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changed istio tests
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@amitslavin
amitslavin committed Jul 31, 2024
1 parent 2a42532 commit 6df160e
Showing 1 changed file with 30 additions and 122 deletions.
152 changes: 30 additions & 122 deletions pkg/network/usm/istio_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,6 @@
package usm

import (
"fmt"
"os"
"os/exec"
"path/filepath"
Expand All @@ -17,19 +16,17 @@ import (

"github.com/DataDog/datadog-agent/pkg/network/config"
"github.com/DataDog/datadog-agent/pkg/network/usm/utils"
"github.com/DataDog/datadog-agent/pkg/util/kernel"

"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)

func TestGetEnvoyPath(t *testing.T) {
_ = createFakeProcFS(t)
_, pid := createFakeProc(t, "/bin")
monitor := newIstioTestMonitor(t)

t.Run("an actual envoy process", func(t *testing.T) {
path := monitor.getEnvoyPath(uint32(1))
assert.True(t, strings.HasSuffix(path, "/usr/local/bin/envoy"))
path := monitor.getEnvoyPath(uint32(pid))
assert.True(t, strings.HasSuffix(path, "/bin/envoy"))
})
t.Run("something else", func(t *testing.T) {
path := monitor.getEnvoyPath(uint32(2))
Expand All @@ -38,20 +35,21 @@ func TestGetEnvoyPath(t *testing.T) {
}

func TestGetEnvoyPathWithConfig(t *testing.T) {
t.Setenv("DD_SERVICE_MONITORING_CONFIG_TLS_ISTIO_ENVOY_PATH", "/envoy-conf")
t.Setenv("DD_SERVICE_MONITORING_CONFIG_TLS_ISTIO_ENVOY_PATH", "/test/envoy")

_ = createFakeProcFS(t)
_, pid := createFakeProc(t, "/test")
monitor := newIstioTestMonitor(t)

t.Run("an actual envoy process", func(t *testing.T) {
path := monitor.getEnvoyPath(uint32(4))
assert.True(t, strings.HasSuffix(path, "/usr/local/bin/envoy-conf"))
path := monitor.getEnvoyPath(uint32(pid))
assert.True(t, strings.HasSuffix(path, "/test/envoy"))
})
}

func TestIstioSync(t *testing.T) {
t.Run("calling sync for the first time", func(t *testing.T) {
procRoot := createFakeProcFS(t)
procRoot1, _ := createFakeProc(t, filepath.Join("test1", "bin"))
procRoot2, _ := createFakeProc(t, filepath.Join("test2", "bin"))
monitor := newIstioTestMonitor(t)
registerRecorder := new(utils.CallbackRecorder)

Expand All @@ -62,10 +60,10 @@ func TestIstioSync(t *testing.T) {
// Calling sync should detect the two envoy processes
monitor.sync()

pathID1, err := utils.NewPathIdentifier(filepath.Join(procRoot, "1", "root", "usr", "local", "bin", "envoy"))
pathID1, err := utils.NewPathIdentifier(filepath.Join(procRoot1, "test1", "bin", "envoy"))
require.NoError(t, err)

pathID2, err := utils.NewPathIdentifier(filepath.Join(procRoot, "3", "root", "usr", "local", "bin", "envoy"))
pathID2, err := utils.NewPathIdentifier(filepath.Join(procRoot2, "test2", "bin", "envoy"))
require.NoError(t, err)

assert.Equal(t, 2, registerRecorder.TotalCalls())
Expand All @@ -74,7 +72,8 @@ func TestIstioSync(t *testing.T) {
})

t.Run("calling sync multiple times", func(t *testing.T) {
procRoot := createFakeProcFS(t)
procRoot1, _ := createFakeProc(t, filepath.Join("test1", "bin"))
procRoot2, _ := createFakeProc(t, filepath.Join("test2", "bin"))
monitor := newIstioTestMonitor(t)
registerRecorder := new(utils.CallbackRecorder)

Expand All @@ -89,131 +88,40 @@ func TestIstioSync(t *testing.T) {
monitor.sync()
monitor.sync()

pathID1, err := utils.NewPathIdentifier(filepath.Join(procRoot, "1/root/usr/local/bin/envoy"))
pathID1, err := utils.NewPathIdentifier(filepath.Join(procRoot1, "test1", "bin", "envoy"))
require.NoError(t, err)

pathID2, err := utils.NewPathIdentifier(filepath.Join(procRoot, "3/root/usr/local/bin/envoy"))
pathID2, err := utils.NewPathIdentifier(filepath.Join(procRoot2, "test2", "bin", "envoy"))
require.NoError(t, err)

// Each PathID should have triggered a callback exactly once
assert.Equal(t, 2, registerRecorder.TotalCalls())
assert.Equal(t, 1, registerRecorder.CallsForPathID(pathID1))
assert.Equal(t, 1, registerRecorder.CallsForPathID(pathID2))
})

t.Run("detecting a dangling process", func(t *testing.T) {
procRoot := createFakeProcFS(t)
monitor := newIstioTestMonitor(t)
registerRecorder := new(utils.CallbackRecorder)
unregisterRecorder := new(utils.CallbackRecorder)

