chore(coreos-cloudinit): bump to 0.7.3

ec2-cloudinit service fails after reboot with "reboot-strategy: off"

Documentation/cloud-config.md

@@ -123,6 +123,7 @@ The `coreos.units.*` parameters define a list of arbitrary systemd units to star
 - **enable**: Boolean indicating whether or not to handle the [Install] section of the unit file. This is similar to running `systemctl enable <name>`. Default value is false.
 - **content**: Plaintext string representing entire unit file. If no value is provided, the unit is assumed to exist already.
 - **command**: Command to execute on unit: start, stop, reload, restart, try-restart, reload-or-restart, reload-or-try-restart. Default value is restart.
+- **mask**: Whether to mask the unit file by symlinking it to `/dev/null` (analogous to `systemctl mask <name>`). Note that unlike `systemctl mask`, **this will destructively remove any existing unit file** located at `/etc/systemd/system/<unit>`, to ensure that the mask succeeds. Default value is false.
 
 **NOTE:** The command field is ignored for all network, netdev, and link units. The systemd-networkd.service unit will be restarted in their place.
 

coreos-cloudinit.go

@@ -11,7 +11,7 @@ import (
 	"github.com/coreos/coreos-cloudinit/system"
 )
 
-const version = "0.7.2"
+const version = "0.7.3"
 
 func init() {
 	//Removes timestamp since it is displayed already during booting

pkg/http_client.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"log"
-	"math"
 	"net"
 	"net/http"
 	neturl "net/url"
@@ -43,6 +42,14 @@ func NewHttpClient() *HttpClient {
 	}
 }
 
+func expBackoff(interval, max time.Duration) time.Duration {
+	interval = interval * 2
+	if interval > max {
+		interval = max
+	}
+	return interval
+}
+
 // Fetches a given URL with support for exponential backoff and maximum retries
 func (h *HttpClient) Get(rawurl string) ([]byte, error) {
 	if rawurl == "" {
@@ -84,6 +91,7 @@ func (h *HttpClient) Get(rawurl string) ([]byte, error) {
 		Transport: transport,
 	}
 
+	duration := 50 * time.Millisecond
 	for retry := 1; retry <= h.MaxRetries; retry++ {
 		log.Printf("Fetching data from %s. Attempt #%d", dataURL, retry)
 
@@ -106,13 +114,8 @@ func (h *HttpClient) Get(rawurl string) ([]byte, error) {
 			log.Printf("Unable to fetch data: %s", err.Error())
 		}
 
-		duration := time.Millisecond * time.Duration((math.Pow(float64(2), float64(retry)) * 100))
-		if duration > h.MaxBackoff {
-			duration = h.MaxBackoff
-		}
-
+		duration = expBackoff(duration, h.MaxBackoff)
 		log.Printf("Sleeping for %v...", duration)
-
 		time.Sleep(duration)
 	}
 

pkg/http_client_test.go

@@ -3,23 +3,38 @@ package pkg
 import (
 	"fmt"
 	"io"
+	"math"
 	"net/http"
 	"net/http/httptest"
 	"testing"
+	"time"
 )
 
-var expBackoffTests = []struct {
-	count int
-	body  string
-}{
-	{0, "number of attempts: 0"},
-	{1, "number of attempts: 1"},
-	{2, "number of attempts: 2"},
+func TestExpBackoff(t *testing.T) {
+	duration := time.Millisecond
+	max := time.Hour
+	for i := 0; i < math.MaxUint16; i++ {
+		duration = expBackoff(duration, max)
+		if duration < 0 {
+			t.Fatalf("duration too small: %v %v", duration, i)
+		}
+		if duration > max {
+			t.Fatalf("duration too large: %v %v", duration, i)
+		}
+	}
 }
 
 // Test exponential backoff and that it continues retrying if a 5xx response is
 // received
 func TestGetURLExpBackOff(t *testing.T) {
+	var expBackoffTests = []struct {
+		count int
+		body  string
+	}{
+		{0, "number of attempts: 0"},
+		{1, "number of attempts: 1"},
+		{2, "number of attempts: 2"},
+	}
 	client := NewHttpClient()
 
 	for i, tt := range expBackoffTests {

system/systemd.go

@@ -179,9 +179,17 @@ func MachineID(root string) string {
 	return id
 }
 
+// MaskUnit masks a Unit by the given name by symlinking its unit file (in
+// /etc/systemd/system) to /dev/null, analogous to `systemctl mask`
+// N.B.: Unlike `systemctl mask`, this function will *remove any existing unit
+// file* in /etc/systemd/system, to ensure that the mask will succeed.
 func MaskUnit(unit string, root string) error {
 	masked := path.Join(root, "etc", "systemd", "system", unit)
-	if err := os.MkdirAll(path.Dir(masked), os.FileMode(0755)); err != nil {
+	if _, err := os.Stat(masked); os.IsNotExist(err) {
+		if err := os.MkdirAll(path.Dir(masked), os.FileMode(0755)); err != nil {
+			return err
+		}
+	} else if err := os.Remove(masked); err != nil {
 		return err
 	}
 	return os.Symlink("/dev/null", masked)

system/systemd_test.go

@@ -154,16 +154,33 @@ func TestMaskUnit(t *testing.T) {
 		t.Fatalf("Unable to create tempdir: %v", err)
 	}
 	defer os.RemoveAll(dir)
-	if err := MaskUnit("foo.service", dir); err != nil {
-		t.Fatalf("Unable to mask unit: %v", err)
-	}
 
-	fullPath := path.Join(dir, "etc", "systemd", "system", "foo.service")
-	target, err := os.Readlink(fullPath)
+	// Ensure mask works with units that do not currently exist
+	if err := MaskUnit("foo.service", dir); err != nil {
+		t.Fatalf("Unable to mask new unit: %v", err)
+	}
+	fooPath := path.Join(dir, "etc", "systemd", "system", "foo.service")
+	fooTgt, err := os.Readlink(fooPath)
 	if err != nil {
 		t.Fatalf("Unable to read link", err)
 	}
-	if target != "/dev/null" {
-		t.Fatalf("unit not masked, got unit target", target)
+	if fooTgt != "/dev/null" {
+		t.Fatalf("unit not masked, got unit target", fooTgt)
+	}
+
+	// Ensure mask works with unit files that already exist
+	barPath := path.Join(dir, "etc", "systemd", "system", "bar.service")
+	if _, err := os.Create(barPath); err != nil {
+		t.Fatalf("Error creating new unit file: %v", err)
+	}
+	if err := MaskUnit("bar.service", dir); err != nil {
+		t.Fatalf("Unable to mask existing unit: %v", err)
+	}
+	barTgt, err := os.Readlink(barPath)
+	if err != nil {
+		t.Fatalf("Unable to read link", err)
+	}
+	if barTgt != "/dev/null" {
+		t.Fatalf("unit not masked, got unit target", barTgt)
 	}
 }