AbsaOSS · benedeki · Mar 13, 2021 · Apr 12, 2021 · Apr 14, 2021 · Apr 14, 2021
@@ -20,7 +20,7 @@ charset = utf-8
 end_of_line = lf
 trim_trailing_whitespace = true
 
-[*.xml]
+[*.{xml,sql,ddl}]
 indent_size = 4
 indent_style = space
 insert_final_newline = true

@@ -1 +1 @@
-* @lokm01 @benedeki @DzMakatun @HuvarVer @dk1844 @AdrianOlosutean
+* @benedeki @dk1844 @AdrianOlosutean
@@ -15,7 +15,7 @@ Steps to reproduce the behavior OR commands run:
 3. Enter value '...'
 4. See error
 
-## Expected behaviour
+## Expected behavior
 A clear and concise description of what you expected to happen.
 
 ## Screenshots

@@ -15,7 +15,7 @@ A description of the requested feature.
 A simple example if applicable.
 
 ## Proposed Solution [Optional]
-Solution Ideas 
+Solution Ideas:
 1. 
 2. 
 3. 
@@ -0,0 +1,18 @@
+---
+name: POC
+about: Proof of Concept, usually a middle-sized effort to test some idea
+labels: 'poc, under discussion, priority: undecided'
+
+---
+
+## Background
+A clear and concise intro into the situation.
+
+## Goal
+The goal that the _Proof of Concept_ wants to test
+
+## Proposed Approach [Optional]
+Approach Ideas:
+1.
+2.
+3.
@@ -28,4 +28,4 @@ jobs:
       - uses: actions/setup-java@v1
         with:
           java-version: 1.8
-      - run: mvn -Plicense-check apache-rat:check
+      - run: mvn --no-transfer-progress -Plicense-check apache-rat:check
@@ -22,7 +22,7 @@ jobs:
     name: Test approved or docs
     runs-on: ubuntu-latest
     steps:
-      - uses: danielchabr/pr-labels-checker@master
+      - uses: danielchabr/pr-labels-checker@v3.0
         id: checkLabel
         with:
           hasSome: PR:tested,PR:no testing needed,docs
@@ -31,7 +31,7 @@ jobs:
     name: Merge not blocked
     runs-on: ubuntu-latest
     steps:
-      - uses: danielchabr/pr-labels-checker@master
+      - uses: danielchabr/pr-labels-checker@v3.0
         id: checkLabel
         with:
           hasNone: PR:reviewing,work in progress

@@ -55,8 +55,6 @@ build.log
 #  syntax: regexp
 #  ^\.pc/
 
-build.log
-
 .cache*
 dependency-reduced-pom.xml
 

@@ -13,17 +13,25 @@
 
 # Enceladus
 
+### <a name="latest_release"/>Latest Release
+[![Maven Central](https://maven-badges.herokuapp.com/maven-central/za.co.absa.enceladus/parent/badge.png)](https://maven-badges.herokuapp.com/maven-central/za.co.absa.enceladus/parent/)
+
 ### <a name="build_status"/>Build Status
 | master | develop |
 | ------------- | ------------- |
 | [![Build Status](https://opensource.bigusdatus.com/jenkins/buildStatus/icon?job=Absa-OSS-Projects%2Fenceladus%2Fmaster)](https://opensource.bigusdatus.com/jenkins/job/Absa-OSS-Projects/job/enceladus/job/master/) | [![Build Status](https://opensource.bigusdatus.com/jenkins/buildStatus/icon?job=Absa-OSS-Projects%2Fenceladus%2Fdevelop)](https://opensource.bigusdatus.com/jenkins/job/Absa-OSS-Projects/job/enceladus/job/develop/) |
 ### <a name="code_quality_status"/>Code Quality Status
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=AbsaOSS_enceladus&metric=alert_status)](https://sonarcloud.io/dashboard?id=AbsaOSS_enceladus)
 
