Refactor handling of environment variables (#2303)

* Refactor environment variables

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

src/utils/api-url.ts

@@ -1,13 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { isMockMode } from './test-modes'
-import { backendUrl } from './backend-url'
-
-/**
- * Generates the url to the api.
- */
-export const apiUrl = isMockMode ? `/api/mock-backend/private/` : `${backendUrl}api/private/`

src/utils/backend-url.ts

@@ -1,30 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { isMockMode } from './test-modes'
-
-/**
- * Generates the backend URL from the environment variable `NEXT_PUBLIC_BACKEND_BASE_URL` or the mock default if mock mode is activated.
- *
- * @throws Error if the environment variable is unset or doesn't end with "/"
- * @return the backend url that should be used in the app
- */
-const generateBackendUrl = (): string => {
-  if (!isMockMode) {
-    const backendUrl = process.env.NEXT_PUBLIC_BACKEND_BASE_URL
-    if (backendUrl === undefined) {
-      throw new Error('NEXT_PUBLIC_BACKEND_BASE_URL is unset and mock mode is disabled')
-    } else if (!backendUrl.endsWith('/')) {
-      throw new Error("NEXT_PUBLIC_BACKEND_BASE_URL must end with an '/'")
-    } else {
-      return backendUrl
-    }
-  } else {
-    return '/'
-  }
-}
-
-export const backendUrl = generateBackendUrl()

src/utils/base-url-from-env-extractor.test.ts

@@ -0,0 +1,68 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { BaseUrlFromEnvExtractor } from './base-url-from-env-extractor'
+
+describe('BaseUrlFromEnvExtractor', () => {
+  it('should return the base urls if both are valid urls', () => {
+    process.env.HD_EDITOR_BASE_URL = 'https://editor.example.org/'
+    process.env.HD_RENDERER_BASE_URL = 'https://renderer.example.org/'
+    const baseUrlFromEnvExtractor = new BaseUrlFromEnvExtractor()
+    const result = baseUrlFromEnvExtractor.extractBaseUrls()
+    expect(result.isPresent()).toBeTruthy()
+    expect(result.get()).toStrictEqual({
+      renderer: 'https://renderer.example.org/',
+      editor: 'https://editor.example.org/'
+    })
+  })
+
+  it('should return an empty optional if no var is set', () => {
+    process.env.HD_EDITOR_BASE_URL = undefined
+    process.env.HD_RENDERER_BASE_URL = undefined
+    const baseUrlFromEnvExtractor = new BaseUrlFromEnvExtractor()
+    expect(baseUrlFromEnvExtractor.extractBaseUrls().isEmpty()).toBeTruthy()
+  })
+
+  it("should return an empty optional if editor base url isn't an URL", () => {
+    process.env.HD_EDITOR_BASE_URL = 'bibedibabedibu'
+    process.env.HD_RENDERER_BASE_URL = 'https://renderer.example.org/'
+    const baseUrlFromEnvExtractor = new BaseUrlFromEnvExtractor()
+    expect(baseUrlFromEnvExtractor.extractBaseUrls().isEmpty()).toBeTruthy()
+  })
+
+  it("should return an empty optional if renderer base url isn't an URL", () => {
+    process.env.HD_EDITOR_BASE_URL = 'https://editor.example.org/'
+    process.env.HD_RENDERER_BASE_URL = 'bibedibabedibu'
+    const baseUrlFromEnvExtractor = new BaseUrlFromEnvExtractor()
+    expect(baseUrlFromEnvExtractor.extractBaseUrls().isEmpty()).toBeTruthy()
+  })
+
+  it("should return an empty optional if editor base url isn't ending with a slash", () => {
+    process.env.HD_EDITOR_BASE_URL = 'https://editor.example.org'
+    process.env.HD_RENDERER_BASE_URL = 'https://renderer.example.org/'
+    const baseUrlFromEnvExtractor = new BaseUrlFromEnvExtractor()
+    expect(baseUrlFromEnvExtractor.extractBaseUrls().isEmpty()).toBeTruthy()
+  })
+
+  it("should return an empty optional if renderer base url isn't ending with a slash", () => {
+    process.env.HD_EDITOR_BASE_URL = 'https://editor.example.org/'
+    process.env.HD_RENDERER_BASE_URL = 'https://renderer.example.org'
+    const baseUrlFromEnvExtractor = new BaseUrlFromEnvExtractor()
+    expect(baseUrlFromEnvExtractor.extractBaseUrls().isEmpty()).toBeTruthy()
+  })
+
+  it('should copy editor base url to renderer base url if renderer base url is omitted', () => {
+    process.env.HD_EDITOR_BASE_URL = 'https://editor.example.org/'
+    delete process.env.HD_RENDERER_BASE_URL
+    const baseUrlFromEnvExtractor = new BaseUrlFromEnvExtractor()
+    const result = baseUrlFromEnvExtractor.extractBaseUrls()
+    expect(result.isPresent()).toBeTruthy()
+    expect(result.get()).toStrictEqual({
+      renderer: 'https://editor.example.org/',
+      editor: 'https://editor.example.org/'
+    })
+  })
+})

