Re-write diagnostic server to support cloud/HTTP

Signed-off-by: Nathan LeClaire <nathan.leclaire@gmail.com>

alpine/packages/diagnostics/capture.go

@@ -0,0 +1,170 @@
+package main
+
+import (
+	"archive/tar"
+	"bytes"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+var (
+	commonCmdCaptures = []CommandCapturer{
+		{"/bin/date", nil},
+		{"/bin/uname", []string{"-a"}},
+		{"/bin/ps", []string{"uax"}},
+		{"/bin/netstat", []string{"-tulpn"}},
+		{"/sbin/iptables-save", nil},
+		{"/sbin/ifconfig", nil},
+		{"/sbin/route", nil},
+		{"/usr/sbin/brctl", nil},
+		{"/bin/dmesg", nil},
+		{"/usr/bin/docker", []string{"ps"}},
+		{"/usr/bin/tail", []string{"-100", "/var/log/docker.log"}},
+		{"/usr/bin/tail", []string{"-100", "/var/log/messages"}},
+		{"/bin/mount", nil},
+		{"/bin/df", nil},
+		{"/bin/ls", []string{"-l", "/var"}},
+		{"/bin/ls", []string{"-l", "/var/lib"}},
+		{"/bin/ls", []string{"-l", "/var/lib/docker"}},
+		{"/usr/bin/diagnostics", nil},
+		{"/bin/ping", []string{"-w", "5", "8.8.8.8"}},
+		{"/bin/cat", []string{"/etc/docker/daemon.json"}},
+		{"/bin/cat", []string{"/etc/network/interfaces"}},
+		{"/bin/cat", []string{"/etc/resolv.conf"}},
+		{"/bin/cat", []string{"/etc/sysctl.conf"}},
+		{"/usr/bin/dig", []string{"docker.com"}},
+		{"/usr/bin/dig", []string{"@8.8.8.8", "docker.com"}},
+		{"/usr/bin/wget", []string{"-O", "-", "http://www.docker.com/"}},
+		{"/usr/bin/wget", []string{"-O", "-", "http://104.239.220.248/"}}, // a www.docker.com address
+		{"/usr/bin/wget", []string{"-O", "-", "http://216.58.213.68/"}},   // a www.google.com address
+		{"/usr/bin/wget", []string{"-O", "-", "http://91.198.174.192/"}},  // a www.wikipedia.com address
+	}
+	localCmdCaptures = []CommandCapturer{
+		{"/usr/bin/tail", []string{"-100", "/var/log/proxy-vsockd.log"}},
+		{"/usr/bin/tail", []string{"-100", "/var/log/service-port-opener.log"}},
+		{"/usr/bin/tail", []string{"-100", "/var/log/vsudd.log"}},
+	}
+	localCaptures = []Capturer{NewDatabaseCapturer()}
+)
+
+func init() {
+	for _, c := range localCmdCaptures {
+		localCmdCaptures = append(localCmdCaptures, c)
+	}
+}
+
+// Capturer defines behavior for structs which will capture arbitrary
+// diagnostic information and write it to a tar archive with a timeout.
+type Capturer interface {
+	Capture(time.Duration, *tar.Writer)
+}
+
+type CommandCapturer struct {
+	command string
+	args    []string
+}
+
+func (cc CommandCapturer) Capture(timeout time.Duration, w *tar.Writer) {
