Add download cache for version dependency files (#2974)

* Add download cache for version files to reduce network calls

Implements a caching mechanism for version dependency files (latest.json and min_cli_version.json) to avoid repeated network requests. The cache expires after 3 hours and is stored in a dedicated download-cache directory. This improves CLI performance by reducing unnecessary downloads while ensuring version information stays reasonably up-to-date.

* Fix unit tests to mock DownloadWithCache method

Author: felipemadero

cmd/root.go

@@ -328,6 +328,13 @@ func setupEnv() (string, error) {
 		return "", err
 	}
 
+	// Create download cache dir if it doesn't exist
+	downloadCacheDir := filepath.Join(baseDir, constants.DownloadCacheDir)
+	if err = os.MkdirAll(downloadCacheDir, os.ModePerm); err != nil {
+		fmt.Printf("failed creating the download cache dir %s: %s\n", downloadCacheDir, err)
+		return "", err
+	}
+
 	return baseDir, nil
 }
 

go.mod

@@ -38,6 +38,7 @@ require (
 	github.com/spf13/pflag v1.0.7
 	github.com/spf13/viper v1.20.1
 	github.com/stretchr/testify v1.10.0
+	go.uber.org/mock v0.5.2
 	go.uber.org/zap v1.27.0
 	golang.org/x/crypto v0.39.0
 	golang.org/x/exp v0.0.0-20250506013437-ce4c2cf36ca6
@@ -225,7 +226,6 @@ require (
 	go.opentelemetry.io/otel/trace v1.36.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.6.0 // indirect
 	go.uber.org/automaxprocs v1.6.0 // indirect
-	go.uber.org/mock v0.5.2 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/net v0.41.0 // indirect
 	golang.org/x/sys v0.33.0 // indirect

internal/mocks/binary_checker.go

@@ -38,6 +38,7 @@ const (
 type Downloader interface {
 	Download(url string) ([]byte, error)
 	DownloadWithTee(url string, path string) ([]byte, error)
+	DownloadWithCache(url string, path string, duration time.Duration) ([]byte, error)
 	GetLatestReleaseVersion(org, repo, component string) (string, error)
 	GetLatestPreReleaseVersion(org, repo, component string) (string, error)
 	GetAllReleasesForRepo(org, repo, component string, kind ReleaseKind) ([]string, error)
@@ -74,6 +75,38 @@ func (d downloader) DownloadWithTee(url string, path string) ([]byte, error) {
 	return bs, os.WriteFile(path, bs, constants.WriteReadReadPerms)
 }
 
+func (d downloader) DownloadWithCache(url string, path string, duration time.Duration) ([]byte, error) {
+	var data []byte
+	var useCache bool
+
+	// Check if cache file exists and is recent
+	if fileInfo, err := os.Stat(path); err == nil {
+		if time.Since(fileInfo.ModTime()) < duration {
+			// Cache is valid, read from it
+			data, err = os.ReadFile(path)
+			if err == nil {
+				useCache = true
+			}
+		}
+	}
+
+	// If cache is not valid or doesn't exist, download
+	if !useCache {
+		var err error
+		data, err = d.Download(url)
+		if err != nil {
+			return nil, err
+		}
+
+		// Save to cache
+		if err := os.MkdirAll(filepath.Dir(path), constants.DefaultPerms755); err == nil {
+			_ = os.WriteFile(path, data, constants.WriteReadReadPerms)
+		}
+	}
+
+	return data, nil
+}
+
 // GetLatestPreReleaseVersion returns the latest available pre release or release version from github
 func (d downloader) GetLatestPreReleaseVersion(org, repo, component string) (string, error) {
 	releases, err := d.GetAllReleasesForRepo(org, repo, component, All)

internal/mocks/downloader.go

@@ -30,6 +30,7 @@ const (
 	AvalancheCliBinDir = "bin"
 	RunDir             = "runs"
 	ServicesDir        = "services"
+	DownloadCacheDir   = "download-cache"
 
 	SuffixSeparator              = "_"
 	SidecarFileName              = "sidecar.json"
@@ -71,6 +72,8 @@ const (
 
 	EVMEventLookupTimeout = 2 * time.Minute
 
+	DownloadCacheExpiration = 3 * time.Hour
+
 	SSHServerStartTimeout       = 1 * time.Minute
 	SSHScriptTimeout            = 2 * time.Minute
 	SSHLongRunningScriptTimeout = 10 * time.Minute
@@ -303,8 +306,10 @@ const (
 	FujiAvalancheGoV113          = "v1.13.0-fuji"
 	AvalancheGoCompatibilityURL  = "https://raw.githubusercontent.com/ava-labs/avalanchego/master/version/compatibility.json"
 	SubnetEVMRPCCompatibilityURL = "https://raw.githubusercontent.com/ava-labs/subnet-evm/master/compatibility.json"
-	CLILatestDependencyURL       = "https://raw.githubusercontent.com/ava-labs/avalanche-cli/main/versions/latest.json"
-	CLIMinVersionURL             = "https://raw.githubusercontent.com/ava-labs/avalanche-cli/main/versions/min_cli_version.json"
+	CLILatestDependencyFileName  = "latest.json"
+	CLIMinVersionFileName        = "min_cli_version.json"
+	CLILatestDependencyURL       = "https://raw.githubusercontent.com/ava-labs/avalanche-cli/main/versions/" + CLILatestDependencyFileName
+	CLIMinVersionURL             = "https://raw.githubusercontent.com/ava-labs/avalanche-cli/main/versions/" + CLIMinVersionFileName
 
 	YesLabel = "Yes"
 	NoLabel  = "No"

internal/mocks/installer.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"path/filepath"
 	"strconv"
 
 	"github.com/ava-labs/avalanche-cli/pkg/application"
@@ -28,13 +29,15 @@ func GetLatestAvalancheGoByProtocolVersion(app *application.Avalanche, rpcVersio
 }
 
 func GetLatestCLISupportedDependencyVersion(app *application.Avalanche, dependencyName string, network models.Network, rpcVersion *int) (string, error) {
-	dependencyBytes, err := app.Downloader.Download(constants.CLILatestDependencyURL)
+	cacheDir := filepath.Join(app.GetBaseDir(), constants.DownloadCacheDir)
+	cacheFile := filepath.Join(cacheDir, constants.CLILatestDependencyFileName)
+	dependencyBytes, err := app.Downloader.DownloadWithCache(constants.CLILatestDependencyURL, cacheFile, constants.DownloadCacheExpiration)
 	if err != nil {
 		return "", err
 	}
 
 	var parsedDependency models.CLIDependencyMap
-	if err = json.Unmarshal(dependencyBytes, &parsedDependency); err != nil {
+	if err := json.Unmarshal(dependencyBytes, &parsedDependency); err != nil {
 		return "", err
 	}