The community uses index.gmi not index.gemini as a root document.

README.md

@@ -42,7 +42,7 @@ openssl ecparam -genkey -name secp384r1 -out server.key
 openssl req -new -x509 -sha256 -key server.key -out server.crt -days 3650
 # Make a Gemini file.
 mkdir content
-echo "# Hello, World!" > content/index.gemini
+echo "# Hello, World!" > content/index.gmi
 # Run the container.
 docker pull adrianhesketh/gemini:latest
 docker run -v `pwd`:/certs -e PORT=1965 -e DOMAIN=localhost -v `pwd`/content:/content -p 1965:1965 adrianhesketh/gemini:latest

filesystem.go

@@ -101,16 +101,16 @@ func FileSystemHandler(fs FileSystem) Handler {
 			return
 		}
 		if stat.IsDir() {
-			// Look for index.gemini first before listing contents.
+			// Look for index.gmi first before listing contents.
 			if !strings.HasSuffix(r.URL.Path, "/") {
 				r.URL.Path += "/"
 			}
-			index, err := fs.Open(r.URL.Path + "index.gemini")
+			index, err := fs.Open(r.URL.Path + "index.gmi")
 			if errors.Is(err, os.ErrNotExist) {
 				DirectoryListingHandler(r.URL.Path, f).ServeGemini(w, r)
 				return
 			}
-			FileContentHandler("index.gemini", index).ServeGemini(w, r)
+			FileContentHandler("index.gmi", index).ServeGemini(w, r)
 			return
 		}
 		FileContentHandler(stat.Name(), f).ServeGemini(w, r)

filesystem_test.go

@@ -20,22 +20,22 @@ func TestFileSystemHandler(t *testing.T) {
 		expectedBody   string
 	}{
 		{
-			name:           "if a directory contains index.gemini, it is used",
+			name:           "if a directory contains index.gmi, it is used",
 			url:            "/a",
 			expectedHeader: geminiSuccessHeader,
-			expectedBody:   "# /tests/a/index.gemini\n",
+			expectedBody:   "# /tests/a/index.gmi\n",
 		},
 		{
 			name:           "files can be accessed directly",
-			url:            "/a/index.gemini",
+			url:            "/a/index.gmi",
 			expectedHeader: geminiSuccessHeader,
-			expectedBody:   "# /tests/a/index.gemini\n",
+			expectedBody:   "# /tests/a/index.gmi\n",
 		},
 		{
 			name:           "a slash prefix is added if missing",
-			url:            "a/index.gemini",
+			url:            "a/index.gmi",
 			expectedHeader: geminiSuccessHeader,
-			expectedBody:   "# /tests/a/index.gemini\n",
+			expectedBody:   "# /tests/a/index.gmi\n",
 		},
 		{
 			name:           "if a directory does not contain an index, a listing is returned",
@@ -50,7 +50,7 @@ func TestFileSystemHandler(t *testing.T) {
 		},
 		{
 			name: "directory traversal attacks are deflected",
-			url:  "../a/index.gemini",
+			url:  "../a/index.gmi",
 			expectedHeader: Header{
 				Code: CodeBadRequest,
 			},

tests/a/index.gemini

@@ -1 +1 @@
-# /tests/a/index.gemini
+# /tests/a/index.gmi

tests/b/c/index.gemini

@@ -1 +1 @@
-# tests/b/c/index.gemini
+# tests/b/c/index.gmi

tests/index.gemini

@@ -1 +1 @@
-# /tests/index.gemini
+# /tests/index.gmi