feat(cmd/network/add): Make the chain context optional

cmd/network/add.go

@@ -1,27 +1,47 @@
 package network
 
 import (
+	"context"
+
 	"github.com/spf13/cobra"
 
 	"github.com/oasisprotocol/oasis-sdk/client-sdk/go/config"
+	"github.com/oasisprotocol/oasis-sdk/client-sdk/go/connection"
 
 	cliConfig "github.com/oasisprotocol/cli/config"
 )
 
 var addCmd = &cobra.Command{
-	Use:   "add <name> <chain-context> <rpc-endpoint>",
+	Use:   "add <name> <rpc-endpoint> [chain-context]",
 	Short: "Add a new network",
-	Args:  cobra.ExactArgs(3),
+	Args:  cobra.RangeArgs(2, 3),
 	Run: func(cmd *cobra.Command, args []string) {
 		cfg := cliConfig.Global()
-		name, chainContext, rpc := args[0], args[1], args[2]
+		name, rpc := args[0], args[1]
 
-		net := config.Network{
-			ChainContext: chainContext,
-			RPC:          rpc,
-		}
 		// Validate initial network configuration early.
 		cobra.CheckErr(config.ValidateIdentifier(name))
+
+		net := config.Network{
+			RPC: rpc,
+		}
+
+		if len(args) >= 3 {
+			net.ChainContext = args[2]
+		} else {
+			// Connect to the network and query the chain context.
+			network := config.Network{
+				RPC: net.RPC,
+			}
+			ctx := context.Background()
+			conn, err := connection.ConnectNoVerify(ctx, &network)
+			cobra.CheckErr(err)
+			chainCtx, err := conn.Consensus().GetChainContext(ctx)
+			cobra.CheckErr(err)
+			net.ChainContext = chainCtx
+			cobra.CheckErr(net.Validate())
+		}
+
 		cobra.CheckErr(net.Validate())
 
 		// Ask user for some additional parameters.

docs/network.md

@@ -32,22 +32,29 @@ the current Mainnet and Testnet endpoints.
 
 ## Add a Network {#add}
 
-Invoke `network add <name> <chain-context> <rpc-endpoint>` to add a new
+Invoke `network add <name> <rpc-endpoint> [chain-context]` to add a new
 endpoint with a specific chain domain separation context and a gRPC address.
 This command is useful, if you want to connect to your own instance of the Oasis
 node instead of relying on the public gRPC endpoints.
 
 For TCP/IP endpoints, run:
 
-![code shell](../examples/network/add-tcpip.in.static)
+![code shell](../examples/network/add-tcpip-ctx.in.static)
 
-![code](../examples/network/add-tcpip.out.static)
+![code](../examples/network/add-tcpip-ctx.out.static)
 
 For Unix sockets, use:
 
-![code shell](../examples/network/add-unix.in.static)
+![code shell](../examples/network/add-unix-ctx.in.static)
+
+![code](../examples/network/add-unix-ctx.out.static)
+
+To automatically detect the chain context, simply omit the `[chain-context]`
+argument:
+
+![code shell](../examples/network/add-tcpip.in.static)
 
-![code](../examples/network/add-unix.out.static)
+![code](../examples/network/add-tcpip.out.static)
 
 ## Add a Local Network {#add-local}
 

examples/network/add-tcpip-ctx.in.static

@@ -0,0 +1 @@
+oasis network add testnet_alt testnet2.grpc.oasis.io:443 0b91b8e4e44b2003a7c5e23ddadb5e14ef5345c0ebcb3ddcae07fa2f244cab76

examples/network/add-tcpip-ctx.out.static

@@ -0,0 +1,3 @@
+? Description: Testnet alternative
+? Denomination symbol: TEST
+? Denomination decimal places: (9)

examples/network/add-tcpip.in.static

@@ -1 +1 @@
-oasis network add testnet_alt 0b91b8e4e44b2003a7c5e23ddadb5e14ef5345c0ebcb3ddcae07fa2f244cab76 testnet2.grpc.oasis.io:443
+oasis network add testnet_alt testnet2.grpc.oasis.io:443

examples/network/add-unix-ctx.in.static

@@ -0,0 +1 @@
+oasis network add testnet_local unix:/node_testnet/data/internal.sock 0b91b8e4e44b2003a7c5e23ddadb5e14ef5345c0ebcb3ddcae07fa2f244cab76