coredns

Gopkg.toml

@@ -49,7 +49,7 @@
   name = "github.com/gravitational/configure"
 
 [[constraint]]
-  branch = "master"
+  version = "1.0.0"
   name = "github.com/gravitational/roundtrip"
 
 [[constraint]]

agent/server_test.go

@@ -421,7 +421,7 @@ func (r *AgentSuite) TestReflectsStatusInStatusCode(c *C) {
 	client, err := r.httpClient(fmt.Sprintf("https://127.0.0.1:%v", rpcPort))
 	c.Assert(err, IsNil)
 
-	resp, err := client.Get(client.Endpoint(""), url.Values{})
+	resp, err := client.Get(context.TODO(), client.Endpoint(""), url.Values{})
 	c.Assert(err, IsNil)
 	c.Assert(resp.Code(), Equals, http.StatusServiceUnavailable)
 

monitoring/collector/docker.go

@@ -17,6 +17,7 @@ limitations under the License.
 package collector
 
 import (
+	"context"
 	"net"
 	"net/http"
 	"net/url"
@@ -85,7 +86,7 @@ func (d *DockerCollector) Collect(ch chan<- prometheus.Metric) error {
 // healthStatus determines status of docker service
 // by fetching the docker's version HTTP endpoint from daemon socket
 func (d *DockerCollector) healthStatus() (bool, error) {
-	resp, err := d.client.Get(d.client.Endpoint("version"), url.Values{})
+	resp, err := d.client.Get(context.TODO(), d.client.Endpoint("version"), url.Values{})
 	if err != nil {
 		return false, trace.Wrap(err, "HTTP request failed: %v", err)
 	}

monitoring/collector/etcd.go

@@ -18,6 +18,7 @@ package collector
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"net/http"
 	"net/url"
@@ -84,7 +85,7 @@ func NewEtcdCollector(config *monitoring.ETCDConfig) (*EtcdCollector, error) {
 
 // Collect implements the prometheus.Collector interface
 func (e *EtcdCollector) Collect(ch chan<- prometheus.Metric) error {
-	resp, err := e.client.Get(e.client.Endpoint("v2", "stats", "leader"), url.Values{})
+	resp, err := e.client.Get(context.TODO(), e.client.Endpoint("v2", "stats", "leader"), url.Values{})
 	if err != nil {
 		return trace.Wrap(err)
 	}
@@ -114,7 +115,7 @@ func (e *EtcdCollector) Collect(ch chan<- prometheus.Metric) error {
 func (e *EtcdCollector) healthStatus() (healthy bool, err error) {
 	result := struct{ Health string }{}
 	nresult := struct{ Health bool }{}
-	resp, err := e.client.Get(e.client.Endpoint("health"), url.Values{})
+	resp, err := e.client.Get(context.TODO(), e.client.Endpoint("health"), url.Values{})
 	if err != nil {
 		return false, trace.Wrap(err)
 	}

monitoring/collector/systemd.go

@@ -29,7 +29,7 @@ var (
 		"flanneld.service",
 		"serf.service",
 		"planet-agent.service",
-		"dnsmasq.service",
+		"coredns.service",
 		"registry.service",
 		"docker.service",
 		"etcd.service",

monitoring/defaults.go

@@ -72,3 +72,8 @@ func GetStorageDriverBootConfigParams(drv string) health.Checker {
 func NewStorageChecker(config StorageConfig) health.Checker {
 	return noopChecker{}
 }
+
+// NewDNSChecker sends some default queries to monitor DNS / service discovery health
+func NewDNSChecker() health.Checker {
+	return noopChecker{}
+}

monitoring/defaults_linux.go

@@ -56,7 +56,7 @@ func DefaultProcessChecker() health.Checker {
 	return &ProcessChecker{[]string{
 		"dockerd",
 		"lxd",
-		"dnsmasq",
+		"coredns",
 		"kube-apiserver",
 		"kube-scheduler",
 		"kube-controller-manager",
@@ -128,3 +128,10 @@ func DefaultBootConfigParams() health.Checker {
 		},
 	)
 }
+
+// NewDNSChecker sends some default queries to monitor DNS / service discovery health
+func NewDNSChecker(questionA []string) health.Checker {
+	return &DNSChecker{
+		QuestionA: questionA,
+	}
+}

monitoring/dns.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2016 Gravitational, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package monitoring
+
+import (
+	"context"
+	"fmt"
+	"net"
+
+	"github.com/gravitational/satellite/agent/health"
+	pb "github.com/gravitational/satellite/agent/proto/agentpb"
+)
+
+// DNSMonitor will monitor a list of DNS servers for valid responses
+type DNSChecker struct {
+	// QuestionA is a slice of questions to ask for A (Host) records
+	QuestionA []string
+}
+
+// Name returns the name of this checker
+func (r *DNSChecker) Name() string { return "dns" }
+
+// Check checks if the DNS servers are responding
+func (r *DNSChecker) Check(ctx context.Context, reporter health.Reporter) {
+	checkFailed := false
+	for _, question := range r.QuestionA {
+		_, err := net.LookupHost(question)
+		if err != nil {
+			detail := fmt.Sprintf("failed to resolve %v", question)
+			reporter.Add(NewProbeFromErr(r.Name(), detail, err))
+			checkFailed = true
+		}
+	}
+
+	if checkFailed {
+		return
+	}
+
+	reporter.Add(&pb.Probe{
+		Checker: r.Name(),
+		Status:  pb.Probe_Running,
+	})
+}