feat(providers): add Dockerfile/Containerfile provider for image analysis

Add a new provider that recognizes Dockerfile and Containerfile manifests
for component and stack analysis. The provider parses FROM lines to extract
the base image reference, then reuses generateImageSBOM to produce a
CycloneDX SBOM. Multi-stage Dockerfiles use the final stage's FROM image.

Implements TC-4937

Assisted-by: Claude Code

Author: a-oren

src/provider.js

@@ -8,6 +8,7 @@ import Javascript_bun from './providers/javascript_bun.js';
 import Javascript_npm from './providers/javascript_npm.js';
 import Javascript_pnpm from './providers/javascript_pnpm.js';
 import Javascript_yarn from './providers/javascript_yarn.js';
+import dockerfileProvider from './providers/oci_dockerfile.js'
 import pythonPipProvider from './providers/python_pip.js'
 import Python_pip_pyproject from './providers/python_pip_pyproject.js'
 import Python_poetry from './providers/python_poetry.js'
@@ -34,7 +35,8 @@ export const availableProviders = [
 	new Python_poetry(),
 	new Python_uv(),
 	new Python_pip_pyproject(),
-	rustCargoProvider]
+	rustCargoProvider,
+	dockerfileProvider]
 
 /**
  * Match a provider by manifest type only (no lock file check). Used for license reading.

src/providers/oci_dockerfile.js

@@ -0,0 +1,103 @@
+import fs from 'node:fs'
+
+import { generateImageSBOM, parseImageRef } from '../oci_image/utils.js'
+
+export default { isSupported, validateLockFile, provideComponent, provideStack, readLicenseFromManifest, packageManagerName() { return 'oci' } }
+
+/** @typedef {import('../provider').Provider} */
+
+/** @typedef {import('../provider').Provided} Provided */
+
+/**
+ * @type {string} ecosystem identifier for OCI image packages
+ * @private
+ */
+const ecosystem = 'oci'
+
+/**
+ * Check if the given manifest name is a Dockerfile or Containerfile.
+ * @param {string} manifestName the manifest file name to check
+ * @returns {boolean} true if the manifest is a Dockerfile or Containerfile
+ */
+function isSupported(manifestName) {
+	return manifestName === 'Dockerfile' || manifestName === 'Containerfile'
+}
+
+/**
+ * Dockerfiles have no lock file, so validation always passes.
+ * @returns {boolean} always true
+ */
+function validateLockFile() { return true; }
+
+/**
+ * Parse the last FROM line from a Dockerfile to extract the base image reference.
+ * In multi-stage builds, the last FROM represents the final stage.
+ * @param {string} manifestContent the content of the Dockerfile
+ * @returns {string} the image reference from the last FROM line
+ * @throws {Error} when no FROM line is found in the Dockerfile
+ */
+export function parseFromImage(manifestContent) {
+	const lines = manifestContent.split(/\r?\n/)
+	let lastFrom = null
+	for (const line of lines) {
+		const trimmed = line.trim()
+		if (/^FROM\s+/i.test(trimmed)) {
+			// Extract image ref: FROM [--platform=...] image [AS name]
+			const withoutFrom = trimmed.replace(/^FROM\s+/i, '')
+			// Skip optional --platform flag
+			const withoutFlags = withoutFrom.replace(/^--\S+\s+/, '')
+			// Take only the image part (before AS alias)
+			const parts = withoutFlags.split(/\s+/)
+			lastFrom = parts[0]
+		}
+	}
+	if (!lastFrom) {
+		throw new Error('No FROM line found in Dockerfile')
+	}
+	return lastFrom
+}
+
+/**
+ * Generate an image SBOM from a Dockerfile manifest using syft.
+ * @param {string} manifest path to the Dockerfile
+ * @param {{}} [opts={}] optional various options to pass along the application
+ * @returns {{ecosystem: string, content: string, contentType: string}}
+ * @private
+ */
+function getImageSBOM(manifest, opts = {}) {
+	const manifestContent = fs.readFileSync(manifest, 'utf-8')
+	const image = parseFromImage(manifestContent)
+	const imageRef = parseImageRef(image, opts)
+	const sbom = generateImageSBOM(imageRef, opts)
+	return {
+		ecosystem,
+		content: JSON.stringify(sbom),
+		contentType: 'application/vnd.cyclonedx+json'
+	}
+}
+
+/**
+ * Provide content and content type for Dockerfile component analysis.
+ * @param {string} manifest path to the Dockerfile
+ * @param {{}} [opts={}] optional various options to pass along the application
+ * @returns {Provided}
+ */
+function provideComponent(manifest, opts = {}) {
+	return getImageSBOM(manifest, opts)
+}
+
+/**
+ * Provide content and content type for Dockerfile stack analysis.
+ * @param {string} manifest path to the Dockerfile
+ * @param {{}} [opts={}] optional various options to pass along the application
+ * @returns {Provided}
+ */
+function provideStack(manifest, opts = {}) {
+	return getImageSBOM(manifest, opts)
+}
+
+/**
+ * Dockerfiles contain no license information.
+ * @returns {null} always null
+ */
+function readLicenseFromManifest() { return null; }

