v2.0.8 Added Support for dynamic EventsFolder directory from extension Handler Environment

integration-test/env/Extension/HandlerEnvironment.json

@@ -7,7 +7,9 @@
       "logFolder": "/var/log/azure/Extension",
       "configFolder": "/var/lib/waagent/Extension/config",
       "statusFolder": "/var/lib/waagent/Extension/status",
-      "heartbeatFile": "/var/lib/waagent/Extension/heartbeat.log"
+      "heartbeatFile": "/var/lib/waagent/Extension/heartbeat.log",
+      "eventsFolder": "/var/log/azure/Extension/events",
+      "eventsFolder_preview": "/var/log/azure/Extension/events"
     }
   }
 ]

integration-test/test/7_vmwatch.bats

@@ -95,7 +95,7 @@ teardown(){
     [[ "$output" == *'VMWatch process started'* ]]
     [[ "$output" == *'--config /var/lib/waagent/Extension/bin/VMWatch/vmwatch.conf'* ]]
     [[ "$output" == *'--input-filter disk_io:outbound_connectivity:clockskew:az_storage_blob'* ]]
-    [[ "$output" == *'Env: [SIGNAL_FOLDER=/var/log/azure/Microsoft.ManagedServices.ApplicationHealthLinux/events VERBOSE_LOG_FILE_FULL_PATH=/var/log/azure/Extension/vmwatch.log]'* ]]
+    [[ "$output" == *'Env: [SIGNAL_FOLDER=/var/log/azure/Extension/events VERBOSE_LOG_FILE_FULL_PATH=/var/log/azure/Extension/vmwatch.log]'* ]]
     [[ "$output" == *'VMWatch is running'* ]]
 
     status_file="$(container_read_extension_status)"
@@ -131,7 +131,7 @@ teardown(){
     [[ "$output" == *'VMWatch process started'* ]]
     [[ "$output" == *'--config /var/lib/waagent/Extension/bin/VMWatch/vmwatch.conf'* ]]
     [[ "$output" == *'--input-filter disk_io:outbound_connectivity'* ]]
-    [[ "$output" == *'Env: [ABC=abc BCD=bcd SIGNAL_FOLDER=/var/log/azure/Microsoft.ManagedServices.ApplicationHealthLinux/events VERBOSE_LOG_FILE_FULL_PATH=/var/log/azure/Extension/vmwatch.log]'* ]]
+    [[ "$output" == *'Env: [ABC=abc BCD=bcd SIGNAL_FOLDER=/var/log/azure/Extension/events VERBOSE_LOG_FILE_FULL_PATH=/var/log/azure/Extension/vmwatch.log]'* ]]
     [[ "$output" == *'VMWatch is running'* ]]
 
     status_file="$(container_read_extension_status)"
@@ -174,7 +174,7 @@ teardown(){
     [[ "$output" == *'VMWatch process started'* ]]
     [[ "$output" == *'--config /var/lib/waagent/Extension/bin/VMWatch/vmwatch.conf'* ]]
     [[ "$output" == *'--input-filter disk_io:outbound_connectivity'* ]]
-    [[ "$output" == *'Env: [SIGNAL_FOLDER=/var/log/azure/Microsoft.ManagedServices.ApplicationHealthLinux/events VERBOSE_LOG_FILE_FULL_PATH=/var/log/azure/Extension/vmwatch.log]'* ]]
+    [[ "$output" == *'Env: [SIGNAL_FOLDER=/var/log/azure/Extension/events VERBOSE_LOG_FILE_FULL_PATH=/var/log/azure/Extension/vmwatch.log]'* ]]
     [[ "$output" == *'VMWatch is running'* ]]
 
     status_file="$(container_read_extension_status)"

main/cmds.go

@@ -2,15 +2,15 @@ package main
 
 import (
 	"fmt"
-	"github.com/Azure/azure-docker-extension/pkg/vmextension"
-	"github.com/go-kit/kit/log"
-	"github.com/pkg/errors"
 	"os"
 	"strings"
 	"time"
+
+	"github.com/go-kit/kit/log"
+	"github.com/pkg/errors"
 )
 
