Merge pull request #1022 from hairyhenderson/internal-main

Move main logic to internal

10 files changed, 275 insertions, 201 deletions

diff --git a/cmd/gomplate/logger.go b/cmd/gomplate/logger.go
deleted file mode 100644
index 2694c89a..00000000
--- a/cmd/gomplate/logger.go
+++ /dev/null
@@ -1,34 +0,0 @@
-package main
-
-import (
-	"context"
-	stdlog "log"
-	"os"
-	"time"
-
-	"github.com/rs/zerolog"
-	"github.com/rs/zerolog/log"
-	"golang.org/x/term"
-)
-
-func initLogger(ctx context.Context) context.Context {
-	// default to warn level
-	zerolog.SetGlobalLevel(zerolog.WarnLevel)
-	zerolog.DurationFieldUnit = time.Second
-
-	stdlogger := log.With().Bool("stdlog", true).Logger()
-	stdlog.SetFlags(0)
-	stdlog.SetOutput(stdlogger)
-
-	if term.IsTerminal(int(os.Stderr.Fd())) {
-		log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr, TimeFormat: "15:04:05"})
-		noLevelWriter := zerolog.ConsoleWriter{
-			Out:         os.Stderr,
-			FormatLevel: func(i interface{}) string { return "" },
-		}
-		stdlogger = stdlogger.Output(noLevelWriter)
-		stdlog.SetOutput(stdlogger)
-	}
-
-	return log.Logger.WithContext(ctx)
-}
diff --git a/cmd/gomplate/main.go b/cmd/gomplate/main.go
index 730ac8eb..ac5fa07b 100644
--- a/cmd/gomplate/main.go
+++ b/cmd/gomplate/main.go
@@ -6,164 +6,22 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"os"
-	"os/exec"
-	"os/signal"
 
-	"github.com/hairyhenderson/gomplate/v3"
-	"github.com/hairyhenderson/gomplate/v3/env"
-	"github.com/hairyhenderson/gomplate/v3/internal/config"
-	"github.com/hairyhenderson/gomplate/v3/version"
-
-	"github.com/rs/zerolog"
-
-	"github.com/spf13/cobra"
+	"github.com/hairyhenderson/gomplate/v3/internal/cmd"
 )
 
-// postRunExec - if templating succeeds, the command following a '--' will be executed
-func postRunExec(ctx context.Context, cfg *config.Config) error {
-	args := cfg.PostExec
-	if len(args) > 0 {
-		log := zerolog.Ctx(ctx)
-		log.Debug().Strs("args", args).Msg("running post-exec command")
-
-		name := args[0]
-		args = args[1:]
-		// nolint: gosec
-		c := exec.CommandContext(ctx, name, args...)
-		c.Stdin = cfg.PostExecInput
-		c.Stderr = os.Stderr
-		c.Stdout = os.Stdout
-
-		// make sure all signals are propagated
-		sigs := make(chan os.Signal, 1)
-		signal.Notify(sigs)
-		go func() {
-			// Pass signals to the sub-process
-			sig := <-sigs
-			if c.Process != nil {
-				// nolint: gosec
-				_ = c.Process.Signal(sig)
-			}
-		}()
-
-		return c.Run()
-	}
-	return nil
-}
-
-// optionalExecArgs - implements cobra.PositionalArgs. Allows extra args following
-// a '--', but not otherwise.
-func optionalExecArgs(cmd *cobra.Command, args []string) error {
-	if cmd.ArgsLenAtDash() == 0 {
-		return nil
-	}
-	return cobra.NoArgs(cmd, args)
-}
-
-func newGomplateCmd() *cobra.Command {
-	rootCmd := &cobra.Command{
-		Use:     "gomplate",
-		Short:   "Process text files with Go templates",
-		Version: version.Version,
-		RunE: func(cmd *cobra.Command, args []string) error {
-			if v, _ := cmd.Flags().GetBool("verbose"); v {
-				zerolog.SetGlobalLevel(zerolog.DebugLevel)
-			}
-			ctx := cmd.Context()
-			log := zerolog.Ctx(ctx)
-
-			cfg, err := loadConfig(cmd, args)
-			if err != nil {
-				return err
-			}
-			ctx = config.ContextWithConfig(ctx, cfg)
-			if cfg.Experimental {
-				log.UpdateContext(func(c zerolog.Context) zerolog.Context {
-					return c.Bool("experimental", true)
-				})
-				log.Info().Msg("experimental functions and features enabled!")
