[SPARK-17058][BUILD] Add maven snapshots-and-staging profile to build/test against staging artifacts

## What changes were proposed in this pull request?

Adds a `snapshots-and-staging profile` so that  RCs of projects like Hadoop and HBase can be used in developer-only build and test runs. There's a comment above the profile telling people not to use this in production.

There's no attempt to do the same for SBT, as Ivy is different.
## How was this patch tested?

Tested by building against the Hadoop 2.7.3 RC 1 JARs

without the profile (and without any local copy of the 2.7.3 artifacts), the build failed

```
mvn install -DskipTests -Pyarn,hadoop-2.7,hive -Dhadoop.version=2.7.3

...

[INFO] ------------------------------------------------------------------------
[INFO] Building Spark Project Launcher 2.1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
Downloading: https://repo1.maven.org/maven2/org/apache/hadoop/hadoop-client/2.7.3/hadoop-client-2.7.3.pom
[WARNING] The POM for org.apache.hadoop:hadoop-client:jar:2.7.3 is missing, no dependency information available
Downloading: https://repo1.maven.org/maven2/org/apache/hadoop/hadoop-client/2.7.3/hadoop-client-2.7.3.jar
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] Spark Project Parent POM ........................... SUCCESS [  4.482 s]
[INFO] Spark Project Tags ................................. SUCCESS [ 17.402 s]
[INFO] Spark Project Sketch ............................... SUCCESS [ 11.252 s]
[INFO] Spark Project Networking ........................... SUCCESS [ 13.458 s]
[INFO] Spark Project Shuffle Streaming Service ............ SUCCESS [  9.043 s]
[INFO] Spark Project Unsafe ............................... SUCCESS [ 16.027 s]
[INFO] Spark Project Launcher ............................. FAILURE [  1.653 s]
[INFO] Spark Project Core ................................. SKIPPED
...
```

With the profile, the build completed

```
mvn install -DskipTests -Pyarn,hadoop-2.7,hive,snapshots-and-staging -Dhadoop.version=2.7.3
```

Author: Steve Loughran <stevel@apache.org>

Closes #14646 from steveloughran/stevel/SPARK-17058-support-asf-snapshots.

1 files changed, 48 insertions, 0 deletions

diff --git a/pom.xml b/pom.xml
index aaf7cfa7eb..04d2eaa1d3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -2694,6 +2694,54 @@
     </profile>
 
     <!--
+     This is a profile to enable the use of the ASF snapshot and staging repositories
+     during a build. It is useful when testing againt nightly or RC releases of dependencies.
+     It MUST NOT be used when building copies of Spark to use in production of for distribution,
+     -->
+    <profile>
+      <id>snapshots-and-staging</id>
+      <properties>
+        <!-- override point for ASF staging/snapshot repos -->
+        <asf.staging>https://repository.apache.org/content/groups/staging/</asf.staging>
+        <asf.snapshots>https://repository.apache.org/content/repositories/snapshots/</asf.snapshots>
+      </properties>
+
+      <pluginRepositories>
+        <pluginRepository>
+          <id>ASF Staging</id>
+          <url>${asf.staging}</url>
+        </pluginRepository>
+        <pluginRepository>
+          <id>ASF Snapshots</id>
+          <url>${asf.snapshots}</url>
+          <snapshots>
+            <enabled>true</enabled>
+          </snapshots>
+          <releases>
+            <enabled>false</enabled>
+          </releases>
+        </pluginRepository>
+
+      </pluginRepositories>
+      <repositories>
+        <repository>
+          <id>ASF Staging</id>
+          <url>${asf.staging}</url>
+        </repository>
+        <repository>
+          <id>ASF Snapshots</id>
+          <url>${asf.snapshots}</url>
+          <snapshots>
+            <enabled>true</enabled>
+          </snapshots>
+          <releases>
+            <enabled>false</enabled>
+          </releases>
+        </repository>
+      </repositories>
+    </profile>
+
+    <!--
       These empty profiles are available in some sub-modules. Declare them here so that
       maven does not complain when they're provided on the command line for a sub-module
       that does not have them.