+### <a name="documentation"/>Documentation
+[![Read the Docs](https://img.shields.io/badge/docs-latest-brightgreen.svg)](https://absaoss.github.io/enceladus/)
+[![Read the Docs](https://img.shields.io/badge/docs-release%20notes-yellow.svg)](https://absaoss.github.io/enceladus/blog/)
+[![Read the Docs](https://img.shields.io/badge/docs-release--1.x-red.svg)](https://absaoss.github.io/enceladus/docs/1.0.0/components)
 ___
 
 <!-- toc -->
 - [What is Enceladus?](#what-is-enceladus)
+    - [REST API](#rest-api)
     - [Menas](#menas)
     - [Standardization](#standardization)
     - [Conformance](#conformance)
@@ -32,20 +40,26 @@ ___
 - [Plugins](#plugins)
     - [Built-in Plugins](#built-in-plugins)
 - [How to contribute](#how-to-contribute)
-- [Documentation](#documentation)
 <!-- tocstop -->
 
 ## What is Enceladus?
 **Enceladus** is a **Dynamic Conformance Engine** which allows data from different formats to be standardized to parquet and conformed to group-accepted common reference (e.g. data for country designation which are **DE** in one source system and **Deutschland** in another, can be conformed to **Germany**).
 
-The project is comprised of three main components:
-### Menas
-This is the user-facing web client, used to **specify the standardization schema**, and **define the steps required to conform** a dataset.  
-There are three models used to do this:
+The project is comprised of four main components:
+
+### REST API
+The REST API exposes the Enceladus endpoints for creating, reading, updating and deleting the models, as well as other functionalities.
+The main three models used are:
  - **Dataset**: Specifies where the dataset will be read from on HDFS (**RAW**), the conformance rules that will be applied to it, and where it will land on HDFS once it is conformed (**PUBLISH**)
  - **Schema**: Specifies the schema towards which the dataset will be standardized
  - **Mapping Table**: Specifies where tables with master reference data can be found (parquet on HDFS), which are used when applying Mapping conformance rules (e.g. the dataset uses **Germany**, which maps to the master reference **DE** in the mapping table)
 
+The REST API exposes a Swagger Documentation UI which documents all the HTTP exposed endpoints. It can be found at **REST_API_HOST/swagger-ui.html**
+
+### Menas
+This is the user-facing web client, used to **specify the standardization schema**, and **define the steps required to conform** a dataset.   
+The Menas web client calls and is based on the REST API to get the needed entities.
+
 ### Standardization
 This is a Spark job which reads an input dataset in any of the supported formats and **produces a parquet dataset with the Menas-specified schema** as output. 
 
@@ -69,43 +83,48 @@ Ensure the properties there fit your environment.
 - Without tests: `mvn clean package -DskipTests `
 - With unit tests: `mvn clean package`
 - With integration tests: `mvn clean package -Pintegration`
-- With component preload file generated: `mvn clean package -PgenerateComponentPreload`
 
 #### Test coverage:
 - Test coverage: `mvn scoverage:report`
 
 The coverage reports are written in each module's `target` directory and aggregated in the root `target` directory.
 
 ## How to run
-#### Menas requirements:
+#### REST API requirements:
 - [**Tomcat 8.5/9.0** installation](https://tomcat.apache.org/download-90.cgi)
 - [**MongoDB 4.0** installation](https://docs.mongodb.com/manual/administration/install-community/)
 - [**Spline UI deployment**](https://absaoss.github.io/spline/) - place the [spline.war](https://search.maven.org/remotecontent?filepath=za/co/absa/spline/spline-web/0.3.9/spline-web-0.3.9.war)
  in your Tomcat webapps directory (rename after downloading to _spline.war_); NB! don't forget to set up the `spline.mongodb.url` configuration for the _war_
 - **HADOOP_CONF_DIR** environment variable, pointing to the location of your hadoop configuration (pointing to a hadoop installation)
 
-The _Spline UI_ can be omitted; in such case the **Menas** `spline.urlTemplate` setting should be set to empty string. 
+The _Spline UI_ can be omitted; in such case the **REST API** `spline.urlTemplate` setting should be set to empty string. 
+
+#### Deploying REST API
+Simply copy the **rest-api.war** file produced when building the project into Tomcat's webapps directory.
+Another possible method is building the Docker image based on the existing Dockerfile and deploying it as a container.
 