+	log.Printf("Running %s", cc.command)
+	c := exec.Command(cc.command, cc.args...)
+	stdoutPipe, err := c.StdoutPipe()
+	if err != nil {
+		log.Fatalf("Failed to create stdout pipe: %s", err)
+	}
+	stderrPipe, err := c.StderrPipe()
+	if err != nil {
+		log.Fatalf("Failed to create stderr pipe: %s", err)
+	}
+	var stdoutBuffer bytes.Buffer
+	var stderrBuffer bytes.Buffer
+	done := make(chan int)
+	go func() {
+		io.Copy(&stdoutBuffer, stdoutPipe)
+		done <- 0
+	}()
+	go func() {
+		io.Copy(&stderrBuffer, stderrPipe)
+		done <- 0
+	}()
+	var timer *time.Timer
+	timer = time.AfterFunc(timeout, func() {
+		timer.Stop()
+		if c.Process != nil {
+			c.Process.Kill()
+		}
+	})
+	_ = c.Run()
+	<-done
+	<-done
+	timer.Stop()
+
+	name := strings.Join(append([]string{path.Base(cc.command)}, cc.args...), " ")
+
+	hdr := &tar.Header{
+		Name: name + ".stdout",
+		Mode: 0644,
+		Size: int64(stdoutBuffer.Len()),
+	}
+	if err = w.WriteHeader(hdr); err != nil {
+		log.Fatalln(err)
+	}
+	if _, err = w.Write(stdoutBuffer.Bytes()); err != nil {
+		log.Fatalln(err)
+	}
+	hdr = &tar.Header{
+		Name: name + ".stderr",
+		Mode: 0644,
+		Size: int64(stderrBuffer.Len()),
+	}
+	if err = w.WriteHeader(hdr); err != nil {
+		log.Fatalln(err)
+	}
+	if _, err = w.Write(stderrBuffer.Bytes()); err != nil {
+		log.Fatalln(err)
+	}
+}
+
+type DatabaseCapturer struct {
+	*CommandCapturer
+}
+
+func NewDatabaseCapturer() DatabaseCapturer {
+	return DatabaseCapturer{
+		&CommandCapturer{
+			command: "/bin/cat",
+		},
+	}
+}
+
+func (dc DatabaseCapturer) Capture(timeout time.Duration, w *tar.Writer) {
+	// Dump the database
+	dbBase := "/Database/branch/master/ro"
+	filepath.Walk(dbBase, func(path string, f os.FileInfo, err error) error {
+		if f.Mode().IsRegular() {
+			dc.CommandCapturer.args = []string{path}
+			dc.CommandCapturer.Capture(timeout, w)
+		}
+		return nil
+	})
+}
+
+// Capture is the outer level wrapper function to trigger the capturing of
+// information.  Clients are expected to call it with a slice of Capturers
+// which define the information to be captured.  By using an interface we can
+// flexibly define various capture actions for the various listeners.
+//
+// It is a passed a tar.Writer which the results of the capture will be written
+// to.
+func Capture(w *tar.Writer, captures []Capturer) {
+	t := 2 * time.Second
+
+	for _, c := range captures {
+		c.Capture(t, w)
+	}
+}

