Merge pull request #2699 from caddyserver/cfadapter

v2: Implement config adapters and WIP Caddyfile adapter

3 files changed, 131 insertions, 16 deletions

diff --git a/cmd/caddy/main.go b/cmd/caddy/main.go
index c1824d7..5f6b8bb 100644
--- a/cmd/caddy/main.go
+++ b/cmd/caddy/main.go
@@ -18,6 +18,7 @@ import (
 	caddycmd "github.com/caddyserver/caddy/v2/cmd"
 
 	// this is where modules get plugged in
+	_ "github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
 	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp"
 	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp/encode"
 	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp/encode/brotli"
diff --git a/cmd/commands.go b/cmd/commands.go
index e63e2d5..99ec642 100644
--- a/cmd/commands.go
+++ b/cmd/commands.go
@@ -31,6 +31,7 @@ import (
 	"strings"
 
 	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/caddyconfig"
 	"github.com/mholt/certmagic"
 	"github.com/mitchellh/go-ps"
 )
@@ -38,6 +39,7 @@ import (
 func cmdStart() (int, error) {
 	startCmd := flag.NewFlagSet("start", flag.ExitOnError)
 	startCmdConfigFlag := startCmd.String("config", "", "Configuration file")
+	startCmdConfigAdapterFlag := startCmd.String("config-adapter", "", "Name of config adapter to apply")
 	startCmd.Parse(os.Args[2:])
 
 	// open a listener to which the child process will connect when
@@ -62,6 +64,9 @@ func cmdStart() (int, error) {
 	if *startCmdConfigFlag != "" {
 		cmd.Args = append(cmd.Args, "--config", *startCmdConfigFlag)
 	}
+	if *startCmdConfigAdapterFlag != "" {
+		cmd.Args = append(cmd.Args, "--config-adapter", *startCmdConfigAdapterFlag)
+	}
 	stdinpipe, err := cmd.StdinPipe()
 	if err != nil {
 		return caddy.ExitCodeFailedStartup,
@@ -137,7 +142,8 @@ func cmdStart() (int, error) {
 func cmdRun() (int, error) {
 	runCmd := flag.NewFlagSet("run", flag.ExitOnError)
 	runCmdConfigFlag := runCmd.String("config", "", "Configuration file")
-	runCmdPrintEnvFlag := runCmd.Bool("print-env", false, "Print environment (useful for debugging)")
+	runCmdConfigAdapterFlag := runCmd.String("config-adapter", "", "Name of config adapter to apply")
+	runCmdPrintEnvFlag := runCmd.Bool("print-env", false, "Print environment")
 	runCmdPingbackFlag := runCmd.String("pingback", "", "Echo confirmation bytes to this address on success")
 	runCmd.Parse(os.Args[2:])
 
@@ -149,16 +155,10 @@ func cmdRun() (int, error) {
 		}
 	}
 
-	// if a config file was specified for bootstrapping
-	// the server instance, load it now
-	var config []byte
-	if *runCmdConfigFlag != "" {
-		var err error
-		config, err = ioutil.ReadFile(*runCmdConfigFlag)
-		if err != nil {
-			return caddy.ExitCodeFailedStartup,
-				fmt.Errorf("reading config file: %v", err)
-		}
+	// get the config in caddy's native format
+	config, err := loadConfig(*runCmdConfigFlag, *runCmdConfigAdapterFlag)
+	if err != nil {
+		return caddy.ExitCodeFailedStartup, err
 	}
 
 	// set a fitting User-Agent for ACME requests
@@ -167,7 +167,7 @@ func cmdRun() (int, error) {
 	certmagic.UserAgent = "Caddy/" + cleanModVersion
 
 	// start the admin endpoint along with any initial config
-	err := caddy.StartAdmin(config)
+	err = caddy.StartAdmin(config)
 	if err != nil {
 		return caddy.ExitCodeFailedStartup,
 			fmt.Errorf("starting caddy administration endpoint: %v", err)
@@ -226,6 +226,7 @@ func cmdStop() (int, error) {
 func cmdReload() (int, error) {
 	reloadCmd := flag.NewFlagSet("load", flag.ExitOnError)
 	reloadCmdConfigFlag := reloadCmd.String("config", "", "Configuration file")
+	reloadCmdConfigAdapterFlag := reloadCmd.String("config-adapter", "", "Name of config adapter to apply")
 	reloadCmdAddrFlag := reloadCmd.String("address", "", "Address of the administration listener, if different from config")
 	reloadCmd.Parse(os.Args[2:])
 
@@ -235,11 +236,10 @@ func cmdReload() (int, error) {
 			fmt.Errorf("no configuration to load (use --config)")
 	}
 
-	// load the configuration file
-	config, err := ioutil.ReadFile(*reloadCmdConfigFlag)
+	// get the config in caddy's native format
+	config, err := loadConfig(*reloadCmdConfigFlag, *reloadCmdConfigAdapterFlag)
 	if err != nil {
-		return caddy.ExitCodeFailedStartup,
-			fmt.Errorf("reading config file: %v", err)
+		return caddy.ExitCodeFailedStartup, err
 	}
 