-type cmdFunc func(ctx *log.Context, hEnv vmextension.HandlerEnvironment, seqNum int) (msg string, err error)
+type cmdFunc func(ctx *log.Context, hEnv HandlerEnvironment, seqNum int) (msg string, err error)
 type preFunc func(ctx *log.Context, seqNum int) error
 
 type cmd struct {
@@ -39,12 +39,12 @@ var (
 	}
 )
 
-func noop(ctx *log.Context, h vmextension.HandlerEnvironment, seqNum int) (string, error) {
+func noop(ctx *log.Context, h HandlerEnvironment, seqNum int) (string, error) {
 	ctx.Log("event", "noop")
 	return "", nil
 }
 
-func install(ctx *log.Context, h vmextension.HandlerEnvironment, seqNum int) (string, error) {
+func install(ctx *log.Context, h HandlerEnvironment, seqNum int) (string, error) {
 	if err := os.MkdirAll(dataDir, 0755); err != nil {
 		return "", errors.Wrap(err, "failed to create data dir")
 	}
@@ -54,7 +54,7 @@ func install(ctx *log.Context, h vmextension.HandlerEnvironment, seqNum int) (st
 	return "", nil
 }
 
-func uninstall(ctx *log.Context, h vmextension.HandlerEnvironment, seqNum int) (string, error) {
+func uninstall(ctx *log.Context, h HandlerEnvironment, seqNum int) (string, error) {
 	{ // a new context scope with path
 		ctx = ctx.With("path", dataDir)
 		ctx.Log("event", "removing data dir", "path", dataDir)
@@ -75,7 +75,7 @@ var (
 	errTerminated = errors.New("Application health process terminated")
 )
 
-func enable(ctx *log.Context, h vmextension.HandlerEnvironment, seqNum int) (string, error) {
+func enable(ctx *log.Context, h HandlerEnvironment, seqNum int) (string, error) {
 	// parse the extension handler settings (not available prior to 'enable')
 	cfg, err := parseAndValidateSettings(ctx, h.HandlerEnvironment.ConfigFolder)
 	if err != nil {

main/constants.go

@@ -16,7 +16,6 @@ const (
 	// and it also doesn't have the latest properties like EventsFolder. Importing a separate package
 	// is possible, but may result in lots of code churn. We will temporarily keep this as a constant since the
 	// events folder is unlikely to change in the future.
-	HandlerEnvironmentEventsFolderPath = "/var/log/azure/Microsoft.ManagedServices.ApplicationHealthLinux/events"
 
 	VMWatchBinaryNameAmd64    = "vmwatch_linux_amd64"
 	VMWatchBinaryNameArm64    = "vmwatch_linux_arm64"

