lambda-zig: A Custom Runtime for AWS Lambda

This is a sample custom runtime built in zig (0.13). Simple projects will execute in <1ms, with a cold start init time of approximately 11ms.

Some custom build steps have been added to build.zig, which will only currently appear if compiling from a linux operating system:

• zig build awslambda_iam: Deploy and record a default IAM role for the lambda function
• zig build awslambda_package: Package the lambda function for upload
• zig build awslambda_deploy: Deploy the lambda function
• zig build awslambda_run: Run the lambda function

Custom options:

• function-name: set the name of the AWS Lambda function
• payload: Use this to set the payload of the function when run using zig build awslambda_run
• region: Use this to set the region for the function deployment/run
• function-role: Name of the role to use for the function. The system will look up the arn from this name, and create if it does not exist
• function-arn: Role arn to use with the function. This must exist

The AWS Lambda function can be compiled as a linux x86_64 or linux aarch64 executable. The build script will set the architecture appropriately

Caveats:

• Building on Windows will not yet work, as the package step still uses system commands due to the need to create a zip file, and the current lack of zip file creation capabilities in the standard library (you can read, but not write, zip files with the standard library). A TODO exists with more information should you wish to file a PR.
• Caching is not yet implemented in the package or deployment steps, so the function will be deployed on every build

A sample project using this runtime can be found at https://git.lerch.org/lobo/lambda-zig-sample

Using the zig package manager

The zig package manager works just fine in build.zig, which works well for use of this runtime.

To add lambda package/deployment steps to another project:

1. zig build init-exe
2. Add a build.zig.zon similar to the below
3. Add a line to build.zig to add necessary build options, etc. Not the build function return type should be changed from void to !void

build.zig:

try @import("lambda-zig").lambdaBuildOptions(b, exe);

build.zig.zon:

.{
    .name = "lambda-zig",
    .version = "0.1.0",
    .dependencies = .{
        .@"lambda-zig" = .{
            .url = "https://git.lerch.org/lobo/lambda-zig/archive/fa13a08c4d91034a9b19d85f8c4c0af4cedaa67e.tar.gz",
            .hash = "122037c357f834ffddf7b3a514f55edd5a4d7a3cde138a4021b6ac51be8fd2926000",
        },
    },
}

That's it! Now you should have the 4 custom build steps