src/utils/base-url-from-env-extractor.ts

@@ -0,0 +1,89 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Optional } from '@mrdrogdrog/optional'
+import type { BaseUrls } from '../components/common/base-url/base-url-context-provider'
+import { Logger } from './logger'
+import { isTestMode } from './test-modes'
+
+/**
+ * Extracts the editor and renderer base urls from the environment variables.
+ */
+export class BaseUrlFromEnvExtractor {
+  private baseUrls: Optional<BaseUrls> | undefined
+  private logger = new Logger('Base URL Configuration')
+
+  private extractUrlFromEnvVar(envVarName: string, envVarValue: string | undefined): Optional<URL> {
+    return Optional.ofNullable(envVarValue)
+      .filter((value) => {
+        const endsWithSlash = value.endsWith('/')
+        if (!endsWithSlash) {
+          this.logger.error(`${envVarName} must end with an '/'`)
+        }
+        return endsWithSlash
+      })
+      .map((value) => {
+        try {
+          return new URL(value)
+        } catch (error) {
+          return null
+        }
+      })
+  }
+
+  private extractEditorBaseUrlFromEnv(): Optional<URL> {
+    const envValue = this.extractUrlFromEnvVar('HD_EDITOR_BASE_URL', process.env.HD_EDITOR_BASE_URL)
+    if (envValue.isEmpty()) {
+      this.logger.error("HD_EDITOR_BASE_URL isn't a valid URL!")
+    }
+    return envValue
+  }
+
+  private extractRendererBaseUrlFromEnv(editorBaseUrl: URL): Optional<URL> {
+    if (isTestMode) {
+      this.logger.info('Test mode activated. Using editor base url for renderer.')
+      return Optional.of(editorBaseUrl)
+    }
+
+    if (!process.env.HD_RENDERER_BASE_URL) {
+      this.logger.info('HD_RENDERER_BASE_URL is unset. Using editor base url for renderer.')
+      return Optional.of(editorBaseUrl)
+    }
+
+    return this.extractUrlFromEnvVar('HD_RENDERER_BASE_URL', process.env.HD_RENDERER_BASE_URL)
+  }
+
+  private renewBaseUrls(): void {
+    this.baseUrls = this.extractEditorBaseUrlFromEnv().flatMap((editorBaseUrl) =>
+      this.extractRendererBaseUrlFromEnv(editorBaseUrl).map((rendererBaseUrl) => {
+        return {
+          editor: editorBaseUrl.toString(),
+          renderer: rendererBaseUrl.toString()
+        }
+      })
+    )
+    this.baseUrls.ifPresent((urls) => {
+      this.logger.info('Editor base URL', urls.editor.toString())
+      this.logger.info('Renderer base URL', urls.renderer.toString())
+    })
+  }
+
+  private isEnvironmentExtractDone(): boolean {
+    return this.baseUrls !== undefined
+  }
+
+  /**
+   * Extracts the editor and renderer base urls from the environment variables.
+   *
+   * @return An {@link Optional} with the base urls.
+   */
+  public extractBaseUrls(): Optional<BaseUrls> {
+    if (!this.isEnvironmentExtractDone()) {
+      this.renewBaseUrls()
+    }
+    return Optional.ofNullable(this.baseUrls).flatMap((value) => value)
+  }
+}

