feat: add command to check for updates

cmd/cliflags/flags.go

@@ -27,55 +27,58 @@ const (
 	DevStreamURIDefault = "https://stream.launchdarkly.com"
 	PortDefault         = "8765"
 
-	AccessTokenFlag  = "access-token"
-	AnalyticsOptOut  = "analytics-opt-out"
-	BaseURIFlag      = "base-uri"
-	CorsEnabledFlag  = "cors-enabled"
-	CorsOriginFlag   = "cors-origin"
-	DataFlag         = "data"
-	DryRunFlag       = "dry-run"
-	DevStreamURIFlag = "dev-stream-uri"
-	EmailsFlag       = "emails"
-	EnvironmentFlag  = "environment"
-	FieldsFlag       = "fields"
-	FlagFlag         = "flag"
-	JSONFlag         = "json"
-	OutputFlag       = "output"
-	PortFlag         = "port"
-	ProjectFlag      = "project"
-	RoleFlag         = "role"
-	SyncOnceFlag     = "sync-once"
+	AccessTokenFlag   = "access-token"
+	AnalyticsOptOut   = "analytics-opt-out"
+	BaseURIFlag       = "base-uri"
+	CorsEnabledFlag   = "cors-enabled"
+	CorsOriginFlag    = "cors-origin"
+	DataFlag          = "data"
+	DryRunFlag        = "dry-run"
+	DevStreamURIFlag  = "dev-stream-uri"
+	EmailsFlag        = "emails"
+	EnvironmentFlag   = "environment"
+	FieldsFlag        = "fields"
+	FlagFlag          = "flag"
+	JSONFlag          = "json"
+	OutputFlag        = "output"
+	PortFlag          = "port"
+	ProjectFlag       = "project"
+	RoleFlag          = "role"
+	SyncOnceFlag      = "sync-once"
+	UpdateCheckOptOut = "update-check-opt-out"
 
-	AccessTokenFlagDescription = "LaunchDarkly access token with write-level access"
-	AnalyticsOptOutDescription = "Opt out of analytics tracking"
-	BaseURIFlagDescription     = "LaunchDarkly base URI"
-	CorsEnabledFlagDescription = "Enable CORS headers for browser-based developer tools (default: false)"
-	CorsOriginFlagDescription  = "Allowed CORS origin. Use '*' for all origins (default: '*')"
-	DevStreamURIDescription    = "Streaming service endpoint that the dev server uses to obtain authoritative flag data. This may be a LaunchDarkly or Relay Proxy endpoint"
-	DryRunFlagDescription      = "Validate the change without persisting it. Returns a preview of the result."
-	EnvironmentFlagDescription = "Default environment key"
-	FieldsFlagDescription      = "Comma-separated list of top-level fields to include in JSON output (e.g., --fields key,name,kind)"
-	FlagFlagDescription        = "Default feature flag key"
-	JSONFlagDescription        = "Output JSON format (shorthand for --output json)"
-	OutputFlagDescription      = "Output format: json, plaintext, or markdown (default: plaintext in a terminal, json otherwise)"
-	PortFlagDescription        = "Port for the dev server to run on"
-	ProjectFlagDescription     = "Default project key"
-	SyncOnceFlagDescription    = "Only sync new projects. Existing projects will neither be resynced nor have overrides specified by CLI flags applied."
+	AccessTokenFlagDescription   = "LaunchDarkly access token with write-level access"
+	AnalyticsOptOutDescription   = "Opt out of analytics tracking"
+	BaseURIFlagDescription       = "LaunchDarkly base URI"
+	CorsEnabledFlagDescription   = "Enable CORS headers for browser-based developer tools (default: false)"
+	CorsOriginFlagDescription    = "Allowed CORS origin. Use '*' for all origins (default: '*')"
+	DevStreamURIDescription      = "Streaming service endpoint that the dev server uses to obtain authoritative flag data. This may be a LaunchDarkly or Relay Proxy endpoint"
+	DryRunFlagDescription        = "Validate the change without persisting it. Returns a preview of the result."
+	EnvironmentFlagDescription   = "Default environment key"
+	FieldsFlagDescription        = "Comma-separated list of top-level fields to include in JSON output (e.g., --fields key,name,kind)"
+	FlagFlagDescription          = "Default feature flag key"
+	JSONFlagDescription          = "Output JSON format (shorthand for --output json)"
+	OutputFlagDescription        = "Output format: json, plaintext, or markdown (default: plaintext in a terminal, json otherwise)"
+	PortFlagDescription          = "Port for the dev server to run on"
+	ProjectFlagDescription       = "Default project key"
+	SyncOnceFlagDescription      = "Only sync new projects. Existing projects will neither be resynced nor have overrides specified by CLI flags applied."
+	UpdateCheckOptOutDescription = "Opt out of update check"
 )
 
