main.go

// Package main implements a Composition Function.
package main

import (
	"time"

	"github.com/alecthomas/kong"

	"github.com/crossplane/function-sdk-go"
	"github.com/crossplane/function-sdk-go/response"
)

// CLI of this Function.
type CLI struct {
	Debug bool `help:"Emit debug logs in addition to info logs." short:"d"`

	Network            string `default:"tcp"                                                                                        help:"Network on which to listen for gRPC connections."`
	Address            string `default:":9443"                                                                                      help:"Address at which to listen for gRPC connections."`
	TLSCertsDir        string `env:"TLS_SERVER_CERTS_DIR"                                                                           help:"Directory containing server certs (tls.key, tls.crt) and the CA used to verify client certificates (ca.crt)"`
	Insecure           bool   `help:"Run without mTLS credentials. If you supply this flag --tls-server-certs-dir will be ignored."`
	TTL                string `default:"${defaultTTL}"                                                                              help:"Function global setting for response TTL."`
	MaxRecvMessageSize int    `default:"4"                                                                                          env:"MAX_RECV_MESSAGE_SIZE"                                                                                        help:"Maximum size of received messages in MB."`
	DefaultSource      string `default:""                                                                                           env:"FUNCTION_GO_TEMPLATING_DEFAULT_SOURCE"                                                                        help:"Default template source to use when input is not provided to the function."`
	DefaultOptions     string `default:""                                                                                           env:"FUNCTION_GO_TEMPLATING_DEFAULT_OPTIONS"                                                                       help:"Comma-separated default template options to use when input is not provided to the function."`
}

// Run this Function.
func (c *CLI) Run() error {
	log, err := function.NewLogger(c.Debug)
	if err != nil {
		return err
	}

	ttl, err := time.ParseDuration(c.TTL)
	if err != nil {
		return err
	}

	return function.Serve(
		&Function{
			log:            log,
			fsys:           &osFS{},
			defaultSource:  c.DefaultSource,
			defaultOptions: c.DefaultOptions,
			ttl:            ttl,
		},
		function.Listen(c.Network, c.Address),
		function.MTLSCertificates(c.TLSCertsDir),
		function.Insecure(c.Insecure),
		function.MaxRecvMessageSize(c.MaxRecvMessageSize*1024*1024))
}

func main() {
	ctx := kong.Parse(
		&CLI{},
		kong.Description("A Crossplane Composition Function."),
		kong.Vars{"defaultTTL": response.DefaultTTL.String()},
	)
	ctx.FatalIfErrorf(ctx.Run())
}