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Wallarm API Firewall demo with Kubernetes

This demo deploys the application httpbin and Wallarm API Firewall as a proxy protecting httpbin API. Both applications are running in the Docker containers in Kubernetes.

System requirements

Before running this demo, please ensure your system meets the following requirements:

Running this demo environment can be resource-intensive. Please ensure you have the following resources available:

  • At least 2 CPU cores

  • At least 6GB volatile memory

Used resources

The following resources are used in this demo:

Demo code description

The demo code runs the Kubernetes cluster with deployed httpbin and API Firewall.

To run the Kubernetes cluster, this demo uses the tool kind which allows running the K8s cluster in minutes using Docker containers as nodes. By using several abstraction layers, kind and its dependencies are packed into the Docker image which starts the Kubernetes cluster.

The demo deployment is configured via the following directories/files:

  • The OpenAPI 3.0 specification for httpbin API is located in the file volumes/helm/api-firewall.yaml under the manifest.body path. Using this specification, API Firewall will validate whether requests and responses sent to the application address match the application API schema.

    This specification does not define the original API schema of httpbin. To demonstrate more transparently the API Firewall features, we have explicitly converted and complicated the original OpenAPI 2.0 schema and saved the changed specification to volumes/helm/api-firewall.yaml > manifest.body.

  • Makefile is the configuration file defining Docker routines.

  • docker-compose.yml is the file defining the following configuration for running the temporary Kubernetes cluster:

    • The kind node building based on docker/Dockerfile.
    • Deployment of the DNS server providing simultaneous Kubernetes and Docker service discovery.
    • Local Docker registry and the dind service deployment.
    • httpbin and API Firewall Docker images configuration.

Step 1: Running the demo code

To run the demo code:

  1. Clone the GitHub repository containing the demo code:

    git clone https://github.com/wallarm/api-firewall.git

  2. Change to the demo/kubernetes directory of the cloned repository:

    cd api-firewall/demo/kubernetes

  3. Run the demo code by using the command below. Please note that running this demo can be resource-intensive. It takes up to 3 minutes to start the demo environment.

    make start
    • The application httpbin protected by API Firewall will be available at http://localhost:8080.
    • The application httpbin unprotected by API Firewall will be available at http://localhost:8090. When testing the demo deployment, you can send requests to the unprotected application to know the difference.

  4. Proceed to the demo testing.

Step 2: Testing the demo

Using the following request, you can test deployed API Firewall:

  • Check that API Firewall blocks requests sent to the unexposed path:

    curl -sD - http://localhost:8080/unexposed/path

    Expected response:

    HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 06:58:29 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0

  • Check that API Firewall blocks requests with string value passed in the parameter that requires integer data type:

    curl -sD - http://localhost:8080/cache/arewfser

    Expected response:

    HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 06:58:29 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0

    This case demonstrates that API Firewall protects the application from Cache-Poisoned DoS attacks.

  • Check that API Firewall blocks requests with the required query parameter int that does not match the following definition:

    ...
{
  "in": "query",
  "name": "int",
  "schema": {
    "type": "integer",
    "minimum": 10,
    "maximum": 100
  },
  "required": true
},
...

    Test the definition by using the following requests:

    # Request with missed required query parameter
curl -sD - http://localhost:8080/get

# Expected response
HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 07:09:08 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0


# Request with the int parameter value which is in a valid range
curl -sD - http://localhost:8080/get?int=15

# Expected response
HTTP/1.1 200 OK
Server: gunicorn/19.9.0
Date: Mon, 31 May 2021 07:09:38 GMT
Content-Type: application/json
Content-Length: 280
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
...


# Request with the int parameter value which is out of range
curl -sD - http://localhost:8080/get?int=5

# Expected response
HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 07:09:27 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0


# Request with the int parameter value which is out of range
curl -sD - http://localhost:8080/get?int=1000

# Expected response
HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 07:09:53 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0


# Request with the int parameter value which is out of range
# POTENTIAL EVIL: 8-byte integer overflow can respond with stack drop
curl -sD - http://localhost:8080/get?int=18446744073710000001

# Expected response
HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 07:10:04 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0

  • Check that API Firewall blocks requests with the query parameter str that does not match the following definition:

    ...
{
  "in": "query",
  "name": "str",
  "schema": {
    "type": "string",
    "pattern": "^.{1,10}-\\d{1,10}$"
  }
},
...

    Test the definition by using the following requests (the int parameter is still required):

    # Request with the str parameter value that does not match the defined regular expression
curl -sD - "http://localhost:8080/get?int=15&str=fasxxx.xxxawe-6354"

# Expected response
HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 07:10:42 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0


# Request with the str parameter value that does not match the defined regular expression
curl -sD - "http://localhost:8080/get?int=15&str=faswerffa-63sss54"

# Expected response
HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 07:10:42 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0


# Request with the str parameter value that matches the defined regular expression
curl -sD - http://localhost:8080/get?int=15&str=ri0.2-3ur0-6354

# Expected response
HTTP/1.1 200 OK
Server: gunicorn/19.9.0
Date: Mon, 31 May 2021 07:11:03 GMT
Content-Type: application/json
Content-Length: 331
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
...


# Request with the str parameter value that does not match the defined regular expression
# POTENTIAL EVIL: SQL Injection
curl -sD - 'http://localhost:8080/get?int=15&str=";SELECT%20*%20FROM%20users.credentials;"'

# Expected response
HTTP/1.1 403 Forbidden
Date: Mon, 31 May 2021 07:12:04 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 0

Step 4: Stopping the demo code

To stop the demo deployment and clear your environment, use the command:

make stop