Initial commit

.eslintignore

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+node_modules/

.eslintrc

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+{
+  "extends": ["prettier", "airbnb-base"],
+  "rules": {
+    "no-console": 0,
+    "import/no-unresolved": 0,
+    "import/no-dynamic-require": 0,
+    "global-require": 0
+  },
+  "overrides": [
+    {
+      "files": ["test/**"],
+      "rules": {
+        "import/no-extraneous-dependencies": 0
+      },
+      "globals": {
+        "describe": true,
+        "it": true,
+        "test": true,
+        "expect": true
+      }
+    }
+  ]
+}

.prettierrc.json

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+{
+  "singleQuote": true
+}

LICENSE

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+MIT License
+
+Copyright (c) 2018 The Ardent Company
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# now-python-wsgi
+*A Now builder for Python WSGI applications*
+
+## Quickstart
+
+If you have an existing WSGI app, getting this builder to work for you is a
+piece of 🍰!
+
+
+### 1. Add a Now configuration
+
+Add a `now.json` file to the root of your application:
+
+```json
+{
+    "version": 2,
+    "name": "python-wsgi-app",
+    "builds": [{
+        "src": "index.py",
+        "use": "@ardent-labs/now-python-wsgi",
+        "config": { "maxLambdaSize": "15mb" }
+    }]
+}
+```
+
+This configuration is doing a few things in the `"builds"` part:
+
+1. `"src": "index.py"`
+   This tells Now that there is one entrypoint to build for. `index.py` is a
+   file we'll create shortly.
+2. `use": "@ardent-labs/now-python-wsgi"`
+   Tell Now to use this builder when deploying your application
+3. `"config": { "maxLambdaSize": "15mb" }`
+   Bump up the maximum size of the built application to accommodate some larger
+   python WSGI libraries (like Django or Flask). This may not be necessary for
+   you.
+
+
+### 2. Add a Now entrypoint
+
+Add `index.py` to the root of your application. This entrypoint should make
+available an object named `application` that is an instance of your WSGI
+application. E.g.:
+
+```python
+# For a Dango app
+from django_app.wsgi import application
+# Replace `django_app` with the appropriate name to point towards your project's
+# wsgi.py file
+```
+
+Look at your framework documentation for help getting access to the WSGI
+application.
+
+If the WSGI instance isn't named `application` you'll need adjust the import so
+the builder can find it when your project is being deployed. E.g.:
+
+```python
+from my_app.wsgi import app as application
+```
+
+
+### 3. Deploy!
+
+That's it, you're ready to go:
+
+```
+$ now
+> Deploying python-wsgi-app
+...
+> Success! Deployment ready [57s]
+```
+
+
+## Additional considerations
+
+### Requirements & runtime
+
+At the time of writing, Zeit Now runs on AWS Lambda in the python 3.6 runtime.
+This has a number of implications on what libaries will be available to you,
+notably:
+
+- PostgreSQL, so psycopg2 won't work out of the box
+- MySQL, so MySQL adapters won't work out of the box either
+- Sqlite, so the built-in Sqlite adapter won't be available
+- Python <3.6, so python 2 code will need an update
+
+
+## Contributing
+
+### To-dos
+
+- [ ] Add tests for various types of requests
+
+
+## Attribution
+
+This implementation draws upon work from:
+
+- [@clement](https://github.com/rclement) on
+   [now-builders/#163](https://github.com/zeit/now-builders/pull/163)
+- [serverless](https://github.com/serverless/serverless) and
+   [serverless-wsgi](https://github.com/logandk/serverless-wsgi)
+- [@sisp](https://github.com/sisp) on
+   [now-builders/#95](https://github.com/zeit/now-builders/pull/95)
+- [Zappa](https://github.com/Miserlou/Zappa) by
+   [@miserlou](https://github.com/Miserlou)

