Packaging the Edge Code

Before uploading to Fastly's Edge, the WASM binary, fastly.toml file and any additional files must be packaged into a gzipped tarball to be uploaded.

Tarball Format

The file should be named your-sanitized-package-name.tar.gz and should minimally have the following files:

your-sanitized-package-name/bin/main.wasm
your-sanitized-package-name/fastly.toml

The sanitized package name is derived from the name property in the fastly.toml file. The algorithm to convert a string to one that is file system friendly is straight-forward and generally involves removing some characters like spaces and punctuation, along with removing diacritics.

For the Fastly CLI, the name property is run against the BaseName function from the github.com/kennygrant/sanitize package as seen here in the CLI code.

Packaging Examples

CLIGo

Creating the Edge Code package using the CLI

The CLI is available from GitHub will automatically create the WASM binary and tarball file. Using the Fastly CLI is described in detail in the Learning Guide.

From the project root, execute the following command. The command for building the package file, fastly compute init, should have created the fastly.toml file in your project root.

% fastly compute build

This will create the following files in the root directory:

pkg/your-sanitized-package-name/bin/main.wasm
pkg/your-sanitized-package-name/fastly.toml
pkg/your-sanitized-package-name.tar.gz

Note: the files under the pkg/your-sanitized-package-name aren't needed. They are left-over artifacts from the packaging process to create the tarball.

Creating the Edge Code package using the Go

Creating the tarball can be done using archive/tar in the standard library. A wapper in github.com/grokify/fastlywasmly/tarutil can be used to assist as so. This uses the Fastly CLI's Go code as a library to read the TOML file to create the package name.

See more at https://github.com/grokify/fastlywasmly

package main

import (
    "fmt"

    "github.com/grokify/fastlywasmly/tarutil"
)

func main() {
    outfile, err := tarutil.BuildEdgePackage(
        "/path/to/fastly.toml",
        "/path/to/anything.wasm or empty if using bindir only",
        "/path/to/option/bin/dir or empty if using wasm only")
    if err != nil {
        panic(err)
    }
    fmt.Printf("WROTE [%s]\n", outfile)
}