feat: added kyverno-json-policies for dockerfile-best-practices

dockerfile-best-practices/detect-multiple-instructions/README.md

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+# Detect if there are any multiple instructions in a single line
+
+This policy is implemented to ensure that container images are built with minimal cached layers. It specifically focuses on detecting and preventing the use of multiple instructions in a single line within Dockerfiles. An example of such a scenario is using '&&' to combine two commands.
+
+## Policy Details:
+
+- **Policy Name:** detect-multiple-instructions
+- **Check Description:** This policy ensures that Dockerfile Container Image Should Be Built with Minimal Cached Layers
+- **Policy Category:** Dockerfile Best Practices
+
+## How It Works:
+
+### Validation Criteria:
+
+**Key** : CmdLine[0]
+**Valid Values** : executables of the command
+**Type** : string
+
+- **Condition:** `CmdLine[0]` contains ` && `
+  - **Result:** FAIL
+  - **Reason:** Multiple instructions in a single line detected.
+
+
+- **Condition:** `CmdLine[0]` doesn't contains ` && `
+  - **Result:** PASS
+  - **Reason:** Single instruction per line, complying with best practices.
+
+### Policy Validation Testing Instructions
+
+To evaluate and test the policy ensuring dockerfile meets poliy requirements:
+
+For testing this policy you will need to:
+- Make sure you have `kyverno-json` installed on the machine
+- Make sure you have [nctl `v3.4.0`](https://downloads.nirmata.io/nctl/downloads/) or above.
+
+
+1. **Extract JSON equivalent of the dockerfile:**
+    ```bash
+    nctl scan dockerfile -r test/good-test/Dockerfile --show-json > payload.json
+    ```
+
+2. **Test the Policy with Kyverno:**
+    ```bash
+    kyverno-json scan --payload payload.json --policy detect-multiple-instructions.yaml
+    ```
+
+    a. **Test Policy Against Valid Payload:**
+    ```bash
+    kyverno-json scan --policy detect-multiple-instructions.yaml --payload test/good-test/good-payload.json
+    ```
+
+    This produces the output:
+    ```
+    Loading policies ...
+    Loading payload ...
+    Pre processing ...
+    Running ( evaluating 1 resource against 1 policy ) ...
+    - detect-multiple-instructions / detect-multiple-instructions /  PASSED
+    Done
+    ```
+
+    b. **Test Against Invalid Payload:**
+    ```bash
+    kyverno-json scan --policy detect-multiple-instructions.yaml --payload test/bad-test/bad-payload.json
+    ```
+
+    This produces the output:
+    ```
+    Loading policies ...
+    Loading payload ...
+    Pre processing ...
+    Running ( evaluating 1 resource against 1 policy ) ...
+    - detect-multiple-instructions / detect-multiple-instructions /  FAILED: Found multiple instructions in a single line: any[0].check.~.(Stages[].Commands[].CmdLine[0].contains(@, ' && '))[0]: Invalid value: true: Expected value: false
+    Done
+    ```
+
+---
+
+This way you can ensure that your dockerfile adhere to policy.

dockerfile-best-practices/detect-multiple-instructions/detect-multiple-instructions.yaml

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+apiVersion: json.kyverno.io/v1alpha1
+kind: ValidatingPolicy
+metadata:
+  name: detect-multiple-instructions
+  annotations:
+    policies.kyverno.io/title: Detect Multiple Instructions in Single Line
+    policies.kyverno.io/category: Dockerfile Best Practices
+    policies.kyverno.io/severity: medium
+    policies.kyverno.io/description: >-
+      This policy ensures that Dockerfile Container Image Should Be Built with Minimal Cached Layers
+spec:
+  rules:
+    - name: detect-multiple-instructions
+      match:
+        any:
+        - (Stages[].Commands[?Name=='RUN'].CmdLine[][] | length(@) > `0`): true
+      assert:
+        all:
+        - message: Found multiple instructions in a single line
+          check:
+            ~.(Stages[].Commands[?Name=='RUN'].CmdLine[][]):
+              (contains(@, ' && ')): false

dockerfile-best-practices/detect-multiple-instructions/test/bad-test/Dockerfile

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+FROM ubuntu:latest
+
+# Update the package repository
+RUN apt-get update && apt-get install -y nano
+
+WORKDIR /app
+
+COPY . /app
+
+EXPOSE 8080
+
+# Example: Run a command when the container starts
+CMD ["echo", "Container is running!"]