 func AllFlagsHelp() map[string]string {
 	return map[string]string{
-		AccessTokenFlag:  AccessTokenFlagDescription,
-		AnalyticsOptOut:  AnalyticsOptOutDescription,
-		BaseURIFlag:      BaseURIFlagDescription,
-		CorsEnabledFlag:  CorsEnabledFlagDescription,
-		CorsOriginFlag:   CorsOriginFlagDescription,
-		DevStreamURIFlag: DevStreamURIDescription,
-		EnvironmentFlag:  EnvironmentFlagDescription,
-		FlagFlag:         FlagFlagDescription,
-		OutputFlag:       OutputFlagDescription,
-		PortFlag:         PortFlagDescription,
-		ProjectFlag:      ProjectFlagDescription,
-		SyncOnceFlag:     SyncOnceFlagDescription,
+		AccessTokenFlag:   AccessTokenFlagDescription,
+		AnalyticsOptOut:   AnalyticsOptOutDescription,
+		BaseURIFlag:       BaseURIFlagDescription,
+		CorsEnabledFlag:   CorsEnabledFlagDescription,
+		CorsOriginFlag:    CorsOriginFlagDescription,
+		DevStreamURIFlag:  DevStreamURIDescription,
+		EnvironmentFlag:   EnvironmentFlagDescription,
+		FlagFlag:          FlagFlagDescription,
+		OutputFlag:        OutputFlagDescription,
+		PortFlag:          PortFlagDescription,
+		ProjectFlag:       ProjectFlagDescription,
+		SyncOnceFlag:      SyncOnceFlagDescription,
+		UpdateCheckOptOut: UpdateCheckOptOutDescription,
 	}
 }

cmd/config/testdata/help.golden

@@ -13,6 +13,7 @@ Supported settings:
 - `port`: Port for the dev server to run on
 - `project`: Default project key
 - `sync-once`: Only sync new projects. Existing projects will neither be resynced nor have overrides specified by CLI flags applied.
+- `update-check-opt-out`: Opt out of update check
 
 Usage:
   ldcli config [flags]

cmd/root.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/google/uuid"
 	"github.com/spf13/cobra"
@@ -35,6 +36,7 @@ import (
 	"github.com/launchdarkly/ldcli/internal/members"
 	"github.com/launchdarkly/ldcli/internal/projects"
 	"github.com/launchdarkly/ldcli/internal/resources"
+	"github.com/launchdarkly/ldcli/internal/update"
 )
 
 type APIClients struct {
@@ -319,6 +321,19 @@ See each command's help for details on how to use the generated script.`, rootCm
 
 	rootCmd.cmd.SetUsageTemplate(getUsageTemplate())
 
