scriptOutputFile.createFileIfNotExists().overwrite(scriptPayload)
logger.info(s"Successfully generated script $scriptFile")
scriptFile
}
}
def printUsage(): Unit = println(ExtractScriptGenConfig.usage)
}
/**
* Fills a Mustache templated file based on a given domain.
* The following documentation considers that we use the script to generate SQL export files.
*
* The schemas should at least, specify :
* - a table name (schemas.name)
* - a file pattern (schemas.pattern) which is used as the export file base name
* - a write mode (schemas.metadata.write): APPEND or OVERWRITE
* - the columns to extract (schemas.attributes.name*)
*
* You also have to provide a Mustache (http://mustache.github.io/mustache.5.html) template file.
*
* Here you'll write your extraction export process (sqlplus for Oracle, pgsql for PostgreSQL as an example).
* In that template you can use the following parameters:
*
* table_name -> the table to export
* delimiter -> the resulting dsv file delimiter
* columns -> the columns to export
* columns is a Mustache map, it gives you access, for each column, to:
* - name -> the column name
* - trailing_col_char -> the separator to append to the column (, if there are more columns to come, "" otherwise)
* Here is an example how to use it in a template:
* SELECT
* {{#columns}}
* TO_CHAR({{name}}){{trailing_col_char}}
* {{/columns}}
* FROM
* {{table_name}};
* export_file -> the export file name
* delta_column -> a delta date column (passed as a Main arg or as a config element), the column which is used to determine new rows for each exports in APPEND mode
* full_export -> if the export is a full or delta export (the logic is to be implemented in your script)
*
* Usage: comet [script-gen] [options]
*
* Command: script-gen
* --domain The domain for which to generate extract scripts
* --templateFile Script template file
* --scriptsOutputDir Scripts output folder
* --deltaColumn The date column which is used to determine new rows for each exports (can be passed table by table as config element)
*/
object Main extends App with StrictLogging {
import ScriptGen._
import settings.metadataStorageHandler
DatasetArea.initMetadata(metadataStorageHandler)
val schemaHandler = new SchemaHandler(metadataStorageHandler)
val domains: List[Domain] = schemaHandler.domains
val arglist = args.toList
logger.info(s"Running Comet $arglist")
ExtractScriptGenConfig.parse(args) match {
case Some(config) =>
// Extracting the domain from the Excel referential file
domains.find(_.name == config.domain) match {
case Some(domain) =>
ScriptGen.generate(
domain,
config.scriptTemplateFile,
config.scriptOutputDir,
config.deltaColumn.orElse(ExtractorSettings.deltaColumns.defaultColumn),
ExtractorSettings.deltaColumns.deltaColumns
)
System.exit(0)
case None =>
logger.error(s"No domain found for domain name ${config.domain}")
System.exit(1)
}
case _ =>
logger.error("Program execution or parameters are wrong, please check usage")
System.exit(1)
}
}