lightbend config：在application.properties文件中传递动态值

Question

I am using lightbend in my scala code so that my application.properties file is away from my jar. I need to pass the current date in application.properties file.

Date_read_write = 20190828 

how do I make this to pick up dynamically, if it is shell script I can mention

Date_read_write=`date +%Y%m%d`

how do I do a similar step in application.properties file?

Update for time addition

below is my application.properties file:

hdfs_link = hdfs://XX.XXX.XXX.XX:8080/sessions/data/events
mediaKey = 1234
eventName = media
Date_read_write = 20190815
time = *_W
parts = *

i am using above to generate hdfs://XX.XXX.XXX.XX:8080/sessions/data/events/1234/media/20190815/*_W/*

using :

val conf = ConfigFactory.load() 
val hdfs_path = conf.getString("hdfs_link")+"/"+conf.getString("mediaKey")+"/"+conf.getString("eventName")+"/"+conf.getString("Date_read_write")+"/"+conf.getString("time")+"/"+conf.getString("parts")

but when i add

--driver-java-options -DDate_read_write=`date --date='1 days ago' '+%Y%m%d'`

to my spark submit commad, my URL is turing to hdfs://XX.XXX.XXX.XX:8080/sessions/data/events/1234/media/20190828/*/*

i have no clue why this addition changes the value of time .

Below is my spark submit command:

nohup spark-submit --master yarn --deploy-mode client --num-executors 20 --executor-cores 6 --driver-memory 10g --executor-memory 10g --class metrics.MasterAggregateTable --files application.properties --driver-java-options -Dconfig.file=application.properties --driver-java-options -DDate_read_write=`date +%Y%m%d` --jars com.datastax.spark_spark-cassandra-connector_2.11-2.3.0.jar UserMetrics.jar &

Answer 1

You can override all the settings in application.properties by system properties.

java -DDate_read_write=`date +%Y%m%d` -jar yourapp.jar

In default uses of the library, exact-match system properties already override the corresponding config properties.

This does not require any changes to the configuration file inside of the jar.

Answer 2

You could consider using an environment variable for that. Just add environment variable substitution in your application.properties file:

date = ${DATE}

Then while you run your app just set DATE variable:

 DATE=`date +%Y%m%d` java -jar yourapp.ja