added to OSN new handler for fetch a block of channel

Signed-off-by: Fedor Partanskiy <fredprtnsk@gmail.com>

Author: pfi79

cmd/osnadmin/main.go

@@ -16,6 +16,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"strconv"
 
 	"github.com/hyperledger/fabric-protos-go-apiv2/common"
 	"github.com/hyperledger/fabric/internal/osnadmin"
@@ -63,6 +64,11 @@ func executeForArgs(args []string) (output string, exit int, err error) {
 	configUpdateEnvelopePath := update.Flag("config-update-envelope", "Path to the file containing an up-to-date config update envelope for the channel").Short('e').Required().String()
 	tlsHandshakeTimeShift := update.Flag("tlsHandshakeTimeShift", "The amount of time to shift backwards for certificate expiration checks during TLS handshakes with the orderer endpoint").Short('t').Default("0").Duration()
 
+	fetch := channel.Command("fetch", "Fetch a specified block, writing it to a file.")
+	fetchChannelID := fetch.Flag("channelID", "Channel ID").Short('c').Required().String()
+	fetchBlockID := fetch.Flag("blockID", "Block ID - <newest|oldest|config|(number)>").Short('b').Required().String()
+	fetchOutputFile := fetch.Flag("outputfile", "Puth to a file.").Short('o').Required().String()
+
 	command, err := app.Parse(args)
 	if err != nil {
 		return "", 1, err
@@ -141,6 +147,14 @@ func executeForArgs(args []string) (output string, exit int, err error) {
 		resp, err = osnadmin.Remove(osnURL, *removeChannelID, caCertPool, tlsClientCert)
 	case update.FullCommand():
 		resp, err = osnadmin.Update(osnURL, marshaledConfigEnvelope, caCertPool, tlsClientCert, *tlsHandshakeTimeShift)
+	case fetch.FullCommand():
+		if *fetchBlockID != "newest" && *fetchBlockID != "oldest" && *fetchBlockID != "config" {
+			_, err = strconv.Atoi(*fetchBlockID)
+			if err != nil {
+				return "", 1, fmt.Errorf("'%s' not equal <newest|oldest|config|(number)>", *fetchBlockID)
+			}
+		}
+		resp, err = osnadmin.Fetch(osnURL, *fetchChannelID, *fetchBlockID, caCertPool, tlsClientCert)
 	}
 	if err != nil {
 		return errorOutput(err), 1, nil
@@ -151,22 +165,28 @@ func executeForArgs(args []string) (output string, exit int, err error) {
 		return errorOutput(err), 1, nil
 	}
 
-	output, err = responseOutput(!*noStatus, resp.StatusCode, bodyBytes)
+	output, err = responseOutput(!*noStatus, resp.StatusCode, bodyBytes, *fetchOutputFile)
 	if err != nil {
 		return errorOutput(err), 1, nil
 	}
 
 	return output, 0, nil
 }
 
-func responseOutput(showStatus bool, statusCode int, responseBody []byte) (string, error) {
+func responseOutput(showStatus bool, statusCode int, responseBody []byte, outputFile string) (string, error) {
 	var buffer bytes.Buffer
 	if showStatus {
 		fmt.Fprintf(&buffer, "Status: %d\n", statusCode)
 	}
 	if len(responseBody) != 0 {
-		if err := json.Indent(&buffer, responseBody, "", "\t"); err != nil {
-			return "", err
+		if outputFile != "" {
+			if err := os.WriteFile(outputFile, responseBody, 0o644); err != nil {
+				return "", err
+			}
+		} else {
+			if err := json.Indent(&buffer, responseBody, "", "\t"); err != nil {
+				return "", err
+			}
 		}
 	}
 	return buffer.String(), nil

cmd/osnadmin/mocks/channel_management.go

@@ -23,6 +23,7 @@ type channelManagement interface {
 	JoinChannel(channelID string, configBlock *cb.Block) (types.ChannelInfo, error)
 	UpdateChannel(channelID string, configUpdateEnvelope *cb.Envelope) (types.ChannelInfo, error)
 	RemoveChannel(channelID string) error
+	FetchBlock(channelID string, blockID string) (*cb.Block, error)
 }
 
 func TestOsnadmin(t *testing.T) {

cmd/osnadmin/osnadmin_suite_test.go

@@ -0,0 +1,15 @@
+package osnadmin
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"net/http"
+)
+
+// Fetch get block from OSN.
+func Fetch(osnURL, channelID string, blockID string, caCertPool *x509.CertPool, tlsClientCert tls.Certificate) (*http.Response, error) {
+	url := fmt.Sprintf("%s/participation/v1/channels/%s/blocks/%s", osnURL, channelID, blockID)
+
+	return httpGet(url, caCertPool, tlsClientCert)
+}