add kubeutil python module to support kubelet check (#1146)

pkg/collector/py/api.c

@@ -1,3 +1,8 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
 // +build cpython
 
 #include "api.h"

pkg/collector/py/api.h

@@ -1,3 +1,8 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
 // +build cpython
 
 #ifndef _PY_API_H

pkg/collector/py/datadog_agent.c

@@ -1,3 +1,8 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
 // +build cpython
 
 #include "datadog_agent.h"

pkg/collector/py/datadog_agent.h

@@ -1,3 +1,8 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
 // +build cpython
 
 #ifndef DATADOG_HEADER

pkg/collector/py/kubeutil.c

@@ -0,0 +1,26 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
+// +build cpython,kubelet
+
+#include "kubeutil.h"
+
+// Functions
+PyObject* GetKubeletConnectionInfo();
+
+static PyMethodDef kubeutilMethods[] = {
+  {"get_connection_info", GetKubeletConnectionInfo, METH_NOARGS, "Get kubelet connection information."},
+  {NULL, NULL}
+};
+
+void initkubeutil()
+{
+  PyGILState_STATE gstate;
+  gstate = PyGILState_Ensure();
+
+  PyObject *ku = Py_InitModule("kubeutil", kubeutilMethods);
+
+  PyGILState_Release(gstate);
+}

pkg/collector/py/kubeutil.go

@@ -0,0 +1,74 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
+// +build cpython,kubelet
+
+package py
+
+import (
+	"time"
+	"unsafe"
+
+	log "github.com/cihub/seelog"
+
+	"github.com/DataDog/datadog-agent/pkg/util/cache"
+	"github.com/DataDog/datadog-agent/pkg/util/kubernetes/kubelet"
+)
+
+// #cgo pkg-config: python-2.7
+// #cgo linux CFLAGS: -std=gnu99
+// #include "api.h"
+// #include "kubeutil.h"
+import "C"
+
+var kubeletCacheKey = cache.BuildAgentKey("py", "kubeutil", "connection_info")
+
+// GetKubeletConnectionInfo returns a dict containing url and credentials to connect to the kubelet.
+// The dict is empty if the kubelet was not detected. The call to kubeutil is cached for 5 minutes.
+// See the documentation of kubelet.GetRawConnectionInfo for dict contents.
+//export GetKubeletConnectionInfo
+func GetKubeletConnectionInfo() *C.PyObject {
+	var creds map[string]string
+	var ok bool
+	dict := C.PyDict_New()
+
+	if cached, hit := cache.Cache.Get(kubeletCacheKey); hit {
+		creds, ok = cached.(map[string]string)
+		if !ok {
+			log.Errorf("invalid cache format, forcing a cache miss")
+			creds = nil
+		}
+	}
+
+	if creds == nil { // Cache miss
+		kubeutil, err := kubelet.GetKubeUtil()
+		if err != nil {
+			// Connection to the kubelet fail, return empty dict
+			return dict
+		}
+		// At this point, we have valid credentials to get
+		creds = kubeutil.GetRawConnectionInfo()
+		cache.Cache.Set(kubeletCacheKey, creds, 5*time.Minute)
+	}
+
+	for k, v := range creds {
+		cKey := C.CString(k)
+		pyKey := C.PyString_FromString(cKey)
+		defer C.Py_DecRef(pyKey)
+		C.free(unsafe.Pointer(cKey))
+
+		cVal := C.CString(v)
+		pyVal := C.PyString_FromString(cVal)
+		defer C.Py_DecRef(pyVal)
+		C.free(unsafe.Pointer(cVal))
+
+		C.PyDict_SetItem(dict, pyKey, pyVal)
+	}
+	return dict
+}
+
+func initkubeutil() {
+	C.initkubeutil()
+}

pkg/collector/py/kubeutil.h

@@ -0,0 +1,15 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
+// +build cpython,kubelet
+
+#ifndef KUBEUTIL_HEADER
+#define KUBEUTIL_HEADER
+
+#include <Python.h>
+
+void initkubeutil();
+
+#endif /* KUBEUTIL_HEADER */

pkg/collector/py/kubeutil_nokubelet.go

@@ -0,0 +1,12 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
+// +build cpython,!kubelet
+
+package py
+
+// Stub
+func initkubeutil() {
+}