-			}
-
-			log.Debug().Msgf("starting %s", cmd.Name())
-			log.Debug().
-				Str("version", version.Version).
-				Str("build", version.GitCommit).
-				Msgf("config is:\n%v", cfg)
-
-			err = gomplate.Run(ctx, cfg)
-			cmd.SilenceErrors = true
-			cmd.SilenceUsage = true
-
-			fmt.Fprintf(os.Stderr, "\n")
-			log.Debug().Int("templatesRendered", gomplate.Metrics.TemplatesProcessed).
-				Int("errors", gomplate.Metrics.Errors).
-				Dur("duration", gomplate.Metrics.TotalRenderDuration).
-				Msg("completed rendering")
-
-			if err != nil {
-				return err
-			}
-			return postRunExec(ctx, cfg)
-		},
-		Args: optionalExecArgs,
-	}
-	return rootCmd
-}
-
-func initFlags(command *cobra.Command) {
-	command.Flags().SortFlags = false
-
-	command.Flags().StringSliceP("datasource", "d", nil, "`datasource` in alias=URL form. Specify multiple times to add multiple sources.")
-	command.Flags().StringSliceP("datasource-header", "H", nil, "HTTP `header` field in 'alias=Name: value' form to be provided on HTTP-based data sources. Multiples can be set.")
-
-	command.Flags().StringSliceP("context", "c", nil, "pre-load a `datasource` into the context, in alias=URL form. Use the special alias `.` to set the root context.")
-
-	command.Flags().StringSlice("plugin", nil, "plug in an external command as a function in name=path form. Can be specified multiple times")
-
-	command.Flags().StringSliceP("file", "f", []string{"-"}, "Template `file` to process. Omit to use standard input, or use --in or --input-dir")
-	command.Flags().StringP("in", "i", "", "Template `string` to process (alternative to --file and --input-dir)")
-	command.Flags().String("input-dir", "", "`directory` which is examined recursively for templates (alternative to --file and --in)")
-
-	command.Flags().StringSlice("exclude", []string{}, "glob of files to not parse")
-	command.Flags().StringSlice("include", []string{}, "glob of files to parse")
-
-	command.Flags().StringSliceP("out", "o", []string{"-"}, "output `file` name. Omit to use standard output.")
-	command.Flags().StringSliceP("template", "t", []string{}, "Additional template file(s)")
-	command.Flags().String("output-dir", ".", "`directory` to store the processed templates. Only used for --input-dir")
-	command.Flags().String("output-map", "", "Template `string` to map the input file to an output path")
-	command.Flags().String("chmod", "", "set the mode for output file(s). Omit to inherit from input file(s)")
-
-	command.Flags().Bool("exec-pipe", false, "pipe the output to the post-run exec command")
-
-	ldDefault := env.Getenv("GOMPLATE_LEFT_DELIM", "{{")
-	rdDefault := env.Getenv("GOMPLATE_RIGHT_DELIM", "}}")
-	command.Flags().String("left-delim", ldDefault, "override the default left-`delimiter` [$GOMPLATE_LEFT_DELIM]")
-	command.Flags().String("right-delim", rdDefault, "override the default right-`delimiter` [$GOMPLATE_RIGHT_DELIM]")
-
-	command.Flags().Bool("experimental", false, "enable experimental features [$GOMPLATE_EXPERIMENTAL]")
-
-	command.Flags().BoolP("verbose", "V", false, "output extra information about what gomplate is doing")
-
-	command.Flags().String("config", defaultConfigFile, "config file (overridden by commandline flags)")
-}
-
 func main() {
 	exitCode := 0
-	// defer the exit first to make sure that other deferred functions have a
-	// chance to run
+	// defer the exit first, so it executes last, to let the deferred cancel run
 	defer func() { os.Exit(exitCode) }()
