Add EXEC_MODE=RAW support to DNS Provider exec (#586)

Author: shupp

cli.go

@@ -230,7 +230,7 @@ Here is an example bash command using the CloudFlare DNS provider:
 	fmt.Fprintln(w, "\tdnspod:\tDNSPOD_API_KEY")
 	fmt.Fprintln(w, "\totc:\tOTC_USER_NAME, OTC_PASSWORD, OTC_PROJECT_NAME, OTC_DOMAIN_NAME, OTC_IDENTITY_ENDPOINT")
 	fmt.Fprintln(w, "\tsakuracloud:\tSAKURACLOUD_ACCESS_TOKEN, SAKURACLOUD_ACCESS_TOKEN_SECRET")
-	fmt.Fprintln(w, "\texec:\tEXEC_PATH")
+	fmt.Fprintln(w, "\texec:\tEXEC_PATH, EXEC_MODE")
 	w.Flush()
 
 	fmt.Println(`

providers/dns/exec/doc.go

@@ -0,0 +1,42 @@
+/*
+Package exec implements a manual DNS provider which runs a program for adding/removing the DNS record.
+
+The file name of the external program is specified in the environment variable `EXEC_PATH`.
+When it is run by lego, three command-line parameters are passed to it:
+The action ("present" or "cleanup"), the fully-qualified domain name, the value for the record and the TTL.
+
+For example, requesting a certificate for the domain 'foo.example.com' can be achieved by calling lego as follows:
+
+	EXEC_PATH=./update-dns.sh \
+		lego --dns exec \
+		--domains foo.example.com \
+		--email [email protected] run
+
+It will then call the program './update-dns.sh' with like this:
+
+	./update-dns.sh "present" "_acme-challenge.foo.example.com." "MsijOYZxqyjGnFGwhjrhfg-Xgbl5r68WPda0J9EgqqI" "120"
+
+The program then needs to make sure the record is inserted.
+When it returns an error via a non-zero exit code, lego aborts.
+
+When the record is to be removed again,
+the program is called with the first command-line parameter set to "cleanup" instead of "present".
+
+If you want to use the raw domain, token, and keyAuth values with your program, you can set `EXEC_MODE=RAW`:
+
+	EXEC_MODE=RAW \
+	EXEC_PATH=./update-dns.sh \
+		lego --dns exec \
+		--domains foo.example.com \
+		--email [email protected] run
+
+It will then call the program './update-dns.sh' like this:
+
+	./update-dns.sh "present" "foo.example.com." "--" "some-token" "KxAy-J3NwUmg9ZQuM-gP_Mq1nStaYSaP9tYQs5_-YsE.ksT-qywTd8058G-SHHWA3RAN72Pr0yWtPYmmY5UBpQ8"
+
+NOTE:
+The `--` is because the token MAY start with a `-`, and the called program may try and interpret a - as indicating a flag.
+In the case of urfave, which is commonly used,
+you can use the `--` delimiter to specify the start of positional arguments, and handle such a string safely.
+*/
+package exec

providers/dns/exec/exec.go

@@ -1,78 +1,100 @@
-// Package exec implements a manual DNS provider which runs a program for
-// adding/removing the DNS record.
-//
-// The file name of the external program is specified in the environment
-// variable EXEC_PATH. When it is run by lego, three command-line parameters
-// are passed to it: The action ("present" or "cleanup"), the fully-qualified domain
-// name, the value for the record and the TTL.
-//
-// For example, requesting a certificate for the domain 'foo.example.com' can
-// be achieved by calling lego as follows:
-//
-//  EXEC_PATH=./update-dns.sh \
-//    lego --dns exec \
-//    --domains foo.example.com \
-//    --email [email protected] run
-//
-// It will then call the program './update-dns.sh' with like this:
-//
-//  ./update-dns.sh "present" "_acme-challenge.foo.example.com." "MsijOYZxqyjGnFGwhjrhfg-Xgbl5r68WPda0J9EgqqI" "120"
-//
-// The program then needs to make sure the record is inserted. When it returns
-// an error via a non-zero exit code, lego aborts.
-//
-// When the record is to be removed again, the program is called with the first
-// command-line parameter set to "cleanup" instead of "present".
 package exec
 
 import (
 	"errors"
+	"fmt"
 	"os"
 	"os/exec"
 	"strconv"
 
