How to add missing SalesforceDX org alias

If you ever added a non-scratch org in SalesforceDX but forgot to add an alias using –alias / -a or simply want to change an alias there is a way easier way when readding all orgs. Simply edit the alias.json file as below.

1. Locate your SalesforceDX settings directory (on Mac that is in ~/.sfdx and on Windows it seems to be %USERPROFILE%\.sfdx)
2. Edit the alias.json file (please note that it uses Unix style endings so use an appropriate editor)
3. Add missing alias mapping or correct incorrect mappings. The file simply maps an alias to the org username shown in “sfdx force:org:list”. Below is an example file.

{
 "orgs": {
   "example.qa": "mheisterberg@example.com.qa",
   "example.uat": "mheisterberg@example.com.uat"
 }
}