Update lego

vendor/github.com/xenolf/lego/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 invalid@example.com 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 invalid@example.com 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