chore!(amneziawg): refactor to be separate from wireguard

- amneziawg is now a VPN protocol and no longer a Wireguard implementation
- Use it with VPN_TYPE=amneziawg
- document AMNEZIAWG_* options in Dockerfile
- document amneziawg support in readme
- separate amneziawg settings and code from wireguard
- re-use code from wireguard whenever possible

internal/configuration/sources/files/amneziawg_test.go

@@ -0,0 +1,82 @@
+package files
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_Source_ParseAmneziawgConf(t *testing.T) {
+	t.Parallel()
+
+	t.Run("no_file", func(t *testing.T) {
+		t.Parallel()
+
+		noFile := filepath.Join(t.TempDir(), "doesnotexist")
+		wireguard, err := ParseAmneziawgConf(noFile)
+		assert.Equal(t, AmneziawgConfig{}, wireguard)
+		assert.NoError(t, err)
+	})
+
+	testCases := map[string]struct {
+		fileContent string
+		amneziawg   AmneziawgConfig
+		errMessage  string
+	}{
+		"ini_load_error": {
+			fileContent: "invalid",
+			errMessage:  "loading ini from reader: key-value delimiter not found: invalid",
+		},
+		"empty_file": {
+			errMessage: `getting interface section: section "interface" does not exist`,
+		},
+		"success": {
+			fileContent: `
+[Interface]
+PrivateKey = QOlCgyA/Sn/c/+YNTIEohrjm8IZV+OZ2AUFIoX20sk8=
+Address = 10.38.22.35/32
+DNS = 193.138.218.74
+Jc = 4
+H1 = 721391205
+I1 = <b 0x1234>
+
+[Peer]
+PresharedKey = YJ680VN+dGrdsWNjSFqZ6vvwuiNhbq502ZL3G7Q3o3g=
+`,
+			amneziawg: AmneziawgConfig{
+				Wireguard: WireguardConfig{
+					PrivateKey:   ptrTo("QOlCgyA/Sn/c/+YNTIEohrjm8IZV+OZ2AUFIoX20sk8="),
+					PreSharedKey: ptrTo("YJ680VN+dGrdsWNjSFqZ6vvwuiNhbq502ZL3G7Q3o3g="),
+					Addresses:    ptrTo("10.38.22.35/32"),
+				},
+				Jc: ptrTo("4"),
+				H1: ptrTo("721391205"),
+				I1: ptrTo("<b 0x1234>"),
+			},
+		},
+	}
+
+	for testName, testCase := range testCases {
+		t.Run(testName, func(t *testing.T) {
+			t.Parallel()
+
+			configFile := filepath.Join(t.TempDir(), "awg.conf")
+			const permission = fs.FileMode(0o600)
+			err := os.WriteFile(configFile, []byte(testCase.fileContent), permission)
+			require.NoError(t, err)
+
+			wireguard, err := ParseAmneziawgConf(configFile)
+
+			assert.Equal(t, testCase.amneziawg, wireguard)
+			if testCase.errMessage != "" {
+				assert.EqualError(t, err, testCase.errMessage)
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}