test: add integration tests for "pebble run"

.github/workflows/integration-test.yml

@@ -0,0 +1,29 @@
+name: Integration Test
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        go: ['1.22']
+
+    name: Go ${{ matrix.go }}
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: ${{ matrix.go }}
+
+    - name: Integration test
+      run: go test -count=1 -tags=integration ./tests/

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 +1,177 @@
+//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 (
+	"fmt"
+	"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, layerFileName, layerYAML string) {
+	t.Helper()
+
+	layersDir := filepath.Join(pebbleDir, "layers")
+	err := os.MkdirAll(layersDir, 0o755)
+	if err != nil {
+		t.Fatalf("Cannot create layers directory: %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 pebbleRun(t *testing.T, pebbleDir string, args ...string) (<-chan servicelog.Entry, <-chan servicelog.Entry) {
+	t.Helper()
+
+	stdoutCh := make(chan servicelog.Entry)
+	stderrCh := make(chan servicelog.Entry)
+
+	cmd := exec.Command("../pebble", append([]string{"run"}, args...)...)
+	cmd.Env = append(os.Environ(), "PEBBLE="+pebbleDir)
+
+	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)
+	}
+
+	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()
+	})
+
+	done := make(chan struct{})
+	go func() {
+		defer close(stdoutCh)
+		defer close(stderrCh)
+
+		readLogs := func(parser *servicelog.Parser, ch chan servicelog.Entry) {
+			for parser.Next() {
+				if err := parser.Err(); err != nil {
+					t.Errorf("Cannot parse Pebble logs: %v", err)
+				}
+				select {
+				case ch <- 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)
+
+		go readLogs(stdoutParser, stdoutCh)
+		go readLogs(stderrParser, stderrCh)
+
+		// Wait for both parsers to finish
+		<-done
+		<-done
+	}()
+
+	return stdoutCh, stderrCh
+}
+
+func waitForLog(t *testing.T, logsCh <-chan servicelog.Entry, expectedLog string, timeout time.Duration) {
+	t.Helper()
+
+	timeoutCh := time.After(timeout)
+	for {
+		select {
+		case log, ok := <-logsCh:
+			if !ok {
+				t.Error("channel closed before all expected logs were received")
+			}
+
+			if strings.Contains(log.Message, expectedLog) {
+				return
+			}
+
+		case <-timeoutCh:
+			t.Fatalf("timed out after %v waiting for log %s", 3*time.Second, expectedLog)
+		}
+	}
+}
+
+func waitForFile(t *testing.T, file string, timeout time.Duration) {
+	t.Helper()
+
+	timeoutCh := time.After(timeout)
+	ticker := time.NewTicker(time.Millisecond)
+	for {
+		select {
+		case <-timeoutCh:
+			t.Fatalf("timeout waiting for file %s", file)
+
+		case <-ticker.C:
+			stat, err := os.Stat(file)
+			if err == nil && stat.Mode().IsRegular() {
+				os.Remove(file)
+				return
+			}
+		}
+	}
+}
+
+func runPebbleCommand(t *testing.T, pebbleDir string, args ...string) 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)
+	}
+
+	return string(output)
+}