test: add integration tests for "pebble run"

tests/README.md

@@ -0,0 +1,23 @@
+# Pebble Integration Tests
+
+## Run Tests
+
+```bash
+go test -count=1 -tags=integration ./tests/
+```
+
+## Developing
+
+### Visual Studio Code Settings
+
+For the VSCode Go and gopls extention to work properly with files containing build tags, add the following:
+
+```json
+{
+    "gopls": {
+        "build.buildFlags": [
+            "-tags=integration"
+        ]
+    }
+}
+```

tests/main_test.go

@@ -0,0 +1,258 @@
+//go:build integration
+
+// Copyright (c) 2024 Canonical Ltd
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as
+// published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package tests
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/canonical/pebble/internals/servicelog"
+)
+
+// TestMain builds the pebble binary before running the integration tests.
+func TestMain(m *testing.M) {
+	goBuild := exec.Command("go", "build", "-o", "../pebble", "../cmd/pebble")
+	if err := goBuild.Run(); err != nil {
+		fmt.Println("Cannot build pebble binary:", err)
+		os.Exit(1)
+	}
+
+	exitCode := m.Run()
+	os.Exit(exitCode)
+}
+
+func createLayer(t *testing.T, pebbleDir string, layerFileName string, layerYAML string) {
+	t.Helper()
+
+	layersDir := filepath.Join(pebbleDir, "layers")
+	err := os.MkdirAll(layersDir, 0o755)
+	if err != nil {
+		t.Fatalf("Cannot create layers directory: pipe: %v", err)
+	}
+
+	layerPath := filepath.Join(layersDir, layerFileName)
+	err = os.WriteFile(layerPath, []byte(layerYAML), 0o755)
+	if err != nil {
+		t.Fatalf("Cannot create layers file: %v", err)
+	}
+}
+
+func createIdentitiesFile(t *testing.T, pebbleDir string, identitiesFileName string, identitiesYAML string) {
+	t.Helper()
+
+	identitiesPath := filepath.Join(pebbleDir, identitiesFileName)
+	if err := os.WriteFile(identitiesPath, []byte(identitiesYAML), 0o755); err != nil {
+		t.Fatalf("Cannot create layers file: %v", err)
+	}
+}
+
+func pebbleRun(t *testing.T, pebbleDir string, args ...string) <-chan servicelog.Entry {
+	t.Helper()
+
+	logsCh := make(chan servicelog.Entry)
+
+	cmd := exec.Command("../pebble", append([]string{"run"}, args...)...)
+	cmd.Env = append(os.Environ(), "PEBBLE="+pebbleDir)
+
+	t.Cleanup(func() {
+		err := cmd.Process.Signal(os.Interrupt)
+		if err != nil {
+			t.Errorf("Error sending SIGINT/Ctrl+C to pebble: %v", err)
+		}
+		cmd.Wait()
+	})
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		t.Fatalf("Cannot create stdout pipe: %v", err)
+	}
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		t.Fatalf("Cannot create stderr pipe: %v", err)
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		t.Fatalf("Error starting 'pebble run': %v", err)
+	}
+
+	done := make(chan struct{})
+	go func() {
+		defer close(logsCh)
+
+		readLogs := func(parser *servicelog.Parser) {
+			for parser.Next() {
+				if err := parser.Err(); err != nil {
+					t.Errorf("Cannot parse Pebble logs: %v", err)
+				}
+				select {
+				case logsCh <- parser.Entry():
+				case <-done:
+					return
+				}
+			}
+		}
+
+		// Both stderr and stdout are needed, because pebble logs to stderr
+		// while with "--verbose", services otuput to stdout.
+		stderrParser := servicelog.NewParser(stderrPipe, 4*1024)
+		stdoutParser := servicelog.NewParser(stdoutPipe, 4*1024)
+
+		// Channel to signal completion and close logsCh
+		done := make(chan struct{})
+		defer close(done)
+
+		go readLogs(stderrParser)
+		go readLogs(stdoutParser)
+
+		// Wait for both parsers to finish
+		<-done
+		<-done
+	}()
+
+	return logsCh
+}
+
+func waitForLogs(logsCh <-chan servicelog.Entry, expectedLogs []string, timeout time.Duration) error {
+	receivedLogs := make(map[string]struct{})
+
+	timeoutCh := time.After(timeout)
+	for {
+		select {
+		case log, ok := <-logsCh:
+			if !ok {
+				return errors.New("channel closed before all expected logs were received")
+			}
+
+			for _, expectedLog := range expectedLogs {
+				if _, ok := receivedLogs[expectedLog]; !ok && containsSubstring(log.Message, expectedLog) {
+					receivedLogs[expectedLog] = struct{}{}
+					break
+				}
+			}
+
+			allLogsReceived := true
+			for _, log := range expectedLogs {
+				if _, ok := receivedLogs[log]; !ok {
+					allLogsReceived = false
+					break
+				}
+			}
+
+			if allLogsReceived {
+				return nil
+			}
+
+		case <-timeoutCh:
+			missingLogs := []string{}
+			for _, log := range expectedLogs {
+				if _, ok := receivedLogs[log]; !ok {
+					missingLogs = append(missingLogs, log)
+				}
+			}
+			return errors.New("timed out waiting for log: " + strings.Join(missingLogs, ", "))
+		}
+	}
+}
+
+func containsSubstring(s, substr string) bool {
+	return strings.Contains(s, substr)
+}
+
+func waitForServices(t *testing.T, pebbleDir string, expectedServices []string, timeout time.Duration) {
+	t.Helper()
+
+	for _, service := range expectedServices {
+		waitForService(t, pebbleDir, service, timeout)
+	}
+}
+
+func waitForService(t *testing.T, pebbleDir string, service string, timeout time.Duration) {
+	t.Helper()
+
+	serviceFilePath := filepath.Join(pebbleDir, service)
+	timeoutCh := time.After(timeout)
+	ticker := time.NewTicker(time.Millisecond)
+	for {
+		select {
+		case <-timeoutCh:
+			t.Errorf("timeout waiting for service %s", service)
+			return
+
+		case <-ticker.C:
+			stat, err := os.Stat(serviceFilePath)
+			if err == nil && stat.Mode().IsRegular() {
+				os.Remove(serviceFilePath)
+				return
+			}
+		}
+	}
+}
+
+func isPortUsedByProcess(t *testing.T, port string, processName string) bool {
+	t.Helper()
+
+	conn, err := net.Listen("tcp", ":"+port)
+	if err == nil {
+		conn.Close()
+		return false
+	}
+	if conn != nil {
+		conn.Close()
+	}
+
+	cmd := exec.Command("lsof", "-i", ":"+port)
+	output, err := cmd.Output()
+	if err != nil {
+		t.Errorf("Error running lsof command: %v", err)
+		return false
+	}
+
+	outputStr := string(output)
+	if strings.Contains(outputStr, processName) {
+		return true
+	}
+
+	return false
+}
+
+func runPebbleCmdAndCheckOutput(t *testing.T, pebbleDir string, expectedOutput []string, args ...string) {
+	t.Helper()
+
+	cmd := exec.Command("../pebble", args...)
+	cmd.Env = append(os.Environ(), "PEBBLE="+pebbleDir)
+
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("error executing pebble command: %v", err)
+	}
+
+	outputStr := string(output)
+
+	for _, expected := range expectedOutput {
+		if !strings.Contains(outputStr, expected) {
+			t.Errorf("Expected output %s not found in command output", expected)
+		}
+	}
+}