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	ctx = initLogger(ctx)
 
-	command := newGomplateCmd()
-	initFlags(command)
-	if err := command.ExecuteContext(ctx); err != nil {
-		log := zerolog.Ctx(ctx)
-		log.Error().Err(err).Send()
+	// need to strip os.Args[0] so we only pass the actual flags
+	err := cmd.Main(ctx, os.Args[1:], os.Stdin, os.Stdout, os.Stderr)
+	if err != nil {
 		exitCode = 1
 	}
 }
diff --git a/cmd/gomplate/main_test.go b/cmd/gomplate/main_test.go
deleted file mode 100644
index 06ab7d0f..00000000
--- a/cmd/gomplate/main_test.go
+++ /dev/null
@@ -1 +0,0 @@
-package main
diff --git a/go.mod b/go.mod
index 904ca1df..a1a1af9c 100644
--- a/go.mod
+++ b/go.mod
@@ -25,9 +25,9 @@ require (
 	github.com/ugorji/go/codec v1.2.2
 	github.com/zealic/xignore v0.3.3
 	gocloud.dev v0.21.0
-	golang.org/x/crypto v0.0.0-20201208171446-5f87f3452ae9
-	golang.org/x/sys v0.0.0-20201214210602-f9fddec55a1e
-	golang.org/x/term v0.0.0-20201117132131-f5c789dd3221
+	golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad
+	golang.org/x/sys v0.0.0-20201223074533-0d417f636930
+	golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c
 	gopkg.in/src-d/go-billy.v4 v4.3.2
 	gopkg.in/src-d/go-git.v4 v4.13.1
diff --git a/go.sum b/go.sum
index c7714e56..9117e65f 100644
--- a/go.sum
+++ b/go.sum
@@ -105,10 +105,7 @@ github.com/aws/aws-sdk-go v1.15.27/go.mod h1:mFuSZ37Z9YOHbQEwBWztmVzqXrEkub65tZo
 github.com/aws/aws-sdk-go v1.17.4/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aws/aws-sdk-go v1.23.20/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aws/aws-sdk-go v1.36.1/go.mod h1:hcU610XS61/+aQV88ixoOzUoG7v3b31pl2zKMmprdro=
-github.com/aws/aws-sdk-go v1.36.8 h1:3nvY3Ax2RC6PN1i0OKppxjq3doHWqiYtvenLQ/oZ5jI=
-github.com/aws/aws-sdk-go v1.36.8/go.mod h1:hcU610XS61/+aQV88ixoOzUoG7v3b31pl2zKMmprdro=
-github.com/aws/aws-sdk-go v1.36.12/go.mod h1:hcU610XS61/+aQV88ixoOzUoG7v3b31pl2zKMmprdro=
-github.com/aws/aws-sdk-go v1.36.15/go.mod h1:hcU610XS61/+aQV88ixoOzUoG7v3b31pl2zKMmprdro=
+github.com/aws/aws-sdk-go v1.36.19 h1:zbJZKkxeDiYxUYFjymjWxPye+qa1G2gRVyhIzZrB9zA=
 github.com/aws/aws-sdk-go v1.36.19/go.mod h1:hcU610XS61/+aQV88ixoOzUoG7v3b31pl2zKMmprdro=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
@@ -258,8 +255,8 @@ github.com/google/pprof v0.0.0-20201023163331-3e6fc7fc9c4c/go.mod h1:kpwsk12EmLe
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/google/subcommands v1.0.1/go.mod h1:ZjhPrFU+Olkh9WazFPsl27BQ4UPiG37m3yTrtFlrHVk=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/google/uuid v1.1.2 h1:EVhdT+1Kseyi1/pUmXKaFxYsDNy9RQYkMWRH68J/W7Y=
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/google/uuid v1.1.3 h1:twObb+9XcuH5B9V1TBCvvvZoO6iEdILi2a76PYn5rJI=
 github.com/google/uuid v1.1.3/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/wire v0.4.0 h1:kXcsA/rIGzJImVqPdhfnr6q0xsS9gU0515q1EPpJ9fE=
 github.com/google/wire v0.4.0/go.mod h1:ngWDr9Qvq3yZA10YrxfyGELY/AFWGVpy9c1LTRi1EoU=
@@ -508,12 +505,10 @@ github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/ugorji/go v1.1.7/go.mod h1:kZn38zHttfInRq0xu/PH0az30d+z6vm202qpg1oXVMw=
-github.com/ugorji/go v1.2.1 h1:dz+JxTe7GZQdErTo7SREc1jQj/hFP1k7jyIAwODoW+k=
-github.com/ugorji/go v1.2.1/go.mod h1:cSVypSfTLm2o9fKxXvQgn3rMmkPXovcWor6Qn5tbFmI=
+github.com/ugorji/go v1.2.2 h1:60ZHIOcsJlo3bJm9CbTVu7OSqT2mxaEmyQbK2NwCkn0=
 github.com/ugorji/go v1.2.2/go.mod h1:bitgyERdV7L7Db/Z5gfd5v2NQMNhhiFiZwpgMw2SP7k=
 github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLYF3GoBXY=
