Update the configureation and main fx code.

.gitignore

@@ -23,3 +23,5 @@ go.work
 xmidt-agent
 
 internal/jwtxt/cmd/example/*
+
+*.dot

config.go

@@ -3,9 +3,79 @@
 
 package main
 
-import "github.com/xmidt-org/sallust"
+import (
+	"fmt"
+	"os"
+
+	"github.com/goschtalt/goschtalt"
+	"github.com/xmidt-org/sallust"
+	"gopkg.in/dealancer/validate.v2"
+)
 
 type Config struct {
 	SpecialValue string
 	Logger       sallust.Config
 }
+
+// Collect and process the configuration files and env vars and
+// produce a configuration object.
+func provideConfig(cli *CLI) (*goschtalt.Config, error) {
+	gs, err := goschtalt.New(
+		goschtalt.StdCfgLayout(applicationName, cli.Files...),
+		goschtalt.ConfigIs("two_words"),
+		goschtalt.DefaultUnmarshalOptions(
+			goschtalt.WithValidator(
+				goschtalt.ValidatorFunc(validate.Validate),
+			),
+		),
+
+		// Seed the program with the default, built-in configuration.
+		// Mark this as a default so it is ordered correctly.
+		goschtalt.AddValue("built-in", goschtalt.Root, defaultConfig,
+			goschtalt.AsDefault()),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	if cli.Show {
+		// handleCLIShow handles the -s/--show option where the configuration is
+		// shown, then the program is exited.
+		//
+		// Exit with success because if the configuration is broken it will be
+		// very hard to debug where the problem originates.  This way you can
+		// see the configuration and then run the service with the same
+		// configuration to see the error.
+
+		fmt.Fprintln(os.Stdout, gs.Explain().String())
+
+		out, err := gs.Marshal()
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+		} else {
+			fmt.Fprintln(os.Stdout, "## Final Configuration\n---\n"+string(out))
+		}
+
+		os.Exit(0)
+	}
+
+	var tmp Config
+	err = gs.Unmarshal(goschtalt.Root, &tmp)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "There is a critical error in the configuration.")
+		fmt.Fprintln(os.Stderr, "Run with -s/--show to see the configuration.")
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+
+		// Exit here to prevent a very difficult to debug error from occurring.
+		os.Exit(0)
+	}
+
+	return gs, nil
+}
+
+// -----------------------------------------------------------------------------
+// Keep the default configuration at the bottom of the file so it is easy to
+// see what the default configuration is.
+// -----------------------------------------------------------------------------
+
+var defaultConfig = Config{}

go.mod

@@ -15,12 +15,14 @@ require (
 	github.com/xmidt-org/wrp-go/v3 v3.2.0
 	go.uber.org/fx v1.20.0
 	go.uber.org/zap v1.26.0
+	gopkg.in/dealancer/validate.v2 v2.1.0
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/uuid v1.3.1 // indirect
 	github.com/goschtalt/approx v1.0.0 // indirect
+	github.com/leodido/go-urn v1.1.0 // indirect
 	github.com/miekg/dns v1.1.25 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect

