caddytls: Allow disabling distributed solving (except http-01)

Author: mholt

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/Masterminds/sprig/v3 v3.3.0
 	github.com/alecthomas/chroma/v2 v2.20.0
 	github.com/aryann/difflib v0.0.0-20210328193216-ff5ff6dc229b
-	github.com/caddyserver/certmagic v0.24.0
+	github.com/caddyserver/certmagic v0.25.0
 	github.com/caddyserver/zerossl v0.1.3
 	github.com/cloudflare/circl v1.6.1
 	github.com/dustin/go-humanize v1.0.1
@@ -17,7 +17,7 @@ require (
 	github.com/google/uuid v1.6.0
 	github.com/klauspost/compress v1.18.0
 	github.com/klauspost/cpuid/v2 v2.3.0
-	github.com/mholt/acmez/v3 v3.1.2
+	github.com/mholt/acmez/v3 v3.1.3
 	github.com/prometheus/client_golang v1.23.0
 	github.com/quic-go/quic-go v0.54.0
 	github.com/smallstep/certificates v0.28.4
@@ -128,7 +128,7 @@ require (
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d // indirect
-	github.com/miekg/dns v1.1.63 // indirect
+	github.com/miekg/dns v1.1.68 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/go-ps v1.0.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect

go.sum

@@ -91,8 +91,8 @@ github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bradfitz/go-smtpd v0.0.0-20170404230938-deb6d6237625/go.mod h1:HYsPBTaaSFSlLx/70C2HPIMNZpVV8+vt/A+FMnYP11g=
 github.com/buger/jsonparser v0.0.0-20181115193947-bf1c66bbce23/go.mod h1:bbYlZJ7hK1yFx9hf58LP0zeX7UjIGs20ufpu3evjr+s=
-github.com/caddyserver/certmagic v0.24.0 h1:EfXTWpxHAUKgDfOj6MHImJN8Jm4AMFfMT6ITuKhrDF0=
-github.com/caddyserver/certmagic v0.24.0/go.mod h1:xPT7dC1DuHHnS2yuEQCEyks+b89sUkMENh8dJF+InLE=
+github.com/caddyserver/certmagic v0.25.0 h1:VMleO/XA48gEWes5l+Fh6tRWo9bHkhwAEhx63i+F5ic=
+github.com/caddyserver/certmagic v0.25.0/go.mod h1:m9yB7Mud24OQbPHOiipAoyKPn9pKHhpSJxXR1jydBxA=
 github.com/caddyserver/zerossl v0.1.3 h1:onS+pxp3M8HnHpN5MMbOMyNjmTheJyWRaZYwn+YTAyA=
 github.com/caddyserver/zerossl v0.1.3/go.mod h1:CxA0acn7oEGO6//4rtrRjYgEoa4MFw/XofZnrYwGqG4=
 github.com/ccoveille/go-safecast v1.6.1 h1:Nb9WMDR8PqhnKCVs2sCB+OqhohwO5qaXtCviZkIff5Q=
@@ -274,11 +274,11 @@ github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d h1:5PJl274Y63IEHC+7izoQE9x6ikvDFZS2mDVS3drnohI=
 github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d/go.mod h1:01TrycV0kFyexm33Z7vhZRXopbI8J3TDReVlkTgMUxE=
-github.com/mholt/acmez/v3 v3.1.2 h1:auob8J/0FhmdClQicvJvuDavgd5ezwLBfKuYmynhYzc=
-github.com/mholt/acmez/v3 v3.1.2/go.mod h1:L1wOU06KKvq7tswuMDwKdcHeKpFFgkppZy/y0DFxagQ=
+github.com/mholt/acmez/v3 v3.1.3 h1:gUl789rjbJSuM5hYzOFnNaGgWPV1xVfnOs59o0dZEcc=
+github.com/mholt/acmez/v3 v3.1.3/go.mod h1:L1wOU06KKvq7tswuMDwKdcHeKpFFgkppZy/y0DFxagQ=
 github.com/microcosm-cc/bluemonday v1.0.1/go.mod h1:hsXNsILzKxV+sX77C5b8FSuKF00vh2OMYv+xgHpAMF4=
-github.com/miekg/dns v1.1.63 h1:8M5aAw6OMZfFXTT7K5V0Eu5YiiL8l7nUAkyN6C9YwaY=
-github.com/miekg/dns v1.1.63/go.mod h1:6NGHfjhpmr5lt3XPLuyfDJi5AXbNIPM9PY6H6sF1Nfs=
+github.com/miekg/dns v1.1.68 h1:jsSRkNozw7G/mnmXULynzMNIsgY2dHC8LO6U6Ij2JEA=
+github.com/miekg/dns v1.1.68/go.mod h1:fujopn7TB3Pu3JM69XaawiU0wqjpL9/8xGop5UrTPps=
 github.com/mitchellh/copystructure v1.2.0 h1:vpKXTN4ewci03Vljg/q9QvCGUDttBOGBIa15WveJJGw=
 github.com/mitchellh/copystructure v1.2.0/go.mod h1:qLl+cE2AmVv+CoeAwDPye/v+N2HKCj9FbZEVFJRxO9s=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=

modules/caddytls/acmeissuer.go

@@ -244,6 +244,9 @@ func (iss *ACMEIssuer) makeIssuerTemplate(ctx caddy.Context) (certmagic.ACMEIssu
 			template.DNS01Solver = iss.Challenges.DNS.solver
 		}
 		template.ListenHost = iss.Challenges.BindHost
+		if iss.Challenges.Distributed != nil {
+			template.DisableDistributedSolvers = !*iss.Challenges.Distributed
+		}
 	}
 
 	if iss.PreferredChains != nil {
@@ -480,6 +483,20 @@ func (iss *ACMEIssuer) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 			}
 			iss.Challenges.TLSALPN.Disabled = true
 
+		case "distributed":
+			if !d.NextArg() {
+				return d.ArgErr()
+			}
+			if d.Val() != "false" {
+				return d.Errf("only accepted value is 'false'")
+			}
+			if iss.Challenges == nil {
+				iss.Challenges = new(ChallengesConfig)
+			}
+			if iss.Challenges.Distributed == nil {
+				iss.Challenges.Distributed = new(bool)
+			}
+
 		case "alt_http_port":
 			if !d.NextArg() {
 				return d.ArgErr()

modules/caddytls/automation.go

@@ -456,6 +456,22 @@ type ChallengesConfig struct {
 	// Optionally customize the host to which a listener
 	// is bound if required for solving a challenge.
 	BindHost string `json:"bind_host,omitempty"`
+
+	// Whether distributed solving is enabled. This is
+	// enabled by default, so this is only used to
+	// disable it, which should only need to be done if
+	// you cannot reliably or affordably use storage
+	// backend for writing/distributing challenge info.
+	// (Applies to HTTP and TLS-ALPN challenges.)
+	// If set to false, challenges can only be solved
+	// from the Caddy instance that initiated the
+	// challenge, with the exception of HTTP challenges
+	// initiated with the same ACME account that this
+	// config uses. (Caddy can still solve those challenges
+	// without explicitly writing the info to storage.)
+	//
+	// Default: true
+	Distributed *bool `json:"distributed,omitempty"`
 }
 
 // HTTPChallengeConfig configures the ACME HTTP challenge.