+	// Start update check in the background so it runs in parallel with command execution.
+	type updateResult struct {
+		info *update.UpdateInfo
+	}
+	updateCh := make(chan updateResult, 1)
+	skipUpdateCheck := viper.GetBool(cliflags.UpdateCheckOptOut) ||
+		!term.IsTerminal(int(os.Stderr.Fd()))
+	if !skipUpdateCheck {
+		go func() {
+			updateCh <- updateResult{info: update.CheckForUpdate(version)}
+		}()
+	}
+
 	err = rootCmd.Execute()
 
 	var outcome string
@@ -349,6 +364,16 @@ See each command's help for details on how to use the generated script.`, rootCm
 	}
 
 	analyticsClient.Wait()
+
+	if !skipUpdateCheck {
+		select {
+		case result := <-updateCh:
+			if result.info != nil && result.info.IsNewer {
+				fmt.Fprint(os.Stderr, update.NotificationMessage(result.info))
+			}
+		case <-time.After(500 * time.Millisecond):
+		}
+	}
 }
 
 // setFlagsFromConfig reads in the config file if it exists and uses any flag values for commands.

internal/config/config.go

@@ -20,14 +20,15 @@ type ReadFile func(name string) ([]byte, error)
 
 // Config represents the data stored in the config file.
 type Config struct {
-	AccessToken     string `json:"access-token,omitempty" yaml:"access-token,omitempty"`
-	AnalyticsOptOut *bool  `json:"analytics-opt-out,omitempty" yaml:"analytics-opt-out,omitempty"`
-	BaseURI         string `json:"base-uri,omitempty" yaml:"base-uri,omitempty"`
-	DevStreamURI    string `json:"dev-stream-uri,omitempty" yaml:"dev-stream-uri,omitempty"`
-	Environment     string `json:"environment,omitempty" yaml:"environment,omitempty"`
-	Flag            string `json:"flag,omitempty" yaml:"flag,omitempty"`
-	Output          string `json:"output,omitempty" yaml:"output,omitempty"`
-	Project         string `json:"project,omitempty" yaml:"project,omitempty"`
+	AccessToken       string `json:"access-token,omitempty" yaml:"access-token,omitempty"`
+	AnalyticsOptOut   *bool  `json:"analytics-opt-out,omitempty" yaml:"analytics-opt-out,omitempty"`
+	BaseURI           string `json:"base-uri,omitempty" yaml:"base-uri,omitempty"`
+	DevStreamURI      string `json:"dev-stream-uri,omitempty" yaml:"dev-stream-uri,omitempty"`
+	Environment       string `json:"environment,omitempty" yaml:"environment,omitempty"`
+	Flag              string `json:"flag,omitempty" yaml:"flag,omitempty"`
+	Output            string `json:"output,omitempty" yaml:"output,omitempty"`
+	Project           string `json:"project,omitempty" yaml:"project,omitempty"`
+	UpdateCheckOptOut *bool  `json:"update-check-opt-out,omitempty" yaml:"update-check-opt-out,omitempty"`
 }
 
 func New(filename string, readFile ReadFile) (Config, error) {
@@ -95,6 +96,13 @@ func (c Config) Update(kvs []string) (Config, []string, error) {
 				c.Output = val.String()
 			case cliflags.ProjectFlag:
 				c.Project = v
+			case cliflags.UpdateCheckOptOut:
+				val, err := strconv.ParseBool(v)
+				if err != nil {
+					return Config{}, nil, errors.NewError("update-check-opt-out must be true or false")
+				}
+
+				c.UpdateCheckOptOut = &val
 			}
 		}
 	}

