feat(migrations): Add migration for inputs.tcp_listener

migrations/all/inputs_tcp_listener.go

@@ -0,0 +1,5 @@
+//go:build !custom || (migrations && (inputs || inputs.tcp_listener))
+
+package all
+
+import _ "github.com/influxdata/telegraf/migrations/inputs_tcp_listener" // register migration

migrations/inputs_tcp_listener/migration.go

@@ -0,0 +1,67 @@
+package inputs_tcp_listener
+
+import (
+	"fmt"
+
+	"github.com/influxdata/toml"
+	"github.com/influxdata/toml/ast"
+
+	"github.com/influxdata/telegraf/migrations"
+)
+
+const allowPendingMessagesMsg = `
+    Replacement 'inputs.socket_listener' does not allow to configure
+    'allowed_pending_messages' and thus the setting is dropped.
+`
+
+// Define "old" data structure
+type tcpListener map[string]interface{}
+
+// Migration function
+func migrate(tbl *ast.Table) ([]byte, string, error) {
+	// Decode the old data structure
+	var old tcpListener
+	if err := toml.UnmarshalTable(tbl, &old); err != nil {
+		return nil, "", err
+	}
+
+	// Copy the setting except the special plugin ones to preserve
+	// all parser settings of the existing (deprecated) config.
+	var msg string
+	plugin := make(map[string]interface{}, len(old))
+	for k, v := range old {
+		switch k {
+		case "service_address":
+			addr, ok := v.(string)
+			if !ok {
+				return nil, "", fmt.Errorf("service_address is not a string but %T", v)
+			}
+			plugin["service_address"] = "tcp://" + addr
+		case "allowed_pending_messages":
+			msg = allowPendingMessagesMsg
+		case "max_tcp_connections":
+			plugin["max_connections"] = v
+		default:
+			plugin[k] = v
+		}
+	}
+
+	// Create the corresponding metric configurations
+	cfg := migrations.CreateTOMLStruct("inputs", "socket_listener")
+	cfg.Add("inputs", "socket_listener", plugin)
+
+	// Marshal the new configuration
+	buf, err := toml.Marshal(cfg)
+	if err != nil {
+		return nil, "", err
+	}
+	buf = append(buf, []byte("\n")...)
+
+	// Create the new content to output
+	return buf, msg, nil
+}
+
+// Register the migration function for the plugin type
+func init() {
+	migrations.AddPluginMigration("inputs.tcp_listener", migrate)
+}

migrations/inputs_tcp_listener/migration_test.go

@@ -0,0 +1,62 @@
+package inputs_tcp_listener_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/influxdata/telegraf/config"
+	_ "github.com/influxdata/telegraf/migrations/inputs_tcp_listener" // register migration
+	_ "github.com/influxdata/telegraf/plugins/inputs/socket_listener" // register plugin
+	_ "github.com/influxdata/telegraf/plugins/parsers/all"            // register parsers
+)
+
+func TestCases(t *testing.T) {
+	// Get all directories in testdata
+	folders, err := os.ReadDir("testcases")
+	require.NoError(t, err)
+
+	for _, f := range folders {
+		// Only handle folders
+		if !f.IsDir() {
+			continue
+		}
+
+		t.Run(f.Name(), func(t *testing.T) {
+			testcasePath := filepath.Join("testcases", f.Name())
+			inputFile := filepath.Join(testcasePath, "telegraf.conf")
+			expectedFile := filepath.Join(testcasePath, "expected.conf")
+
+			// Read the expected output
+			expected := config.NewConfig()
+			require.NoError(t, expected.LoadConfig(expectedFile))
+			require.NotEmpty(t, expected.Inputs)
+
+			// Read the input data
+			input, remote, err := config.LoadConfigFile(inputFile)
+			require.NoError(t, err)
+			require.False(t, remote)
+			require.NotEmpty(t, input)
+
+			// Migrate
+			output, n, err := config.ApplyMigrations(input)
+			require.NoError(t, err)
+			require.NotEmpty(t, output)
+			require.GreaterOrEqual(t, n, uint64(1))
+			actual := config.NewConfig()
+			require.NoError(t, actual.LoadConfigData(output))
+
+			// Test the output
+			require.Len(t, actual.Inputs, len(expected.Inputs))
+			actualIDs := make([]string, 0, len(expected.Inputs))
+			expectedIDs := make([]string, 0, len(expected.Inputs))
+			for i := range actual.Inputs {
+				actualIDs = append(actualIDs, actual.Inputs[i].ID())
+				expectedIDs = append(expectedIDs, expected.Inputs[i].ID())
+			}
+			require.ElementsMatch(t, expectedIDs, actualIDs)
+		})
+	}
+}

migrations/inputs_tcp_listener/testcases/allow_pending_messages/expected.conf

@@ -0,0 +1,3 @@
+[[inputs.socket_listener]]
+service_address = "tcp://127.0.0.1:8000"
+data_format = "influx"

migrations/inputs_tcp_listener/testcases/allow_pending_messages/telegraf.conf

@@ -0,0 +1,5 @@
+[[inputs.tcp_listener]]
+  service_address = "127.0.0.1:8000"
+  allowed_pending_messages = 1000
+
+  data_format = "influx"

migrations/inputs_tcp_listener/testcases/parser/expected.conf

@@ -0,0 +1,10 @@
+[[inputs.socket_listener]]
+service_address = "tcp://127.0.0.1:8000"
+data_format = "xpath_json"
+xpath_native_types = true
+[[inputs.socket_listener.xpath]]
+metric_name = "/name"
+timestamp = "/timestamp"
+timestamp_format = "unix_ms"
+field_selection = "/fields/*"
+tag_selection = "/tags/*"

migrations/inputs_tcp_listener/testcases/parser/telegraf.conf

@@ -0,0 +1,13 @@
+[[inputs.tcp_listener]]
+  service_address = "127.0.0.1:8000"
+
+  data_format = "xpath_json"
+  xpath_native_types = true
+
+  # Configuration matching the first (ENERGY) message
+  [[inputs.tcp_listener.xpath]]
+    metric_name = "/name"
+    timestamp = "/timestamp"
+    timestamp_format = "unix_ms"
+    field_selection = "/fields/*"
+    tag_selection = "/tags/*"

migrations/inputs_tcp_listener/testcases/simple/expected.conf

@@ -0,0 +1,3 @@
+[[inputs.socket_listener]]
+service_address = "tcp://127.0.0.1:8000"
+data_format = "influx"

migrations/inputs_tcp_listener/testcases/simple/telegraf.conf

@@ -0,0 +1,4 @@
+[[inputs.tcp_listener]]
+  service_address = "127.0.0.1:8000"
+
+  data_format = "influx"