main/handlerenv.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// HandlerEnvFileName is the file name of the Handler Environment as placed by the
+// Azure Linux Guest Agent.
+const HandlerEnvFileName = "HandlerEnvironment.json"
+
+// HandlerEnvironment describes the handler environment configuration presented
+// to the extension handler by the Azure Linux Guest Agent.
+type HandlerEnvironment struct {
+	Version            float64 `json:"version"`
+	Name               string  `json:"name"`
+	HandlerEnvironment struct {
+		HeartbeatFile       string `json:"heartbeatFile"`
+		StatusFolder        string `json:"statusFolder"`
+		ConfigFolder        string `json:"configFolder"`
+		LogFolder           string `json:"logFolder"`
+		EventsFolder        string `json:"eventsFolder"`
+		EventsFolderPreview string `json:"eventsFolder_preview"`
+		DeploymentID        string `json:"deploymentid"`
+		RoleName            string `json:"rolename"`
+		Instance            string `json:"instance"`
+		HostResolverAddress string `json:"hostResolverAddress"`
+	}
+}
+
+// GetHandlerEnv locates the HandlerEnvironment.json file by assuming it lives
+// next to or one level above the extension handler (read: this) executable,
+// reads, parses and returns it.
+func GetHandlerEnv() (he HandlerEnvironment, _ error) {
+	dir, err := scriptDir()
+	if err != nil {
+		return he, fmt.Errorf("vmextension: cannot find base directory of the running process: %v", err)
+	}
+	paths := []string{
+		filepath.Join(dir, HandlerEnvFileName),       // this level (i.e. executable is in [EXT_NAME]/.)
+		filepath.Join(dir, "..", HandlerEnvFileName), // one up (i.e. executable is in [EXT_NAME]/bin/.)
+	}
+	var b []byte
+	for _, p := range paths {
+		o, err := ioutil.ReadFile(p)
+		if err != nil && !os.IsNotExist(err) {
+			return he, fmt.Errorf("vmextension: error examining HandlerEnvironment at '%s': %v", p, err)
+		} else if err == nil {
+			b = o
+			break
+		}
+	}
+	if b == nil {
+		return he, fmt.Errorf("vmextension: Cannot find HandlerEnvironment at paths: %s", strings.Join(paths, ", "))
+	}
+	return ParseHandlerEnv(b)
+}
+
+// scriptDir returns the absolute path of the running process.
+func scriptDir() (string, error) {
+	p, err := filepath.Abs(os.Args[0])
+	if err != nil {
+		return "", err
+	}
+	return filepath.Dir(p), nil
+}
+
+// ParseHandlerEnv parses the
+// /var/lib/waagent/[extension]/HandlerEnvironment.json format.
+func ParseHandlerEnv(b []byte) (he HandlerEnvironment, _ error) {
+	var hf []HandlerEnvironment
+
+	if err := json.Unmarshal(b, &hf); err != nil {
+		return he, fmt.Errorf("vmextension: failed to parse handler env: %v", err)
+	}
+	if len(hf) != 1 {
+		return he, fmt.Errorf("vmextension: expected 1 config in parsed HandlerEnvironment, found: %v", len(hf))
+	}
+	return hf[0], nil
+}

main/main.go

@@ -8,7 +8,6 @@ import (
 	"strings"
 	"syscall"
 
-	"github.com/Azure/azure-docker-extension/pkg/vmextension"
 	"github.com/go-kit/kit/log"
 )
 
@@ -42,12 +41,12 @@ func main() {
 	}()
 
 	// parse extension environment
-	hEnv, err := vmextension.GetHandlerEnv()
+	hEnv, err := GetHandlerEnv()
 	if err != nil {
 		ctx.Log("message", "failed to parse handlerenv", "error", err)
 		os.Exit(cmd.failExitCode)
 	}
-	seqNum, err := vmextension.FindSeqNum(hEnv.HandlerEnvironment.ConfigFolder)
+	seqNum, err := FindSeqNum(hEnv.HandlerEnvironment.ConfigFolder)
 	if err != nil {
 		ctx.Log("messsage", "failed to find sequence number", "error", err)
 	}

main/reportstatus.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"github.com/Azure/azure-docker-extension/pkg/vmextension"
 	"github.com/go-kit/kit/log"
 	"github.com/pkg/errors"
 )
@@ -11,7 +10,7 @@ import (
 // status.
 //
 // If an error occurs reporting the status, it will be logged and returned.
-func reportStatus(ctx *log.Context, hEnv vmextension.HandlerEnvironment, seqNum int, t StatusType, c cmd, msg string) error {
+func reportStatus(ctx *log.Context, hEnv HandlerEnvironment, seqNum int, t StatusType, c cmd, msg string) error {
 	if !c.shouldReportStatus {
 		ctx.Log("status", "not reported for operation (by design)")
 		return nil
@@ -24,7 +23,7 @@ func reportStatus(ctx *log.Context, hEnv vmextension.HandlerEnvironment, seqNum
 	return nil
 }
 
-func reportStatusWithSubstatuses(ctx *log.Context, hEnv vmextension.HandlerEnvironment, seqNum int, t StatusType, op string, msg string, substatuses []SubstatusItem) error {
+func reportStatusWithSubstatuses(ctx *log.Context, hEnv HandlerEnvironment, seqNum int, t StatusType, op string, msg string, substatuses []SubstatusItem) error {
 	s := NewStatus(t, op, msg)
 	for _, substatus := range substatuses {
 		s.AddSubstatusItem(substatus)

main/reportstatus_test.go

@@ -6,7 +6,6 @@ import (
 	"path/filepath"
 	"testing"
 
