Merge pull request #97 from draios/nodejs-bad-rest-api

Example showing running bash via a bad rest api.

examples/nodejs-bad-rest-api/README.md

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+#Demo of falco with bash exec via poorly designed REST API.
+
+## Introduction
+
+This example shows how a server could have a poorly designed API that
+allowed a client to execute arbitrary programs on the server, and how
+that behavior can be detected using Sysdig Falco.
+
+`server.js` in this directory defines the server. The poorly designed
+API is this route handler:
+
+```javascript
+router.get('/exec/:cmd', function(req, res) {
+    var output = child_process.execSync(req.params.cmd);
+    res.send(output);
+});
+
+app.use('/api', router);
+```
+
+It blindly takes the url portion after `/api/exec/<cmd>` and tries to
+execute it. A horrible design choice(!), but allows us to easily show
+Sysdig falco's capabilities.
+
+## Demo architecture
+
+### Start everything using docker-compose
+
+From this directory, run the following:
+
+```
+$ docker-compose -f demo.yml up
+```
+
+This starts the following containers:
+
+* express_server: simple express server exposing a REST API under the endpoint `/api/exec/<cmd>`.
+* falco: will detect when you execute a shell via the express server.
+
+### Access urls under `/api/exec/<cmd>` to run arbitrary commands.
+
+Run the following commands to execute arbitrary commands like 'ls', 'pwd', etc:
+
+```
+$ curl http://localhost:8080/api/exec/ls
+
+demo.yml
+node_modules
+package.json
+README.md
+server.js
+```
+
+```
+$ curl http://localhost:8080/api/exec/pwd
+
+.../examples/nodejs-bad-rest-api
+```
+
+### Try to run bash via `/api/exec/bash`, falco sends alert.
+
+If you try to run bash via `/api/exec/bash`, falco will generate an alert:
+
+```
+falco          | 22:26:53.536628076: Warning Shell spawned in a container other than entrypoint (user=root container_id=6f339b8aeb0a container_name=express_server shell=bash parent=sh cmdline=bash )
+```

examples/nodejs-bad-rest-api/demo.yml

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+# Owned by software vendor, serving install-software.sh.
+express_server:
+  container_name: express_server
+  image: node:latest
+  working_dir: /usr/src/app
+  command: bash -c "npm install && node server.js"
+  ports:
+    - "8080:8080"
+  volumes:
+        - ${PWD}:/usr/src/app
+
+falco:
+  container_name: falco
+  image: sysdig/falco:latest
+  privileged: true
+  volumes:
+    - /var/run/docker.sock:/host/var/run/docker.sock
+    - /dev:/host/dev
+    - /proc:/host/proc:ro
+    - /boot:/host/boot:ro
+    - /lib/modules:/host/lib/modules:ro
+    - /usr:/host/usr:ro
+    - ${PWD}/../../rules/falco_rules.yaml:/etc/falco_rules.yaml
+  tty: true

examples/nodejs-bad-rest-api/package.json

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+{
+    "name": "bad-rest-api",
+    "main": "server.js",
+    "dependencies": {
+	"express": "~4.0.0"
+    }
+}

examples/nodejs-bad-rest-api/server.js

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+var express    = require('express');        // call express
+var app        = express();                 // define our app using express
+var child_process = require('child_process');
+
+var port = process.env.PORT || 8080;        // set our port
+
+// ROUTES FOR OUR API
+// =============================================================================
+var router = express.Router();              // get an instance of the express Router
+
+// test route to make sure everything is working (accessed at GET http://localhost:8080/api)
+router.get('/', function(req, res) {
+    res.json({ message: 'API available'});
+});
+
+router.get('/exec/:cmd', function(req, res) {
+    var output = child_process.execSync(req.params.cmd);
+    res.send(output);
+});
+
+app.use('/api', router);
+
+app.listen(port);
+console.log('Server running on port: ' + port);
+