internal/update/update.go

@@ -0,0 +1,184 @@
+package update
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/launchdarkly/ldcli/internal/config"
+)
+
+const (
+	defaultGitHubReleasesURL = "https://api.github.com/repos/launchdarkly/ldcli/releases/latest"
+	cacheTTL                 = 24 * time.Hour
+	cacheFilename            = "update-check.json"
+	httpTimeout              = 3 * time.Second
+)
+
+var releasesURL = defaultGitHubReleasesURL
+
+type UpdateInfo struct {
+	CurrentVersion string
+	LatestVersion  string
+	IsNewer        bool
+}
+
+type cacheEntry struct {
+	LatestVersion string    `json:"latest_version"`
+	CheckedAt     time.Time `json:"checked_at"`
+}
+
+type githubRelease struct {
+	TagName string `json:"tag_name"`
+}
+
+// cacheFilePathFn is a function variable to allow test overrides.
+var cacheFilePathFn = defaultCacheFilePath
+
+func defaultCacheFilePath() string {
+	configFile := config.GetConfigFile()
+	return filepath.Join(filepath.Dir(configFile), cacheFilename)
+}
+
+func readCache() (*cacheEntry, error) {
+	data, err := os.ReadFile(cacheFilePathFn())
+	if err != nil {
+		return nil, err
+	}
+
+	var entry cacheEntry
+	if err := json.Unmarshal(data, &entry); err != nil {
+		return nil, err
+	}
+
+	return &entry, nil
+}
+
+func writeCache(entry *cacheEntry) {
+	data, err := json.Marshal(entry)
+	if err != nil {
+		return
+	}
+
+	_ = os.MkdirAll(filepath.Dir(cacheFilePathFn()), os.ModePerm)
+	_ = os.WriteFile(cacheFilePathFn(), data, 0644)
+}
+
+func fetchLatestVersion(client *http.Client) (string, error) {
+	req, err := http.NewRequest(http.MethodGet, releasesURL, nil)
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Accept", "application/vnd.github.v3+json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("unexpected status: %d", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	var release githubRelease
+	if err := json.Unmarshal(body, &release); err != nil {
+		return "", err
+	}
+
+	return normalizeVersion(release.TagName), nil
+}
+
+// normalizeVersion strips a leading "v" prefix if present.
+func normalizeVersion(v string) string {
+	return strings.TrimPrefix(v, "v")
+}
+
+// compareVersions returns true if latest is newer than current.
+// Uses a simple split-and-compare on major.minor.patch integers.
+func compareVersions(current, latest string) bool {
+	parseParts := func(v string) [3]int {
+		var parts [3]int
+		n, _ := fmt.Sscanf(v, "%d.%d.%d", &parts[0], &parts[1], &parts[2])
+		if n < 1 {
+			return [3]int{}
+		}
+		return parts
+	}
+
+	c := parseParts(current)
+	l := parseParts(latest)
+
+	for i := 0; i < 3; i++ {
+		if l[i] > c[i] {
+			return true
+		}
+		if l[i] < c[i] {
+			return false
+		}
+	}
+
+	return false
+}
+
+// CheckForUpdate checks GitHub for the latest release and compares it to the
+// current version. It caches the result to avoid hitting the network on every
+// invocation. Returns nil when no update is available or on any error.
+func CheckForUpdate(currentVersion string) *UpdateInfo {
+	currentVersion = normalizeVersion(currentVersion)
+	if currentVersion == "dev" || currentVersion == "test" || currentVersion == "" {
+		return nil
+	}
+
+	cached, err := readCache()
+	if err == nil && time.Since(cached.CheckedAt) < cacheTTL {
+		if !compareVersions(currentVersion, cached.LatestVersion) {
+			return nil
+		}
+		return &UpdateInfo{
+			CurrentVersion: currentVersion,
+			LatestVersion:  cached.LatestVersion,
+			IsNewer:        true,
+		}
+	}
+
+	client := &http.Client{Timeout: httpTimeout}
+	latest, err := fetchLatestVersion(client)
+	if err != nil {
+		return nil
+	}
+
+	writeCache(&cacheEntry{
+		LatestVersion: latest,
+		CheckedAt:     time.Now(),
+	})
+
+	if !compareVersions(currentVersion, latest) {
+		return nil
+	}
+
+	return &UpdateInfo{
+		CurrentVersion: currentVersion,
+		LatestVersion:  latest,
+		IsNewer:        true,
+	}
+}
+
+// NotificationMessage returns a user-facing string about the available update.
+func NotificationMessage(info *UpdateInfo) string {
+	return fmt.Sprintf(
+		"\nA new version of ldcli is available: %s → %s\nhttps://github.com/launchdarkly/ldcli/releases/latest\n",
+		info.CurrentVersion,
+		info.LatestVersion,
+	)
+}