with :443 instead of localhost, at each time of browser request my backend log:
2020/03/21 17:12:38 [INFO] Obtaining new certificate for wordpress01
2020/03/21 17:12:38 [INFO][wordpress01] Obtain certificate; acquiring lock...
2020/03/21 17:12:38 [INFO][wordpress01] Obtain: Lock acquired; proceeding...
2020/03/21 17:12:39 [INFO][wordpress01] Waiting on rate limiter...
2020/03/21 17:12:39 [INFO][wordpress01] Done waiting
2020/03/21 17:12:39 [INFO] [wordpress01] acme: Obtaining bundled SAN certificate given a CSR
2020/03/21 17:12:39 [ERROR] acme: error: 400 :: POST :: https://acme-v02.api.letsencrypt.org/acme/new-order :: urn:ietf:params:acme:error:rejectedIdentifier :: Error creating new order :: Cannot issue for "wordpress01": Domain name needs at least one dot, url: (challenge=tls-alpn-01 remaining=[http-01])
2020/03/21 17:12:41 [INFO] [wordpress01] acme: Obtaining bundled SAN certificate given a CSR
2020/03/21 17:12:42 [ERROR] acme: error: 400 :: POST :: https://acme-v02.api.letsencrypt.org/acme/new-order :: urn:ietf:params:acme:error:rejectedIdentifier :: Error creating new order :: Cannot issue for "wordpress01": Domain name needs at least one dot, url: (challenge=http-01 remaining=[])
2020/03/21 17:12:44 [INFO][wordpress01] Obtain: Releasing lock
2020/03/21 17:12:44 http: TLS handshake error from 10.244.32.196:42398: [wordpress01] Obtain: [wordpress01] acme: error: 400 :: POST :: https://acme-v02.api.letsencrypt.org/acme/new-order :: urn:ietf:params:acme:error:rejectedIdentifier :: Error creating new order :: Cannot issue for "wordpress01": Domain name needs at least one dot, url:
and frontend:
2020/03/21 17:13:05.959 ERROR http.log.error.log0 remote error: tls: internal error {"request": {"method": "GET", "uri": "/", "proto": "HTTP/2.0", "remote_addr": "127.0.0.1:53864", "host": "domain.com", "headers": {"Accept-Encoding": ["gzip, deflate, br"], "Dnt": ["1"], "Upgrade-Insecure-Requests": ["1"], "Cache-Control": ["max-age=0"], "Te": ["trailers"], "User-Agent": ["Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:74.0) Gecko/20100101 Firefox/74.0"], "Accept": ["text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"], "Accept-Language": ["fr,fr-FR;q=0.8,en-US;q=0.5,en;q=0.3"]}, "tls": {"resumed": false, "version": 772, "ciphersuite": 4865, "proto": "h2", "proto_mutual": true, "server_name": "domain.com"}}, "status": 502, "err_id": "4iqeqncyf", "err_trace": "reverseproxy.(*Handler).ServeHTTP (reverseproxy.go:363)"}
2020/03/21 17:13:05.960 ERROR http.log.access.log0 handled request {"request": {"method": "GET", "uri": "/", "proto": "HTTP/2.0", "remote_addr": "127.0.0.1:53864", "host": "domain.com", "headers": {"Accept": ["text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"], "Accept-Language": ["fr,fr-FR;q=0.8,en-US;q=0.5,en;q=0.3"], "Accept-Encoding": ["gzip, deflate, br"], "Dnt": ["1"], "Upgrade-Insecure-Requests": ["1"], "Cache-Control": ["max-age=0"], "Te": ["trailers"], "User-Agent": ["Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:74.0) Gecko/20100101 Firefox/74.0"]}, "tls": {"resumed": false, "version": 772, "ciphersuite": 4865, "proto": "h2", "proto_mutual": true, "server_name": "domain.com"}}, "common_log": "127.0.0.1 - - [21/Mar/2020:17:13:05 +0000] \"GET / HTTP/2.0\" 502 0", "latency": 4.556397078, "size": 0, "status": 502, "resp_headers": {"Server": ["Caddy"]}}