Implement config adapters and beginning of Caddyfile adapter

Along with several other changes, such as renaming caddyhttp.ServerRoute
to caddyhttp.Route, exporting some types that were not exported before,
and tweaking the caddytls TLS values to be more consistent.

Notably, we also now disable automatic cert management for names which
already have a cert (manually) loaded into the cache. These names no
longer need to be specified in the "skip_certificates" field of the
automatic HTTPS config, because they will be skipped automatically.

1 files changed, 350 insertions, 0 deletions

diff --git a/caddyconfig/httpcaddyfile/addresses.go b/caddyconfig/httpcaddyfile/addresses.go
new file mode 100644
index 0000000..6ecee26
--- /dev/null
+++ b/caddyconfig/httpcaddyfile/addresses.go
@@ -0,0 +1,350 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package httpcaddyfile
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	"github.com/mholt/certmagic"
+)
+
+// mapAddressToServerBlocks returns a map of listener address to list of server
+// blocks that will be served on that address. To do this, each server block is
+// expanded so that each one is considered individually, although keys of a
+// server block that share the same address stay grouped together so the config
+// isn't repeated unnecessarily. For example, this Caddyfile:
+//
+// 	example.com {
+// 		bind 127.0.0.1
+// 	}
+// 	www.example.com, example.net/path, localhost:9999 {
+// 		bind 127.0.0.1 1.2.3.4
+// 	}
+//
+// has two server blocks to start with. But expressed in this Caddyfile are
+// actually 4 listener addresses: 127.0.0.1:443, 1.2.3.4:443, 127.0.0.1:9999,
+// and 127.0.0.1:9999. This is because the bind directive is applied to each
+// key of its server block (specifying the host part), and each key may have
+// a different port. And we definitely need to be sure that a site which is
+// bound to be served on a specific interface is not served on others just
+// beceause that is more convenient: it would be a potential security risk
+// if the difference between interfaces means private vs. public.
+//
+// So what this function does for the example above is iterate each server
+// block, and for each server block, iterate its keys. For the first, it
+// finds one key (example.com) and determines its listener address
+// (127.0.0.1:443 - because of 'bind' and automatic HTTPS). It then adds
+// the listener address to the map value returned by this function, with
+// the first server block as one of its associations.
+//
+// It then iterates each key on the second server block and associates them
+// with one or more listener addresses. Indeed, each key in this block has
+// two listener addresses because of the 'bind' directive. Once we know
+// which addresses serve which keys, we can create a new server block for
+// each address containing the contents of the server block and only those
+// specific keys of the server block which use that address.
+//
+// It is possible and even likely that some keys in the returned map have
+// the exact same list of server blocks (i.e. they are identical). This
+// happens when multiple hosts are declared with a 'bind' directive and
+// the resulting listener addresses are not shared by any other server
+// block (or the other server blocks are exactly identical in their token
+// contents). This happens with our example above because 1.2.3.4:443
+// and 1.2.3.4:9999 are used exclusively with the second server block. This
+// repetition may be undesirable, so call consolidateAddrMappings() to map
+// multiple addresses to the same lists of server blocks (a many:many mapping).
+// (Doing this is essentially a map-reduce technique.)