src/utils/customize-assets-url.ts

@@ -1,15 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { backendUrl } from './backend-url'
-import { isMockMode } from './test-modes'
-
-/**
- * Generates the url to the assets.
- */
-export const customizeAssetsUrl = isMockMode
-  ? `/mock-public/`
-  : process.env.NEXT_PUBLIC_CUSTOMIZE_ASSETS_URL || `${backendUrl}public/`

src/utils/is-positive-answer.ts

@@ -1,15 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-/**
- * Checks if the given string is a positive answer (yes, true or 1).
- *
- * @param value The value to check
- */
-export const isPositiveAnswer = (value: string) => {
-  const lowerValue = value.toLowerCase()
-  return lowerValue === 'yes' || lowerValue === '1' || lowerValue === 'true'
-}

src/utils/test-modes.js

@@ -0,0 +1,44 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/**
+ * This file is intentionally a js and not a ts file because it is used in `next.config.js`
+ */
+
+/**
+ * Checks if the given string is a positive answer (yes, true or 1).
+ *
+ * @param {string} value The value to check
+ * @return {boolean} {@code true} if the value describes a positive answer string
+ */
+const isPositiveAnswer = (value) => {
+  const lowerValue = value.toLowerCase()
+  return lowerValue === 'yes' || lowerValue === '1' || lowerValue === 'true'
+}
+
+/**
+ * Defines if the current runtime is built in e2e test mode.
+ * @type boolean
+ */
+const isTestMode = !!process.env.NEXT_PUBLIC_TEST_MODE && isPositiveAnswer(process.env.NEXT_PUBLIC_TEST_MODE)
+
+/**
+ * Defines if the current runtime should use the mocked backend.
+ * @type boolean
+ */
+const isMockMode = !!process.env.NEXT_PUBLIC_USE_MOCK_API && isPositiveAnswer(process.env.NEXT_PUBLIC_USE_MOCK_API)
+
+/**
+ * Defines if the current runtime was built in development mode.
+ * @type boolean
+ */
+const isDevMode = process.env.NODE_ENV === 'development'
+
+module.exports = {
+  isTestMode,
+  isMockMode,
+  isDevMode
+}

src/utils/test-modes.ts

@@ -1,23 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { isPositiveAnswer } from './is-positive-answer'
-
-/**
- * Checks if the current runtime is built in e2e test mode.
- */
-export const isTestMode = !!process.env.NEXT_PUBLIC_TEST_MODE && isPositiveAnswer(process.env.NEXT_PUBLIC_TEST_MODE)
-
-/**
- * Checks if the current runtime should use the mocked backend.
- */
-export const isMockMode =
-  !!process.env.NEXT_PUBLIC_USE_MOCK_API && isPositiveAnswer(process.env.NEXT_PUBLIC_USE_MOCK_API)
-
-/**
- * Checks if the current runtime was built in development mode.
- */
-export const isDevMode = process.env.NODE_ENV === 'development'

src/utils/uri-origin-boundary.tsx

@@ -0,0 +1,27 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import React, { Fragment, useMemo } from 'react'
+import type { PropsWithChildren } from 'react'
+import { isClientSideRendering } from './is-client-side-rendering'
+import { useBaseUrl } from '../hooks/common/use-base-url'
+
+/**
+ * Checks if the url of the current browser window matches the expected origin.
+ * This is necessary to ensure that the render endpoint is only opened from the rendering origin.
+ *
+ * @param children The children react element that should be rendered if the origin is correct
+ */
+export const ExpectedOriginBoundary: React.FC<PropsWithChildren> = ({ children }) => {
+  const baseUrl = useBaseUrl()
+  const expectedOrigin = useMemo(() => new URL(baseUrl).origin, [baseUrl])
+
+  if (isClientSideRendering() && window.location.origin !== expectedOrigin) {
+    return <span>{`You can't open this page using this URL. For this endpoint "${expectedOrigin}" is expected.`}</span>
+  } else {
+    return <Fragment>{children}</Fragment>
+  }
+}