External Dependencies
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An external dependency is a library that includes code that you can't or don't want to implement yourself. For example, you might use an official library for an external service or a custom implementation of a data structure or algorithm.
Atlas App Services automatically transpiles dependencies and also supports most built-in Node.js modules.
Note
Create Your Own Modules
Though most npm modules are written by third parties, you can also create and publish your own npm modules to house logic specific to your application. You can make your modules available to the Node.js community or reserve them for private use. For more information, check out npm's guide on Contributing packages to the registry.
Add an External Package
To import and use an external dependency, you first need to add the dependency to your application. You can either add packages by name or upload a directory of dependencies.
Important
Override Existing Dependencies
You can only use one method at a time to specify the external packages your app can use. The most recent method that you used to specify dependencies is the source of truth and overrides previous specifications.
For example, a package added by name through the UI overrides any copies of the same package that you've added previously, including those in an uploaded dependency directory.
Add Packages by Name and Version
You can add packages from the npm registry to your app by name. You can either add a specific version or use the latest version.
Add Dependency Information
In the Add Dependency modal window that pops up from your actions in the previous step, include the following information:
Field | Description |
---|---|
Define a Package Name | The name of the npm package. |
Package Version | Optional. Specific version of the dependency to use.
By default, App Services uses the latest version available. |
Click the Add button to start adding the package.
You can track the status of adding the dependency in the progress tracker at the bottom of the window. The progress tracker provides a message letting you know if the package succeeded or failed. Failure messages contain additional information about why the package could not be added.
If drafts are enabled, you will also need to click Review & Deploy to apply these changes.
Push the Dependencies to App Services
Go to the root directory of your App:
cd path/to/MyRealmApp Push the latest version of your app with all the dependencies in the
package.json
:appservices push --include-package-json Follow the CLI prompts to confirm that you want to include the dependencies in your operation. The CLI will start adding the dependencies to your App.
Enable Github Automatic Deployment
Enable Github Automatic Deployments so you can redeploy your App whenever you push configuration updates to a specified branch on Github.
Check Operation Success
The App Services GitHub app automatically deploys your updated app configuration after you push the commit. You can check the status of the deployment and confirm that all packages were successfully added from the Deployment screen of the App Services UI.
If anything fails during deployment, none of the dependencies are
installed. Remove the failing dependencies from the package.json
file and try again.
Upload a Dependency Directory
You can upload a zipped node_modules
directory of packages to your
app. Zipped dependency directories may not exceed 15MB.
Locally Install External Dependencies
To upload external dependencies, you first need a local
node_modules
folder containing at least one Node.js package. You
can use the following code snippet to install a dependency locally
you would like to upload:
npm install <package name>
If the node_modules
folder does not already exist, this command
automatically creates it.
Note
Alternative Methods of Installation
You can also configure a package.json
and run the
npm install
command to install all packages (and their
dependencies) listed in your package.json
.
To learn more about npm and node_modules
, consult the
npm documentation.
Create a Dependency Archive
Now that you've downloaded all of your npm modules, you need to
package them up in an archive so you can upload them to App Services.
Create an archive containing the node_modules
folder:
tar -czf node_modules.tar.gz node_modules/
Note
Supported Archive Formats
App Services supports .tar
, .tar.gz
, .tgz
, and .zip
archive
formats.
Upload the Dependency Archive
Once you've created an archive containing your dependencies, you can upload your dependency archive using the App Services UI or the App Services CLI:
Select Functions from the left navigation menu.
Select the Dependencies tab.
Click the Upload button.
In the file picker, select the
node_modules.tar.gz
archive you just created and click Open. App Services automatically uploads the archive file, which may take several minutes depending on the speed of your internet connection and the size of your dependency archive.Whether the operation succeeded or failed, App Services displays a banner indicating the success or failure of the operation. If successful, the Dependencies tab displays a list of the dependencies that you included in your dependency archive. If drafts are enabled, you will also need to click Review & Deploy to apply these changes. If drafts are disabled, the change will take effect within 5 to 60 seconds depending on the size of your dependency archive.
Add the
node_modules
archive to your/functions
directory:mv node_modules.tar.gz ./myapp/functions Push your application with the
--include-node-modules
option:appservices push --include-node-modules
Import a Package in a Function
You can import built-in modules and external packages that you've added
to your app and then use them in your functions. To import a package,
call require()
with the package name from within the function body.
Important
Where Do I Import Modules?
Node.js projects commonly place require()
calls in the global
scope of each file, but App Services does not support this
pattern. You must place App Services require()
calls
within a function scope.
Import a Full Module
exports = () => { const R = require("ramda"); return R.map(x => x*2, [1,2,3]); }
Import a Module Subfolder
exports = function(arg){ const cloneDeep = require("lodash/cloneDeep"); var original = { name: "Deep" }; var copy = cloneDeep(original); copy.name = "John"; console.log(`original: ${original.name}`); console.log(`copy: ${copy.name}`); return (original != copy); };