docs: Add nginx docs

Signed-off-by: Anurag Rajawat <[email protected]>

docs/getting_started.md

@@ -13,10 +13,10 @@ observability. It includes detailed commands for each step along with their expl
 
 ## 2. Deploying SentryFlow
 
-Configure SentryFlow receiver by following [this](receivers.md). Then deploy SentryFlow by following `kubectl` command:
+Configure SentryFlow receiver by following [this](receivers.md). Then deploy updated SentryFlow manifest by following `kubectl` command:
 
 ```shell
-kubectl apply -f https://raw.githubusercontent.com/5GSEC/SentryFlow/refs/heads/main/deployments/sentryflow.yaml
+kubectl apply -f sentryflow.yaml
 ```
 
 This will create a namespace named `sentryflow` and will deploy the necessary Kubernetes resources.

docs/receivers.md

@@ -6,3 +6,10 @@ SentryFlow supports following receivers:
 
 - [Istio sidecar](https://istio.io/latest/docs/setup/) service mesh. To integrate SentryFlow with it, refer
   to [this](receivers/service-mesh/istio/istio.md).
+- [Nginx Inc.](https://docs.nginx.com/nginx-ingress-controller/) ingress controller. To integrate SentryFlow with it,
+  refer to [this](receivers/other/ingress-controller/nginx-inc/nginx_inc.md).
+
+## Non-Kubernetes
+
+- [Nginx web server](https://nginx.org/) running on Virtual Machine or Bare-Metal. To integrate SentryFlow
+  with it, refer to [this](receivers/other/web-server/nginx/nginx.md).

docs/receivers/other/ingress-controller/nginx-inc/nginx_inc.md

@@ -0,0 +1,204 @@
+# Nginx Incorporation Ingress Controller
+
+## Description
+
+This guide provides a step-by-step process to integrate SentryFlow
+with [Nginx Inc.](https://docs.nginx.com/nginx-ingress-controller/) Ingress Controller, aimed at enhancing API
+observability. It includes detailed commands for each step along with their explanations.
+
+SentryFlow make use of following to provide visibility into API calls:
+
+- [Nginx njs](https://nginx.org/en/docs/njs/) module.
+- [Njs filter](../../../../../filter/nginx).
+
+## Prerequisites
+
+- Nginx Inc. Ingress Controller.
+  Follow [this](https://docs.nginx.com/nginx-ingress-controller/installation/installing-nic/) to deploy it.
+
+## How to
+
+To Observe API calls of your workloads served by Nginx inc. ingress controller in Kubernetes environment, follow
+the below
+steps:
+
+1. Create the following configmap in the same namespace as ingress controller.
+
+```shell
+cat <<EOF | kubectl apply -f -
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: sentryflow-nginx-inc
+  namespace: <ingress-controller-namespace>
+data:
+  sentryflow.js: |
+    const DEFAULT_KEY = "sentryFlow";
+    const ResStatusKey = ":status"
+    const MAX_BODY_SIZE = 1_000_000; // 1 MB
+    
+    function requestHandler(r, data, flags) {
+        r.sendBuffer(data, flags);
+        r.done();
+        
+        let responseBody = ""
+        try {
+            responseBody = new TextDecoder("utf-8")
+                .decode(new Uint8Array(data));
+        } catch (error) {
+            r.error(`failed to decode data, error: ${error}`)
+        }
+        
+        if (responseBody.length > MAX_BODY_SIZE) {
+            responseBody = ""
+        }
+        
+        let apiEvent = {
+            "metadata": {
+                "timestamp": Date.parse(r.variables.time_iso8601.split("+")[0]) / 1000,
+                "receiver_name": "nginx",
+                "receiver_version": ngx.version,
+            },
+            "source": {
+                "ip": r.remoteAddress,
+                "port": r.variables.remote_port,
+            },
+            "destination": {
+                "ip": r.variables.server_addr,
+                "port": r.variables.server_port,
+            },
+            "request": {
+                "headers": {},
+                "body": r.requestText || "",
+            },
+            "response": {
+                "headers": {},
+                "body": responseBody,
+            },
+            "protocol": r.variables.server_protocol,
+        };
+        
+        for (const header in r.headersIn) {
+            apiEvent.request.headers[header] = r.headersIn[header];
+        }
+        
+        apiEvent.request.headers[":scheme"] = r.variables.scheme
+        apiEvent.request.headers[":path"] = r.uri
+        apiEvent.request.headers[":method"] = r.variables.request_method
+        
+        apiEvent.request.headers["body_bytes_sent"] = r.variables.body_bytes_sent
+        
+        apiEvent.request.headers["request_length"] = r.variables.request_length
+        
+        apiEvent.request.headers["request_time"] = r.variables.request_time
+        
+        apiEvent.request.headers["query"] = r.variables.query_string
+        
+        for (const header in r.headersOut) {
+            apiEvent.response.headers[header] = r.headersOut[header];
+        }
+        apiEvent.response.headers[ResStatusKey] = r.variables.status
+        
+        ngx.shared.apievents.set(DEFAULT_KEY, JSON.stringify(apiEvent));
+    }
+    
+    async function dispatchHttpCall(r) {
+        try {
+            let apiEvent = ngx.shared.apievents.get(DEFAULT_KEY);
+            await r.subrequest("/sentryflow", {
+                method: "POST", body: apiEvent, detached: true
+            })
+        } catch (error) {
+            r.error(`failed to dispatch HTTP call to SentryFlow, error: ${error}`)
+            return;
+        } finally {
+            ngx.shared.apievents.clear();
+        }
+        
+        r.return(200, "OK");
+    }
+    
+    export default {requestHandler, dispatchHttpCall};
+EOF
+```
+
+2. Add the following volume and volume-mount in ingress controller deployment:
+
+```yaml
+...
+volumes:
+  - name: sentryflow-nginx-inc
+    configMap:
+      name: sentryflow-nginx-inc
+...
+...
+volumeMounts:
+  - mountPath: /etc/nginx/njs/sentryflow.js
+    name: sentryflow-nginx-inc
+    subPath: sentryflow.js
+```
+
+3. Update ingress controller configmap as follows:
+
+```yaml
+...
+data:
+  http-snippets: |
+    js_path "/etc/nginx/njs/";
+    subrequest_output_buffer_size 8k;
+    js_shared_dict_zone zone=apievents:1M timeout=300s evict;
+    js_import main from sentryflow.js;
+  location-snippets: |
+    js_body_filter main.requestHandler buffer_type=buffer;
+    mirror      /mirror_request;
+    mirror_request_body on;
+  server-snippets: |
+    location /mirror_request {
+      internal;
+      js_content main.dispatchHttpCall;
+    }
+    location /sentryflow {
+      internal;
+      # Update SentryFlow URL with path to ingest access logs if required.
+      proxy_pass http://sentryflow.sentryflow:8081/api/v1/events;
+      proxy_method      POST;
+      proxy_set_header accept "application/json";
+      proxy_set_header Content-Type "application/json";
+    }
+```
+
+4. Download SentryFlow manifest file
+
+  ```shell
+  curl -sO https://raw.githubusercontent.com/5GSEC/SentryFlow/refs/heads/main/deployments/sentryflow.yaml
+  ```
+
+5. Update the `.receivers` configuration in `sentryflow` [configmap](../../../../../deployments/sentryflow.yaml) as
+   follows:
+
+  ```yaml
+  filters:
+    server:
+      port: 8081
+    # Following is required for `nginx-inc-ingress-controller` receiver.  
+    nginxIngress:
+      deploymentName: <nginx-ingress-controller-deploy-name>
+      configMapName: <nginx-ingress-configmap-name>
+      sentryFlowNjsConfigMapName: <sentryflow-nginx-inc-configmap-name>
+
+  receivers:
+    others:
+      - name: nginx-inc-ingress-controller # SentryFlow makes use of `name` to configure receivers. DON'T CHANGE IT.
+        namespace: <ingress-controller-namespace> # Kubernetes namespace in which you've deployed the ingress controller.
+    ...
+  ```
+
+6. Deploy SentryFlow
+
+  ```shell
+  kubectl apply -f sentryflow.yaml
+  ```
+
+7. Trigger API calls to generate traffic.
+
+8. Use SentryFlow [log client](../../../../client) to see the API Events.