 	// get the address of the admin listener and craft endpoint URL
@@ -306,3 +306,52 @@ func cmdEnviron() (int, error) {
 	}
 	return caddy.ExitCodeSuccess, nil
 }
+
+func cmdAdaptConfig() (int, error) {
+	adaptCmd := flag.NewFlagSet("adapt", flag.ExitOnError)
+	adaptCmdAdapterFlag := adaptCmd.String("adapter", "", "Name of config adapter")
+	adaptCmdInputFlag := adaptCmd.String("input", "", "Configuration file to adapt")
+	adaptCmdPrettyFlag := adaptCmd.Bool("pretty", false, "Format the output for human readability")
+	adaptCmd.Parse(os.Args[2:])
+
+	if *adaptCmdAdapterFlag == "" || *adaptCmdInputFlag == "" {
+		return caddy.ExitCodeFailedStartup,
+			fmt.Errorf("usage: caddy adapt-config --adapter <name> --input <file>")
+	}
+
+	cfgAdapter := caddyconfig.GetAdapter(*adaptCmdAdapterFlag)
+	if cfgAdapter == nil {
+		return caddy.ExitCodeFailedStartup,
+			fmt.Errorf("unrecognized config adapter: %s", *adaptCmdAdapterFlag)
+	}
+
+	input, err := ioutil.ReadFile(*adaptCmdInputFlag)
+	if err != nil {
+		return caddy.ExitCodeFailedStartup,
+			fmt.Errorf("reading input file: %v", err)
+	}
+
+	opts := make(map[string]string)
+	if *adaptCmdPrettyFlag {
+		opts["pretty"] = "true"
+	}
+
+	adaptedConfig, warnings, err := cfgAdapter.Adapt(input, opts)
+	if err != nil {
+		return caddy.ExitCodeFailedStartup, err
+	}
+
+	// print warnings to stderr
+	for _, warn := range warnings {
+		msg := warn.Message
+		if warn.Directive != "" {
+			msg = fmt.Sprintf("%s: %s", warn.Directive, warn.Message)
+		}
+		log.Printf("[WARNING][%s] %s:%d: %s", *adaptCmdAdapterFlag, warn.File, warn.Line, msg)
+	}
+
+	// print result to stdout
+	fmt.Println(string(adaptedConfig))
+
+	return caddy.ExitCodeSuccess, nil
+}
diff --git a/cmd/main.go b/cmd/main.go
index 16d065b..e0a3686 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -25,6 +25,7 @@ import (
 	"os"
 
 	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/caddyconfig"
 )
 
 // Main implements the main function of the caddy command.
@@ -62,6 +63,7 @@ var commands = map[string]commandFunc{
 	"version":      cmdVersion,
 	"list-modules": cmdListModules,
 	"environ":      cmdEnviron,
+	"adapt-config": cmdAdaptConfig,
 }
 
 func usageString() string {
@@ -85,3 +87,66 @@ func handlePingbackConn(conn net.Conn, expect []byte) error {
 	}
 	return nil
 }
+
+// loadConfig loads the config from configFile and adapts it
+// using adapterName. If adapterName is specified, configFile
+// must be also. It prints any warnings to stderr, and returns
+// the resulting JSON config bytes.
+func loadConfig(configFile, adapterName string) ([]byte, error) {
+	// specifying an adapter without a config file is ambiguous
+	if configFile == "" && adapterName != "" {
+		return nil, fmt.Errorf("cannot adapt config without config file (use --config)")
+	}
+
+	// load initial config and adapter
+	var config []byte
+	var cfgAdapter caddyconfig.Adapter
+	var err error
+	if configFile != "" {
+		config, err = ioutil.ReadFile(configFile)
+		if err != nil {
+			return nil, fmt.Errorf("reading config file: %v", err)
+		}
+	} else if adapterName == "" {
+		// as a special case when no config file or adapter
+		// is specified, see if the Caddyfile adapter is
+		// plugged in, and if so, try using a default Caddyfile
+		cfgAdapter = caddyconfig.GetAdapter("caddyfile")
+		if cfgAdapter != nil {
+			config, err = ioutil.ReadFile("Caddyfile")
+			if err != nil && !os.IsNotExist(err) {
+				return nil, fmt.Errorf("reading default Caddyfile: %v", err)
+			}
+			configFile = "Caddyfile"
+		}
+	}
+
+	// load config adapter
+	if adapterName != "" {
+		cfgAdapter = caddyconfig.GetAdapter(adapterName)
+		if cfgAdapter == nil {
+			return nil, fmt.Errorf("unrecognized config adapter: %s", adapterName)
+		}
+	}
+
+	// adapt config
+	if cfgAdapter != nil {
+		adaptedConfig, warnings, err := cfgAdapter.Adapt(config, map[string]string{
+			"filename": configFile,
+			// TODO: all other options... (http-port, etc...)
+		})
+		if err != nil {
+			return nil, fmt.Errorf("adapting config using %s: %v", adapterName, err)
+		}
+		for _, warn := range warnings {
+			msg := warn.Message
+			if warn.Directive != "" {
+				msg = fmt.Sprintf("%s: %s", warn.Directive, warn.Message)
+			}
+			fmt.Printf("[WARNING][%s] %s:%d: %s", adapterName, warn.File, warn.Line, msg)
+		}
+		config = adaptedConfig
+	}
+
+	return config, nil
+}