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, 492 insertions, 0 deletions

diff --git a/caddyconfig/caddyfile/parse.go b/caddyconfig/caddyfile/parse.go
new file mode 100755
index 0000000..cc91e3d
--- /dev/null
+++ b/caddyconfig/caddyfile/parse.go
@@ -0,0 +1,492 @@
+// Copyright 2015 Light Code Labs, LLC
+//
+// 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 caddyfile
+
+import (
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// Parse parses the input just enough to group tokens, in
+// order, by server block. No further parsing is performed.
+// Server blocks are returned in the order in which they appear.
+// Directives that do not appear in validDirectives will cause
+// an error. If you do not want to check for valid directives,
+// pass in nil instead.
+func Parse(filename string, input io.Reader, validDirectives []string) ([]ServerBlock, error) {
+	tokens, err := allTokens(input)
+	if err != nil {
+		return nil, err
+	}
+	p := parser{Dispenser: NewDispenser(filename, tokens), validDirectives: validDirectives}
+	return p.parseAll()
+}
+
+// allTokens lexes the entire input, but does not parse it.
+// It returns all the tokens from the input, unstructured
+// and in order.
+func allTokens(input io.Reader) ([]Token, error) {
+	l := new(lexer)
+	err := l.load(input)
+	if err != nil {
+		return nil, err
+	}
+	var tokens []Token
+	for l.next() {
+		tokens = append(tokens, l.token)
+	}
+	return tokens, nil
+}
+
+type parser struct {
+	*Dispenser
+	block           ServerBlock // current server block being parsed
+	validDirectives []string    // a directive must be valid or it's an error
+	eof             bool        // if we encounter a valid EOF in a hard place
+	definedSnippets map[string][]Token
+}
+
+func (p *parser) parseAll() ([]ServerBlock, error) {
+	var blocks []ServerBlock
+
+	for p.Next() {
+		err := p.parseOne()
+		if err != nil {
+			return blocks, err
+		}
+		if len(p.block.Keys) > 0 {
+			blocks = append(blocks, p.block)
+		}
+	}
+
+	return blocks, nil
+}
+
+func (p *parser) parseOne() error {
+	p.block = ServerBlock{Tokens: make(map[string][]Token)}
+
+	return p.begin()
+}
+
+func (p *parser) begin() error {
+	if len(p.tokens) == 0 {
+		return nil
+	}
+
+	err := p.addresses()
+
+	if err != nil {
+		return err
+	}
+
+	if p.eof {
+		// this happens if the Caddyfile consists of only
+		// a line of addresses and nothing else
+		return nil
+	}
+
+	if ok, name := p.isSnippet(); ok {
+		if p.definedSnippets == nil {
+			p.definedSnippets = map[string][]Token{}
+		}
+		if _, found := p.definedSnippets[name]; found {
+			return p.Errf("redeclaration of previously declared snippet %s", name)
+		}
+		// consume all tokens til matched close brace
+		tokens, err := p.snippetTokens()
+		if err != nil {
+			return err
+		}
+		p.definedSnippets[name] = tokens
+		// empty block keys so we don't save this block as a real server.
+		p.block.Keys = nil
+		return nil
+	}
+
+	return p.blockContents()
+}
+
+func (p *parser) addresses() error {
+	var expectingAnother bool
+
+	for {
+		tkn := replaceEnvVars(p.Val())
+
+		// special case: import directive replaces tokens during parse-time
+		if tkn == "import" && p.isNewLine() {
+			err := p.doImport()
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		// Open brace definitely indicates end of addresses
+		if tkn == "{" {
+			if expectingAnother {
+				return p.Errf("Expected another address but had '%s' - check for extra comma", tkn)
+			}
+			break
+		}
+
+		if tkn != "" { // empty token possible if user typed ""
+			// Trailing comma indicates another address will follow, which
+			// may possibly be on the next line
+			if tkn[len(tkn)-1] == ',' {
+				tkn = tkn[:len(tkn)-1]
+				expectingAnother = true
+			} else {
+				expectingAnother = false // but we may still see another one on this line
+			}
+
+			p.block.Keys = append(p.block.Keys, tkn)
+		}
+
+		// Advance token and possibly break out of loop or return error
+		hasNext := p.Next()
+		if expectingAnother && !hasNext {
+			return p.EOFErr()
+		}
+		if !hasNext {
+			p.eof = true
+			break // EOF
+		}
+		if !expectingAnother && p.isNewLine() {
+			break
+		}
+	}
+
+	return nil
+}
+
+func (p *parser) blockContents() error {
+	errOpenCurlyBrace := p.openCurlyBrace()
+	if errOpenCurlyBrace != nil {
+		// single-server configs don't need curly braces
+		p.cursor--
+	}
+
+	err := p.directives()
+	if err != nil {
+		return err
+	}
+
+	// Only look for close curly brace if there was an opening
+	if errOpenCurlyBrace == nil {
+		err = p.closeCurlyBrace()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// directives parses through all the lines for directives
+// and it expects the next token to be the first
+// directive. It goes until EOF or closing curly brace
+// which ends the server block.
