httpcaddyfile: Warn on importing empty file; skip dotfiles (#5320)

* httpcaddyfile: Change the parse rules when empty file or dotfile with a glob.

* Fixes #5295
* Empty file should just log a warning, and result in no tokens.
* The last segment of the path is '*', it should skip any dotfiles.
* The last segment of the path is '.*', it should read all dotfiles in a dir.

* httpcaddyfile: Regard empty files as import files which include only white space.

caddyconfig/caddyfile/parse.go

@@ -389,6 +389,20 @@ func (p *parser) doImport() error {
 			} else {
 				return p.Errf("File to import not found: %s", importPattern)
 			}
+		} else {
+			// See issue #5295 - should skip any files that start with a . when iterating over them.
+			sep := string(filepath.Separator)
+			segGlobPattern := strings.Split(globPattern, sep)
+			if strings.HasPrefix(segGlobPattern[len(segGlobPattern)-1], "*") {
+				var tmpMatches []string
+				for _, m := range matches {
+					seg := strings.Split(m, sep)
+					if !strings.HasPrefix(seg[len(seg)-1], ".") {
+						tmpMatches = append(tmpMatches, m)
+					}
+				}
+				matches = tmpMatches
+			}
 		}
 
 		// collect all the imported tokens
@@ -451,6 +465,12 @@ func (p *parser) doSingleImport(importFile string) ([]Token, error) {
 		return nil, p.Errf("Could not read imported file %s: %v", importFile, err)
 	}
 
+	// only warning in case of empty files
+	if len(input) == 0 || len(strings.TrimSpace(string(input))) == 0 {
+		caddy.Log().Warn("Import file is empty", zap.String("file", importFile))
+		return []Token{}, nil
+	}
+
 	importedTokens, err := allTokens(importFile, input)
 	if err != nil {
 		return nil, p.Errf("Could not read tokens while importing %s: %v", importFile, err)

caddyconfig/caddyfile/parse_test.go

@@ -187,6 +187,23 @@ func TestParseOneAndImport(t *testing.T) {
 
 		{`import testdata/not_found.txt`, true, []string{}, []int{}},
 
+		// empty file should just log a warning, and result in no tokens
+		{`import testdata/empty.txt`, false, []string{}, []int{}},
+
+		{`import testdata/only_white_space.txt`, false, []string{}, []int{}},
+
+		// import path/to/dir/* should skip any files that start with a . when iterating over them.
+		{`localhost
+		  dir1 arg1
+		  import testdata/glob/*`, false, []string{
+			"localhost",
+		}, []int{2, 3, 1}},
+
+		// import path/to/dir/.* should continue to read all dotfiles in a dir.
+		{`import testdata/glob/.*`, false, []string{
+			"host1",
+		}, []int{1, 2}},
+
 		{`""`, false, []string{}, []int{}},
 
 		{``, false, []string{}, []int{}},

caddyconfig/caddyfile/testdata/glob/.dotfile.txt

@@ -0,0 +1,4 @@
+host1 {
+	dir1
+	dir2 arg1
+}

caddyconfig/caddyfile/testdata/glob/import_test1.txt

@@ -0,0 +1,2 @@
+dir2 arg1 arg2
+dir3

caddyconfig/caddyfile/testdata/only_white_space.txt

@@ -0,0 +1,7 @@
+
+
+ 
+  
+　
+
+