 	"github.com/xenolf/lego/acme"
+	"github.com/xenolf/lego/log"
+	"github.com/xenolf/lego/platform/config/env"
 )
 
+// Config Provider configuration.
+type Config struct {
+	Program string
+	Mode    string
+}
+
 // DNSProvider adds and removes the record for the DNS challenge by calling a
 // program with command-line parameters.
 type DNSProvider struct {
-	program string
+	config *Config
 }
 
 // NewDNSProvider returns a new DNS provider which runs the program in the
 // environment variable EXEC_PATH for adding and removing the DNS record.
 func NewDNSProvider() (*DNSProvider, error) {
-	s := os.Getenv("EXEC_PATH")
-	if s == "" {
-		return nil, errors.New("environment variable EXEC_PATH not set")
+	values, err := env.Get("EXEC_PATH")
+	if err != nil {
+		return nil, fmt.Errorf("exec: %v", err)
 	}
 
-	return NewDNSProviderProgram(s)
+	return NewDNSProviderConfig(&Config{
+		Program: values["EXEC_PATH"],
+		Mode:    os.Getenv("EXEC_MODE"),
+	})
+}
+
+// NewDNSProviderConfig returns a new DNS provider which runs the given configuration
+// for adding and removing the DNS record.
+func NewDNSProviderConfig(config *Config) (*DNSProvider, error) {
+	if config == nil {
+		return nil, errors.New("the configuration is nil")
+	}
+
+	return &DNSProvider{config: config}, nil
 }
 
 // NewDNSProviderProgram returns a new DNS provider which runs the given program
 // for adding and removing the DNS record.
+// Deprecated: use NewDNSProviderConfig instead
 func NewDNSProviderProgram(program string) (*DNSProvider, error) {
-	return &DNSProvider{program: program}, nil
+	if len(program) == 0 {
+		return nil, errors.New("the program is undefined")
+	}
+
+	return NewDNSProviderConfig(&Config{Program: program})
 }
 
 // Present creates a TXT record to fulfil the dns-01 challenge.
 func (d *DNSProvider) Present(domain, token, keyAuth string) error {
-	fqdn, value, ttl := acme.DNS01Record(domain, keyAuth)
-	cmd := exec.Command(d.program, "present", fqdn, value, strconv.Itoa(ttl))
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
+	var args []string
+	if d.config.Mode == "RAW" {
+		args = []string{"present", "--", domain, token, keyAuth}
+	} else {
+		fqdn, value, ttl := acme.DNS01Record(domain, keyAuth)
+		args = []string{"present", fqdn, value, strconv.Itoa(ttl)}
+	}
+
+	cmd := exec.Command(d.config.Program, args...)
+
+	output, err := cmd.CombinedOutput()
+	if len(output) > 0 {
+		log.Println(string(output))
+	}
 
-	return cmd.Run()
+	return err
 }
 
 // CleanUp removes the TXT record matching the specified parameters
 func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error {
-	fqdn, value, ttl := acme.DNS01Record(domain, keyAuth)
-	cmd := exec.Command(d.program, "cleanup", fqdn, value, strconv.Itoa(ttl))
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
+	var args []string
+	if d.config.Mode == "RAW" {
+		args = []string{"cleanup", "--", domain, token, keyAuth}
+	} else {
+		fqdn, value, ttl := acme.DNS01Record(domain, keyAuth)
+		args = []string{"cleanup", fqdn, value, strconv.Itoa(ttl)}
+	}
+
+	cmd := exec.Command(d.config.Program, args...)
+
+	output, err := cmd.CombinedOutput()
+	if len(output) > 0 {
+		log.Println(string(output))
+	}
 
-	return cmd.Run()
+	return err
 }