A Serverless v1.x plugin to build your lambda functions with Webpack.
This plugin is for you if you want to use the latest Javascript version with Babel; use custom resource loaders, optimize your packaged functions individually and much more!
- Configuration possibilities range from zero-config to fully customizable
- Support of
serverless package,serverless deployandserverless deploy function - Support of
serverless invoke localandserverless invoke local --watch - Support of
serverless runandserverless run --watch - Integrates with
serverless-offlineto simulate local API Gateway endpoints - When enabled in your service configuration, functions are packaged and compiled individually, resulting in smaller Lambda packages that contain only the code and dependencies needed to run the function. This allows the plugin to fully utilize WebPack's Tree-Shaking optimization.
- Improved extensibility for plugin authors (see For Developers section)
- Serverless 1.12+ is now required
For the complete release notes see the end of this document.
$ npm install serverless-webpack --save-devAdd the plugin to your serverless.yml file:
plugins:
- serverless-webpackBy default the plugin will look for a webpack.config.js in the service directory.
Alternatively, you can specify a different file or configuration in serverless.yml:
custom:
webpack: ./folder/my-webpack.config.jsAn base Webpack configuration might look like this:
// webpack.config.js
module.exports = {
entry: './handler.js',
target: 'node',
module: {
loaders: [ ... ]
}
};serverless-webpack exposes a lib object, that can be used in your webpack.config.js to make the configuration easier and to build fully dynamic configurations. This is the preferred way to configure webpack - the plugin will take care of as much of the configuration (and subsequent changes in your services) as it can.
You can let the plugin determine the correct handler entry points at build time. Then you do not have to care anymore when you add or remove functions from your service:
// webpack.config.js
const slsw = require('serverless-webpack');
module.exports = {
...
entry: slsw.lib.entries,
...
};Custom entries that are not part of the SLS build process can be added too:
// webpack.config.js
const _ = require('lodash');
const slsw = require('serverless-webpack');
module.exports = {
...
entry: _.assign({
myCustomEntry1: './custom/path/something.js'
}, slsw.lib.entries),
...
};The lib export also provides the serverless and options properties, through
which you can access the Serverless instance and the options given on the command-line.
This enables you to have a fully customized dynamic configuration, that can evaluate anything available in the Serverless framework. There are really no limits.
Samples are: The current stage and the complete service definition. You thereby have access to anything that a Serverless plugin would have access to.
Both properties should be handled with care and should never be written to, as that will modify the running framework and leads to unpredictable behavior!
If you have cool use cases with the full customization, we might add your solution to the plugin examples as showcase.
Note that, if the output configuration is not set, it will automatically be
generated to write bundles in the .webpack directory. If you set your own output
configuration make sure to add a libraryTarget
for best compatibility with external dependencies:
// webpack.config.js
const path = require('path');
module.exports = {
// ...
output: {
libraryTarget: 'commonjs',
path: path.resolve(__dirname, '.webpack'),
filename: '[name].js',
},
// ...
};By default, the plugin will print a quite verbose bundle information to your console. However, if
you are not satisfy with the current output info, you can overwrite it in your webpack.config.js
// webpack.config.js
module.export = {
// ...
stats: 'minimal'
// ...
}All the stats config can be found in webpack's documentation
By default, the plugin will try to bundle all dependencies. However, you don't
want to include all modules in some cases such as selectively import, excluding
builtin package (ie: aws-sdk) and handling webpack-incompatible modules.
In this case you might add external modules in
Webpack's externals configuration.
Those modules can be included in the Serverless bundle with the webpackIncludeModules
option in serverless.yml:
// webpack.config.js
var nodeExternals = require('webpack-node-externals')
module.exports = {
// we use webpack-node-externals to excludes all node deps.
// You can manually set the externals too.
externals: [nodeExternals()],
}# serverless.yml
custom:
webpackIncludeModules: true # enable auto-packing of external modulesAll modules stated in externals will be excluded from bundled files. If an excluded module
is stated as dependencies in package.json, it will be packed into the Serverless
artifact under the node_modules directory.
By default, the plugin will use the package.json file in working directory, If you want to
use a different package file, set packagePath to your custom package.json:
# serverless.yml
custom:
webpackIncludeModules:
packagePath: '../package.json' # relative path to custom package.json file.Note that only relative path is supported at the moment.