-github.com/ugorji/go/codec v1.2.1 h1:/TRfW3XKkvWvmAYyCUaQlhoCDGjcvNR8xVVA/l5p/jQ=
-github.com/ugorji/go/codec v1.2.1/go.mod h1:s/WxCRi46t8rA+fowL40EnmD7ec0XhR7ZypxeBNdzsM=
+github.com/ugorji/go/codec v1.2.2 h1:08Gah8d+dXj4cZNUHhtuD/S4PXD5WpVbj5B8/ClELAQ=
 github.com/ugorji/go/codec v1.2.2/go.mod h1:OM8g7OAy52uYl3Yk+RE/3AS1nXFn1Wh4PPLtupCxbuU=
 github.com/urfave/cli v1.22.4/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
 github.com/xanzy/ssh-agent v0.2.1 h1:TCbipTQL2JiiCprBWx9frJ2eJlCYT00NmctrHxVAr70=
@@ -555,8 +550,8 @@ golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20200728195943-123391ffb6de/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201002170205-7f63de1d35b0/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201203163018-be400aefbc4c/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
-golang.org/x/crypto v0.0.0-20201208171446-5f87f3452ae9 h1:sYNJzB4J8toYPQTM6pAkcmBRgw9SnQKP9oXCHfgy604=
-golang.org/x/crypto v0.0.0-20201208171446-5f87f3452ae9/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
+golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad h1:DN0cp81fZ3njFcrLCytUHRSUkqBjfTo4Tx9RJTWs0EY=
+golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -695,12 +690,14 @@ golang.org/x/sys v0.0.0-20200803210538-64077c9b5642/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200828194041-157a740278f4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200905004654-be1d3432aa8f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201201145000-ef89a241ccb3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201202213521-69691e467435/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201214210602-f9fddec55a1e h1:AyodaIpKjppX+cBfTASF2E1US3H2JFBj920Ot3rtDjs=
-golang.org/x/sys v0.0.0-20201214210602-f9fddec55a1e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/term v0.0.0-20201117132131-f5c789dd3221 h1:/ZHdbVpdR/jk3g30/d4yUL0JU9kksj8+F/bnQUVLGDM=
+golang.org/x/sys v0.0.0-20201223074533-0d417f636930 h1:vRgIt+nup/B/BwIS0g2oC0haq0iqbV3ZA+u6+0TlNCo=
+golang.org/x/sys v0.0.0-20201223074533-0d417f636930/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
+golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf h1:MZ2shdL+ZM/XzY3ZGOnh4Nlpnxz5GSOhOmtHo3iPU6M=
+golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
diff --git a/cmd/gomplate/config.go b/internal/cmd/config.go
index caaf4963..c3b49582 100644
--- a/cmd/gomplate/config.go
+++ b/internal/cmd/config.go
@@ -1,4 +1,4 @@
-package main
+package cmd
 
 import (
 	"context"
diff --git a/cmd/gomplate/config_test.go b/internal/cmd/config_test.go
index 97b9a89f..0b59662c 100644
--- a/cmd/gomplate/config_test.go
+++ b/internal/cmd/config_test.go
@@ -1,4 +1,4 @@
-package main
+package cmd
 
 import (
 	"context"
diff --git a/internal/cmd/logger.go b/internal/cmd/logger.go
new file mode 100644
index 00000000..a60dc96f
--- /dev/null
+++ b/internal/cmd/logger.go
@@ -0,0 +1,37 @@
+package cmd
+
+import (
+	"context"
+	"io"
+	stdlog "log"
+	"os"
+	"time"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"golang.org/x/term"
+)
+
+func initLogger(ctx context.Context, out io.Writer) context.Context {
+	// default to warn level
+	zerolog.SetGlobalLevel(zerolog.WarnLevel)
+	zerolog.DurationFieldUnit = time.Second
+
+	stdlogger := log.With().Bool("stdlog", true).Logger()
+	stdlog.SetFlags(0)
+	stdlog.SetOutput(stdlogger)
+
+	if f, ok := out.(*os.File); ok {
+		if term.IsTerminal(int(f.Fd())) {