-	"github.com/Azure/azure-docker-extension/pkg/vmextension"
 	"github.com/go-kit/kit/log"
 	"github.com/stretchr/testify/require"
 )
@@ -23,7 +22,7 @@ func Test_statusMsg(t *testing.T) {
 }
 
 func Test_reportStatus_fails(t *testing.T) {
-	fakeEnv := vmextension.HandlerEnvironment{}
+	fakeEnv := HandlerEnvironment{}
 	fakeEnv.HandlerEnvironment.StatusFolder = "/non-existing/dir/"
 
 	err := reportStatus(log.NewContext(log.NewNopLogger()), fakeEnv, 1, StatusSuccess, cmdEnable, "")
@@ -36,7 +35,7 @@ func Test_reportStatus_fileExists(t *testing.T) {
 	require.Nil(t, err)
 	defer os.RemoveAll(tmpDir)
 
-	fakeEnv := vmextension.HandlerEnvironment{}
+	fakeEnv := HandlerEnvironment{}
 	fakeEnv.HandlerEnvironment.StatusFolder = tmpDir
 
 	require.Nil(t, reportStatus(log.NewContext(log.NewNopLogger()), fakeEnv, 1, StatusError, cmdEnable, "FOO ERROR"))
@@ -53,7 +52,7 @@ func Test_reportStatus_checksIfShouldBeReported(t *testing.T) {
 		require.Nil(t, err)
 		defer os.RemoveAll(tmpDir)
 
-		fakeEnv := vmextension.HandlerEnvironment{}
+		fakeEnv := HandlerEnvironment{}
 		fakeEnv.HandlerEnvironment.StatusFolder = tmpDir
 		require.Nil(t, reportStatus(log.NewContext(log.NewNopLogger()), fakeEnv, 2, StatusSuccess, c, ""))
 

main/seqnum.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// FindSeqnum finds the file with the highest number under configFolder
+// named like 0.settings, 1.settings so on.
+func FindSeqNum(configFolder string) (int, error) {
+	g, err := filepath.Glob(configFolder + "/*.settings")
+	if err != nil {
+		return 0, err
+	}
+	seqs := make([]int, len(g))
+	for _, v := range g {
+		f := filepath.Base(v)
+		i, err := strconv.Atoi(strings.Replace(f, ".settings", "", 1))
+		if err != nil {
+			return 0, fmt.Errorf("Can't parse int from filename: %s", f)
+		}
+		seqs = append(seqs, i)
+	}
+	if len(seqs) == 0 {
+		return 0, fmt.Errorf("Can't find out seqnum from %s, not enough files.", configFolder)
+	}
+	sort.Sort(sort.Reverse(sort.IntSlice(seqs)))
+	return seqs[0], nil
+}

main/vmWatch.go

@@ -3,13 +3,13 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"github.com/Azure/azure-docker-extension/pkg/vmextension"
-	"github.com/go-kit/kit/log"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
 	"time"
+
+	"github.com/go-kit/kit/log"
 )
 
 type VMWatchStatus string
@@ -49,7 +49,7 @@ func (r *VMWatchResult) GetMessage() string {
 
 // We will setup and execute VMWatch as a separate process. Ideally VMWatch should run indefinitely,
 // but as a best effort we will attempt at most 3 times to run the process
-func executeVMWatch(ctx *log.Context, s *vmWatchSettings, h vmextension.HandlerEnvironment, vmWatchResultChannel chan VMWatchResult) {
+func executeVMWatch(ctx *log.Context, s *vmWatchSettings, hEnv HandlerEnvironment, vmWatchResultChannel chan VMWatchResult) {
 	var vmWatchErr error
 	defer func() {
 		if r := recover(); r != nil {
@@ -63,11 +63,11 @@ func executeVMWatch(ctx *log.Context, s *vmWatchSettings, h vmextension.HandlerE
 
 	// Best effort to start VMWatch process each time it fails
 	for i := 1; i <= VMWatchMaxProcessAttempts; i++ {
-		vmWatchErr = executeVMWatchHelper(ctx, i, s, h)
+		vmWatchErr = executeVMWatchHelper(ctx, i, s, hEnv)
 	}
 }
 