+func (st *ServerType) mapAddressToServerBlocks(originalServerBlocks []caddyfile.ServerBlock) (map[string][]caddyfile.ServerBlock, error) {
+	sbmap := make(map[string][]caddyfile.ServerBlock)
+
+	for i, sblock := range originalServerBlocks {
+		// within a server block, we need to map all the listener addresses
+		// implied by the server block to the keys of the server block which
+		// will be served by them; this has the effect of treating each
+		// key of a server block as its own, but without having to repeat its
+		// contents in cases where multiple keys really can be served together
+		addrToKeys := make(map[string][]string)
+		for j, key := range sblock.Keys {
+			// a key can have multiple listener addresses if there are multiple
+			// arguments to the 'bind' directive (although they will all have
+			// the same port, since the port is defined by the key or is implicit
+			// through automatic HTTPS)
+			addrs, err := st.listenerAddrsForServerBlockKey(sblock, key)
+			if err != nil {
+				return nil, fmt.Errorf("server block %d, key %d (%s): determining listener address: %v", i, j, key, err)
+			}
+
+			// associate this key with each listener address it is served on
+			for _, addr := range addrs {
+				addrToKeys[addr] = append(addrToKeys[addr], key)
+			}
+		}
+
+		// now that we know which addresses serve which keys of this
+		// server block, we iterate that mapping and create a list of
+		// new server blocks for each address where the keys of the
+		// server block are only the ones which use the address; but
+		// the contents (tokens) are of course the same
+		for addr, keys := range addrToKeys {
+			sbmap[addr] = append(sbmap[addr], caddyfile.ServerBlock{
+				Keys:   keys,
+				Tokens: sblock.Tokens,
+			})
+		}
+	}
+
+	return sbmap, nil
+}
+
+// consolidateAddrMappings eliminates repetition of identical server blocks in a mapping of
+// single listener addresses to lists of server blocks. Since multiple addresses may serve
+// identical sites (server block contents), this function turns a 1:many mapping into a
+// many:many mapping. Server block contents (tokens) must be exactly identical so that
+// reflect.DeepEqual returns true in order for the addresses to be combined. Identical
+// entries are deleted from the addrToServerBlocks map. Essentially, each pairing (each
+// association from multiple addresses to multiple server blocks; i.e. each element of
+// the returned slice) becomes a server definition in the output JSON.
+func (st *ServerType) consolidateAddrMappings(addrToServerBlocks map[string][]caddyfile.ServerBlock) []sbAddrAssociation {
+	var sbaddrs []sbAddrAssociation
+	for addr, sblocks := range addrToServerBlocks {
+		// we start with knowing that at least this address
+		// maps to these server blocks
+		a := sbAddrAssociation{
+			addresses:    []string{addr},
+			serverBlocks: sblocks,
+		}
+
+		// now find other addresses that map to identical
+		// server blocks and add them to our list of
+		// addresses, while removing them from the map
+		for otherAddr, otherSblocks := range addrToServerBlocks {
+			if addr == otherAddr {
+				continue
+			}
+			if reflect.DeepEqual(sblocks, otherSblocks) {
+				a.addresses = append(a.addresses, otherAddr)
+				delete(addrToServerBlocks, otherAddr)
+			}
+		}
+
+		sbaddrs = append(sbaddrs, a)
+	}
+	return sbaddrs
+}
+
+func (st *ServerType) listenerAddrsForServerBlockKey(sblock caddyfile.ServerBlock, key string) ([]string, error) {
+	addr, err := standardizeAddress(key)
+	if err != nil {
+		return nil, fmt.Errorf("parsing key: %v", err)
+	}
+
+	lnPort := defaultPort
+	if addr.Port != "" {
+		// port explicitly defined
+		lnPort = addr.Port
+	} else if certmagic.HostQualifies(addr.Host) {
+		// automatic HTTPS
+		lnPort = strconv.Itoa(certmagic.HTTPSPort)
+	}
+
+	// the bind directive specifies hosts, but is optional
+	var lnHosts []string
+	for i, token := range sblock.Tokens["bind"] {
+		if i == 0 {
+			continue
+		}
+		lnHosts = append(lnHosts, token.Text)
+	}
+	if len(lnHosts) == 0 {
+		lnHosts = []string{""}
+	}
+
+	// use a map to prevent duplication
+	listeners := make(map[string]struct{})
+	for _, host := range lnHosts {
+		listeners[net.JoinHostPort(host, lnPort)] = struct{}{}
+	}
+
+	// now turn map into list
+	var listenersList []string
+	for lnStr := range listeners {
+		listenersList = append(listenersList, lnStr)
+	}
+	// sort.Strings(listenersList) // TODO: is sorting necessary?
+
+	return listenersList, nil
+}
+
+// Address represents a site address. It contains
+// the original input value, and the component
+// parts of an address. The component parts may be
+// updated to the correct values as setup proceeds,
+// but the original value should never be changed.
+//
+// The Host field must be in a normalized form.
+type Address struct {
+	Original, Scheme, Host, Port, Path string
+}
+
+// String returns a human-friendly print of the address.