+			log.Logger = log.Output(zerolog.ConsoleWriter{Out: f, TimeFormat: "15:04:05"})
+			noLevelWriter := zerolog.ConsoleWriter{
+				Out:         f,
+				FormatLevel: func(i interface{}) string { return "" },
+			}
+			stdlogger = stdlogger.Output(noLevelWriter)
+			stdlog.SetOutput(stdlogger)
+		}
+	}
+
+	return log.Logger.WithContext(ctx)
+}
diff --git a/internal/cmd/main.go b/internal/cmd/main.go
new file mode 100644
index 00000000..e4d6008d
--- /dev/null
+++ b/internal/cmd/main.go
@@ -0,0 +1,167 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"os/signal"
+
+	"github.com/hairyhenderson/gomplate/v3"
+	"github.com/hairyhenderson/gomplate/v3/env"
+	"github.com/hairyhenderson/gomplate/v3/internal/config"
+	"github.com/hairyhenderson/gomplate/v3/version"
+
+	"github.com/rs/zerolog"
+	"github.com/spf13/cobra"
+)
+
+// postRunExec - if templating succeeds, the command following a '--' will be executed
+func postRunExec(ctx context.Context, cfg *config.Config) error {
+	args := cfg.PostExec
+	if len(args) > 0 {
+		log := zerolog.Ctx(ctx)
+		log.Debug().Strs("args", args).Msg("running post-exec command")
+
+		name := args[0]
+		args = args[1:]
+		// nolint: gosec
+		c := exec.CommandContext(ctx, name, args...)
+		c.Stdin = cfg.PostExecInput
+		c.Stderr = os.Stderr
+		c.Stdout = os.Stdout
+
+		// make sure all signals are propagated
+		sigs := make(chan os.Signal, 1)
+		signal.Notify(sigs)
+		go func() {
+			// Pass signals to the sub-process
+			sig := <-sigs
+			if c.Process != nil {
+				// nolint: gosec
+				_ = c.Process.Signal(sig)
+			}
+		}()
+
+		return c.Run()
+	}
+	return nil
+}
+
+// optionalExecArgs - implements cobra.PositionalArgs. Allows extra args following
+// a '--', but not otherwise.
+func optionalExecArgs(cmd *cobra.Command, args []string) error {
+	if cmd.ArgsLenAtDash() == 0 {
+		return nil
+	}
+	return cobra.NoArgs(cmd, args)
+}
+
+// NewGomplateCmd -
+func NewGomplateCmd() *cobra.Command {
+	rootCmd := &cobra.Command{
+		Use:     "gomplate",
+		Short:   "Process text files with Go templates",
+		Version: version.Version,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if v, _ := cmd.Flags().GetBool("verbose"); v {
+				zerolog.SetGlobalLevel(zerolog.DebugLevel)
+			}
+			ctx := cmd.Context()
+			log := zerolog.Ctx(ctx)
+
+			cfg, err := loadConfig(cmd, args)
+			if err != nil {
+				return err
+			}
+			ctx = config.ContextWithConfig(ctx, cfg)
+			if cfg.Experimental {
+				log.UpdateContext(func(c zerolog.Context) zerolog.Context {
+					return c.Bool("experimental", true)
+				})
+				log.Info().Msg("experimental functions and features enabled!")
+			}
+
+			log.Debug().Msgf("starting %s", cmd.Name())
+			log.Debug().
+				Str("version", version.Version).
+				Str("build", version.GitCommit).
+				Msgf("config is:\n%v", cfg)
+
+			err = gomplate.Run(ctx, cfg)
+			cmd.SilenceErrors = true
+			cmd.SilenceUsage = true
+
+			fmt.Fprintf(os.Stderr, "\n")
+			log.Debug().Int("templatesRendered", gomplate.Metrics.TemplatesProcessed).
+				Int("errors", gomplate.Metrics.Errors).
+				Dur("duration", gomplate.Metrics.TotalRenderDuration).
+				Msg("completed rendering")
+
+			if err != nil {
+				return err
+			}
+			return postRunExec(ctx, cfg)
+		},
+		Args: optionalExecArgs,
+	}
+	return rootCmd
+}
+
+// InitFlags -
+func InitFlags(command *cobra.Command) {
+	command.Flags().SortFlags = false
+
+	command.Flags().StringSliceP("datasource", "d", nil, "`datasource` in alias=URL form. Specify multiple times to add multiple sources.")