-func executeVMWatchHelper(ctx *log.Context, attempt int, vmWatchSettings *vmWatchSettings, handlerEnvironment vmextension.HandlerEnvironment) (err error) {
+func executeVMWatchHelper(ctx *log.Context, attempt int, vmWatchSettings *vmWatchSettings, hEnv HandlerEnvironment) (err error) {
 	pid := -1
 	var cmd *exec.Cmd
 	defer func() {
@@ -79,9 +79,9 @@ func executeVMWatchHelper(ctx *log.Context, attempt int, vmWatchSettings *vmWatc
 	}()
 
 	// Setup command
-	cmd, err = setupVMWatchCommand(vmWatchSettings, handlerEnvironment)
+	cmd, err = setupVMWatchCommand(vmWatchSettings, hEnv)
 	if err != nil {
-		err = fmt.Errorf("[%v][PID -1] Attempt %d: VMWatch setup failed. Error: %w", time.Now().UTC().Format(time.RFC3339), pid, attempt, err)
+		err = fmt.Errorf("[%v][PID -1] Attempt %d: VMWatch setup failed. Error: %w", time.Now().UTC().Format(time.RFC3339), attempt, err)
 		ctx.Log("error", err.Error())
 		return err
 	}
@@ -125,7 +125,7 @@ func killVMWatch(ctx *log.Context, cmd *exec.Cmd) error {
 	return nil
 }
 
-func setupVMWatchCommand(s *vmWatchSettings, h vmextension.HandlerEnvironment) (*exec.Cmd, error) {
+func setupVMWatchCommand(s *vmWatchSettings, hEnv HandlerEnvironment) (*exec.Cmd, error) {
 	processDirectory, err := GetProcessDirectory()
 	if err != nil {
 		return nil, err
@@ -142,7 +142,7 @@ func setupVMWatchCommand(s *vmWatchSettings, h vmextension.HandlerEnvironment) (
 
 	cmd := exec.Command(GetVMWatchBinaryFullPath(processDirectory), args...)
 
-	cmd.Env = GetVMWatchEnvironmentVariables(s.ParameterOverrides, h)
+	cmd.Env = GetVMWatchEnvironmentVariables(s.ParameterOverrides, hEnv)
 
 	return cmd, nil
 }
@@ -169,14 +169,14 @@ func GetVMWatchBinaryFullPath(processDirectory string) string {
 	return filepath.Join(processDirectory, "VMWatch", binaryName)
 }
 
-func GetVMWatchEnvironmentVariables(parameterOverrides map[string]interface{}, h vmextension.HandlerEnvironment) []string {
+func GetVMWatchEnvironmentVariables(parameterOverrides map[string]interface{}, hEnv HandlerEnvironment) []string {
 	var arr []string
 	for key, value := range parameterOverrides {
 		arr = append(arr, fmt.Sprintf("%s=%s", key, value))
 	}
 
-	arr = append(arr, fmt.Sprintf("SIGNAL_FOLDER=%s", HandlerEnvironmentEventsFolderPath))
-	arr = append(arr, fmt.Sprintf("VERBOSE_LOG_FILE_FULL_PATH=%s", filepath.Join(h.HandlerEnvironment.LogFolder, VMWatchVerboseLogFileName)))
+	arr = append(arr, fmt.Sprintf("SIGNAL_FOLDER=%s", hEnv.HandlerEnvironment.EventsFolder))
+	arr = append(arr, fmt.Sprintf("VERBOSE_LOG_FILE_FULL_PATH=%s", filepath.Join(hEnv.HandlerEnvironment.LogFolder, VMWatchVerboseLogFileName)))
 
 	return arr
 }

misc/manifest.xml

@@ -2,7 +2,7 @@
 <ExtensionImage xmlns="http://schemas.microsoft.com/windowsazure">
   <ProviderNameSpace>Microsoft.ManagedServices</ProviderNameSpace>
   <Type>ApplicationHealthLinux</Type>
-  <Version>2.0.7</Version>
+  <Version>2.0.8</Version>
   <Label>Microsoft Azure Application Health Extension for Linux Virtual Machines</Label>
   <HostingResources>VmRole</HostingResources>
   <MediaLink></MediaLink>