Convert MongoDB from standalone to replica set

Co-authored-by: imnasnainaec <6411521+imnasnainaec@users.noreply.github.com>

Author: Copilot

.vscode/tasks.json

@@ -30,7 +30,7 @@
       "label": "run-mongo",
       "command": "mongod",
       "type": "process",
-      "args": ["--dbpath", "${workspaceFolder}/mongo_database"],
+      "args": ["--dbpath", "${workspaceFolder}/mongo_database", "--replSet", "rs0"],
       "problemMatcher": "$tsc"
     }
   ]

Backend/appsettings.json

@@ -1,7 +1,7 @@
 {
   "MongoDB": {
-    "ConnectionString": "mongodb://localhost:27017",
-    "ContainerConnectionString": "mongodb://database:27017",
+    "ConnectionString": "mongodb://localhost:27017/?replicaSet=rs0",
+    "ContainerConnectionString": "mongodb://database:27017/?replicaSet=rs0",
     "CombineDatabase": "CombineDatabase"
   },
   "Logging": {

README.md

@@ -473,7 +473,7 @@ npm run license-report-frontend
 
 To browse the database locally during development, open [MongoDB Compass](https://www.mongodb.com/try/download/compass).
 
-1. Under New Connection, enter `mongodb://localhost:27017`
+1. Under New Connection, enter `mongodb://localhost:27017/?replicaSet=rs0`
 2. Under Databases, select CombineDatabase
 
 ### Add or Update Dictionary Files

database/init/00-replica-set.js

@@ -0,0 +1,31 @@
+// Initialize the replica set on first startup.
+// See: https://www.mongodb.com/docs/manual/tutorial/convert-standalone-to-replica-set/
+//
+// MONGO_INITDB_REPLICA_HOST can be set to the resolvable hostname:port
+// used to advertise this member (e.g. the Kubernetes Service name "database:27017").
+// It defaults to "localhost:27017" for local development.
+try {
+  rs.status();
+} catch (e) {
+  print(`Replica set not yet initialized (${e}), initializing now...`);
+  const host = process.env.MONGO_INITDB_REPLICA_HOST || "localhost:27017";
+  rs.initiate({ _id: "rs0", members: [{ _id: 0, host: host }] });
+  // Wait for replica set to reach PRIMARY state before other init scripts run.
+  const maxWaitMs = 30000;
+  const intervalMs = 500;
+  let waited = 0;
+  let isPrimary = false;
+  while (!isPrimary && waited < maxWaitMs) {
+    sleep(intervalMs);
+    waited += intervalMs;
+    const status = rs.status();
+    isPrimary =
+      status.members !== undefined &&
+      status.members.some((m) => m.stateStr === "PRIMARY");
+  }
+  if (!isPrimary) {
+    throw new Error(
+      `Replica set did not reach PRIMARY state after ${maxWaitMs}ms`
+    );
+  }
+}

deploy/helm/thecombine/charts/database/templates/database.yaml

@@ -46,6 +46,12 @@ spec:
         - image: {{ include "database.containerImage" . }}
           imagePullPolicy: {{ .Values.global.imagePullPolicy }}
           name: database
+          args:
+            - "--replSet"
+            - "rs0"
+          env:
+            - name: MONGO_INITDB_REPLICA_HOST
+              value: "database:27017"
           ports:
             - containerPort: 27017
           resources:

package.json

@@ -8,8 +8,7 @@
     "backend": "dotnet watch --project Backend/BackendFramework.csproj",
     "build": "parcel build",
     "build:analyze": "npm run build -- --reporter @parcel/reporter-bundle-analyzer",
-    "predatabase": "node scripts/setupMongo.js",
-    "database": "mongod --dbpath=./mongo_database",
+    "database": "node scripts/startDatabase.js",
     "drop-database": "tsc scripts/dropDB.ts && node scripts/dropDB.js",
     "find-circular-deps": "npx --ignore-scripts -y madge -c src/index.tsx --ts-config tsconfig.json",
     "fmt-backend": "      dotnet format                     && dotnet format                     Backend.Tests",