+func (p *parser) directives() error {
+	for p.Next() {
+		// end of server block
+		if p.Val() == "}" {
+			break
+		}
+
+		// special case: import directive replaces tokens during parse-time
+		if p.Val() == "import" {
+			err := p.doImport()
+			if err != nil {
+				return err
+			}
+			p.cursor-- // cursor is advanced when we continue, so roll back one more
+			continue
+		}
+
+		// normal case: parse a directive on this line
+		if err := p.directive(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// doImport swaps out the import directive and its argument
+// (a total of 2 tokens) with the tokens in the specified file
+// or globbing pattern. When the function returns, the cursor
+// is on the token before where the import directive was. In
+// other words, call Next() to access the first token that was
+// imported.
+func (p *parser) doImport() error {
+	// syntax checks
+	if !p.NextArg() {
+		return p.ArgErr()
+	}
+	importPattern := replaceEnvVars(p.Val())
+	if importPattern == "" {
+		return p.Err("Import requires a non-empty filepath")
+	}
+	if p.NextArg() {
+		return p.Err("Import takes only one argument (glob pattern or file)")
+	}
+	// splice out the import directive and its argument (2 tokens total)
+	tokensBefore := p.tokens[:p.cursor-1]
+	tokensAfter := p.tokens[p.cursor+1:]
+	var importedTokens []Token
+
+	// first check snippets. That is a simple, non-recursive replacement
+	if p.definedSnippets != nil && p.definedSnippets[importPattern] != nil {
+		importedTokens = p.definedSnippets[importPattern]
+	} else {
+		// make path relative to the file of the _token_ being processed rather
+		// than current working directory (issue #867) and then use glob to get
+		// list of matching filenames
+		absFile, err := filepath.Abs(p.Dispenser.File())
+		if err != nil {
+			return p.Errf("Failed to get absolute path of file: %s: %v", p.Dispenser.filename, err)
+		}
+
+		var matches []string
+		var globPattern string
+		if !filepath.IsAbs(importPattern) {
+			globPattern = filepath.Join(filepath.Dir(absFile), importPattern)
+		} else {
+			globPattern = importPattern
+		}
+		if strings.Count(globPattern, "*") > 1 || strings.Count(globPattern, "?") > 1 ||
+			(strings.Contains(globPattern, "[") && strings.Contains(globPattern, "]")) {
+			// See issue #2096 - a pattern with many glob expansions can hang for too long
+			return p.Errf("Glob pattern may only contain one wildcard (*), but has others: %s", globPattern)
+		}
+		matches, err = filepath.Glob(globPattern)
+
+		if err != nil {
+			return p.Errf("Failed to use import pattern %s: %v", importPattern, err)
+		}
+		if len(matches) == 0 {
+			if strings.ContainsAny(globPattern, "*?[]") {
+				log.Printf("[WARNING] No files matching import glob pattern: %s", importPattern)
+			} else {
+				return p.Errf("File to import not found: %s", importPattern)
+			}
+		}
+
+		// collect all the imported tokens
+
+		for _, importFile := range matches {
+			newTokens, err := p.doSingleImport(importFile)
+			if err != nil {
+				return err
+			}
+			importedTokens = append(importedTokens, newTokens...)
+		}
+	}
+
+	// splice the imported tokens in the place of the import statement
+	// and rewind cursor so Next() will land on first imported token
+	p.tokens = append(tokensBefore, append(importedTokens, tokensAfter...)...)
+	p.cursor--
+
+	return nil
+}
+
+// doSingleImport lexes the individual file at importFile and returns
+// its tokens or an error, if any.
+func (p *parser) doSingleImport(importFile string) ([]Token, error) {
+	file, err := os.Open(importFile)
+	if err != nil {
+		return nil, p.Errf("Could not import %s: %v", importFile, err)
+	}
+	defer file.Close()
+
+	if info, err := file.Stat(); err != nil {
+		return nil, p.Errf("Could not import %s: %v", importFile, err)
+	} else if info.IsDir() {
+		return nil, p.Errf("Could not import %s: is a directory", importFile)
+	}
+
+	importedTokens, err := allTokens(file)
+	if err != nil {
+		return nil, p.Errf("Could not read tokens while importing %s: %v", importFile, err)
+	}
+
+	// Tack the file path onto these tokens so errors show the imported file's name
+	// (we use full, absolute path to avoid bugs: issue #1892)
+	filename, err := filepath.Abs(importFile)
+	if err != nil {
+		return nil, p.Errf("Failed to get absolute path of file: %s: %v", p.Dispenser.filename, err)
+	}
+	for i := 0; i < len(importedTokens); i++ {
+		importedTokens[i].File = filename
+	}
+
+	return importedTokens, nil
+}
+
+// directive collects tokens until the directive's scope
+// closes (either end of line or end of curly brace block).