alpine/packages/diagnostics/etc/init.d/diagnostics

@@ -9,6 +9,25 @@ start()
 {
 	ebegin "Checking system state"
 
-	/usr/bin/diagnostics-server &
+	DIAGNOSTICS_SERVER_FLAGS=""
+
+	case "$(mobyplatform)" in
+		"aws")
+			DIAGNOSTICS_SERVER_FLAGS="-http"
+		;;
+		"azure")
+			DIAGNOSTICS_SERVER_FLAGS="-http"
+		;;
+		"windows")
+			# TODO(Rolf/David): Are these correct?
+			DIAGNOSTICS_SERVER_FLAGS="-hvsock -rawtcp"
+		;;
+		"mac")
+			# TODO(Justin/Anil): Are these correct?
+			DIAGNOSTICS_SERVER_FLAGS="-vsock -rawtcp"
+		;;
+	esac
+
+	/usr/bin/diagnostics-server ${DIAGNOSTICS_SERVER_FLAGS} &
 	/usr/bin/diagnostics
 }

alpine/packages/diagnostics/http.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"archive/tar"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+)
+
+const (
+	dockerSock    = "/var/run/docker.sock"
+	lgtm          = "LGTM"
+	httpMagicPort = ":44554" // chosen arbitrarily due to IANA availability -- might change
+)
+
+var (
+	cloudCaptures = []Capturer{}
+)
+
+func init() {
+	for _, c := range commonCmdCaptures {
+		cloudCaptures = append(cloudCaptures, c)
+	}
+}
+
+// HTTPDiagnosticListener sets a health check and optional diagnostic endpoint
+// for cloud editions.
+type HTTPDiagnosticListener struct{}
+
+func (h HTTPDiagnosticListener) Listen() {
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		if _, err := os.Stat(dockerSock); os.IsNotExist(err) {
+			http.Error(w, "Docker socket not found -- daemon is down", http.StatusServiceUnavailable)
+			return
+		}
+		if _, err := w.Write([]byte(lgtm)); err != nil {
+			log.Println("Error writing HTTP success response:", err)
+			return
+		}
+	})
+
+	http.HandleFunc("/diagnose", func(w http.ResponseWriter, r *http.Request) {
+		dir, err := ioutil.TempDir("", "diagnostics")
+		if err != nil {
+			log.Println("Error creating temp dir on diagnostic request:", err)
+			return
+		}
+
+		file, err := ioutil.TempFile(dir, "diagnostics")
+		if err != nil {
+			log.Println("Error creating temp file on diagnostic request:", err)
+			return
+		}
+
+		tarWriter := tar.NewWriter(file)
+
+		Capture(tarWriter, cloudCaptures)
+
+		// TODO: upload written (and gzipped?) tar file to our S3
+		// bucket with specific path convention (per-user?  by date?)
+	})
+
+	// Start HTTP server to indicate general Docker health.
+	// TODO: no magic port?
+	http.ListenAndServe(httpMagicPort, nil)
+}

alpine/packages/diagnostics/hvsock.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"log"
+	"syscall"
+
+	"github.com/rneugeba/virtsock/go/hvsock"
+)
+
+type HVSockDiagnosticListener struct{}
+
+func (l HVSockDiagnosticListener) Listen() {
+	svcid, _ := hvsock.GuidFromString("445BA2CB-E69B-4912-8B42-D7F494D007EA")
+	hvsock, err := hvsock.Listen(hvsock.HypervAddr{VmId: hvsock.GUID_WILDCARD, ServiceId: svcid})
+	if err != nil {
+		if errno, ok := err.(syscall.Errno); !ok || errno != syscall.EAFNOSUPPORT {
+			log.Printf("Failed to bind to hvsock port: %s", err)
+		}
+	}
+
+	for {
+		TarRespond(hvsock)
+	}
+}

alpine/packages/diagnostics/main.go

@@ -1,132 +1,12 @@
 package main
 
 import (
-	"archive/tar"
-	"bytes"
-	"io"
+	"flag"
 	"log"
 	"log/syslog"
-	"net"
-	"os"
-	"os/exec"
-	"path"
-	"path/filepath"
-	"strings"
-	"syscall"
-	"time"
-
-	"github.com/rneugeba/virtsock/go/hvsock"
-	"github.com/rneugeba/virtsock/go/vsock"
 )
 
-func run(timeout time.Duration, w *tar.Writer, command string, args ...string) {
-	log.Printf("Running %s", command)
-	c := exec.Command(command, args...)
-	stdoutPipe, err := c.StdoutPipe()
-	if err != nil {
-		log.Fatalf("Failed to create stdout pipe: %s", err)
-	}
-	stderrPipe, err := c.StderrPipe()
-	if err != nil {
-		log.Fatalf("Failed to create stderr pipe: %s", err)
-	}
-	var stdoutBuffer bytes.Buffer
-	var stderrBuffer bytes.Buffer
-	done := make(chan int)
-	go func() {
-		io.Copy(&stdoutBuffer, stdoutPipe)
-		done <- 0
-	}()
-	go func() {
-		io.Copy(&stderrBuffer, stderrPipe)
-		done <- 0
-	}()
-	var timer *time.Timer
-	timer = time.AfterFunc(timeout, func() {
-		timer.Stop()
-		if c.Process != nil {
-			c.Process.Kill()
-		}
-	})
-	_ = c.Run()
-	<-done
-	<-done
-	timer.Stop()
-
-	name := strings.Join(append([]string{path.Base(command)}, args...), " ")
-
-	hdr := &tar.Header{
-		Name: name + ".stdout",
-		Mode: 0644,
-		Size: int64(stdoutBuffer.Len()),
-	}
-	if err = w.WriteHeader(hdr); err != nil {
-		log.Fatalln(err)
-	}
-	if _, err = w.Write(stdoutBuffer.Bytes()); err != nil {
-		log.Fatalln(err)
-	}
-	hdr = &tar.Header{
-		Name: name + ".stderr",
-		Mode: 0644,
-		Size: int64(stderrBuffer.Len()),
-	}
-	if err = w.WriteHeader(hdr); err != nil {
-		log.Fatalln(err)
-	}
-	if _, err = w.Write(stderrBuffer.Bytes()); err != nil {
-		log.Fatalln(err)
-	}
-
-}
-
-func capture(w *tar.Writer) {
-	t := 2 * time.Second
-
-	run(t, w, "/bin/date")
-	run(t, w, "/bin/uname", "-a")
-	run(t, w, "/bin/ps", "uax")
-	run(t, w, "/bin/netstat", "-tulpn")
-	run(t, w, "/sbin/iptables-save")
-	run(t, w, "/sbin/ifconfig", "-a")
-	run(t, w, "/sbin/route", "-n")
-	run(t, w, "/usr/sbin/brctl", "show")
-	run(t, w, "/bin/dmesg")
-	run(t, w, "/usr/bin/docker", "ps")
-	run(t, w, "/usr/bin/tail", "-100", "/var/log/docker.log")
-	run(t, w, "/usr/bin/tail", "-100", "/var/log/messages")
-	run(t, w, "/usr/bin/tail", "-100", "/var/log/proxy-vsockd.log")
-	run(t, w, "/usr/bin/tail", "-100", "/var/log/service-port-opener.log")
-	run(t, w, "/usr/bin/tail", "-100", "/var/log/vsudd.log")
-	run(t, w, "/bin/mount")
-	run(t, w, "/bin/df")
-	run(t, w, "/bin/ls", "-l", "/var")
-	run(t, w, "/bin/ls", "-l", "/var/lib")
-	run(t, w, "/bin/ls", "-l", "/var/lib/docker")
-	run(t, w, "/usr/bin/diagnostics")
-	run(t, w, "/bin/ping", "-w", "5", "8.8.8.8")
-	run(t, w, "/bin/cat", "/etc/docker/daemon.json")
-	run(t, w, "/bin/cat", "/etc/network/interfaces")
-	run(t, w, "/bin/cat", "/etc/resolv.conf")
-	run(t, w, "/bin/cat", "/etc/sysctl.conf")
-	run(t, w, "/usr/bin/dig", "docker.com")
-	run(t, w, "/usr/bin/dig", "@8.8.8.8", "docker.com")
-	run(t, w, "/usr/bin/wget", "-O", "-", "http://www.docker.com/")
-	run(t, w, "/usr/bin/wget", "-O", "-", "http://104.239.220.248/") // a www.docker.com address
-	run(t, w, "/usr/bin/wget", "-O", "-", "http://216.58.213.68/")   // a www.google.com address
-	run(t, w, "/usr/bin/wget", "-O", "-", "http://91.198.174.192/")  // a www.wikipedia.com address
-
-	// Dump the database
-	dbBase := "/Database/branch/master/ro"
-	filepath.Walk(dbBase, func(path string, f os.FileInfo, err error) error {
-		if f.Mode().IsRegular() {
-			run(t, w, "/bin/cat", path)
-		}
-		return nil
-	})
-}
-
-func main() {
+func init() {
 	syslog, err := syslog.New(syslog.LOG_INFO|syslog.LOG_DAEMON, "diagnostics")
 	if err != nil {
 		log.Fatalln("Failed to open syslog", err)
@@ -134,51 +14,48 @@ func main() {
 
 	log.SetOutput(syslog)
 	log.SetFlags(0)
+}
 
-	listeners := make([]net.Listener, 0)
+type DiagnosticListener interface {
+	// Listen(), a blocking method intended to be invoked in its own
+	// goroutine, will listen for a diagnostic information request and
+	// capture the desired information if one is received.
+	Listen()
+}
 
