chore: propagate writer

Author: ldez

docs/data/zz_cli_help.toml

@@ -143,5 +143,14 @@ OPTIONS:
 [[command]]
 title   = "lego dnshelp"
 content = """
+Credentials for DNS providers must be passed through environment variables.
 
+To display the documentation for a specific DNS provider, run:
+
+  $ lego dnshelp -c code
+
+Supported DNS providers:
+  acme-dns, active24, alidns, allinkl, arvancloud, auroradns, autodns, azure, azuredns, bindman, bluecat, bookmyname, brandit, bunny, checkdomain, civo, clouddns, cloudflare, cloudns, cloudru, cloudxns, conoha, constellix, corenetworks, cpanel, derak, desec, designate, digitalocean, directadmin, dnshomede, dnsimple, dnsmadeeasy, dnspod, dode, domeneshop, dreamhost, duckdns, dyn, dynu, easydns, edgedns, efficientip, epik, exec, exoscale, f5xc, freemyip, gandi, gandiv5, gcloud, gcore, glesys, godaddy, googledomains, hetzner, hostingde, hosttech, httpnet, httpreq, huaweicloud, hurricane, hyperone, ibmcloud, iij, iijdpf, infoblox, infomaniak, internetbs, inwx, ionos, ipv64, iwantmyname, joker, liara, lightsail, limacity, linode, liquidweb, loopia, luadns, mailinabox, manageengine, manual, metaname, metaregistrar, mijnhost, mittwald, myaddr, mydnsjp, mythicbeasts, namecheap, namedotcom, namesilo, nearlyfreespeech, netcup, netlify, nicmanager, nifcloud, njalla, nodion, ns1, oraclecloud, otc, ovh, pdns, plesk, porkbun, rackspace, rainyun, rcodezero, regfish, regru, rfc2136, rimuhosting, route53, safedns, sakuracloud, scaleway, selectel, selectelv2, selfhostde, servercow, shellrent, simply, sonic, spaceship, stackpath, technitium, tencentcloud, timewebcloud, transip, ultradns, variomedia, vegadns, vercel, versio, vinyldns, vkcloud, volcengine, vscale, vultr, webnames, websupport, wedos, westcn, yandex, yandex360, yandexcloud, zoneee, zonomi
+
+More information: https://go-acme.github.io/lego/dns
 """

internal/clihelp/generator.go

@@ -97,14 +97,18 @@ func createStubApp() *cli.Command {
 	}
 }
 
-func run(ctx context.Context, cmd *cli.Command, args []string) (h commandHelp, err error) {
-	w := cmd.Writer
-	defer func() { cmd.Writer = w }()
+func run(ctx context.Context, app *cli.Command, args []string) (h commandHelp, err error) {
+	w := app.Writer
+	defer func() { app.Writer = w }()
 
 	var buf bytes.Buffer
-	cmd.Writer = &buf
+	app.Writer = &buf
 
-	if err := cmd.Run(ctx, args); err != nil {
+	if app.Command(args[1]) != nil {
+		app.Command(args[1]).Writer = app.Writer
+	}
+
+	if err := app.Run(ctx, args); err != nil {
 		return h, err
 	}