[8.x](backport #6276) Fix/5163 retry download upgrade verifiers

changelog/fragments/1733936340-add-retries-for-download-upgrade-verifiers.yaml

@@ -0,0 +1,30 @@
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: bug-fix
+
+# Change summary; a 80ish characters long description of the change.
+summary: added retries for requesting download verifiers when upgrading the agent
+
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# NOTE: This field will be rendered only for breaking-change and known-issue kinds at the moment.
+#description:
+
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: "elastic-agent"
+# PR URL; optional; the PR number that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+pr: https://github.com/elastic/elastic-agent/pull/6276
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+#issue: https://github.com/owner/repo/1234

internal/pkg/agent/application/upgrade/artifact/download/composed/verifier.go

@@ -5,6 +5,7 @@
 package composed
 
 import (
+	"context"
 	goerrors "errors"
 
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/artifact"
@@ -39,11 +40,11 @@ func NewVerifier(log *logger.Logger, verifiers ...download.Verifier) *Verifier {
 }
 
 // Verify checks the package from configured source.
-func (v *Verifier) Verify(a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultPgp bool, pgpBytes ...string) error {
+func (v *Verifier) Verify(ctx context.Context, a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultPgp bool, pgpBytes ...string) error {
 	var errs []error
 
 	for _, verifier := range v.vv {
-		e := verifier.Verify(a, version, skipDefaultPgp, pgpBytes...)
+		e := verifier.Verify(ctx, a, version, skipDefaultPgp, pgpBytes...)
 		if e == nil {
 			// Success
 			return nil

internal/pkg/agent/application/upgrade/artifact/download/composed/verifier_test.go

@@ -5,6 +5,7 @@
 package composed
 
 import (
+	"context"
 	"errors"
 	"testing"
 
@@ -24,7 +25,7 @@ func (d *ErrorVerifier) Name() string {
 	return "error"
 }
 
-func (d *ErrorVerifier) Verify(artifact.Artifact, agtversion.ParsedSemVer, bool, ...string) error {
+func (d *ErrorVerifier) Verify(context.Context, artifact.Artifact, agtversion.ParsedSemVer, bool, ...string) error {
 	d.called = true
 	return errors.New("failing")
 }
@@ -39,7 +40,7 @@ func (d *FailVerifier) Name() string {
 	return "fail"
 }
 
-func (d *FailVerifier) Verify(artifact.Artifact, agtversion.ParsedSemVer, bool, ...string) error {
+func (d *FailVerifier) Verify(context.Context, artifact.Artifact, agtversion.ParsedSemVer, bool, ...string) error {
 	d.called = true
 	return &download.InvalidSignatureError{File: "", Err: errors.New("invalid signature")}
 }
@@ -54,7 +55,7 @@ func (d *SuccVerifier) Name() string {
 	return "succ"
 }
 
-func (d *SuccVerifier) Verify(artifact.Artifact, agtversion.ParsedSemVer, bool, ...string) error {
+func (d *SuccVerifier) Verify(context.Context, artifact.Artifact, agtversion.ParsedSemVer, bool, ...string) error {
 	d.called = true
 	return nil
 }
@@ -90,7 +91,7 @@ func TestVerifier(t *testing.T) {
 	testVersion := agtversion.NewParsedSemVer(1, 2, 3, "", "")
 	for _, tc := range testCases {
 		d := NewVerifier(log, tc.verifiers[0], tc.verifiers[1], tc.verifiers[2])
-		err := d.Verify(artifact.Artifact{Name: "a", Cmd: "a", Artifact: "a/a"}, *testVersion, false)
+		err := d.Verify(context.Background(), artifact.Artifact{Name: "a", Cmd: "a", Artifact: "a/a"}, *testVersion, false)
 
 		assert.Equal(t, tc.expectedResult, err == nil)
 

internal/pkg/agent/application/upgrade/artifact/download/fs/verifier.go

@@ -5,6 +5,7 @@
 package fs
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"os"
@@ -65,7 +66,7 @@ func NewVerifier(log *logger.Logger, config *artifact.Config, pgp []byte) (*Veri
 
