[SPARK-8506] Add pakages to R context created through init.

Author: Holden Karau <holden@pigscanfly.ca>

Closes #6928 from holdenk/SPARK-8506-sparkr-does-not-provide-an-easy-way-to-depend-on-spark-packages-when-performing-init-from-inside-of-r and squashes the following commits:

b60dd63 [Holden Karau] Add an example with the spark-csv package
fa8bc92 [Holden Karau] typo: sparm -> spark
865a90c [Holden Karau] strip spaces for comparision
c7a4471 [Holden Karau] Add some documentation
c1a9233 [Holden Karau] refactor for testing
c818556 [Holden Karau] Add pakages to R

3 files changed, 56 insertions, 9 deletions

diff --git a/R/pkg/R/client.R b/R/pkg/R/client.R
index 1281c41213..cf2e5ddeb7 100644
--- a/R/pkg/R/client.R
+++ b/R/pkg/R/client.R
@@ -34,24 +34,36 @@ connectBackend <- function(hostname, port, timeout = 6000) {
   con
 }
 
-launchBackend <- function(args, sparkHome, jars, sparkSubmitOpts) {
+determineSparkSubmitBin <- function() {
   if (.Platform$OS.type == "unix") {
     sparkSubmitBinName = "spark-submit"
   } else {
     sparkSubmitBinName = "spark-submit.cmd"
   }
+  sparkSubmitBinName
+}
+
+generateSparkSubmitArgs <- function(args, sparkHome, jars, sparkSubmitOpts, packages) {
+  if (jars != "") {
+    jars <- paste("--jars", jars)
+  }
+
+  if (packages != "") {
+    packages <- paste("--packages", packages)
+  }
 
+  combinedArgs <- paste(jars, packages, sparkSubmitOpts, args, sep = " ")
+  combinedArgs
+}
+
+launchBackend <- function(args, sparkHome, jars, sparkSubmitOpts, packages) {
+  sparkSubmitBin <- determineSparkSubmitBin()
   if (sparkHome != "") {
     sparkSubmitBin <- file.path(sparkHome, "bin", sparkSubmitBinName)
   } else {
     sparkSubmitBin <- sparkSubmitBinName
   }
-
-  if (jars != "") {
-    jars <- paste("--jars", jars)
-  }
-
-  combinedArgs <- paste(jars, sparkSubmitOpts, args, sep = " ")
+  combinedArgs <- generateSparkSubmitArgs(args, sparkHome, jars, sparkSubmitOpts, packages)
   cat("Launching java with spark-submit command", sparkSubmitBin, combinedArgs, "\n")
   invisible(system2(sparkSubmitBin, combinedArgs, wait = F))
 }
diff --git a/R/pkg/R/sparkR.R b/R/pkg/R/sparkR.R
index dbde0c44c5..8f81d5640c 100644
--- a/R/pkg/R/sparkR.R
+++ b/R/pkg/R/sparkR.R
@@ -81,6 +81,7 @@ sparkR.stop <- function() {
 #' @param sparkExecutorEnv Named list of environment variables to be used when launching executors.
 #' @param sparkJars Character string vector of jar files to pass to the worker nodes.
 #' @param sparkRLibDir The path where R is installed on the worker nodes.
+#' @param sparkPackages Character string vector of packages from spark-packages.org
 #' @export
 #' @examples
 #'\dontrun{
@@ -100,7 +101,8 @@ sparkR.init <- function(
   sparkEnvir = list(),
   sparkExecutorEnv = list(),
   sparkJars = "",
-  sparkRLibDir = "") {
+  sparkRLibDir = "",
+  sparkPackages = "") {
 
   if (exists(".sparkRjsc", envir = .sparkREnv)) {
     cat("Re-using existing Spark Context. Please stop SparkR with sparkR.stop() or restart R to create a new Spark Context\n")
@@ -129,7 +131,8 @@ sparkR.init <- function(
         args = path,
         sparkHome = sparkHome,
         jars = jars,
-        sparkSubmitOpts = Sys.getenv("SPARKR_SUBMIT_ARGS", "sparkr-shell"))
+        sparkSubmitOpts = Sys.getenv("SPARKR_SUBMIT_ARGS", "sparkr-shell"),
+        sparkPackages = sparkPackages)
     # wait atmost 100 seconds for JVM to launch
     wait <- 0.1
     for (i in 1:25) {
diff --git a/R/pkg/inst/tests/test_client.R b/R/pkg/inst/tests/test_client.R
new file mode 100644
index 0000000000..30b05c1a2a
--- /dev/null
+++ b/R/pkg/inst/tests/test_client.R
@@ -0,0 +1,32 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+context("functions in client.R")
+
+test_that("adding spark-testing-base as a package works", {
+  args <- generateSparkSubmitArgs("", "", "", "",
+                                  "holdenk:spark-testing-base:1.3.0_0.0.5")
+  expect_equal(gsub("[[:space:]]", "", args),
+               gsub("[[:space:]]", "",
+                    "--packages holdenk:spark-testing-base:1.3.0_0.0.5"))
+})
+
+test_that("no package specified doesn't add packages flag", {
+  args <- generateSparkSubmitArgs("", "", "", "", "")
+  expect_equal(gsub("[[:space:]]", "", args),
+               "")
+})