Allow dynamic flag

.gitignore

@@ -0,0 +1 @@
+.DS_Store

Dockerfile

@@ -1,16 +1,18 @@
-FROM node:boron
+FROM node:lts-alpine
 
 COPY phaserquest/ /usr/src/app
 COPY _files/ /tmp/
 
-RUN apt-get update && \
-    apt-get -y upgrade && \
-    npm install && \
-    npm install pm2 -g && \
-    useradd -m ctf && \
+RUN cd /usr/src/app && \
+    npm install -g cnpm --registry=https://registry.npm.taobao.org && \
+    cnpm install && \
+    cnpm install pm2 -g && \
+    addgroup -S ctf && adduser -S ctf -G ctf && \
     mv /tmp/processes.yml /root/processes.yml && \
     mv /tmp/flag /flag && \
     mv /tmp/readflag /readflag && \
+    mv /tmp/start.sh /start.sh && \
+    chmod +x /start.sh && \
     chmod 555 /readflag && \
     chmod u+s /readflag && \
     chmod 500 /flag && \
@@ -19,4 +21,6 @@ RUN apt-get update && \
 
 WORKDIR /usr/src/app
 
-EXPOSE 10081
+EXPOSE 8081
+
+ENTRYPOINT ["/start.sh"]

_files/processes.yml

@@ -7,4 +7,4 @@ apps:
     gid: 'ctf'
     output: '/root/out'
     error: '/root/error'
-    args: ["-p 10081","--mongoServer=mongo","--waitForDatabase=5000"]
+    args: ["-p 8081","--mongoServer=db","--waitForDatabase=5000"]

_files/start.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+echo $FLAG > /flag
+
+export FLAG=not_flag
+FLAG=not_flag
+
+pm2-runtime /root/processes.yml

docker-compose.yml

@@ -1,12 +1,21 @@
 version: '2.0'
 
+networks:
+  game_network:
+    driver: bridge
+    ipam:
+      config:
+        - subnet: 172.91.0.0/16
+
 services:
   mongo:
     image: 'mongo:3.4.4'
     ports:
       - '127.0.0.1:27017:27017'
-    volumes:
-      - 'mongo:/data/db'
+    networks:
+      game_network:
+        aliases:
+          - db
 
   phaserquest:
     tty: true
@@ -19,6 +28,12 @@ services:
     image: ctftraining/starctf_2019_996game
     command: pm2-runtime /root/processes.yml
     ports:
-      - '127.0.0.1:8081:10081'
+      - '127.0.0.1:8081:8081'
+    environment:
+      - FLAG=flag{test_flag}
+    networks:
+      game_network:
+        aliases:
+          - web
 volumes:
   mongo: