E2E tests log the Agent's logs on failure

Printing them when tests succeed causes too much spam when running with
the verbose flag (yes, it's too verbose for verbose mode).

end-to-end/manual_token_input_test.go

@@ -39,6 +39,7 @@ func TestManualTokenInput(t *testing.T) {
 			ctx := context.Background()
 
 			testSetup(t)
+			defer logWindowsAgentJournal(t, true)
 
 			// Either runs the ubuntupro app before...
 			if tc.whenToken == beforeDistroRegistration {

end-to-end/organization_token_test.go

@@ -39,6 +39,7 @@ func TestOrganizationProvidedToken(t *testing.T) {
 			ctx := context.Background()
 
 			testSetup(t)
+			defer logWindowsAgentJournal(t, true)
 
 			if tc.whenToken == beforeDistroRegistration {
 				activateOrgSubscription(t)

end-to-end/purchase_test.go

@@ -52,6 +52,7 @@ func TestPurchase(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			testSetup(t)
+			defer logWindowsAgentJournal(t, true)
 
 			settings := contractsmockserver.DefaultSettings()
 

end-to-end/utils_test.go

@@ -15,6 +15,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/canonical/ubuntu-pro-for-windows/common"
 	"github.com/canonical/ubuntu-pro-for-windows/common/wsltestutils"
 	"github.com/stretchr/testify/require"
 	"github.com/ubuntu/gowsl"
@@ -179,3 +180,25 @@ func logWslProServiceJournal(t *testing.T, ctx context.Context, d gowsl.Distro)
 	}
 	t.Logf("wsl-pro-service logs:\n%s\n", out)
 }
+
+func logWindowsAgentJournal(t *testing.T, skipOnSuccess bool) {
+	t.Helper()
+
+	if skipOnSuccess && !t.Failed() {
+		return
+	}
+
+	localAppData := os.Getenv("LocalAppData")
+	if localAppData == "" {
+		t.Log("could not access Windows Agent's logs: $env:LocalAppData is not assigned")
+		return
+	}
+
+	out, err := os.ReadFile(filepath.Join(localAppData, common.LocalAppDataDir, "log"))
+	if err != nil {
+		t.Logf("could not read Windows Agent's logs: %v", err)
+		return
+	}
+
+	t.Logf("Windows Agent's logs:\n%s\n", out)
+}