Create CDN interaction api

server/src/lib/cdn/cdn.ts

@@ -0,0 +1,40 @@
+import fs from "fs";
+import path from "path";
+import { KTCDN_ROOT } from "../env/env";
+import CreateLogCtx from "../logger/logger";
+import { promisify } from "util";
+
+const readFilePromise = promisify(fs.readFile);
+const writeFilePromise = promisify(fs.writeFile);
+
+const logger = CreateLogCtx(__filename);
+
+/**
+ * Joins a file location against the location of the CDN static store.
+ */
+function CDNRoot(fileLoc: string) {
+    return path.join(KTCDN_ROOT, fileLoc);
+}
+
+/**
+ * Retrieves the data of the file at the given CDN location.
+ */
+export function Retrieve(fileLoc: string) {
+    logger.debug(`Retrieving path ${fileLoc}.`);
+
+    return readFilePromise(CDNRoot(fileLoc));
+}
+
+/**
+ * Flag for fs.open to write a file but NOT overwrite it if it already exists.
+ */
+const WRITE_NO_OVERWRITE = "wx";
+
+/**
+ * Stores the provided buffer or string as a file at the given location.
+ */
+export function Store(fileLoc: string, data: Buffer | string) {
+    logger.debug(`Storing path ${fileLoc}.`);
+
+    return writeFilePromise(CDNRoot(fileLoc), data, { flag: WRITE_NO_OVERWRITE });
+}

server/src/lib/env/env.ts

@@ -11,6 +11,7 @@ const envVars = [
     "KTBSV_EAG_API_URL",
     "KTBSV_ARC_API_URL",
     "KTBSV_ARC_AUTH_TOKEN",
+    "KTCDN_ROOT",
 ];
 
 for (const eVar of envVars) {
@@ -27,3 +28,4 @@ export const FLO_API_URL = process.env.KTBSV_FLO_API_URL!;
 export const EAG_API_URL = process.env.KTBSV_EAG_API_URL!;
 export const ARC_API_URL = process.env.KTBSV_ARC_API_URL!;
 export const ARC_AUTH_TOKEN = process.env.KTBSV_ARC_AUTH_TOKEN!;
+export const KTCDN_ROOT = process.env.KTCDN_ROOT!;