 // Verify checks downloaded package on preconfigured
 // location against a key stored on elastic.co website.
-func (v *Verifier) Verify(a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultPgp bool, pgpBytes ...string) error {
+func (v *Verifier) Verify(ctx context.Context, a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultPgp bool, pgpBytes ...string) error {
 	filename, err := artifact.GetArtifactName(a, version, v.config.OS(), v.config.Arch())
 	if err != nil {
 		return fmt.Errorf("could not get artifact name: %w", err)

internal/pkg/agent/application/upgrade/artifact/download/fs/verifier_test.go

@@ -29,12 +29,11 @@ import (
 
 var testVersion = agtversion.NewParsedSemVer(7, 5, 1, "", "")
 
-var (
-	agentSpec = artifact.Artifact{
-		Name:     "Elastic Agent",
-		Cmd:      "elastic-agent",
-		Artifact: "beat/elastic-agent"}
-)
+var agentSpec = artifact.Artifact{
+	Name:     "Elastic Agent",
+	Cmd:      "elastic-agent",
+	Artifact: "beat/elastic-agent",
+}
 
 func TestFetchVerify(t *testing.T) {
 	// See docs/pgp-sign-verify-artifact.md for how to generate a key, export
@@ -47,7 +46,8 @@ func TestFetchVerify(t *testing.T) {
 	targetPath := filepath.Join("testdata", "download")
 	ctx := context.Background()
 	a := artifact.Artifact{
-		Name: "elastic-agent", Cmd: "elastic-agent", Artifact: "beats/elastic-agent"}
+		Name: "elastic-agent", Cmd: "elastic-agent", Artifact: "beats/elastic-agent",
+	}
 	version := agtversion.NewParsedSemVer(8, 0, 0, "", "")
 
 	filename := "elastic-agent-8.0.0-darwin-x86_64.tar.gz"
@@ -80,7 +80,7 @@ func TestFetchVerify(t *testing.T) {
 	// first download verify should fail:
 	// download skipped, as invalid package is prepared upfront
 	// verify fails and cleans download
-	err = verifier.Verify(a, *version, false)
+	err = verifier.Verify(ctx, a, *version, false)
 	var checksumErr *download.ChecksumMismatchError
 	require.ErrorAs(t, err, &checksumErr)
 
@@ -109,7 +109,7 @@ func TestFetchVerify(t *testing.T) {
 	_, err = os.Stat(ascTargetFilePath)
 	require.NoError(t, err)
 
-	err = verifier.Verify(a, *version, false)
+	err = verifier.Verify(ctx, a, *version, false)
 	require.NoError(t, err)
 
 	// Bad GPG public key.
@@ -126,7 +126,7 @@ func TestFetchVerify(t *testing.T) {
 
 	// Missing .asc file.
 	{
-		err = verifier.Verify(a, *version, false)
+		err = verifier.Verify(ctx, a, *version, false)
 		require.Error(t, err)
 
 		// Don't delete these files when GPG validation failure.
@@ -139,7 +139,7 @@ func TestFetchVerify(t *testing.T) {
 		err = os.WriteFile(targetFilePath+".asc", []byte("bad sig"), 0o600)
 		require.NoError(t, err)
 
-		err = verifier.Verify(a, *version, false)
+		err = verifier.Verify(ctx, a, *version, false)
 		var invalidSigErr *download.InvalidSignatureError
 		assert.ErrorAs(t, err, &invalidSigErr)
 
@@ -157,7 +157,8 @@ func prepareFetchVerifyTests(
 	targetDir,
 	filename,
 	targetFilePath,
-	hashTargetFilePath string) error {
+	hashTargetFilePath string,
+) error {
 	sourceFilePath := filepath.Join(dropPath, filename)
 	hashSourceFilePath := filepath.Join(dropPath, filename+".sha512")
 
@@ -202,6 +203,7 @@ func TestVerify(t *testing.T) {
 
 	for _, tc := range tt {
 		t.Run(tc.Name, func(t *testing.T) {
+			ctx := context.Background()
 			log, obs := loggertest.New("TestVerify")
 			targetDir := t.TempDir()
 