Sometimes it might happen that you use dynamic requires in your code, i.e. you
require modules that are only known at runtime. Webpack is not able to detect
such externals and the compiled package will miss the needed dependencies.
In such cases you can force the plugin to include certain modules by setting
them in the forceInclude array property. However the module must appear in
your service's production dependencies in package.json.
# serverless.yml
custom:
webpackIncludeModules:
forceInclude:
- module1
- module2You can forcefully exclude detected external modules, e.g. if you have a module in your dependencies that is already installed at your provider's environment.
Just add them to the forceExclude array property and they will not be packaged.
# serverless.yml
custom:
webpackIncludeModules:
forceExclude:
- module1
- module2If you specify a module in both arrays, forceInclude and forceExclude, the
exclude wins and the module will not be packaged.
You can find an example setups in the examples folder.
If you do not enable individual packaging in your service (serverless.yml), the plugin creates one ZIP file for all functions (the service package) that includes all node modules used in the service. This is the fastest packaging, but not the optimal one, as node modules are always packaged, that are not needed by some functions.
A better way to do the packaging, is to enable individual packaging in your service:
# serverless.yml
...
package:
individually: true
...This will switch the plugin to per function packaging which makes use of the multi-compiler feature of Webpack. That means, that Webpack compiles and optimizes each function individually, removing unnecessary imports and reducing code sizes significantly. Tree-Shaking only makes sense with this approach.
Now the needed external node modules are also detected by Webpack per function and the plugin only packages the needed ones into the function artifacts. As a result, the deployed artifacts are smaller, depending on the functions and cold-start times (to install the functions into the cloud at runtime) are reduced too.
The individual packaging will automatically apply the automatic entry resolution (see above) and you will not be able to configure the entry config in webpack. An error will be thrown if you are trying to override the entry in webpack.config.js with other unsupported values.
The individual packaging needs more time at the packaging phase, but you'll get that paid back twice at runtime.
The normal Serverless deploy procedure will automatically bundle with Webpack:
- Create the Serverless project with
serverless create -t aws-nodejs - Install Serverless Webpack as above
- Deploy with
serverless deploy
The plugin fully integrates with serverless invoke local. To run your bundled functions
locally you can:
$ serverless invoke local --function <function-name>All options that are supported by invoke local can be used as usual:
--functionor-f(required) is the name of the function to run--pathor-p(optional) is a JSON file path used as the function input event--dataor-d(optional) inline JSON data used as the function input event
❗ The old
webpack invokecommand has been disabled.
Or to run a function every time the source files change use the --watch option
together with serverless invoke local:
$ serverless invoke local --function <function-name> --path event.json --watchEverytime the sources are changed, the function will be executed again with the changed sources. The command will watch until the process is terminated.
If you have your sources located on a file system that does not offer events,
you can enable polling with the --webpack-use-polling=<time in ms> option.
If you omit the value, it defaults to 3000 ms.
All options that are supported by invoke local can be used as usual:
--functionor-f(required) is the name of the function to run--pathor-p(optional) is a JSON file path used as the function input event--dataor-d(optional) inline JSON data used as the function input event
❗ The old
webpack watchcommand has been disabled.
The serverless run command is supported with the plugin. To test a local
service with the Serverless Emulator, you can use the serverless run
command as documented by Serverless. The command will compile the code before
it uploads it into the event gateway.
You can enable source watch mode with serverless run --watch. The plugin will
then watch for any source changes, recompile and redeploy the code to the event
gateway. So you can just keep the event gateway running and test new code immediately.
The plugin integrates very well with serverless-offline to simulate AWS Lambda and AWS API Gateway locally.
Add the plugins to your serverless.yml file and make sure that serverless-webpack
precedes serverless-offline as the order is important:
plugins:
...
- serverless-webpack
...
- serverless-offline
...Run serverless offline or serverless offline start to start the Lambda/API simulation.
In comparison to serverless offline, the start command will fire an init and a end lifecycle hook which is needed for serverless-offline and e.g. serverless-dynamodb-local to switch off resources (see below).
You can find an example setup in the examples folder.
By default the plugin starts in watch mode when triggered through serverless offline, i.e.
it automatically recompiles your code if it detects a change in the used sources.
After a change it might take some seconds until the emulated endpoints are updated.