 #### Deploying Menas
-Simply copy the **menas.war** file produced when building the project into Tomcat's webapps directory. 
+There are several ways of deploying Menas:
+- Tomcat deployment: copy the **menas.war** file produced when building the project into Tomcat's webapps directory. The **"apiUrl"** value in package.json should be set either before building or after building the artifact and modifying it in place
+- Docker deployment: build the Docker image based on the existing Dockerfile and deploy it as a container. The **API_URL** environment variable should be provided when running the container 
+- CDN deployment: copy the built contents in the **dist** directory into your preferred CDN server. The **"apiUrl"** value in package.json in the **dist** directory should be set
 
-#### Speed up initial loading time of menas
-- Build the project with the generateComponentPreload profile. Component preload will greatly reduce the number of HTTP requests required for the initial load of Menas
+#### Speed up initial loading time of REST API
 - Enable the HTTP compression
-- Configure `spring.resources.cache.cachecontrol.max-age` in `application.properties` of Menas for caching of static resources
+- Configure `spring.resources.cache.cachecontrol.max-age` in `application.properties` of REST API for caching of static resources
 
 #### Standardization and Conformance requirements:
 - [**Spark 2.4.4 (Scala 2.11)** installation](https://spark.apache.org/downloads.html)
 - [**Hadoop 2.7** installation](https://hadoop.apache.org/releases.html)
-- **Menas** running instance
+- **REST API** running instance
 - **Menas Credentials File** in your home directory or on HDFS (a configuration file for authenticating the Spark jobs with Menas) 
    - **Use with in-memory authentication**
 e.g. `~/menas-credential.properties`:
 ```
 username=user
 password=changeme
 ```
-- **Menas Keytab File** in your home directory or on HDFS
+- **REST API Keytab File** in your home directory or on HDFS
    - **Use with kerberos authentication**, see [link](https://kb.iu.edu/d/aumh) for details on creating keytab files
  - **Directory structure** for the **RAW** dataset should follow the convention of `<path_to_dataset_in_menas>/<year>/<month>/<day>/v<dataset_version>`. This date is specified with the `--report-date` option when running the **Standardization** and **Conformance** jobs.
  - **_INFO file** must be present along with the **RAW** data on HDFS as per the above directory structure. This is a file tracking control measures via [Atum](https://github.com/AbsaOSS/atum), an example can be found [here](examples/data/input/_INFO).
@@ -131,7 +150,7 @@ password=changeme
 --row-tag <tag>
 ```
 * Here `row-tag` is a specific option for `raw-format` of type `XML`. For more options for different types please see our WIKI.
-* In case Menas is configured for in-memory authentication (e.g. in dev environments), replace `--menas-auth-keytab` with `--menas-credentials-file`
+* In case REST API is configured for in-memory authentication (e.g. in dev environments), replace `--menas-auth-keytab` with `--menas-credentials-file`
 
 #### Running Conformance
 ```
@@ -175,7 +194,7 @@ password=changeme
 --row-tag <tag>
 ```
 
-* In case Menas is configured for in-memory authentication (e.g. in dev environments), replace `--menas-auth-keytab` with `--menas-credentials-file`
+* In case REST API is configured for in-memory authentication (e.g. in dev environments), replace `--menas-auth-keytab` with `--menas-credentials-file`
 
 #### Helper scripts for running Standardization, Conformance or both together
 
@@ -272,8 +291,8 @@ The list of all options for running Standardization, Conformance and the combine
 
