Add k8s audit support to falco event generator

Currently, the falco event generator only generates system call
activity. This adds support for k8s_audit events by adding a script +
supporting k8s object files that generate activity that matches the k8s
audit event ruleset.

The main script is k8s_event_generator.sh, which loops over the files in
the yaml subdirectory, running kubectl apply -f for each.

In the interests of keeping things self-contained, all objects are
created in a `falco-event-generator` namespace. This means that some
activity related with cluster roles/cluster role bindings is not
performed.

Each k8s object has annotations that note:

1. The specific falco rules that should trigger.
2. A user-friendly message to print when apply-ing the file.

You can provide a specific rule name to the script. If provided, only
those objects related to that rule will trigger. The default is "all",
meaning that all objects are created.

The script loops forever, deleting the falco-event-generator namespace
after each iteration.

Additionally, the docker image has been updated to also copy the script
+ supporting files, as well as fetching the latest available `kubectl`
binary. The entrypoint is now a script that allows choosing between:
 - syscall activity: run with .... "syscall"
 - k8s_audit activity: run with .... "k8s_audit"
 - spawn a shell: run with .... "bash"

The default is "syscall" to preserve existing behavior.

In most cases, you'll need to provide kube config
files/directories that allow access to your cluster. A
command like the following will work:

```
docker run -v $HOME/.kube:/root/.kube -it falcosecurity/falco-event-generator
k8s_audit
```

Signed-off-by: Mark Stemm <mark.stemm@gmail.com>

docker/event-generator/Dockerfile

@@ -1,7 +1,10 @@
 FROM alpine:latest
 LABEL maintainer="opensource@sysdig.com"
-RUN apk add --no-cache bash g++
+RUN apk add --no-cache bash g++ curl
 COPY ./event_generator.cpp /usr/local/bin
+COPY ./docker-entrypoint.sh ./k8s_event_generator.sh /
+COPY ./yaml /yaml
 RUN mkdir -p /var/lib/rpm
 RUN g++ --std=c++0x /usr/local/bin/event_generator.cpp -o /usr/local/bin/event_generator
-CMD ["/usr/local/bin/event_generator"]
+RUN curl -o /usr/local/bin/kubectl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl && chmod +x /usr/local/bin/kubectl
+ENTRYPOINT ["/docker-entrypoint.sh"]

docker/event-generator/docker-entrypoint.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+CMD=${1:-syscall}
+
+shift
+
+set -euo pipefail
+
+if [[ "$CMD" == "syscall" ]]; then
+    /usr/local/bin/event_generator
+elif [[ "$CMD" == "k8s_audit" ]]; then
+    . k8s_event_generator.sh
+elif [[ "$CMD" == "bash" ]]; then
+    bash
+else
+    echo "Unknown command. Can be one of"
+    echo "   \"syscall\": generate falco syscall-related activity"
+    echo "   \"k8s_audit\": generate falco k8s audit-related activity"
+    echo "   \"bash\": spawn a shell"
+    exit 1
+fi

docker/event-generator/k8s_event_generator.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# You can pass a specific falco rule name and only yaml files matching
+# that rule will be considered. The default is "all", meaning all yaml
+# files will be applied.
+
+RULE=${1:-all}
+
+# Replace any '/' in RULES with a '.' and any space with a dash. (K8s
+# label values can not contain slashes/spaces)
+RULE=$(echo "$RULE" | tr '/ ' '.-')
+
+echo "***Testing kubectl configuration..."
+kubectl version --short
+
+while true; do
+
+    RET=$(kubectl get namespaces --output=name | grep falco-event-generator || true)
+
+    if [[ "$RET" == *falco-event-generator* ]]; then
+	echo "***Deleting existing falco-event-generator namespace..."
+	kubectl delete namespace falco-event-generator
+    fi
+
+    echo "***Creating falco-event-generator namespace..."
+    kubectl create namespace falco-event-generator
+
+    for file in yaml/*.yaml; do
+
+	MATCH=0
+	if [[ "${RULE}" == "all" ]]; then
+	    MATCH=1
+	else
+	    RET=$(grep -E "falco.rules:.*${RULE}" $file || true)
+	    if [[ "$RET" != "" ]]; then
+		MATCH=1
+	    fi
+	fi
+
+	if [[ $MATCH == 1 ]]; then
+	    MESSAGES=$(grep -E 'message' $file | cut -d: -f2 | tr '\n' ',')
+	    RULES=$(grep -E 'falco.rules' $file | cut -d: -f2 | tr '\n' ',')
+
+	    # The message uses dashes in place of spaces, convert them back to spaces
+	    MESSAGES=$(echo "$MESSAGES" | tr '-' ' ' | sed -e 's/ *//' | sed  -e 's/,$//')
+	    RULES=$(echo "$RULES" | tr '-' ' '| tr '.' '/' | sed -e 's/ *//' | sed  -e 's/,$//')
+
+	    echo "***$MESSAGES (Rule(s) $RULES)..."
+	    kubectl apply -f $file
+	    sleep 2
+	fi
+    done
+
+    sleep 10
+done

docker/event-generator/yaml/configmap-private-creds.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: private-creds-configmap
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: private-creds-configmap
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: Create.Modify-Configmap-With-Private-Credentials
+    message: Creating-configmap-with-private-credentials
+data:
+  ui.properties: |
+    color.good=purple
+    color.bad=yellow
+    allow.textmode=true
+    password=some_secret_password

