Add DNS01 support to the CLI

cli.go

@@ -108,6 +108,19 @@ func main() {
 			Name:  "tls",
 			Usage: "Set the port and interface to use for TLS based challenges to listen on. Supported: interface:port or :port",
 		},
+		cli.StringFlag{
+			Name: "dns",
+			Usage: "Enable the DNS challenge for solving using a provider." +
+				"\n\tCredentials for providers have to be passed through environment variables." +
+				"\n\tFor a more detailed explanation of the parameters, please see the online docs." +
+				"\n\tValid providers:" +
+				"\n\tcloudflare: CLOUDFLARE_EMAIL, CLOUDFLARE_API_KEY" +
+				"\n\tdigitalocean: DO_AUTH_TOKEN" +
+				"\n\tdnsimple: DNSIMPLE_EMAIL, DNSIMPLE_API_KEY" +
+				"\n\troute53: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION_NAME" +
+				"\n\trfc2136: RFC2136_TSIG_KEY, RFC2136_TSIG_SECRET, RFC2136_NAMESERVER, RFC2136_ZONE" +
+				"\n\tmanual: none",
+		},
 	}
 
 	app.Run(os.Args)

cli_handlers.go

@@ -51,6 +51,39 @@ func setup(c *cli.Context) (*Configuration, *Account, *acme.Client) {
 		client.SetTLSAddress(c.GlobalString("tls"))
 	}
 
+	if c.GlobalIsSet("dns") {
+		var err error
+		var provider acme.ChallengeProvider
+		switch c.GlobalString("dns") {
+		case "cloudflare":
+			provider, err = acme.NewDNSProviderCloudFlare("", "")
+		case "digitalocean":
+			authToken := os.Getenv("DO_AUTH_TOKEN")
+
+			provider, err = acme.NewDNSProviderDigitalOcean(authToken)
+		case "dnsimple":
+			provider, err = acme.NewDNSProviderDNSimple("", "")
+		case "route53":
+			awsRegion := os.Getenv("AWS_REGION")
+			provider, err = acme.NewDNSProviderRoute53("", "", awsRegion)
+		case "rfc2136":
+			nameserver := os.Getenv("RFC2136_NAMESERVER")
+			zone := os.Getenv("RFC2136_ZONE")
+			tsigKey := os.Getenv("RFC2136_TSIG_KEY")
+			tsigSecret := os.Getenv("RFC2136_TSIG_SECRET")
+
+			provider, err = acme.NewDNSProviderRFC2136(nameserver, zone, tsigKey, tsigSecret)
+		case "manual":
+			provider, err = acme.NewDNSProviderManual()
+		}
+
+		if err != nil {
+			logger().Fatal(err)
+		}
+
+		client.SetChallengeProvider(acme.DNS01, provider)
+	}
+
 	return conf, acc, client
 }