initial implementation of caddyfile macros

caddyfile/parse.go

@@ -54,6 +54,7 @@ type parser struct {
 	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
+	definedMacros   map[string][]Token
 }
 
 func (p *parser) parseAll() ([]ServerBlock, error) {
@@ -95,6 +96,25 @@ func (p *parser) begin() error {
 		return nil
 	}
 
+	if ok, name := p.isMacro(); ok {
+		if p.definedMacros == nil {
+			p.definedMacros = map[string][]Token{}
+		}
+		if p.definedMacros[name] != nil {
+			p.Errf("redeclaration of previously declared macro %s", name)
+		}
+
+		// consume all tokens til matched close brace
+		tokens, err := p.macroTokens()
+		if err != nil {
+			return err
+		}
+		p.definedMacros[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()
 }
 
@@ -221,7 +241,15 @@ func (p *parser) doImport() error {
 	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 macros. That is a simple, non-recursive replacement
+	if p.definedMacros[importPattern] != nil {
+		importedTokens = p.definedMacros[importPattern]
+	} else {
 		// make path relative to Caddyfile rather than current working directory (issue #867)
 		// and then use glob to get list of matching filenames
 		absFile, err := filepath.Abs(p.Dispenser.filename)
@@ -249,12 +277,8 @@ func (p *parser) doImport() error {
 			}
 		}
 
-	// splice out the import directive and its argument (2 tokens total)
-	tokensBefore := p.tokens[:p.cursor-1]
-	tokensAfter := p.tokens[p.cursor+1:]
-
 		// collect all the imported tokens
-	var importedTokens []Token
+
 		for _, importFile := range matches {
 			newTokens, err := p.doSingleImport(importFile)
 			if err != nil {
@@ -286,6 +310,7 @@ func (p *parser) doImport() error {
 
 			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
@@ -433,3 +458,45 @@ type ServerBlock struct {
 	Keys   []string
 	Tokens map[string][]Token
 }
+
+func (p *parser) isMacro() (bool, string) {
+	keys := p.block.Keys
+	// "macro foo {}" style
+	if len(keys) == 2 && keys[0] == "macro" {
+		return true, keys[1]
+	}
+	// (foo) style. What to do if more than one server key and some have ()?
+	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) macroTokens() ([]Token, error) {
+	// TODO: disallow imports in macros for simplicity at import time
+	// macro 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
+}

caddyfile/parse_test.go

@@ -15,6 +15,7 @@
 package caddyfile
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -514,3 +515,43 @@ func testParser(input string) parser {
 	p := parser{Dispenser: NewDispenser("Caddyfile", buf)}
 	return p
 }
+
+func TestMacro(t *testing.T) {
+	for _, tst := range []string{"(common)", "macro common"} {
+		t.Run(tst, func(t *testing.T) {
+			p := testParser(fmt.Sprintf(`
+				%s {
+					gzip foo
+					errors stderr
+				}	
+				http://example.com {
+					import common
+				}
+			`, tst))
+			blocks, err := p.parseAll()
+			if err != nil {
+				t.Fatal(err)
+			}
+			for _, b := range blocks {
+				t.Log(b.Keys)
+				t.Log(b.Tokens)
+			}
+			if len(blocks) != 1 {
+				t.Fatalf("Expect exactly one server block. Got %d.", len(blocks))
+			}
+			if actual, expected := blocks[0].Keys[0], "http://example.com"; expected != actual {
+				t.Errorf("Expected server name to be '%s' but was '%s'", expected, actual)
+			}
+			if len(blocks[0].Tokens) != 2 {
+				t.Fatalf("Server block should have tokens from import")
+			}
+			if actual, expected := blocks[0].Tokens["gzip"][0].Text, "gzip"; expected != actual {
+				t.Errorf("Expected argument to be '%s' but was '%s'", expected, actual)
+			}
+			if actual, expected := blocks[0].Tokens["errors"][1].Text, "stderr"; expected != actual {
+				t.Errorf("Expected argument to be '%s' but was '%s'", expected, actual)
+			}
+		})
+	}
+
+}