fix(striker-ui-api): change process ownership after port binding

striker-ui-api/src/index.ts

@@ -1,7 +1,24 @@
+import { getgid, getuid, setgid, setuid } from 'process';
+
+import { PGID, PUID, PORT } from './lib/consts';
+
 import app from './app';
+import { stderr, stdout } from './lib/shell';
+
+stdout(`Starting process with ownership ${getuid()}:${getgid()}`);
+
+app.listen(PORT, () => {
+  try {
+    // Group must be set before user to avoid permission error.
+    setgid(PGID);
+    setuid(PUID);
+
+    stdout(`Process ownership changed to ${getuid()}:${getgid()}.`);
+  } catch (error) {
+    stderr(`Failed to change process ownership; CAUSE: ${error}`);
 
-import SERVER_PORT from './lib/consts/SERVER_PORT';
+    process.exit(1);
+  }
 
-app.listen(SERVER_PORT, () => {
-  console.log(`Listening on localhost:${SERVER_PORT}.`);
+  stdout(`Listening on localhost:${PORT}.`);
 });

striker-ui-api/src/lib/consts/PROCESS_OWNER.ts

@@ -0,0 +1,2 @@
+export const PUID = process.env.PUID ?? 'striker-ui-api';
+export const PGID = process.env.PGID ?? PUID;

striker-ui-api/src/lib/consts/SERVER_PORT.ts

@@ -1,3 +1 @@
-const SERVER_PORT = process.env.SERVER_PORT ?? 8080;
-
-export default SERVER_PORT;
+export const PORT = process.env.PORT ?? 8080;

striker-ui-api/src/lib/consts/index.ts

@@ -0,0 +1,2 @@
+export * from './PROCESS_OWNER';
+export * from './SERVER_PORT';