+func (a Address) String() string {
+	if a.Host == "" && a.Port == "" {
+		return ""
+	}
+	scheme := a.Scheme
+	if scheme == "" {
+		if a.Port == strconv.Itoa(certmagic.HTTPSPort) {
+			scheme = "https"
+		} else {
+			scheme = "http"
+		}
+	}
+	s := scheme
+	if s != "" {
+		s += "://"
+	}
+	if a.Port != "" &&
+		((scheme == "https" && a.Port != strconv.Itoa(caddyhttp.DefaultHTTPSPort)) ||
+			(scheme == "http" && a.Port != strconv.Itoa(caddyhttp.DefaultHTTPPort))) {
+		s += net.JoinHostPort(a.Host, a.Port)
+	} else {
+		s += a.Host
+	}
+	if a.Path != "" {
+		s += a.Path
+	}
+	return s
+}
+
+// VHost returns a sensible concatenation of Host:Port/Path from a.
+// It's basically the a.Original but without the scheme.
+func (a Address) VHost() string {
+	if idx := strings.Index(a.Original, "://"); idx > -1 {
+		return a.Original[idx+3:]
+	}
+	return a.Original
+}
+
+// Normalize normalizes URL: turn scheme and host names into lower case
+func (a Address) Normalize() Address {
+	path := a.Path
+	if !caseSensitivePath {
+		path = strings.ToLower(path)
+	}
+
+	// ensure host is normalized if it's an IP address
+	host := a.Host
+	if ip := net.ParseIP(host); ip != nil {
+		host = ip.String()
+	}
+
+	return Address{
+		Original: a.Original,
+		Scheme:   strings.ToLower(a.Scheme),
+		Host:     strings.ToLower(host),
+		Port:     a.Port,
+		Path:     path,
+	}
+}
+
+// Key is similar to String, just replaces scheme and host values with modified values.
+// Unlike String it doesn't add anything default (scheme, port, etc)
+func (a Address) Key() string {
+	res := ""
+	if a.Scheme != "" {
+		res += a.Scheme + "://"
+	}
+	if a.Host != "" {
+		res += a.Host
+	}
+	if a.Port != "" {
+		if strings.HasPrefix(a.Original[len(res):], ":"+a.Port) {
+			// insert port only if the original has its own explicit port
+			res += ":" + a.Port
+		}
+	}
+	if a.Path != "" {
+		res += a.Path
+	}
+	return res
+}
+
+// standardizeAddress parses an address string into a structured format with separate
+// scheme, host, port, and path portions, as well as the original input string.
+func standardizeAddress(str string) (Address, error) {
+	httpPort, httpsPort := strconv.Itoa(certmagic.HTTPPort), strconv.Itoa(certmagic.HTTPSPort)
+
+	input := str
+
+	// Split input into components (prepend with // to assert host by default)
+	if !strings.Contains(str, "//") && !strings.HasPrefix(str, "/") {
+		str = "//" + str
+	}
+	u, err := url.Parse(str)
+	if err != nil {
+		return Address{}, err
+	}
+
+	// separate host and port
+	host, port, err := net.SplitHostPort(u.Host)
+	if err != nil {
+		host, port, err = net.SplitHostPort(u.Host + ":")
+		if err != nil {
+			host = u.Host
+		}
+	}
+
+	// see if we can set port based off scheme
+	if port == "" {
+		if u.Scheme == "http" {
+			port = httpPort
+		} else if u.Scheme == "https" {
+			port = httpsPort
+		}
+	}
+
+	// repeated or conflicting scheme is confusing, so error
+	if u.Scheme != "" && (port == "http" || port == "https") {
+		return Address{}, fmt.Errorf("[%s] scheme specified twice in address", input)
+	}
+
+	// error if scheme and port combination violate convention
+	if (u.Scheme == "http" && port == httpsPort) || (u.Scheme == "https" && port == httpPort) {
+		return Address{}, fmt.Errorf("[%s] scheme and port violate convention", input)
+	}
+
+	// standardize http and https ports to their respective port numbers
+	if port == "http" {
+		u.Scheme = "http"
+		port = httpPort
+	} else if port == "https" {
+		u.Scheme = "https"
+		port = httpsPort
+	}
+
+	return Address{Original: input, Scheme: u.Scheme, Host: host, Port: port, Path: u.Path}, err
+}
+
+const (
+	defaultPort       = "2015"
+	caseSensitivePath = false
+)