+	command.Flags().StringSliceP("datasource-header", "H", nil, "HTTP `header` field in 'alias=Name: value' form to be provided on HTTP-based data sources. Multiples can be set.")
+
+	command.Flags().StringSliceP("context", "c", nil, "pre-load a `datasource` into the context, in alias=URL form. Use the special alias `.` to set the root context.")
+
+	command.Flags().StringSlice("plugin", nil, "plug in an external command as a function in name=path form. Can be specified multiple times")
+
+	command.Flags().StringSliceP("file", "f", []string{"-"}, "Template `file` to process. Omit to use standard input, or use --in or --input-dir")
+	command.Flags().StringP("in", "i", "", "Template `string` to process (alternative to --file and --input-dir)")
+	command.Flags().String("input-dir", "", "`directory` which is examined recursively for templates (alternative to --file and --in)")
+
+	command.Flags().StringSlice("exclude", []string{}, "glob of files to not parse")
+	command.Flags().StringSlice("include", []string{}, "glob of files to parse")
+
+	command.Flags().StringSliceP("out", "o", []string{"-"}, "output `file` name. Omit to use standard output.")
+	command.Flags().StringSliceP("template", "t", []string{}, "Additional template file(s)")
+	command.Flags().String("output-dir", ".", "`directory` to store the processed templates. Only used for --input-dir")
+	command.Flags().String("output-map", "", "Template `string` to map the input file to an output path")
+	command.Flags().String("chmod", "", "set the mode for output file(s). Omit to inherit from input file(s)")
+
+	command.Flags().Bool("exec-pipe", false, "pipe the output to the post-run exec command")
+
+	ldDefault := env.Getenv("GOMPLATE_LEFT_DELIM", "{{")
+	rdDefault := env.Getenv("GOMPLATE_RIGHT_DELIM", "}}")
+	command.Flags().String("left-delim", ldDefault, "override the default left-`delimiter` [$GOMPLATE_LEFT_DELIM]")
+	command.Flags().String("right-delim", rdDefault, "override the default right-`delimiter` [$GOMPLATE_RIGHT_DELIM]")
+
+	command.Flags().Bool("experimental", false, "enable experimental features [$GOMPLATE_EXPERIMENTAL]")
+
+	command.Flags().BoolP("verbose", "V", false, "output extra information about what gomplate is doing")
+
+	command.Flags().String("config", defaultConfigFile, "config file (overridden by commandline flags)")
+}
+
+// Main -
+func Main(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) error {
+	ctx = initLogger(ctx, stderr)
+
+	command := NewGomplateCmd()
+	InitFlags(command)
+	command.SetArgs(args)
+	command.SetIn(stdin)
+	command.SetOut(stdout)
+	command.SetErr(stderr)
+
+	err := command.ExecuteContext(ctx)
+	if err != nil {
+		log := zerolog.Ctx(ctx)
+		log.Error().Err(err).Send()
+	}
+	return err
+}
diff --git a/internal/cmd/main_test.go b/internal/cmd/main_test.go
new file mode 100644
index 00000000..5c688443
--- /dev/null
+++ b/internal/cmd/main_test.go
@@ -0,0 +1,50 @@
+package cmd
+
+import (
+	"context"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestOptionalExecArgs(t *testing.T) {
+	cmd := &cobra.Command{}
+	cmd.SetArgs(nil)
+	cmd.ParseFlags(nil)
+
+	err := optionalExecArgs(cmd, nil)
+	assert.NoError(t, err)
+
+	cmd = &cobra.Command{}
+	cmd.SetArgs(nil)
+	cmd.ParseFlags(nil)
+
+	err = optionalExecArgs(cmd, []string{"bogus"})
+	assert.Error(t, err)
+
+	cmd = &cobra.Command{}
+	cmd.SetArgs(nil)
+	cmd.ParseFlags([]string{"--", "foo"})
+
+	err = optionalExecArgs(cmd, []string{})
+	assert.NoError(t, err)
+
+	cmd = &cobra.Command{}
+	cmd.SetArgs(nil)
+	cmd.ParseFlags([]string{"--"})
+
+	err = optionalExecArgs(cmd, []string{"foo"})
+	assert.NoError(t, err)
+}
+
+func TestRunMain(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	err := Main(ctx, []string{"-h"}, nil, nil, nil)
+	assert.NoError(t, err)
+
+	err = Main(ctx, []string{"--bogus"}, nil, nil, nil)
+	assert.Error(t, err)
+}