pkg/collector/py/kubeutil_test.go

@@ -0,0 +1,51 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2018 Datadog, Inc.
+
+// +build cpython,kubelet
+
+// NOTICE: See TestMain function in `utils_test.go` for Python initialization
+package py
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/DataDog/datadog-agent/pkg/config"
+	"github.com/DataDog/datadog-agent/pkg/util/cache"
+	"github.com/DataDog/datadog-agent/pkg/util/kubernetes/kubelet"
+)
+
+func TestGetKubeletConnectionInfoNotFound(t *testing.T) {
+	config.Datadog.Set("kubernetes_http_kubelet_port", 0)
+	config.Datadog.Set("kubernetes_https_kubelet_port", 0)
+	kubelet.ResetGlobalKubeUtil()
+	cache.Cache.Delete(kubeletCacheKey)
+
+	check, _ := getCheckInstance("testkubeutil", "TestCheck")
+	err := check.Run()
+	assert.Nil(t, err)
+
+	warnings := check.GetWarnings()
+	require.Len(t, warnings, 1)
+	assert.Equal(t, "Kubelet not found", warnings[0].Error())
+}
+
+func TestGetKubeletConnectionInfoFromCache(t *testing.T) {
+	dummyCreds := map[string]string{
+		"url": "https://10.0.0.1:10250",
+	}
+	cache.Cache.Set(kubeletCacheKey, dummyCreds, 5*time.Minute)
+
+	check, _ := getCheckInstance("testkubeutil", "TestCheck")
+	err := check.Run()
+	assert.Nil(t, err)
+
+	warnings := check.GetWarnings()
+	require.Len(t, warnings, 1)
+	assert.Equal(t, "Found kubelet at https://10.0.0.1:10250", warnings[0].Error())
+}

pkg/collector/py/py.go

@@ -110,7 +110,7 @@ func Initialize(paths ...string) *python.PyThreadState {
 	// (all these calls will take care of the GIL)
 	initAPI()          // `aggregator` module
 	initDatadogAgent() // `datadog_agent` module
-
+	initkubeutil()     // `kubeutil` module if compiled in
 	// return the state so the caller can resume
 	return state
 }

pkg/collector/py/tests/testkubeutil.py

@@ -0,0 +1,16 @@
+# Unless explicitly stated otherwise all files in this repository are licensed
+# under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/).
+# Copyright 2018 Datadog, Inc.
+
+from checks import AgentCheck
+from kubeutil import get_connection_info
+
+
+class TestCheck(AgentCheck):
+    def check(self, instance):
+        creds = get_connection_info()
+        if creds.get("url"):
+            self.warning("Found kubelet at " + creds.get("url"))
+        else:
+            self.warning("Kubelet not found")

pkg/util/kubernetes/auth.go

@@ -31,7 +31,7 @@ func GetBearerToken(authTokenPath string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("could not read token from %s: %s", authTokenPath, err)
 	}
-	return fmt.Sprintf("bearer %s", token), nil
+	return string(token), nil
 }
 
 // GetCertificates loads the certificate and the private key

pkg/util/kubernetes/kubelet/init.go

@@ -28,20 +28,19 @@ func isConfiguredTLSVerify() bool {
 	return config.Datadog.GetBool("kubelet_tls_verify")
 }
 
-func getTLSConfig() (*tls.Config, error) {
+func buildTLSConfig(verifyTLS bool, caPath string) (*tls.Config, error) {
 	tlsConfig := &tls.Config{}
-	if isConfiguredTLSVerify() == false {
+	if verifyTLS == false {
 		tlsConfig.InsecureSkipVerify = true
 		return tlsConfig, nil
 	}
 
-	certPath := config.Datadog.GetString("kubelet_client_ca")
-	if certPath == "" {
+	if caPath == "" {
 		log.Debugf("kubelet_client_ca isn't configured: certificate authority must be trusted")
 		return nil, nil
 	}
 
-	caPool, err := kubernetes.GetCertificateAuthority(certPath)
+	caPool, err := kubernetes.GetCertificateAuthority(caPath)
 	if err != nil {
 		return tlsConfig, err
 	}