dockerfile-best-practices/detect-multiple-instructions/test/bad-test/bad-payload.json

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+{
+    "MetaArgs": null,
+    "Stages": [
+      {
+        "Name": "",
+        "BaseName": "ubuntu:latest",
+        "Platform": "",
+        "Comment": "",
+        "SourceCode": "FROM ubuntu:latest",
+        "Location": [
+          {
+            "Start": {
+              "Line": 1,
+              "Character": 0
+            },
+            "End": {
+              "Line": 1,
+              "Character": 0
+            }
+          }
+        ],
+        "From": {
+          "Image": "ubuntu:latest"
+        },
+        "Commands": [
+          {
+            "CmdLine": [
+              "apt-get update && apt-get install -y nano"
+            ],
+            "Files": null,
+            "FlagsUsed": [],
+            "Name": "RUN",
+            "PrependShell": true
+          },
+          {
+            "Name": "WORKDIR",
+            "Path": "/app"
+          },
+          {
+            "Chmod": "",
+            "Chown": "",
+            "DestPath": "/app",
+            "From": "",
+            "Link": false,
+            "Name": "COPY",
+            "SourceContents": null,
+            "SourcePaths": [
+              "."
+            ]
+          },
+          {
+            "Name": "EXPOSE",
+            "Ports": [
+              "8080"
+            ]
+          },
+          {
+            "CmdLine": [
+              "echo",
+              "Container is running!"
+            ],
+            "Files": null,
+            "Name": "CMD",
+            "PrependShell": false
+          }
+        ]
+      }
+    ]
+  }

dockerfile-best-practices/detect-multiple-instructions/test/good-test/Dockerfile

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+FROM ubuntu:latest
+
+# Update the package repository
+RUN apt-get update
+
+WORKDIR /app
+
+COPY . /app
+
+EXPOSE 8080
+
+# Example: Run a command when the container starts
+CMD ["echo", "&& is not present"]

dockerfile-best-practices/detect-multiple-instructions/test/good-test/good-payload.json

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+{
+    "MetaArgs": null,
+    "Stages": [
+      {
+        "Name": "",
+        "BaseName": "ubuntu:latest",
+        "Platform": "",
+        "Comment": "",
+        "SourceCode": "FROM ubuntu:latest",
+        "Location": [
+          {
+            "Start": {
+              "Line": 1,
+              "Character": 0
+            },
+            "End": {
+              "Line": 1,
+              "Character": 0
+            }
+          }
+        ],
+        "From": {
+          "Image": "ubuntu:latest"
+        },
+        "Commands": [
+          {
+            "CmdLine": [
+              "apt-get update"
+            ],
+            "Files": null,
+            "FlagsUsed": [
+
+            ],
+            "Name": "RUN",
+            "PrependShell": true
+          },
+          {
+            "Name": "WORKDIR",
+            "Path": "/app"
+          },
+          {
+            "Chmod": "",
+            "Chown": "",
+            "DestPath": "/app",
+            "From": "",
+            "Link": false,
+            "Name": "COPY",
+            "SourceContents": null,
+            "SourcePaths": [
+              "."
+            ]
+          },
+          {
+            "Name": "EXPOSE",
+            "Ports": [
+              "8080"
+            ]
+          },
+          {
+            "CmdLine": [
+              "echo",
+              "&& is not present"
+            ],
+            "Files": null,
+            "Name": "CMD",
+            "PrependShell": false
+          }
+        ]
+      }
+    ]
+  }

