test: complete dotenvx example and add docs

Author: mkalygin

examples/dotenvx-pm2/.env

@@ -0,0 +1,4 @@
+DE=dotenv_initial
+SH_DE=dotenv_initial
+DE_PM=dotenv_initial
+SH_DE_PM=dotenv_initial

examples/dotenvx-pm2/.env.initial

@@ -0,0 +1,4 @@
+DE=dotenv_updated
+SH_DE=dotenv_updated
+DE_PM=dotenv_updated
+SH_DE_PM=dotenv_updated

examples/dotenvx-pm2/.env.updated

@@ -1,8 +1,21 @@
+This is an example of using [dotenvx](https://dotenvx.com/) with pm2.
 
-To start http application in cluster mode:
+It demonstrates how to update the environment for forked and clustered apps using dotenvx.
+
+In this example, the environment variables come from three sources and are applied in the following order (dotenv files take precedence because of the `--overload` option used):
+- shell environment
+- dotenv files `.env.initial` or `.env.updated`.
+- pm2 ecosystem config `ecosystem.config.cjs`
+
+See `package.json` scripts for the actual commands.
 
 ```bash
-$ pm2 start ecosystem.config.js
-# OR
-$ pm2 start http.js -i max
+# install dotenvx
+npm install
+# start apps with `initial` environment and `.env.initial` dotenv file
+npm run start:json
+# reload apps with `updated` environment and `.env.updated` dotenv file
+npm run reload:json
+# delete apps
+npm run delete:json
 ```

examples/dotenvx-pm2/README.md

@@ -3,25 +3,39 @@ module.exports = {
     {
       name: 'forked_app',
       script: './index.js',
-      env: {
+      env_initial: {
         PORT: 8001,
-        PM: 'pm2',
-        SH_PM: 'pm2',
-        DE_PM: 'pm2',
-        SH_DE_PM: 'pm2',
+        PM: 'pm2_initial',
+        SH_PM: 'pm2_initial',
+        DE_PM: 'pm2_initial',
+        SH_DE_PM: 'pm2_initial',
+      },
+      env_updated: {
+        PORT: 8001,
+        PM: 'pm2_updated',
+        SH_PM: 'pm2_updated',
+        DE_PM: 'pm2_updated',
+        SH_DE_PM: 'pm2_updated',
       },
     },
     {
       name: 'clustered_app',
       script: './index.js',
       instances: 2,
       exec_mode: 'cluster',
-      env: {
+      env_initial: {
+        PORT: 8002,
+        PM: 'pm2_initial',
+        SH_PM: 'pm2_initial',
+        DE_PM: 'pm2_initial',
+        SH_DE_PM: 'pm2_initial',
+      },
+      env_updated: {
         PORT: 8002,
-        PM: 'pm2',
-        SH_PM: 'pm2',
-        DE_PM: 'pm2',
-        SH_DE_PM: 'pm2',
+        PM: 'pm2_updated',
+        SH_PM: 'pm2_updated',
+        DE_PM: 'pm2_updated',
+        SH_DE_PM: 'pm2_updated',
       },
     },
   ],

examples/dotenvx-pm2/ecosystem.config.cjs

@@ -7,15 +7,10 @@
   "author": "Michael Kalygin",
   "license": "MIT",
   "scripts": {
-    "start:json:simple": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env -- ../../bin/pm2 start ecosystem.config.cjs",
-    "start:json:overload": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env --overload -- ../../bin/pm2 start ecosystem.config.cjs",
-    "start:pid:simple": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env -- ../../bin/pm2 start forked_app clustered_app",
-    "start:pid:overload": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env --overload -- ../../bin/pm2 start forked_app clustered_app",
-    "reload:json:simple": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env -- ../../bin/pm2 reload ecosystem.config.cjs --update-env",
-    "reload:json:overload": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env --overload -- ../../bin/pm2 reload ecosystem.config.cjs --update-env",
-    "reload:pid:simple": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env -- ../../bin/pm2 reload forked_app clustered_app --update-env",
-    "reload:pid:overload": "SH=shell SH_DE=shell SH_PM=shell SH_DE_PM=shell dotenvx run --env-file .env --overload -- ../../bin/pm2 reload forked_app clustered_app --update-env",
-    "delete": "../../bin/pm2 delete ecosystem.config.cjs"
+    "start:json": "SH=shell_initial SH_DE=shell_initial SH_PM=shell_initial SH_DE_PM=shell_initial dotenvx run --env-file .env.initial --overload -- ../../bin/pm2 start ecosystem.config.cjs --env initial",
+    "reload:json": "SH=shell_updated SH_DE=shell_updated SH_PM=shell_updated SH_DE_PM=shell_updated dotenvx run --env-file .env.updated --overload -- ../../bin/pm2 reload ecosystem.config.cjs --env updated --update-env",
+    "delete:json": "../../bin/pm2 delete ecosystem.config.cjs",
+    "test:json": "../../bin/pm2 update && npm run delete:json && npm run start:json && npm run reload:json"
   },
   "dependencies": {
     "@dotenvx/dotenvx": "^1.10.2"