download-and-install-pip.js

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+const path = require('path');
+const fetch = require('node-fetch');
+const execa = require('execa');
+const { createWriteStream } = require('fs');
+
+const getWritableDirectory = require('@now/build-utils/fs/get-writable-directory.js'); // eslint-disable-line import/no-extraneous-dependencies
+
+const url = 'https://bootstrap.pypa.io/get-pip.py';
+
+// downloads `get-pip.py` and returns its absolute path
+async function downloadGetPipScript() {
+  console.log('downloading "get-pip.py"...');
+  const res = await fetch(url);
+
+  if (!res.ok || res.status !== 200) {
+    throw new Error(`Could not download "get-pip.py" from "${url}"`);
+  }
+
+  const dir = await getWritableDirectory();
+  const filePath = path.join(dir, 'get-pip.py');
+  const writeStream = createWriteStream(filePath);
+
+  return new Promise((resolve, reject) => {
+    res.body
+      .on('error', reject)
+      .pipe(writeStream)
+      .on('finish', () => resolve(filePath));
+  });
+}
+
+// downloads and installs `pip` (respecting
+// process.env.PYTHONUSERBASE), and returns
+// the absolute path to it
+async function downloadAndInstallPip() {
+  if (!process.env.PYTHONUSERBASE) {
+    // this is the directory in which `pip` will be
+    // installed to. `--user` will assume `~` if this
+    // is not set, and `~` is not writeable on AWS Lambda.
+    // let's refuse to proceed
+    throw new Error(
+      'Could not install "pip": "PYTHONUSERBASE" env var is not set',
+    );
+  }
+  const getPipFilePath = await downloadGetPipScript();
+
+  console.log('runing "python get-pip.py"...');
+  try {
+    await execa('python3', [getPipFilePath, '--user'], { stdio: 'inherit' });
+  } catch (err) {
+    console.log('could not install pip');
+    throw err;
+  }
+
+  return path.join(process.env.PYTHONUSERBASE, 'bin', 'pip');
+}
+
+module.exports = downloadAndInstallPip;

index.js

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+const path = require('path');
+const execa = require('execa');
+const { readFile, writeFile } = require('fs.promised');
+const getWritableDirectory = require('@now/build-utils/fs/get-writable-directory.js'); // eslint-disable-line import/no-extraneous-dependencies
+const download = require('@now/build-utils/fs/download.js'); // eslint-disable-line import/no-extraneous-dependencies
+const glob = require('@now/build-utils/fs/glob.js'); // eslint-disable-line import/no-extraneous-dependencies
+const { createLambda } = require('@now/build-utils/lambda.js'); // eslint-disable-line import/no-extraneous-dependencies
+
+const downloadAndInstallPip = require('./download-and-install-pip');
+
+async function pipInstall(pipPath, srcDir, ...args) {
+  console.log(`running "pip install -t ${srcDir} ${args.join(' ')}"...`);
+  try {
+    await execa(pipPath, ['install', '-t', srcDir, ...args], {
+      stdio: 'inherit',
+    });
+  } catch (err) {
+    console.log(`failed to run "pip install -t ${srcDir} ${args.join(' ')}"`);
+    throw err;
+  }
+}
+
+exports.config = {
+  maxLambdaSize: '5mb',
+};
+
+exports.build = async ({ files, entrypoint }) => {
+  console.log('downloading files...');
+
+  const srcDir = await getWritableDirectory();
+
+  // eslint-disable-next-line no-param-reassign
+  files = await download(files, srcDir);
+
+  // this is where `pip` will be installed to
+  // we need it to be under `/tmp`
+  const pyUserBase = await getWritableDirectory();
+  process.env.PYTHONUSERBASE = pyUserBase;
+
+  const pipPath = await downloadAndInstallPip();
+
+  console.log('installing handler requirements');
+  await pipInstall(pipPath, srcDir, '-r',
+    path.join(__dirname, 'requirements.txt'));
+
+  const entryDirectory = path.dirname(entrypoint);
+  const requirementsTxt = path.join(entryDirectory, 'requirements.txt');
+
+  if (files[requirementsTxt]) {
+    console.log('found local "requirements.txt"');
+
+    const requirementsTxtPath = files[requirementsTxt].fsPath;
+    await pipInstall(pipPath, srcDir, '-r', requirementsTxtPath);
+  } else if (files['requirements.txt']) {
+    console.log('found global "requirements.txt"');
+
+    const requirementsTxtPath = files['requirements.txt'].fsPath;
+    await pipInstall(pipPath, srcDir, '-r', requirementsTxtPath);
+  }
+
+  const originalNowHandlerPyContents = await readFile(
+    path.join(__dirname, 'now_python_wsgi', 'handler.py'),
+    'utf8',
+  );
+  // will be used on `from $here import handler`
+  // for example, `from api.users import handler`
+  console.log('entrypoint is', entrypoint);
+  const userHandlerFilePath = entrypoint
+    .replace(/\//g, '.')
+    .replace(/\.py$/, '');
+  const nowHandlerPyContents = originalNowHandlerPyContents.replace(
+    '__NOW_HANDLER_FILENAME',
+    userHandlerFilePath,
+  );
+
+  // in order to allow the user to have `server.py`, we need our `server.py` to be called
+  // somethig else
+  const nowHandlerPyFilename = 'now__handler__python';
+
+  await writeFile(
+    path.join(srcDir, `${nowHandlerPyFilename}.py`),
+    nowHandlerPyContents,
+  );
+
+  const lambda = await createLambda({
+    files: await glob('**', srcDir),
+    handler: `${nowHandlerPyFilename}.now_handler`,
+    runtime: 'python3.6',
+    environment: {},
+  });
+
+  return {
+    [entrypoint]: lambda,
+  };
+};

now_python_wsgi/__init__.py

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+from .handler import handler # noqa