go.sum

@@ -6,6 +6,7 @@ github.com/alecthomas/repr v0.1.0 h1:ENn2e1+J3k09gyj2shc0dHr/yjaWSHRlrJ4DPMevDqE
 github.com/alecthomas/repr v0.1.0/go.mod h1:2kn6fqh/zIyPLmm3ugklbEi5hg5wS435eygvNfaDQL8=
 github.com/benbjohnson/clock v1.3.0 h1:ip6w0uFQkncKQ979AypyG0ER7mqUSBdKLOgAle/AT8A=
 github.com/benbjohnson/clock v1.3.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/foxcpp/go-mockdns v1.0.0 h1:7jBqxd3WDWwi/6WhDvacvH1XsN3rOLXyHM1uhvIx6FI=
@@ -30,6 +31,8 @@ github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
 github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/leodido/go-urn v1.1.0 h1:Sm1gr51B1kKyfD2BlRcLSiEkffoG96g6TPv6eRoEiB8=
+github.com/leodido/go-urn v1.1.0/go.mod h1:+cyI34gQWZcE1eQU7NVgKkkzdXDQHr1dBMtdAPozLkw=
 github.com/miekg/dns v1.1.25 h1:dFwPR6SfLtrSwgDcIq2bcU/gVutB4sNApq2HBdqcakg=
 github.com/miekg/dns v1.1.25/go.mod h1:bPDLeHnStXmXAq1m/Ch/hvfNHr14JKNPMBo3VZKjuso=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
@@ -40,6 +43,8 @@ github.com/psanford/memfs v0.0.0-20210214183328-a001468d78ef h1:NKxTG6GVGbfMXc2m
 github.com/psanford/memfs v0.0.0-20210214183328-a001468d78ef/go.mod h1:tcaRap0jS3eifrEEllL6ZMd9dg8IlDpi2S1oARrQ+NI=
 github.com/rogpeppe/go-internal v1.8.1 h1:geMPLpDpQOgVyCg5z5GoRwLHepNdb71NXb67XFkP+Eg=
 github.com/rogpeppe/go-internal v1.8.1/go.mod h1:JeRgkft04UBgHMgCIwADu4Pn6Mtm5d4nPKWu0nJ5d+o=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/ugorji/go/codec v1.2.11 h1:BMaWp1Bb6fHwEtbplGBGJ498wD+LKlNSl25MjdZY4dU=
@@ -86,6 +91,8 @@ gonum.org/v1/gonum v0.13.0/go.mod h1:/WPYRckkfWrhWefxyYTfrTtQR0KH4iyHNuzxqXAKyAU
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/dealancer/validate.v2 v2.1.0 h1:XY95SZhVH1rBe8uwtnQEsOO79rv8GPwK+P3VWhQfJbA=
+gopkg.in/dealancer/validate.v2 v2.1.0/go.mod h1:EipWMj8hVO2/dPXVlYRe9yKcgVd5OttpQDiM1/wZ0DE=
 gopkg.in/natefinch/lumberjack.v2 v2.2.1 h1:bBRl1b0OH9s/DuPhuXpNl+VtCaJXFZ5/uEFST95x9zc=
 gopkg.in/natefinch/lumberjack.v2 v2.2.1/go.mod h1:YD8tP3GAjkrDg1eZH7EGmyESg/lsYskCTPBJVb9jqSc=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

invalid.yml

@@ -0,0 +1,5 @@
+# SPDX-FileCopyrightText: 2023 Comcast Cable Communications Management, LLC
+# SPDX-License-Identifier: Apache-2.0
+---
+invalid:
+  invalid: invalid

main.go

@@ -36,28 +36,28 @@ var (
 type CLI struct {
 	Dev   bool     `optional:"" short:"d" help:"Run in development mode."`
 	Show  bool     `optional:"" short:"s" help:"Show the configuration and exit."`
+	Graph string   `optional:"" short:"g" help:"Output the dependency graph to the specified file."`
 	Files []string `optional:"" short:"f" help:"Specific configuration files or directories."`
 }
 
-// xmidiAgent is the main entry point for the program.  It is responsible for
-// setting up the dependency injection framework and invoking the program.
-func xmidtAgent(args []string) error {
+// xmidtAgent is the main entry point for the program.  It is responsible for
+// setting up the dependency injection framework and returning the app object.
+func xmidtAgent(args []string) (*fx.App, error) {
 	var (
 		gscfg *goschtalt.Config
 
-		// Capture if the program is being run in dev mode so the extra stuff
-		// is output as requested.
-		dev devMode
+		// Capture the dependency tree in case we need to debug something.
+		g fx.DotGraph
 
-		// Capture if the program should gracefully exit early & without
-		// reporting an error via logging.
-		early earlyExit
+		// Capture the command line arguments.
+		cli *CLI
 	)
 
 	app := fx.New(
 		fx.Supply(cliArgs(args)),
-		fx.Supply(&early),
-		fx.Supply(&dev),
+		fx.Populate(&g),
+		fx.Populate(&gscfg),
+		fx.Populate(&cli),
 