@@ -220,7 +222,7 @@ func TestVerify(t *testing.T) {
 			pgpKey := prepareTestCase(t, agentSpec, testVersion, config)
 
 			testClient := NewDownloader(config)
-			artifactPath, err := testClient.Download(context.Background(), agentSpec, testVersion)
+			artifactPath, err := testClient.Download(ctx, agentSpec, testVersion)
 			require.NoError(t, err, "fs.Downloader could not download artifacts")
 			_, err = testClient.DownloadAsc(context.Background(), agentSpec, *testVersion)
 			require.NoError(t, err, "fs.Downloader could not download artifacts .asc file")
@@ -231,7 +233,7 @@ func TestVerify(t *testing.T) {
 			testVerifier, err := NewVerifier(log, config, pgpKey)
 			require.NoError(t, err)
 
-			err = testVerifier.Verify(agentSpec, *testVersion, false, tc.RemotePGPUris...)
+			err = testVerifier.Verify(ctx, agentSpec, *testVersion, false, tc.RemotePGPUris...)
 			require.NoError(t, err)
 
 			// log message informing remote PGP was skipped
@@ -246,7 +248,6 @@ func TestVerify(t *testing.T) {
 // It creates the necessary key to sing the artifact and returns the public key
 // to verify the signature.
 func prepareTestCase(t *testing.T, a artifact.Artifact, version *agtversion.ParsedSemVer, cfg *artifact.Config) []byte {
-
 	filename, err := artifact.GetArtifactName(a, *version, cfg.OperatingSystem, cfg.Architecture)
 	require.NoErrorf(t, err, "could not get artifact name")
 

internal/pkg/agent/application/upgrade/artifact/download/http/common_test.go

@@ -55,7 +55,28 @@ func getTestCases() []testCase {
 	}
 }
 
-func getElasticCoServer(t *testing.T) (*httptest.Server, []byte) {
+type extResCode map[string]struct {
+	resCode int
+	count   int
+}
+
+type testDials struct {
+	extResCode
+}
+
+func (td *testDials) withExtResCode(k string, statusCode int, count int) {
+	td.extResCode[k] = struct {
+		resCode int
+		count   int
+	}{statusCode, count}
+}
+
+func (td *testDials) reset() {
+	*td = testDials{extResCode: make(extResCode)}
+}
+
+func getElasticCoServer(t *testing.T) (*httptest.Server, []byte, *testDials) {
+	td := testDials{extResCode: make(extResCode)}
 	correctValues := map[string]struct{}{
 		fmt.Sprintf("%s-%s-%s", beatSpec.Cmd, version, "i386.deb"):             {},
 		fmt.Sprintf("%s-%s-%s", beatSpec.Cmd, version, "amd64.deb"):            {},
@@ -81,7 +102,6 @@ func getElasticCoServer(t *testing.T) (*httptest.Server, []byte) {
 			ext = ".tar.gz"
 		}
 		packageName = strings.TrimSuffix(packageName, ext)
-
 		switch ext {
 		case ".sha512":
 			resp = []byte(fmt.Sprintf("%x %s", hash, packageName))
@@ -103,11 +123,17 @@ func getElasticCoServer(t *testing.T) (*httptest.Server, []byte) {
 			return
 		}
 
+		if v, ok := td.extResCode[ext]; ok && v.count != 0 {
+			w.WriteHeader(v.resCode)
+			v.count--
+			td.extResCode[ext] = v
+		}
+
 		_, err := w.Write(resp)
 		assert.NoErrorf(t, err, "mock elastic.co server: failes writing response")
 	})
 
-	return httptest.NewServer(handler), pub
+	return httptest.NewServer(handler), pub, &td
 }
 
 func getElasticCoClient(server *httptest.Server) http.Client {

internal/pkg/agent/application/upgrade/artifact/download/http/downloader_test.go

@@ -44,7 +44,7 @@ func TestDownload(t *testing.T) {
 	log, _ := logger.New("", false)
 	timeout := 30 * time.Second
 	testCases := getTestCases()
-	server, _ := getElasticCoServer(t)
+	server, _, _ := getElasticCoServer(t)
 	elasticClient := getElasticCoClient(server)
 
 	config := &artifact.Config{
@@ -359,7 +359,6 @@ type downloadHttpResponse struct {
 }
 