If you have your sources located on a file system that does not offer events,
e.g. a mounted volume in a Docker container, you can enable polling with the
--webpack-use-polling=<time in ms> option. If you omit the value, it defaults
to 3000 ms.
If you do not use the default path and override it in your Webpack configuration,
you have use the --location option.
Configure your service the same as mentioned above, but additionally add the serverless-dynamodb-local
plugin as follows:
plugins:
- serverless-webpack
- serverless-dynamodb-local
- serverless-offlineRun serverless offline start.
You can reduce the clutter generated by serverless-offline with --dontPrintOutput and
disable timeouts with --noTimeout.
If you use serverless offline to run your integration tests, you might want to
disable the automatic watch mode with the --webpack-no-watch switch.
To just bundle and see the output result use:
$ serverless webpack --out distOptions are:
--outor-o(optional) The output directory. Defaults to.webpack.
❗ The serve command has been removed. See above how to achieve the
same functionality with the serverless-offline plugin.
In the examples folder there is a Serverless project using this
plugin with Babel. To try it, from inside the example folder:
npm installto install dependenciesserverless invoke local -f helloto run the example function
Plugin commands are supported by the following providers. ⁇ indicates that command has not been tested with that provider.
| AWS Lambda | Apache OpenWhisk | Azure Functions | Google Cloud Functions | |
|---|---|---|---|---|
| webpack | ✔︎ | ✔︎ | ⁇ | ⁇ |
| invoke local | ✔︎ | ✔︎ | ⁇ | ⁇ |
| invoke local --watch | ✔︎ | ✔︎ | ⁇ | ⁇ |
The plugin exposes a complete lifecycle model that can be hooked by other plugins to extend the functionality of the plugin or add additional actions.
All events (H) can be hooked by a plugin.
-> webpack:validate
-> webpack:validate:validate (H)
-> webpack:compile
-> webpack:compile:compile (H)
-> webpack:package
-> webpack:package:packExternalModules (H)
-> webpack:package:packageModules (H)
The following list shows all lifecycles that are invoked/started by the plugin when running a command or invoked by a hook.
-> before:package:createDeploymentArtifacts
-> webpack:validate
-> webpack:compile
-> webpack:package
-> before:deploy:function:packageFunction
-> webpack:validate
-> webpack:compile
-> webpack:package
-> before:invoke:local:invoke
-> webpack:validate
-> webpack:compile
-> webpack
-> webpack:validate
-> webpack:compile
-> webpack:package
-> before:offline:start
-> webpack:validate
-> webpack:compile
-> before:offline:start:init
-> webpack:validate
-> webpack:compile
-
4.1.0
-
4.0.0
- BREAKING: Expose lifecycle events for plugin authors #254
- Fixed deprecated hook warning #126
- Support forceExclude option for external modules #247
- Support stats output configuration in webpack config #260
- Google: Only integrate package.json but not node modules into artifact #264
- Documentation fixes and updates #265
- Updated examples #250
-
3.1.2
- Fix issue where dependencies with dots in their names would not be installed #251
-
3.1.1
- Fix issue where locked dependencies (package-lock.json) were ignored #245
-
3.1.0
- Allow filesystem polling in watch mode (
--webpack-use-polling) #215 - Allow forced include of not referenced modules #217
- Automatically include peer dependencies of used modules #223
- Show explicit message if the provided webpack config can not be loaded #234
- Improve examples #227
- Update 3rd party provider compatibility table #221
- Added automatic Travis and Coveralls builds to increase stability
- Allow filesystem polling in watch mode (
-
3.0.0
- Integrate with
serverless invoke local#151 - Support watch mode with
serverless invoke local --watch - Stabilized and improved the bundling of node modules #116, #117
- Improved interoperability with Serverless and 3rd party plugins #173
- Support individual packaging of the functions in a service #120
- Allow setting stdio max buffers for NPM operations #185
- Support bundling of node modules via node-externals whitelist #186
- Removed the
webpack servecommand in favor ofserverless-offline#152 - Updated examples #179
- Added missing unit tests to improve code stability
- Fixed unit tests to run on Windows #145
- Integrate with
-
2.2.2
- Reverted breaking change introduced in default output config #202
-
2.2.1
- Restore functionality for Google provider #193
-
2.2.0
-
2.1.0
-
2.0.0