// Setup test callbacks
monitor.registerCB = registerRecorder.Callback()
monitor.unregisterCB = unregisterRecorder.Callback()

monitor.sync()

// The first call to sync() will start tracing PIDs 1 and 3, but not PID 2
assert.Contains(t, monitor.registry.GetRegisteredProcesses(), uint32(1))
assert.NotContains(t, monitor.registry.GetRegisteredProcesses(), uint32(2))
assert.Contains(t, monitor.registry.GetRegisteredProcesses(), uint32(3))

// At this point we should have received:
// * 2 register calls
// * 0 unregister calls
assert.Equal(t, 2, registerRecorder.TotalCalls())
assert.Equal(t, 0, unregisterRecorder.TotalCalls())

// Now we emulate a process termination for PID 3 by removing it from the fake
// procFS tree
require.NoError(t, os.RemoveAll(filepath.Join(procRoot, "3")))

// Once we call sync() again, PID 3 termination should be detected
// and the unregister callback should be executed
monitor.sync()
assert.Equal(t, 1, unregisterRecorder.TotalCalls())
assert.NotContains(t, monitor.registry.GetRegisteredProcesses(), uint32(3))
})
}

// This creates a bare-bones procFS with a structure that looks like
// the following:
//
// proc/
// ├── 1
// │   └── root
// │   └── usr
// │   └── local
// │   └── bin
// │   └── envoy
// ...
//
// This ProcFS contains 3 PIDs:
//
// PID 1 -> Envoy process
// PID 2 -> Bash process
// PID 3 -> Envoy process
func createFakeProcFS(t *testing.T) (procRoot string) {
_, err := os.Stat("/usr/bin/busybox")
if err != nil {
t.Skip("skip for the moment as some distro are not friendly with busybox package")
}

// createFakeProc creates a fake envoy process in the given temporary directory.
// returns the temporary directory and the PID of the fake envoy process.
func createFakeProc(t *testing.T, path string) (procRoot string, pid int) {
procRoot = t.TempDir()
binDir := filepath.Join(procRoot, path)
err := os.MkdirAll(binDir, os.ModePerm)
require.NoError(t, err)
fakeEnvoyPath := filepath.Join(binDir, "envoy")

// Inject fake ProcFS path
previousFn := kernel.ProcFSRoot
kernel.ProcFSRoot = func() string { return procRoot }
t.Cleanup(func() {
kernel.ProcFSRoot = previousFn
})

createFile(t,
filepath.Join(procRoot, "1", "root", "usr", "local", "bin", "envoy"),
"",
)
createFile(t,
filepath.Join(procRoot, "3", "root", "usr", "local", "bin", "envoy"),
"",
)
createFile(t,
filepath.Join(procRoot, "4", "root", "usr", "bin", "envoy-conf"),
"",
)

require.NoError(t, exec.Command("cp", "/usr/bin/busybox", filepath.Join(procRoot, "ash")).Run())
require.NoError(t, exec.Command("cp", "/usr/bin/busybox", filepath.Join(procRoot, "envoy")).Run())

runFakeProcess(t, procRoot, "1", "/usr/local/bin/envoy")
runFakeProcess(t, procRoot, "3", "/usr/local/bin/envoy")
runFakeProcess(t, procRoot, "4", "/usr/local/bin/envoy-conf")

return
}
// we are using the `yes` command as a fake envoy binary.
require.NoError(t, exec.Command("cp", "/usr/bin/yes", fakeEnvoyPath).Run())

func runFakeProcess(t *testing.T, root, pid, binPath string) {
pidPath := filepath.Join(root, pid)
require.NoError(t, os.MkdirAll(pidPath, 0755))

cmd := exec.Command("unshare", "--fork", "--pid", "-R", root, "/ash", "-c", fmt.Sprintf("sleep 10 > %s", binPath))
cmd := exec.Command(fakeEnvoyPath)
require.NoError(t, cmd.Start())

createSymlink(t,
binPath,
filepath.Join(pidPath, "exe"),
)
}

func createFile(t *testing.T, path, data string) {
dir := filepath.Dir(path)
require.NoError(t, os.MkdirAll(dir, 0775))
require.NoError(t, os.WriteFile(path, []byte(data), 0775))
}
// Schedule process termination after the test
t.Cleanup(func() {
_ = cmd.Process.Kill()
})

func createSymlink(t *testing.T, target, link string) {
dir := filepath.Dir(link)
require.NoError(t, os.MkdirAll(dir, 0775))
require.NoError(t, os.Symlink(target, link))
return procRoot, cmd.Process.Pid
}

func newIstioTestMonitor(t *testing.T) *istioMonitor {
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