docs/receivers/other/web-server/nginx/nginx.md

@@ -0,0 +1,95 @@
+# Nginx Web Server
+
+## Description
+
+This guide provides a step-by-step process to integrate SentryFlow
+with [Nginx webserver](https://nginx.org/), aimed at enhancing API
+observability. It includes detailed commands for each step along with their explanations.
+
+SentryFlow make use of following to provide visibility into API calls:
+
+- [Nginx njs](https://nginx.org/en/docs/njs/) module.
+- [Njs filter](../../../../../filter/nginx).
+
+## Prerequisites
+
+- Nginx web server.
+- [Nginx-njs-module](https://github.com/nginx/njs?tab=readme-ov-file#downloading-and-installing).
+
+## How to
+
+To Observe API calls of your application running on a virtual machine (VM) behind a Nginx web server, follow the below
+steps:
+
+1. Copy [sentryflow.js](../../../../../filter/nginx/sentryflow.js) file to `/etc/nginx/njs/` directory as
+   `sentryflow.js`.
+2. Edit `nginx.conf` file located in `/etc/nginx/` directory as follows:
+
+```nginx configuration
+load_module /etc/nginx/modules/ngx_http_js_module.so;
+...
+http {
+    ...
+    subrequest_output_buffer_size 8k;
+    js_path "/etc/nginx/njs/";
+    js_shared_dict_zone zone=apievents:1M timeout=60s evict;
+    js_import main from sentryflow.js;
+    ...
+    server {
+        location / {
+            js_body_filter main.requestHandler buffer_type=buffer;
+            mirror      /mirror_request;
+            mirror_request_body on;
+        }
+        
+        location /mirror_request {
+            internal;
+            js_content main.dispatchHttpCall;
+        }
+        
+        location /sentryflow {
+            internal;
+            
+            # SentryFlow URL with path to ingest access logs.
+            proxy_pass http://<sentryflow_url>/api/v1/events;
+            
+            proxy_method      POST;
+            proxy_set_header accept "application/json";
+            proxy_set_header Content-Type "application/json";
+        }
+        ...
+    }
+} 
+```
+
+Here is the sample [nginx.conf](../../../../../filter/nginx/nginx.conf) file for reference.
+
+3. Reload `nginx`:
+
+```shell
+$ sudo nginx -s reload
+```
+
+4. Update the `.receivers` configuration in `sentryflow` [configmap](../../../../deployments/sentryflow.yaml) as
+   follows:
+
+  ```yaml
+  filters:
+    server:
+      port: 8081
+
+  receivers:
+    others:
+      - name: nginx-webserver # SentryFlow makes use of `name` to configure receivers. DON'T CHANGE IT.
+    ...
+  ```
+
+5. Deploy SentryFlow
+
+  ```shell
+  kubectl apply -f sentryflow.yaml
+  ```
+
+6. Trigger API calls to generate traffic.
+
+7. Use SentryFlow [log client](../../../../client) to see the API Events.