Add Serverless Container Support

[rogersgt]

What did you implement:

Closes #698

How did you implement it:

I added another function to validate.js to get the actual handler name from the function definition, now that serverless rolled out image for custom runtimes.

Review the following documentation: serverless documentation: https://www.serverless.com/blog/container-support-for-lambda. The only gap between feature support defined in the above article and this commit, is the ability to inherit the docker image's default command property. For example, serverless-webpack can't read the CMD property for the following Dockerfile:

# Dockerfile
FROM public.ecr.aws/lambda/nodejs:12
CMD "index.handler"

However you can simply set the function.image.command[0] property in serverless.yml as an override. I assume this would be the desired approach for most use cases, when sharing a docker image for all functions within the service.

# serverless.yml
service:
  ...
provider:
  ...
functions:
  myFunction1:
    image:
      name: public.ecr.aws/lambda/nodejs:12
      command:
        - 'index.handler1'
  myFunction2:
    image:
      name: public.ecr.aws/lambda/nodejs:12
      command:
        - 'index.handler2'

How can we verify it:

• I added to the existing unit tests to check for a function definition with no handler property, and has image.command instead. Run npm run test to quickly validate test coverage:

• On my branch I went into serverless-webpack and did a yalc publish to locally mock the npm package.
• I created a new serverless docker project with

• I opened the new project in my editor; I then ran the following:

npm init
npm install
npm install webpack serverless-webpack bestzip --dev
yalc link serverless-webpack # do a local install of my serverless-webpack branch

• I added a plugins section with serverless-webpack:

• I added a command array to the existing image property for the function called hello:

Note app.js contains a function called handler.

• I added the following to a new file called webpack.config.js

const path = require('path');
const slsw = require('serverless-webpack');

module.exports = {
  entry: slsw.lib.entries,
  target: 'node',
  optimization: {
    minimize: false,
  },
  performance: {
    hints: false,
  },
  output: {
    libraryTarget: 'commonjs2',
    path: path.join(__dirname, '.webpack'),
    filename: '[name].js',
    sourceMapFilename: '[file].map',
  },
};

• I then ran serverless package

• I then ran serverless deploy

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Make sure code coverage hasn't dropped
• Provide verification config / commands / resources
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO

[j0k3r]

Thanks for that!
I need to find some times to review it.

[j0k3r]

This looks good to me, thanks for adding tests & updating the README too.
As it's a new feature, I defined the milestone to 5.5.0.

I'll check for this milestone later if we can add more new features before merging it into master.
I also need to release 5.4.1 first.

[rogersgt]

This looks good to me, thanks for adding tests & updating the README too.
As it's a new feature, I defined the milestone to 5.5.0.

I'll check for this milestone later if we can add more new features before merging it into master.
I also need to release 5.4.1 first.

Thanks @j0k3r !

[j0k3r]

Will be shipped with 5.5.0 🚀

[j0k3r]

Can you rebase against the master so I'll be able to merge the PR? Thanks 🙏

[rogersgt]

Can you rebase against the master so I'll be able to merge the PR? Thanks 🙏

Just updated! Let me know if you need anything else.

[flavianh]

I'm sorry @j0k3r I may be missing something, but how does the files resulting from the webpack bundle get into the container? It seems that you are bundling on one side, and writing the original app.js on the other.

[j0k3r]

@flavianh I don't know I've never used it.
Maybe you should check the Serverless doc or open a different issue with more information about what you expect, what you got, some code and config to check, etc.

[primosoft-dev-2]

I'm sorry @j0k3r I may be missing something, but how does the files resulting from the webpack bundle get into the container? It seems that you are bundling on one side, and writing the original app.js on the other.

@flavianh I have found a fix for this issue.
Instead of copying the whole code into the docker container while building an image, we can copy the zip file in the .serverless folder.
In the Dockerfile we can write something like below:

RUN yum install unzip -y

WORKDIR /var/task

COPY ./.serverless/{service-name}.zip ./

RUN unzip {service-name}.zip

RUN rm {service-name}.zip

[yuto-moriizumi]

I'm sorry @j0k3r I may be missing something, but how does the files resulting from the webpack bundle get into the container? It seems that you are bundling on one side, and writing the original app.js on the other.

@flavianh I have found a fix for this issue. Instead of copying the whole code into the docker container while building an image, we can copy the zip file in the .serverless folder. In the Dockerfile we can write something like below:

RUN yum install unzip -y

WORKDIR /var/task

COPY ./.serverless/{service-name}.zip ./

RUN unzip {service-name}.zip

RUN rm {service-name}.zip

This worked very well! I spent hours for finding this information... Shouldn't this be included in the documentation?

[j0k3r]

@yuto-moriizumi feel free to submit a PR to add it