Merge pull request #319 from mbanzon/issue-304

parser: Allow use of environment variables in tokens

caddy/parse/parsing.go

@@ -71,6 +71,8 @@ func (p *parser) addresses() error {
 	for {
 		tkn := p.Val()
 
+		tkn = getValFromEnv(tkn)
+
 		// special case: import directive replaces tokens during parse-time
 		if tkn == "import" && p.isNewLine() {
 			err := p.doImport()
@@ -241,6 +243,7 @@ func (p *parser) directive() error {
 		} else if p.Val() == "}" && nesting == 0 {
 			return p.Err("Unexpected '}' because no matching opening brace")
 		}
+		p.tokens[p.cursor].text = getValFromEnv(p.tokens[p.cursor].text)
 		p.block.Tokens[dir] = append(p.block.Tokens[dir], p.tokens[p.cursor])
 	}
 
@@ -327,3 +330,26 @@ func (sb serverBlock) HostList() []string {
 	}
 	return sbHosts
 }
+
+func getValFromEnv(s string) string {
+	s = replaceEnvReferences(s, "{$", "}")
+	s = replaceEnvReferences(s, "{%", "%}")
+	return s
+}
+
+func replaceEnvReferences(s, refStart, refEnd string) string {
+	index := strings.Index(s, refStart)
+	for index != -1 {
+		endIndex := strings.Index(s, refEnd)
+		if endIndex != -1 {
+			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
+}

caddy/parse/parsing_test.go

@@ -1,6 +1,7 @@
 package parse
 
 import (
+	"os"
 	"strings"
 	"testing"
 )
@@ -364,6 +365,81 @@ func TestParseAll(t *testing.T) {
 	}
 }
 
+func TestEnvironmentReplacement(t *testing.T) {
+	setupParseTests()
+
+	os.Setenv("MY_PORT", "8080")
+	os.Setenv("MY_ADDRESS", "servername.com")
+	os.Setenv("MY_ADDRESS2", "127.0.0.1")
+
+	for i, test := range []struct {
+		input     string
+		addresses [][]address // addresses per server block, in order
+	}{
+		{`{$MY_ADDRESS}`, [][]address{
+			{{"servername.com", ""}},
+		}},
+
+		{`{$MY_ADDRESS}:{$MY_PORT}`, [][]address{
+			[]address{{"servername.com", "8080"}},
+		}},
+
+		{`{$MY_ADDRESS2}:1234 {
+		  }
+		  localhost:{$MY_PORT} {
+		  }`, [][]address{
+			[]address{{"127.0.0.1", "1234"}},
+			[]address{{"localhost", "8080"}},
+		}},
+
+		{`{%MY_ADDRESS%}`, [][]address{
+			{{"servername.com", ""}},
+		}},
+
+		{`{%MY_ADDRESS%}:{%MY_PORT%}`, [][]address{
+			[]address{{"servername.com", "8080"}},
+		}},
+
+		{`{%MY_ADDRESS2%}:1234 {
+		  }
+		  localhost:{%MY_PORT%} {
+		  }`, [][]address{
+			[]address{{"127.0.0.1", "1234"}},
+			[]address{{"localhost", "8080"}},
+		}},
+	} {
+		p := testParser(test.input)
+		blocks, err := p.parseAll()
+
+		if err != nil {
+			t.Errorf("Test %d: Expected no error, but got: %v", i, err)
+		}
+
+		if len(blocks) != len(test.addresses) {
+			t.Errorf("Test %d: Expected %d server blocks, got %d",
+				i, len(test.addresses), len(blocks))
+			continue
+		}
+		for j, block := range blocks {
+			if len(block.Addresses) != len(test.addresses[j]) {
+				t.Errorf("Test %d: Expected %d addresses in block %d, got %d",
+					i, len(test.addresses[j]), j, len(block.Addresses))
+				continue
+			}
+			for k, addr := range block.Addresses {
+				if addr.Host != test.addresses[j][k].Host {
+					t.Errorf("Test %d, block %d, address %d: Expected host to be '%s', but was '%s'",
+						i, j, k, test.addresses[j][k].Host, addr.Host)
+				}
+				if addr.Port != test.addresses[j][k].Port {
+					t.Errorf("Test %d, block %d, address %d: Expected port to be '%s', but was '%s'",
+						i, j, k, test.addresses[j][k].Port, addr.Port)
+				}
+			}
+		}
+	}
+}
+
 func setupParseTests() {
 	// Set up some bogus directives for testing
 	ValidDirectives = map[string]struct{}{