[next] Heroku Support (#2240)

* feat: added env-rewrite support

* feat: added heroku support via app.json

* fix: fixed readme linting error

* fix: fixed error in app.json

* fix: improved environment variables exposed by app.json

src/core/server/config.ts

@@ -59,7 +59,7 @@ const config = convict({
     env: "LOCALE",
   },
   enable_graphiql: {
-    doc: "When true, this will enable the GraphiQL routes",
+    doc: "When true, this will enable the GraphiQL interface at /graphiql",
     format: Boolean,
     default: false,
     env: "ENABLE_GRAPHIQL",
@@ -103,7 +103,8 @@ const config = convict({
     sensitive: true,
   },
   signing_secret: {
-    doc: "",
+    doc:
+      "The shared secret to use to sign JSON Web Tokens (JWT) with the selected signing algorithm.",
     format: "*",
     default: "keyboard cat", // TODO: (wyattjoh) evaluate best solution
     env: "SIGNING_SECRET",

src/index.ts

@@ -1,4 +1,5 @@
 import dotenv from "dotenv";
+import { rewrite } from "env-rewrite";
 import sourceMapSupport from "source-map-support";
 
 // Configure the source map support so stack traces will reference the source
@@ -7,6 +8,15 @@ sourceMapSupport.install({
   environment: "node",
 });
 
+// Ensure that we always process the rewrites silently, otherwise it may fail in
+// environments like Heroku.
+process.env.REWRITE_ENV_SILENT = "TRUE";
+
+// Perform rewrites to the runtime environment variables based on the contents
+// of the process.env.REWRITE_ENV if it exists. This is done here as it is the
+// entrypoint for the entire applications configuration.
+rewrite();
+
 // Apply all the configuration provided in the .env file if it isn't already in
 // the environment.
 dotenv.config();

src/types/env-rewrite.d.ts

@@ -0,0 +1,3 @@
+declare module "env-rewrite" {
+  export function rewrite(): void;
+}