[FAB-11334] Adds a 'peer node unjoin' CLI entrypoint to unjoin a peer…

… from a channel (#2769)

This change adds a Viper cobra.Command to unjoin the peer from a specified channel.

Signed-off-by: Josh Kneubuhl <jkneubuh@us.ibm.com>

docs/source/commands/peernode.md

@@ -19,6 +19,7 @@ The `peer node` command has the following subcommands:
   * resume
   * rollback
   * start
+  * unjoin
   * upgrade-dbs
 
 ## peer node pause
@@ -98,6 +99,19 @@ Flags:
 ```
 
 
+## peer node unjoin
+```
+Unjoin the peer from a channel.  When the command is executed, the peer must be offline.
+
+Usage:
+  peer node unjoin [flags]
+
+Flags:
+  -c, --channelID string   Channel to unjoin.
+  -h, --help               help for unjoin
+```
+
+
 ## peer node upgrade-dbs
 ```
 Upgrades databases by directly updating the database format or dropping the databases. Dropped databases will be rebuilt with new format upon peer restart. When the command is executed, the peer must be offline.
@@ -176,6 +190,17 @@ peer node start --peer-chaincodedev
 starts a peer node in chaincode development mode. Normally chaincode containers are started
 and maintained by peer. However in chaincode development mode, chaincode is built and started by the user. This mode is useful during chaincode development phase for iterative development.
 
+### peer node unjoin example 
+
+The following command: 
+
+```
+peer node unjoin -c mychannel
+```
+
+unjoins the peer from channel `mychannel`, removing all content from the ledger and transient storage.  When unjoining a channel, the peer must be shut down.
+
+
 ### peer node upgrade-dbs example
 
 The following command:

docs/wrappers/peer_node_postscript.md

@@ -65,6 +65,17 @@ peer node start --peer-chaincodedev
 starts a peer node in chaincode development mode. Normally chaincode containers are started
 and maintained by peer. However in chaincode development mode, chaincode is built and started by the user. This mode is useful during chaincode development phase for iterative development.
 
+### peer node unjoin example 
+
+The following command: 
+
+```
+peer node unjoin -c mychannel
+```
+
+unjoins the peer from channel `mychannel`, removing all content from the ledger and transient storage.  When unjoining a channel, the peer must be shut down.
+
+
 ### peer node upgrade-dbs example
 
 The following command:

docs/wrappers/peer_node_preamble.md

@@ -14,4 +14,5 @@ The `peer node` command has the following subcommands:
   * resume
   * rollback
   * start
+  * unjoin
   * upgrade-dbs

internal/peer/node/node.go

@@ -15,7 +15,7 @@ import (
 
 const (
 	nodeFuncName = "node"
-	nodeCmdDes   = "Operate a peer node: start|reset|rollback|pause|resume|rebuild-dbs|upgrade-dbs."
+	nodeCmdDes   = "Operate a peer node: start|reset|rollback|pause|resume|rebuild-dbs|unjoin|upgrade-dbs."
 )
 
 var logger = flogging.MustGetLogger("nodeCmd")
@@ -28,6 +28,7 @@ func Cmd() *cobra.Command {
 	nodeCmd.AddCommand(pauseCmd())
 	nodeCmd.AddCommand(resumeCmd())
 	nodeCmd.AddCommand(rebuildDBsCmd())
+	nodeCmd.AddCommand(unjoinCmd())
 	nodeCmd.AddCommand(upgradeDBsCmd())
 	return nodeCmd
 }

internal/peer/node/unjoin.go

@@ -0,0 +1,62 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package node
+
+import (
+	"path/filepath"
+
+	coreconfig "github.com/hyperledger/fabric/core/config"
+	"github.com/hyperledger/fabric/core/ledger/kvledger"
+	"github.com/hyperledger/fabric/core/transientstore"
+	"github.com/hyperledger/fabric/internal/peer/common"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+func unjoinCmd() *cobra.Command {
+	var channelID string
+
+	cmd := &cobra.Command{
+		Use:   "unjoin",
+		Short: "Unjoin the peer from a channel.",
+		Long:  "Unjoin the peer from a channel.  When the command is executed, the peer must be offline.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if channelID == common.UndefinedParamValue {
+				return errors.New("Must supply channel ID")
+			}
+
+			if err := unjoinChannel(channelID); err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+	flags := cmd.Flags()
+	flags.StringVarP(&channelID, "channelID", "c", common.UndefinedParamValue, "Channel to unjoin.")
+
+	return cmd
+}
+
+// unjoin the peer from a channel.
+func unjoinChannel(channelID string) error {
+	// transient storage must be scrubbed prior to removing the kvledger for the channel.  Once the
+	// kvledger storage has been removed, a subsequent ledger removal will return a "no such ledger" error.
+	// By removing the transient storage prior to deleting the ledger, a crash may be recovered by re-running
+	// the peer unjoin.
+	transientStoragePath := filepath.Join(coreconfig.GetPath("peer.fileSystemPath"), "transientstore")
+	if err := transientstore.Drop(transientStoragePath, channelID); err != nil {
+		return err
+	}
+
+	config := ledgerConfig()
+	if err := kvledger.UnjoinChannel(config, channelID); err != nil {
+		return err
+	}
+
+	return nil
+}

internal/peer/node/unjoin_test.go

@@ -0,0 +1,37 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package node
+
+import (
+	"os"
+	"testing"
+
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/require"
+)
+
+func TestUnjoinCmd(t *testing.T) {
+	t.Run("when the channelID is not specified", func(t *testing.T) {
+		cmd := unjoinCmd()
+		args := []string{}
+		cmd.SetArgs(args)
+		err := cmd.Execute()
+		require.EqualError(t, err, "Must supply channel ID")
+	})
+
+	t.Run("when the channel does not exist", func(t *testing.T) {
+		testPath := "/tmp/hyperledger/test"
+		os.RemoveAll(testPath)
+		viper.Set("peer.fileSystemPath", testPath)
+		defer os.RemoveAll(testPath)
+
+		cmd := unjoinCmd()
+		cmd.SetArgs([]string{"-c", "invalid_channel_does_not_exist"})
+		err := cmd.Execute()
+		require.EqualError(t, err, "unjoin channel [invalid_channel_does_not_exist]: cannot update ledger status, ledger [invalid_channel_does_not_exist] does not exist")
+	})
+}

scripts/help_docs.sh

@@ -99,7 +99,7 @@ generateOrCheck \
         docs/wrappers/peer_channel_postscript.md \
         "${commands[@]}"
 
-commands=("peer node pause" "peer node rebuild-dbs" "peer node reset" "peer node resume" "peer node rollback" "peer node start" "peer node upgrade-dbs")
+commands=("peer node pause" "peer node rebuild-dbs" "peer node reset" "peer node resume" "peer node rollback" "peer node start" "peer node unjoin" "peer node upgrade-dbs")
 generateOrCheck \
         docs/source/commands/peernode.md \
         docs/wrappers/peer_node_preamble.md \