+// It expects the currently-loaded token to be a directive
+// (or } that ends a server block). The collected tokens
+// are loaded into the current server block for later use
+// by directive setup functions.
+func (p *parser) directive() error {
+	dir := replaceEnvVars(p.Val())
+	nesting := 0
+
+	if !p.validDirective(dir) {
+		return p.Errf("Unknown directive '%s'", dir)
+	}
+
+	// The directive itself is appended as a relevant token
+	p.block.Tokens[dir] = append(p.block.Tokens[dir], p.tokens[p.cursor])
+
+	for p.Next() {
+		if p.Val() == "{" {
+			nesting++
+		} else if p.isNewLine() && nesting == 0 {
+			p.cursor-- // read too far
+			break
+		} else if p.Val() == "}" && nesting > 0 {
+			nesting--
+		} else if p.Val() == "}" && nesting == 0 {
+			return p.Err("Unexpected '}' because no matching opening brace")
+		} else if p.Val() == "import" && p.isNewLine() {
+			if err := p.doImport(); err != nil {
+				return err
+			}
+			p.cursor-- // cursor is advanced when we continue, so roll back one more
+			continue
+		}
+		p.tokens[p.cursor].Text = replaceEnvVars(p.tokens[p.cursor].Text)
+		p.block.Tokens[dir] = append(p.block.Tokens[dir], p.tokens[p.cursor])
+	}
+
+	if nesting > 0 {
+		return p.EOFErr()
+	}
+	return nil
+}
+
+// openCurlyBrace expects the current token to be an
+// opening curly brace. This acts like an assertion
+// because it returns an error if the token is not
+// a opening curly brace. It does NOT advance the token.
+func (p *parser) openCurlyBrace() error {
+	if p.Val() != "{" {
+		return p.SyntaxErr("{")
+	}
+	return nil
+}
+
+// closeCurlyBrace expects the current token to be
+// a closing curly brace. This acts like an assertion
+// because it returns an error if the token is not
+// a closing curly brace. It does NOT advance the token.
+func (p *parser) closeCurlyBrace() error {
+	if p.Val() != "}" {
+		return p.SyntaxErr("}")
+	}
+	return nil
+}
+
+// validDirective returns true if dir is in p.validDirectives.
+func (p *parser) validDirective(dir string) bool {
+	if p.validDirectives == nil {
+		return true
+	}
+	for _, d := range p.validDirectives {
+		if d == dir {
+			return true
+		}
+	}
+	return false
+}
+
+// replaceEnvVars replaces environment variables that appear in the token
+// and understands both the $UNIX and %WINDOWS% syntaxes.
+func replaceEnvVars(s string) string {
+	s = replaceEnvReferences(s, "{%", "%}")
+	s = replaceEnvReferences(s, "{$", "}")
+	return s
+}
+
+// replaceEnvReferences performs the actual replacement of env variables
+// in s, given the placeholder start and placeholder end strings.
+func replaceEnvReferences(s, refStart, refEnd string) string {
+	index := strings.Index(s, refStart)
+	for index != -1 {
+		endIndex := strings.Index(s[index:], refEnd)
+		if endIndex == -1 {
+			break
+		}
+
+		endIndex += index
+		if endIndex > index+len(refStart) {
+			ref := s[index : endIndex+len(refEnd)]
+			s = strings.Replace(s, ref, os.Getenv(ref[len(refStart):len(ref)-len(refEnd)]), -1)
+		} else {
+			return s
+		}
+		index = strings.Index(s, refStart)
+	}
+	return s
+}
+
+// ServerBlock associates any number of keys (usually addresses
+// of some sort) with tokens (grouped by directive name).
+type ServerBlock struct {
+	Keys   []string
+	Tokens map[string][]Token
+}
+
+func (p *parser) isSnippet() (bool, string) {
+	keys := p.block.Keys
+	// A snippet block is a single key with parens. Nothing else qualifies.
+	if len(keys) == 1 && strings.HasPrefix(keys[0], "(") && strings.HasSuffix(keys[0], ")") {
+		return true, strings.TrimSuffix(keys[0][1:], ")")
+	}
+	return false, ""
+}
+
+// read and store everything in a block for later replay.
+func (p *parser) snippetTokens() ([]Token, error) {
+	// snippet must have curlies.
+	err := p.openCurlyBrace()
+	if err != nil {
+		return nil, err
+	}
+	count := 1
+	tokens := []Token{}
+	for p.Next() {
+		if p.Val() == "}" {
+			count--
+			if count == 0 {
+				break
+			}
+		}
+		if p.Val() == "{" {
+			count++
+		}
+		tokens = append(tokens, p.tokens[p.cursor])
+	}
+	// make sure we're matched up
+	if count != 0 {
+		return nil, p.SyntaxErr("}")
+	}
+	return tokens, nil
+}