-	ip, err := net.Listen("tcp", ":62374")
-	if err != nil {
-		log.Printf("Failed to bind to TCP port 62374: %s", err)
-	} else {
-		listeners = append(listeners, ip)
+// DiagnosticUploader uploads the collected information to the mothership.
+type DiagnosticUploader interface {
+	Upload() error
 }
-	vsock, err := vsock.Listen(uint(62374))
-	if err != nil {
-		if errno, ok := err.(syscall.Errno); !ok || errno != syscall.EAFNOSUPPORT {
-			log.Printf("Failed to bind to vsock port 62374: %s", err)
+
+func main() {
+	flHTTP := flag.Bool("http", false, "Enable diagnostic HTTP listener")
+	flVSock := flag.Bool("vsock", false, "Enable vsock listener")
+	flHVSock := flag.Bool("hvsock", false, "Enable hvsock listener")
+	flRawTCP := flag.Bool("rawtcp", false, "Enable raw TCP listener")
+
+	flag.Parse()
+
+	listeners := make([]DiagnosticListener, 0)
+
+	if *flHTTP {
+		listeners = append(listeners, HTTPDiagnosticListener{})
 	}
-	} else {
-		listeners = append(listeners, vsock)
+
+	if *flVSock {
+		listeners = append(listeners, VSockDiagnosticListener{})
 	}
-	svcid, _ := hvsock.GuidFromString("445BA2CB-E69B-4912-8B42-D7F494D007EA")
-	hvsock, err := hvsock.Listen(hvsock.HypervAddr{VmId: hvsock.GUID_WILDCARD, ServiceId: svcid})
-	if err != nil {
-		if errno, ok := err.(syscall.Errno); !ok || errno != syscall.EAFNOSUPPORT {
-			log.Printf("Failed to bind to hvsock port: %s", err)
+
+	if *flHVSock {
+		listeners = append(listeners, HVSockDiagnosticListener{})
 	}
-	} else {
-		listeners = append(listeners, hvsock)
+
+	if *flRawTCP {
+		listeners = append(listeners, RawTCPDiagnosticListener{})
 	}
 
 	for _, l := range listeners {
-		go func(l net.Listener) {
-			for {
-				conn, err := l.Accept()
-				if err != nil {
-					log.Printf("Error accepting connection: %s", err)
-					return // no more listening
-				}
-				go func(conn net.Conn) {
-					w := tar.NewWriter(conn)
-					capture(w)
-					if err := w.Close(); err != nil {
-						log.Println(err)
-					}
-					conn.Close()
-				}(conn)
-			}
-		}(l)
+		go l.Listen()
 	}
 	forever := make(chan int)
 	<-forever

alpine/packages/diagnostics/rawtcp.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"log"
+	"net"
+)
+
+type RawTCPDiagnosticListener struct{}
+
+func (l RawTCPDiagnosticListener) Listen() {
+	ip, err := net.Listen("tcp", ":62374")
+	if err != nil {
+		log.Printf("Failed to bind to TCP port 62374: %s", err)
+	}
+
+	for {
+		TarRespond(ip)
+	}
+}

alpine/packages/diagnostics/run.go

@@ -0,0 +1 @@
+package main

alpine/packages/diagnostics/tar_respond.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"archive/tar"
+	"log"
+	"net"
+)
+
+// TarRespond is used to write back a tar archive over a connection for the
+// lower-level listener types.
+//
+// In local virtualization (which this is for) we write back a tar file
+// directly and the client takes care of shipping the result to the mothership.
+//
+// By contrast, in cloud editions we expect each node to ship the captured
+// information on its own, so this function is not used.
+//
+// This is a deliberate design to choice to ensure that it is possible in the
+// future for diagnostic information to be reported from nodes which have have
+// been separated via network partition from the node which initiates
+// diagnostic collection, and/or if we decide to automatically collect
+// diagnostic information from nodes which deem *themselves* unhealthy at a
+// future time.
+func TarRespond(l net.Listener) {
+	conn, err := l.Accept()
+	if err != nil {
+		log.Printf("Error accepting connection: %s", err)
+		return
+	}
+
+	w := tar.NewWriter(conn)
+
+	Capture(w, localCaptures)
+
+	if err := w.Close(); err != nil {
+		log.Println(err)
+	}
+
+	conn.Close()
+}

alpine/packages/diagnostics/vsock.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"log"
+	"syscall"
+
+	"github.com/rneugeba/virtsock/go/vsock"
+)
+
+type VSockDiagnosticListener struct{}
+
+func (l VSockDiagnosticListener) Listen() {
+	vsock, err := vsock.Listen(uint(62374))
+	if err != nil {
+		if errno, ok := err.(syscall.Errno); !ok || errno != syscall.EAFNOSUPPORT {
+			log.Printf("Failed to bind to vsock port 62374: %s", err)
+		}
+	}
+
+	for {
+		TarRespond(vsock)
+	}
+}