test(agentcompat): add agent runtime harness

Co-authored-by: naiba/CloudCode <hi+cloudcode@nai.ba>

integration/agentcompat/internal/agent/fixture.go

@@ -0,0 +1,119 @@
+//go:build linux
+
+package agent
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/nezhahq/nezha/integration/agentcompat/internal/workspace"
+)
+
+func agentBuildSpec(sourceDir string) workspace.BuildSpec {
+	return workspace.BuildSpec{Name: "agent", SourceDir: sourceDir, Package: "./cmd/agent", Tags: []string{"agentcompat"}, Ldflags: []string{"-X", "github.com/nezhahq/agent/pkg/monitor.Version=v2.1.0"}}
+}
+
+func (agent *Agent) prepareFixture(ctx context.Context, config AgentStartConfig) error {
+	if err := agent.prepareConfig(config); err != nil {
+		return err
+	}
+	if err := agent.prepareFMObserver(config); err != nil {
+		return err
+	}
+	if err := agent.prepareBinary(ctx, config); err != nil {
+		return err
+	}
+	if err := agent.grantWorkspaceOwnership(config); err != nil {
+		return err
+	}
+	agent.prepareEnvironment(config)
+	return nil
+}
+
+func (agent *Agent) prepareConfig(config AgentStartConfig) error {
+	configPath, err := agent.workspace.PayloadPath("config.yml")
+	if err != nil {
+		return err
+	}
+	agent.configPath = configPath
+	content := fmt.Sprintf("server: %q\nclient_secret: %q\nuuid: %q\ndisable_auto_update: true\ndisable_command_execute: false\ndisable_nat: false\nreport_delay: 1\nip_report_period: 30\ntls: %t\ninsecure_tls: false\ndebug: %t\n", config.Endpoint, config.Secret, config.UUID, config.TLS, config.Debug)
+	if err := os.WriteFile(configPath, []byte(content), 0o600); err != nil {
+		return fmt.Errorf("write agent config: %w", err)
+	}
+	if !config.TLS || config.CAFilePath == "" {
+		return nil
+	}
+	ca, err := os.ReadFile(config.CAFilePath)
+	if err != nil {
+		return fmt.Errorf("read agent CA certificate: %w", err)
+	}
+	caPath, err := agent.workspace.PayloadPath("agent-ca.crt")
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(caPath, ca, 0o600); err != nil {
+		return fmt.Errorf("write agent CA certificate: %w", err)
+	}
+	agent.caFilePath = caPath
+	return nil
+}
+
+func (agent *Agent) prepareFMObserver(config AgentStartConfig) error {
+	if config.FMObserverRunID == "" {
+		return nil
+	}
+	agent.fmObserverPath = fmObserverSocketPath(agent.workspace.Root())
+	observer, err := newFMProducerObserver(agent.fmObserverPath)
+	if err != nil {
+		return err
+	}
+	agent.fmObserver = observer
+	return nil
+}
+
+func (agent *Agent) prepareBinary(ctx context.Context, config AgentStartConfig) error {
+	if config.PreparedBinary != nil {
+		binaryPath, release, err := config.PreparedBinary.acquire()
+		if err != nil {
+			return err
+		}
+		agent.binaryPath = binaryPath
+		agent.releaseBinary = release
+		agent.releasePending = true
+		return nil
+	}
+	binaryPath, err := agent.workspace.Build(ctx, agentBuildSpec(config.SourceDir))
+	if err != nil {
+		return err
+	}
+	agent.binaryPath = binaryPath
+	return nil
+}
+
+func (agent *Agent) grantWorkspaceOwnership(config AgentStartConfig) error {
+	if config.Credential == nil {
+		return nil
+	}
+	if err := filepath.WalkDir(agent.workspace.Root(), func(path string, _ os.DirEntry, walkErr error) error {
+		if walkErr != nil {
+			return walkErr
+		}
+		return os.Chown(path, int(config.Credential.Uid), int(config.Credential.Gid))
+	}); err != nil {
+		return fmt.Errorf("grant agent workspace ownership: %w", err)
+	}
+	return nil
+}
+
+func (agent *Agent) prepareEnvironment(config AgentStartConfig) {
+	environment := filteredEnvironment()
+	if config.FMObserverRunID != "" {
+		environment = append(environment, "AGENTCOMPAT_FM_OBSERVER_SOCKET="+agent.fmObserverPath, "AGENTCOMPAT_FM_OBSERVER_RUN_ID="+config.FMObserverRunID)
+	}
+	if config.TLS && agent.caFilePath != "" {
+		environment = append(environment, "SSL_CERT_FILE="+agent.caFilePath)
+	}
+	agent.environment = append([]string(nil), environment...)
+}