title: How to set a custom environment variable in EMR to be available for a spark Application
body: <p>I need to set a custom environment variable in EMR to be available when running a spark application. </p>
  
  <p>I have tried adding this: </p>
  
  <pre><code>                   ...
                     --configurations '[                                    
                                        {
                                        "Classification": "spark-env",
                                        "Configurations": [
                                          {
                                          "Classification": "export",
                                          "Configurations": [],
                                          "Properties": { "SOME-ENV-VAR": "qa1" }
                                          }
                                        ],
                                        "Properties": {}
                                        }
                                        ]'
                     ...
  </code></pre>
  
  <p>and also tried to replace "spark-env with <code>hadoop-env</code>
  but nothing seems to work.</p>
  
  <p>There is <a href="https://forums.aws.amazon.com/thread.jspa?threadID=223617" rel="noreferrer">this</a> answer from the aws forums. but I can't figure out how to apply it.
  I'm running on EMR 5.3.1 and launch it with a preconfigured step from the cli: <code>aws emr create-cluster...</code></p>