 |            Option                     |                           Description                                                                                                                                                       |
 |---------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| --menas-auth-keytab **filename**      | A keytab file used for Kerberized authentication to Menas. Cannot be used together with `--menas-credentials-file`.                                                                         |
-| --menas-credentials-file **filename** | A credentials file containing a login and a password used to authenticate to Menas. Cannot be used together with `--menas-auth-keytab`.                                                     |
+| --menas-auth-keytab **filename**      | A keytab file used for Kerberized authentication to REST API. Cannot be used together with `--menas-credentials-file`.                                                                         |
+| --menas-credentials-file **filename** | A credentials file containing a login and a password used to authenticate to REST API. Cannot be used together with `--menas-auth-keytab`.                                                     |
 | --dataset-name **name**               | A dataset name to be standardized or conformed.                                                                                                                                             |
 | --dataset-version **version**         | A version of a dataset to be standardized or conformed.                                                                                                                                     |
 | --report-date **YYYY-mm-dd**          | A date specifying a day for which a raw data is landed.                                                                                                                                     |
@@ -336,6 +355,3 @@ A module containing [examples](examples/README.md) of the project usage.
 
 ## How to contribute
 Please see our [**Contribution Guidelines**](CONTRIBUTING.md).
-
-## Documentation
-Please see the [documentation pages](https://absaoss.github.io/enceladus/).
@@ -21,7 +21,7 @@
     <parent>
         <groupId>za.co.absa.enceladus</groupId>
         <artifactId>parent</artifactId>
-        <version>2.23.0</version>
+        <version>3.0.0-SNAPSHOT</version>
     </parent>
 
     <properties>

@@ -71,14 +71,14 @@ sealed abstract class AuthClient(username: String, restTemplate: RestTemplate, a
 
   private def getAuthHeaders(response: ResponseEntity[String]): HttpHeaders = {
     val headers = response.getHeaders
-    val sessionCookie = headers.get("set-cookie").asScala.head
+    val jwt = headers.get("JWT").asScala.head
     val csrfToken = headers.get("X-CSRF-TOKEN").asScala.head
 
-    log.info(s"Session Cookie: $sessionCookie")
+    log.info(s"JWT: $jwt")
     log.info(s"CSRF Token: $csrfToken")
 
     val resultHeaders = new HttpHeaders()
-    resultHeaders.add("cookie", sessionCookie)
+    resultHeaders.add("JWT", jwt)
     resultHeaders.add("X-CSRF-TOKEN", csrfToken)
     resultHeaders
   }

@@ -18,43 +18,75 @@ package za.co.absa.enceladus.dao.rest
 import org.apache.commons.lang.exception.ExceptionUtils
 import org.slf4j.LoggerFactory
 import org.springframework.web.client.{ResourceAccessException, RestClientException}
+import za.co.absa.enceladus.dao.rest.CrossHostApiCaller.logger
 import za.co.absa.enceladus.dao.{DaoException, RetryableException}
 
+import scala.annotation.tailrec
 import scala.util.{Failure, Random, Try}
 
-protected object CrossHostApiCaller {
+object CrossHostApiCaller {
 
-  def apply(apiBaseUrls: List[String]): CrossHostApiCaller = {