docker/event-generator/yaml/disallowed-pod-deployment.yaml

@@ -0,0 +1,25 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: disallowed-pod-deployment
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: disallowed-pod-deployment
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: Create-Disallowed-Pod
+    message: Creating-pod-with-image-outside-of-allowed-images
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: disallowed-pod-busybox
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: disallowed-pod-busybox
+        app.kubernetes.io/part-of: falco-event-generator
+    spec:
+      containers:
+        - name: busybox
+          image: busybox
+          command: ["/bin/sh", "-c", "while true; do echo sleeping; sleep 3600; done"]

docker/event-generator/yaml/hostnetwork-deployment.yaml

@@ -0,0 +1,26 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: hostnetwork-deployment
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: hostnetwork-deployment
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: Create-HostNetwork-Pod
+    message: Creating-deployment-with-hostNetwork-true-pod
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: hostnetwork-busybox
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: hostnetwork-busybox
+        app.kubernetes.io/part-of: falco-event-generator
+    spec:
+      hostNetwork: true
+      containers:
+        - name: busybox
+          image: busybox
+          command: ["/bin/sh", "-c", "while true; do echo sleeping; sleep 3600; done"]

docker/event-generator/yaml/nodeport-service.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: nodeport-service
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: nodeport-service
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: Create-NodePort-Service
+    message: Creating-service-of-type-NodePort
+spec:
+  type: NodePort
+  ports:
+    - port: 80
+  selector:
+    app: busybox

docker/event-generator/yaml/privileged-deployment.yaml

@@ -0,0 +1,27 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: privileged-deployment
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: privileged-deployment
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: Create-Privileged-Pod
+    message: Creating-deployment-with-privileged-true-pod
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: privileged-busybox
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: privileged-busybox
+        app.kubernetes.io/part-of: falco-event-generator
+    spec:
+      containers:
+        - securityContext:
+            privileged: true
+          name: busybox
+          image: busybox
+          command: ["/bin/sh", "-c", "while true; do echo sleeping; sleep 3600; done"]

docker/event-generator/yaml/role-pod-exec.yaml

@@ -0,0 +1,17 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: pod-exec-role
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: pod-exec-role
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: ClusterRole-With-Pod-Exec-Created
+    message: Creating-role-that-can-exec-to-pods
+rules:
+- apiGroups:
+    - ""
+  resources:
+    - "pods/exec"
+  verbs:
+    - get

docker/event-generator/yaml/role-wildcard-resources.yaml

@@ -0,0 +1,17 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: wildcard-resources-role
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: wildcard-resources-role
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: ClusterRole-With-Write-Privileges-Created
+    message: Creating-role-with-wildcard-resources
+rules:
+- apiGroups:
+    - ""
+  resources:
+    - "*"
+  verbs:
+    - get

docker/event-generator/yaml/role-write-privileges.yaml

@@ -0,0 +1,17 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: write-privileges-role
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: write-privileges-role
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: ClusterRole-With-Write-Privileges-Created
+    message: Creating-role-with-write-privileges
+rules:
+- apiGroups:
+    - ""
+  resources:
+    - "pods"
+  verbs:
+    - create

docker/event-generator/yaml/sensitive-mount-deployment.yaml

@@ -0,0 +1,32 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: sensitive-mount-deployment
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: sensitive-mount-deployment
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: Create-Sensitive-Mount-Pod
+    message: Creating-deployment-with-pod-mounting-sensitive-path-from-host
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: sensitive-mount-busybox
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: sensitive-mount-busybox
+        app.kubernetes.io/part-of: falco-event-generator
+    spec:
+      containers:
+        - name: busybox
+          image: busybox
+          command: ["/bin/sh", "-c", "while true; do echo sleeping; sleep 3600; done"]
+          volumeMounts:
+            - mountPath: /host/etc
+              name: etc
+      volumes:
+        - name: etc
+          hostPath:
+            path: /etc

docker/event-generator/yaml/vanilla-configmap.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: vanilla-configmap
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: vanilla-configmap
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: K8s-ConfigMap-Created
+    message: Creating-configmap
+data:
+  ui.properties: |
+    color.good=purple
+    color.bad=yellow
+    allow.textmode=true

docker/event-generator/yaml/vanilla-deployment.yaml

@@ -0,0 +1,25 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: vanilla-deployment
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: vanilla-deployment
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: K8s-Deployment-Created
+    message: Creating-deployment
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: vanilla-busybox
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: vanilla-busybox
+        app.kubernetes.io/part-of: falco-event-generator
+    spec:
+      containers:
+        - name: busybox
+          image: busybox
+          command: ["/bin/sh", "-c", "while true; do echo sleeping; sleep 3600; done"]

docker/event-generator/yaml/vanilla-role-rolebinding-serviceaccount.yaml

@@ -0,0 +1,46 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: vanilla-role
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: vanilla-role
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: K8s-Role.Clusterrole-Created
+    message: Creating-role
+rules:
+- apiGroups:
+    - ""
+  resources:
+    - "pods"
+  verbs:
+    - list
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: vanilla-role-binding
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: vanilla-role-binding
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: K8s-Role.Clusterrolebinding-Created
+    message: Creating-rolebinding
+roleRef:
+  kind: Role
+  name: vanilla-role
+  apiGroup: rbac.authorization.k8s.io
+subjects:
+  - kind: ServiceAccount
+    name: vanilla-service-account
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: vanilla-serviceaccount
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: vanilla-serviceaccount
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: K8s-Serviceaccount-Created
+    message: Creating-serviceaccount

docker/event-generator/yaml/vanilla-service.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: vanilla-service
+  namespace: falco-event-generator
+  labels:
+    app.kubernetes.io/name: vanilla-service
+    app.kubernetes.io/part-of: falco-event-generator
+    falco.rules: K8s-Service-Created
+    message: Creating-service
+spec:
+  type: ClusterIP
+  ports:
+    - port: 80
+  selector:
+    app: busybox