test/providers/oci_dockerfile.test.js

@@ -0,0 +1,96 @@
+import { expect } from 'chai'
+
+import dockerfileProvider, { parseFromImage } from '../../src/providers/oci_dockerfile.js'
+
+suite('testing the Dockerfile/Containerfile data provider', () => {
+
+	suite('isSupported', () => {
+		/** Verifies that isSupported returns true for Dockerfile and Containerfile, false for others. */
+		['Dockerfile', 'Containerfile'].forEach(name => {
+			test(`returns true for ${name}`, () => {
+				expect(dockerfileProvider.isSupported(name)).to.equal(true)
+			})
+		});
+
+		['package.json', 'go.mod', 'Cargo.toml', 'dockerfile', 'containerfile', 'Dockerfile.dev'].forEach(name => {
+			test(`returns false for ${name}`, () => {
+				expect(dockerfileProvider.isSupported(name)).to.equal(false)
+			})
+		})
+	})
+
+	suite('validateLockFile', () => {
+		/** Verifies that validateLockFile always returns true since Dockerfiles have no lock file. */
+		test('always returns true', () => {
+			expect(dockerfileProvider.validateLockFile()).to.equal(true)
+		})
+	})
+
+	suite('readLicenseFromManifest', () => {
+		/** Verifies that readLicenseFromManifest returns null since Dockerfiles have no license info. */
+		test('returns null', () => {
+			expect(dockerfileProvider.readLicenseFromManifest()).to.equal(null)
+		})
+	})
+
+	suite('packageManagerName', () => {
+		/** Verifies that packageManagerName returns oci. */
+		test('returns oci', () => {
+			expect(dockerfileProvider.packageManagerName()).to.equal('oci')
+		})
+	})
+
+	suite('parseFromImage', () => {
+		/** Verifies that a single FROM line extracts the correct image reference. */
+		test('extracts image from single-stage Dockerfile', () => {
+			const content = 'FROM node:18\nRUN npm install\n'
+			expect(parseFromImage(content)).to.equal('node:18')
+		})
+
+		/** Verifies that the last FROM line is used in multi-stage Dockerfiles. */
+		test('uses last FROM in multi-stage Dockerfile', () => {
+			const content = [
+				'FROM node:18 AS builder',
+				'RUN npm run build',
+				'',
+				'FROM nginx:alpine',
+				'COPY --from=builder /app/dist /usr/share/nginx/html',
+			].join('\n')
+			expect(parseFromImage(content)).to.equal('nginx:alpine')
+		})
+
+		/** Verifies that --platform flags are skipped when parsing FROM lines. */
+		test('handles --platform flag', () => {
+			const content = 'FROM --platform=linux/amd64 ubuntu:22.04\n'
+			expect(parseFromImage(content)).to.equal('ubuntu:22.04')
+		})
+
+		/** Verifies that image references with digests are parsed correctly. */
+		test('handles image with digest', () => {
+			const content = 'FROM httpd@sha256:abc123\n'
+			expect(parseFromImage(content)).to.equal('httpd@sha256:abc123')
+		})
+
+		/** Verifies that an error is thrown when no FROM line is present. */
+		test('throws when no FROM line found', () => {
+			const content = 'RUN echo hello\n'
+			expect(() => parseFromImage(content)).to.throw('No FROM line found in Dockerfile')
+		})
+
+		/** Verifies that FROM line parsing is case-insensitive. */
+		test('handles case-insensitive FROM keyword', () => {
+			const content = 'from alpine:3.18\n'
+			expect(parseFromImage(content)).to.equal('alpine:3.18')
+		})
+
+		/** Verifies that comment lines and blank lines are ignored. */
+		test('ignores comments and blank lines', () => {
+			const content = [
+				'# This is a comment',
+				'',
+				'FROM registry.example.com/myapp:latest',
+			].join('\n')
+			expect(parseFromImage(content)).to.equal('registry.example.com/myapp:latest')
+		})
+	})
+})