Kind of similar to what Druid has in https://druid.apache.org/docs/latest/configuration/#configuration-interpolation
${env:METADATA_STORAGE_TYPE:-mysql} tries to read the env METADATA_STORAGE_TYPE and uses mysql (or -mysql? - needs to be checked) in case the env var is not present.
Kind of similar to what Druid has in https://druid.apache.org/docs/latest/configuration/#configuration-interpolation
${env:METADATA_STORAGE_TYPE:-mysql}tries to read the envMETADATA_STORAGE_TYPEand usesmysql(or-mysql? - needs to be checked) in case the env var is not present.