Reward HN: Node script for recursive shell layout variable exchange in templates

Charlie Layers March 29, 2022

Replace shell-layout atmosphere variables recursively. Presents capability in construction environments associated to envsubst with some additional aspects.

The procedure it works

Where you accumulate an environment variable file:

appsettings.construction.env

DB_ADMIN_PASSWORD=123456
DB_APP_USER_PASSWORD=654321

and a template file:

appsettings.Env.json.envt

{
  "App": {
    "DbAdminPassword": "${DB_ADMIN_PASSWORD}",
    "DbAppUserPassword": "${DB_APP_USER_PASSWORD}",
  }
}

Encompass this script for your source and bustle the next reveal from within the conclude level directory from which recursive search would possibly possibly well perhaps impartial easy originate:

node configure.js appsettings.construction.env

On this case this would possibly possibly well invent the file:

appsettings.Building.json

{
  "App": {
    "DbAdminPassword": "123456",
    "DbAppUserPassword": "654321",
  }
}

You would possibly perhaps perhaps perhaps presumably also utilize version administration system ignore scripts (e.g. .gitignore) to discontinuance the output info being dedicated, and forestall secrets and ways being dedicated to repositories.

Functions

(Optionally available) Case Controllable Atmosphere Name in Output File Name

Within the above example appsettings.Env.json.envt became appsettings.Building.json, from an environment file with the title appsettings.construction.env

Listing how the atmosphere title segment .Env. in the template (.envt) file title used to be modified with .Building. from the atmosphere title segment of the enter atmosphere (.env) file. The atmosphere title segment in the template file will also be .Env(pascal case),.ENV(upper case) or.env` (decrease case), and would possibly possibly well perhaps impartial output the atmosphere title in the identical case in the output file. Listing that an environment title segment is non-obligatory.