dockerfile-best-practices/prefer-copy-over-add/README.md

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+# Prefer COPY over ADD Instructions in Dockerfile
+
+This policy ensures that container images are built using commands that result in known outcomes. Specifically, it advocates for the preference of using the `COPY` instruction over `ADD` in Dockerfiles. By adhering to this policy, you enhance the predictability and transparency of the image-building process.
+
+## Policy Details:
+
+- **Policy Name:** prefer-copy-over-add
+- **Check Description:** This policy checks whether Dockerfiles use the ADD instructions for copying files into the container image.
+- **Policy Category:** Dockerfile Best Practices
+
+## How It Works:
+
+### Validation Criteria:
+
+**Key** : ADD
+
+- **Condition:** If `ADD` exists
+  - **Result:** FAIL
+  - **Reason:**  Using `ADD` can introduce unnecessary complexity and ambiguity, potentially leading to unintended consequences. The policy recommends preferring COPY for explicit file copying.
+
+- **Condition:**  If `ADD` doesn't exist
+  - **Result:** PASS
+  - **Reason:** This indicates compliance with the policy, as the absence of ADD aligns with the best practice of using COPY for file operations.
+
+### Policy Validation Testing Instructions
+
+To evaluate and test the policy ensuring dockerfile meets poliy requirements:
+
+For testing this policy you will need to:
+- Make sure you have `kyverno-json` installed on the machine
+- Make sure you have [nctl `v3.4.0`](https://downloads.nirmata.io/nctl/downloads/) or above.
+
+
+1. **Extract JSON equivalent of the dockerfile:**
+    ```bash
+    nctl scan dockerfile -r test/good-test/Dockerfile --show-json > payload.json
+    ```
+
+2. **Test the Policy with Kyverno:**
+    ```bash
+    kyverno-json scan --payload payload.json --policy prefer-copy-over-add.yaml
+    ```
+
+    a. **Test Policy Against Valid Payload:**
+    ```bash
+    kyverno-json scan --policy prefer-copy-over-add.yaml --payload test/good-test/good-payload.json
+    ```
+
+    This produces the output:
+    ```
+    Loading policies ...
+    Loading payload ...
+    Pre processing ...
+    Running ( evaluating 1 resource against 1 policy ) ...
+    - prefer-copy-over-add / prefer-copy-over-add /  PASSED
+    Done
+    ```
+
+    b. **Test Against Invalid Payload:**
+    ```bash
+    kyverno-json scan --policy prefer-copy-over-add.yaml --payload test/bad-test/bad-payload.json
+    ```
+
+    This produces the output:
+    ```
+    Loading policies ...
+    Loading payload ...
+    Pre processing ...
+    Running ( evaluating 1 resource against 1 policy ) ...
+    - prefer-copy-over-add / prefer-copy-over-add /  FAILED: Avoid the use of ADD instructions in Dockerfiles: any[0].check.(Stages[].Commands[?Name=='ADD'].Link[] | length(@) > `0`): Invalid value: true: Expected value: false
+    Done
+    ```
+
+---
+
+By following this policy, you can ensure that your Dockerfile adopts a more straightforward and transparent approach to file copying, promoting better image building practices.

dockerfile-best-practices/prefer-copy-over-add/prefer-copy-over-add.yaml

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+apiVersion: json.kyverno.io/v1alpha1
+kind: ValidatingPolicy
+metadata:
+  name: prefer-copy-over-add
+  annotations:
+    policies.kyverno.io/title: Prefer COPY over ADD in Dockerfile
+    policies.kyverno.io/category: Dockerfile Best Practices
+    policies.kyverno.io/severity: medium
+    policies.kyverno.io/description: >-
+      This policy ensures that COPY instructions are used instead of ADD instructions in Dockerfiles.
+spec:
+  rules:
+    - name: prefer-copy-over-add
+      match:
+        any:
+        - (Stages[].Commands[] | length(@) > `0`): true
+      assert:
+        any:
+        - message: Avoid the use of ADD instructions in Dockerfiles
+          check:
+            (Stages[].Commands[?Name=='ADD'].Link[] | length(@) > `0`): false

dockerfile-best-practices/prefer-copy-over-add/test/bad-test/Dockerfile

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+FROM ubuntu:latest
+
+WORKDIR /app
+
+ADD . /app/
+
+RUN apt-get update && apt-get install -y nano
+
+COPY . /app
+
+EXPOSE 8080
+
+# Example: Run a command when the container starts
+CMD ["echo", "ADD is present in the Dockerfile"]