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 deploy
andserverless deploy function
- Support of
serverless invoke local
andserverless invoke local --watch
- Integrates with
serverless-offline
to 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.
- Support for individual packaging and optimization
- Integrate with
serverless invoke local
(including watch mode) - Stabilized package handling
- Improved compatibility with other plugins
- Updated examples
For the complete release notes see the end of this document.
$ npm install serverless-webpack --save-dev
Add the plugin to your serverless.yml
file:
plugins:
- serverless-webpack
By 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.js
An 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
module.exports = {
// ...
output: {
libraryTarget: 'commonjs',
path: '.webpack',
filename: 'handler.js', // this should match the first part of function handler in `serverless.yml`
},
// ...
};
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 modules
All 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.
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 should be combined with the automatic entry resolution (see above).
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:
--function
or-f
(required) is the name of the function to run--path
or-p
(optional) is a JSON file path used as the function input event--data
or-d
(optional) inline JSON data used as the function input event
❗ The old
webpack invoke
command 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 --watch
Everytime 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:
--function
or-f
(required) is the name of the function to run--path
or-p
(optional) is a JSON file path used as the function input event--data
or-d
(optional) inline JSON data used as the function input event
❗ The old
webpack watch
command has been disabled.
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.
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-offline
Run serverless offline start
.
You can reduce the clutter generated by serverless-offline
with --dontPrintOutput
and
disable timeouts with --noTimeout
.
To just bundle and see the output result use:
$ serverless webpack --out dist
Options are:
--out
or-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 install
to install dependenciesserverless invoke local -f hello
to 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 | ✔︎ | ✔︎ | ⁇ | ⁇ |
-
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 serve
command 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