 		fx.WithLogger(func(log *zap.Logger) fxevent.Logger {
 			return &fxevent.ZapLogger{Logger: log}
@@ -66,92 +66,58 @@ func xmidtAgent(args []string) error {
 		fx.Provide(
 			provideCLI,
 			provideLogger,
-
-			// Collect and process the configuration files and env vars and
-			// produce a configuration object.
-			func(cli *CLI) (*goschtalt.Config, error) {
-				return goschtalt.New(
-					goschtalt.StdCfgLayout(applicationName, cli.Files...),
-					goschtalt.ConfigIs("two_words"),
-
-					// Seed the program with the default, built-in configuration
-					goschtalt.AddValue("built-in", goschtalt.Root,
-						Config{
-							SpecialValue: "default",
-						},
-						goschtalt.AsDefault(), // Mark this as a default so it is ordered correctly
-					),
-				)
-			},
+			provideConfig,
 
 			goschtalt.UnmarshalFunc[sallust.Config]("logger", goschtalt.Optional()),
 		),
 
-		fx.Invoke(
-			handleCLIShow,
-			func(gs *goschtalt.Config) {
-				gscfg = gs
-			},
-		),
+		fx.Invoke(),
 	)
 
-	if dev {
-		defer func() {
-			fmt.Fprintln(os.Stderr, gscfg.Explain().String())
-		}()
+	if cli != nil && cli.Graph != "" {
+		_ = os.WriteFile(cli.Graph, []byte(g), 0600)
 	}
 
-	if err := app.Err(); err != nil || early {
-		return err
+	if err := app.Err(); err != nil {
+		return nil, err
 	}
 
-	app.Run()
-
-	return nil
+	return app, nil
 }
 
 func main() {
-	err := xmidtAgent(os.Args[1:])
-
+	app, err := xmidtAgent(os.Args[1:])
 	if err == nil {
+		app.Run()
 		return
 	}
 
 	fmt.Fprintln(os.Stderr, err)
 	os.Exit(-1)
 }
 
-// Provides a named type so it's a bit easier to flow through & use in fx.
-type earlyExit bool
-
-// Provides a named type so it's a bit easier to flow through & use in fx.
-type devMode bool
-
 // Provides a named type so it's a bit easier to flow through & use in fx.
 type cliArgs []string
 
-// handleCLIShow handles the -s/--show option where the configuration is shown,
-// then the program is exited.
-func handleCLIShow(cli *CLI, cfg *goschtalt.Config, early *earlyExit) {
-	if !cli.Show {
-		return
-	}
+// Handle the CLI processing and return the processed input.
+func provideCLI(args cliArgs) (*CLI, error) {
+	return provideCLIWithOpts(args, false)
+}
 
-	fmt.Fprintln(os.Stdout, cfg.Explain().String())
+func provideCLIWithOpts(args cliArgs, testOpts bool) (*CLI, error) {
+	var cli CLI
 
-	out, err := cfg.Marshal()
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-	} else {
-		fmt.Fprintln(os.Stdout, "## Final Configuration\n---\n"+string(out))
-	}
+	// Create a no-op option to satisfy the kong.New() call.
+	var opt kong.Option = kong.OptionFunc(
+		func(*kong.Kong) error {
+			return nil
+		},
+	)
 
-	*early = earlyExit(true)
-}
+	if testOpts {
+		opt = kong.Writers(nil, nil)
+	}
 
-// Handle the CLI processing and return the processed input.
-func provideCLI(args cliArgs, dev *devMode, early *earlyExit) (*CLI, error) {
-	var cli CLI
 	parser, err := kong.New(&cli,
 		kong.Name(applicationName),
 		kong.Description("The cpe agent for Xmidt service.\n"+
@@ -161,25 +127,21 @@ func provideCLI(args cliArgs, dev *devMode, early *earlyExit) (*CLI, error) {
 			fmt.Sprintf("\tBuilt By: %s\n", builtBy),
 		),
 		kong.UsageOnError(),
+		opt,
 	)
 	if err != nil {
 		return nil, err
 	}
 
-	parser.Exit = func(i int) {
-		// Exit early on error, but we still need to return the CLI object
-		// otherwise fx will complain & hide the useful message we want to print.
-		*early = earlyExit(true)
+	if testOpts {
+		parser.Exit = func(_ int) { panic("exit") }
 	}
 
-	fmt.Printf("parser: %p\n", parser)
 	_, err = parser.Parse(args)
 	if err != nil {
 		parser.FatalIfErrorf(err)
 	}
 
-	// Mark the devMode state so the collector can be output
-	*dev = devMode(cli.Dev)
 	return &cli, nil
 }