A standalone single-node Hadoop image for Docker

1. Build the Docker image and run it

   1. Inside the root directory, run this command to create the image:

   docker build . -t hadoop:1

   2. Inside the root directory, run this command to initiate the container:

   docker run -it --name hadoop --rm -p 50070:50070 -p 8088:8088 hadoop:1

   3. Check web interfaces of Hadoop:

   http://localhost:50070/explorer.html#/example

   http://localhost:8088/cluster

2. Compile the MapReduce program and run it inside Hadoop prompt

   1. You can run this to start the PI Calculation example:

   $ /root/hadoop/bin/hadoop jar /root/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-3.1.1.jar pi 1 10

   2. Copy sample file into HDFS input directory:

   $ /root/hadoop/bin/hadoop fs -mkdir -p /example

   $ /root/hadoop/bin/hadoop fs -put /root/example/criptomoedas.txt /example

   3. Setup Java environment variables:

   $ export JAVA_HOME=/usr/java/latest

   $ export PATH=${JAVA_HOME}/bin:${PATH}

   $ export HADOOP_CLASSPATH=${JAVA_HOME}/lib/tools.jar

   4. Compile MapReduce Java job into a .jar file:

   $ /root/hadoop/bin/hadoop com.sun.tools.javac.Main /root/example/WordCount.java

   $ cd root/example

   $ jar cf wc.jar WordCount*.class

   $ cd ..

   $ cd ..

   $ jar tvf /root/example/wc.jar

   5. Run the job:

   $ /root/hadoop/bin/hadoop jar /root/example/wc.jar WordCount /example/criptomoedas.txt /example/criptomoedas_mapreduce_result

   6. Show the results:

   $ /root/hadoop/bin/hadoop fs -cat /example/criptomoedas_mapreduce_result/part-00000