 func TestDownloadVersion(t *testing.T) {
-
 	type fields struct {
 		config *artifact.Config
 	}
@@ -485,7 +484,6 @@ func TestDownloadVersion(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-
 			targetDirPath := t.TempDir()
 
 			handleDownload := func(rw http.ResponseWriter, req *http.Request) {
@@ -527,5 +525,4 @@ func TestDownloadVersion(t *testing.T) {
 			assert.Equalf(t, filepath.Join(targetDirPath, tt.want), got, "Download(%v, %v)", tt.args.a, tt.args.version)
 		})
 	}
-
 }

internal/pkg/agent/application/upgrade/artifact/download/http/verifier.go

@@ -53,6 +53,9 @@ func NewVerifier(log *logger.Logger, config *artifact.Config, pgp []byte) (*Veri
 		httpcommon.WithModRoundtripper(func(rt http.RoundTripper) http.RoundTripper {
 			return download.WithHeaders(rt, download.Headers)
 		}),
+		httpcommon.WithModRoundtripper(func(rt http.RoundTripper) http.RoundTripper {
+			return WithBackoff(rt, log)
+		}),
 	)
 	if err != nil {
 		return nil, err
@@ -88,7 +91,7 @@ func (v *Verifier) Reload(c *artifact.Config) error {
 
 // Verify checks downloaded package on preconfigured
 // location against a key stored on elastic.co website.
-func (v *Verifier) Verify(a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultPgp bool, pgpBytes ...string) error {
+func (v *Verifier) Verify(ctx context.Context, a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultPgp bool, pgpBytes ...string) error {
 	artifactPath, err := artifact.GetArtifactPath(a, version, v.config.OS(), v.config.Arch(), v.config.TargetDirectory)
 	if err != nil {
 		return errors.New(err, "retrieving package path")
@@ -98,7 +101,7 @@ func (v *Verifier) Verify(a artifact.Artifact, version agtversion.ParsedSemVer,
 		return fmt.Errorf("failed to verify SHA512 hash: %w", err)
 	}
 
-	if err = v.verifyAsc(a, version, skipDefaultPgp, pgpBytes...); err != nil {
+	if err = v.verifyAsc(ctx, a, version, skipDefaultPgp, pgpBytes...); err != nil {
 		var invalidSignatureErr *download.InvalidSignatureError
 		if errors.As(err, &invalidSignatureErr) {
 			if err := os.Remove(artifactPath); err != nil {
@@ -116,7 +119,7 @@ func (v *Verifier) Verify(a artifact.Artifact, version agtversion.ParsedSemVer,
 	return nil
 }
 
-func (v *Verifier) verifyAsc(a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultKey bool, pgpSources ...string) error {
+func (v *Verifier) verifyAsc(ctx context.Context, a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultKey bool, pgpSources ...string) error {
 	filename, err := artifact.GetArtifactName(a, version, v.config.OS(), v.config.Arch())
 	if err != nil {
 		return errors.New(err, "retrieving package name")
@@ -132,7 +135,7 @@ func (v *Verifier) verifyAsc(a artifact.Artifact, version agtversion.ParsedSemVe
 		return errors.New(err, "composing URI for fetching asc file", errors.TypeNetwork)
 	}
 
-	ascBytes, err := v.getPublicAsc(ascURI)
+	ascBytes, err := v.getPublicAsc(ctx, ascURI)
 	if err != nil {
 		return errors.New(err, fmt.Sprintf("fetching asc file from %s", ascURI), errors.TypeNetwork, errors.M(errors.MetaKeyURI, ascURI))
 	}
@@ -163,8 +166,8 @@ func (v *Verifier) composeURI(filename, artifactName string) (string, error) {
 	return uri.String(), nil
 }
 
-func (v *Verifier) getPublicAsc(sourceURI string) ([]byte, error) {
-	ctx, cancelFn := context.WithTimeout(context.Background(), 30*time.Second)
+func (v *Verifier) getPublicAsc(ctx context.Context, sourceURI string) ([]byte, error) {
+	ctx, cancelFn := context.WithTimeout(ctx, 30*time.Second)
 	defer cancelFn()
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, sourceURI, nil)
 	if err != nil {