-    new CrossHostApiCaller(apiBaseUrls, Random.nextInt(apiBaseUrls.size))
+  private val logger  = LoggerFactory.getLogger(classOf[CrossHostApiCaller])
+
+  final val DefaultUrlsRetryCount: Int = 0
+
+  private def createInstance(apiBaseUrls: Seq[String], urlsRetryCount: Int, startWith: Option[Int]): CrossHostApiCaller = {
+    val maxTryCount: Int = (if (urlsRetryCount < 0) {
+      logger.warn(s"Urls retry count cannot be negative ($urlsRetryCount). Using default number of retries instead ($DefaultUrlsRetryCount).") //scalastyle:ignore maxLineLength
+      DefaultUrlsRetryCount
+    } else {
+      urlsRetryCount
+    }) + 1
+    val currentHostIndex = startWith.getOrElse(Random.nextInt(Math.max(apiBaseUrls.size, 1)))
+    new CrossHostApiCaller(apiBaseUrls.toVector, maxTryCount, currentHostIndex)
   }
 
+  def apply(apiBaseUrls: Seq[String], urlsRetryCount: Int = DefaultUrlsRetryCount, startWith: Option[Int] = None): CrossHostApiCaller = {
+    createInstance(apiBaseUrls, urlsRetryCount, startWith)
+  }
 }
 
-protected class CrossHostApiCaller(apiBaseUrls: List[String], var currentHostIndex: Int) extends ApiCaller {
-  private val logger  = LoggerFactory.getLogger(this.getClass)
+protected class CrossHostApiCaller private(apiBaseUrls: Vector[String], maxTryCount: Int, private var currentHostIndex: Int)
+  extends ApiCaller {
+
+  def baseUrlsCount: Int = apiBaseUrls.size
+
+  def currentBaseUrl: String = apiBaseUrls(currentHostIndex)
+
+  def nextBaseUrl(): String = {
+    currentHostIndex = (currentHostIndex + 1) % baseUrlsCount
+    currentBaseUrl
+  }
 
-  private val maxAttempts = apiBaseUrls.size - 1
 
   def call[T](fn: String => T): T = {
+    def logFailure(error: Throwable, url: String, attemptNumber: Int, nextUrl: Option[String]): Unit = {
+      val rootCause = ExceptionUtils.getRootCauseMessage(error)
+      val switching = nextUrl.map(s => s", switching host to $s").getOrElse("")
+      logger.warn(s"Request failed on host $url (attempt $attemptNumber of $maxTryCount)$switching - $rootCause")
+    }
 
-    def attempt(index: Int, attemptCount: Int = 0): Try[T] = {
-      currentHostIndex = index
-      val currentBaseUrl = apiBaseUrls(index)
-      Try {
-        fn(currentBaseUrl)
+    @tailrec
+    def attempt(url: String, attemptNumber: Int, urlsTried: Int): Try[T] = {
+      val result =Try {
+        fn(url)
       }.recoverWith {
         case e @ (_: ResourceAccessException | _: RestClientException) => Failure(DaoException("Server non-responsive", e))
-      }.recoverWith {
-        case e: RetryableException if attemptCount < maxAttempts =>
-          val nextIndex = (index + 1) % apiBaseUrls.size
-          val nextBaseUrl = apiBaseUrls(nextIndex)
-          val rootCause = ExceptionUtils.getRootCauseMessage(e)
-          logger.warn(s"Request failed on host $currentBaseUrl, switching host to $nextBaseUrl - $rootCause")
-          attempt(nextIndex, attemptCount + 1)
+      }
+      //using match instead of recoverWith to make the function @tailrec
+      result match {
+        case Failure(e: RetryableException) if attemptNumber < maxTryCount =>
+          logFailure(e, url, attemptNumber, None)
+          attempt(url, attemptNumber + 1, urlsTried)
+        case Failure(e: RetryableException) if urlsTried < baseUrlsCount =>
+          val nextUrl = nextBaseUrl()
+          logFailure(e, url, attemptNumber, Option(nextUrl))
+          attempt(nextUrl, 1, urlsTried + 1)
+        case _ => result
       }
     }
 
-    attempt(currentHostIndex).get
+    attempt(currentBaseUrl,1, 1).get
   }
 
 }
@@ -29,7 +29,7 @@ object MenasConnectionStringParser {
         .replaceAll("/$", "")
         .replaceAll("/api$", "")
       )
-      .toSet
+      .distinct
       .toList
   }