config-ssh: always support agent name in host alias (#3036)

cli/configssh.go

@@ -89,18 +89,23 @@ func sshFetchWorkspaceConfigs(ctx context.Context, client *codersdk.Client) ([]s
 			}
 
 			wc := sshWorkspaceConfig{Name: workspace.Name}
+			var agents []codersdk.WorkspaceAgent
 			for _, resource := range resources {
 				if resource.Transition != codersdk.WorkspaceTransitionStart {
 					continue
 				}
-				for _, agent := range resource.Agents {
-					hostname := workspace.Name
-					if len(resource.Agents) > 1 {
-						hostname += "." + agent.Name
-					}
-					wc.Hosts = append(wc.Hosts, hostname)
-				}
+				agents = append(agents, resource.Agents...)
 			}
+
+			// handle both WORKSPACE and WORKSPACE.AGENT syntax
+			if len(agents) == 1 {
+				wc.Hosts = append(wc.Hosts, workspace.Name)
+			}
+			for _, agent := range agents {
+				hostname := workspace.Name + "." + agent.Name
+				wc.Hosts = append(wc.Hosts, hostname)
+			}
+
 			workspaceConfigs[i] = wc
 
 			return nil

cli/configssh_test.go

@@ -1,6 +1,8 @@
 package cli_test
 
 import (
+	"bufio"
+	"bytes"
 	"context"
 	"fmt"
 	"io"
@@ -692,3 +694,152 @@ func TestConfigSSH_FileWriteAndOptionsFlow(t *testing.T) {
 		})
 	}
 }
+
+func TestConfigSSH_Hostnames(t *testing.T) {
+	t.Parallel()
+
+	type resourceSpec struct {
+		name   string
+		agents []string
+	}
+	tests := []struct {
+		name      string
+		resources []resourceSpec
+		expected  []string
+	}{
+		{
+			name: "one resource with one agent",
+			resources: []resourceSpec{
+				{name: "foo", agents: []string{"agent1"}},
+			},
+			expected: []string{"coder.@", "coder.@.agent1"},
+		},
+		{
+			name: "one resource with two agents",
+			resources: []resourceSpec{
+				{name: "foo", agents: []string{"agent1", "agent2"}},
+			},
+			expected: []string{"coder.@.agent1", "coder.@.agent2"},
+		},
+		{
+			name: "two resources with one agent",
+			resources: []resourceSpec{
+				{name: "foo", agents: []string{"agent1"}},
+				{name: "bar"},
+			},
+			expected: []string{"coder.@", "coder.@.agent1"},
+		},
+		{
+			name: "two resources with two agents",
+			resources: []resourceSpec{
+				{name: "foo", agents: []string{"agent1"}},
+				{name: "bar", agents: []string{"agent2"}},
+			},
+			expected: []string{"coder.@.agent1", "coder.@.agent2"},
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			var resources []*proto.Resource
+			for _, resourceSpec := range tt.resources {
+				resource := &proto.Resource{
+					Name: resourceSpec.name,
+					Type: "aws_instance",
+				}
+				for _, agentName := range resourceSpec.agents {
+					resource.Agents = append(resource.Agents, &proto.Agent{
+						Id:   uuid.NewString(),
+						Name: agentName,
+					})
+				}
+				resources = append(resources, resource)
+			}
+
+			provisionResponse := []*proto.Provision_Response{{
+				Type: &proto.Provision_Response_Complete{
+					Complete: &proto.Provision_Complete{
+						Resources: resources,
+					},
+				},
+			}}
+
+			client := coderdtest.New(t, &coderdtest.Options{IncludeProvisionerD: true})
+			user := coderdtest.CreateFirstUser(t, client)
+			// authToken := uuid.NewString()
+			version := coderdtest.CreateTemplateVersion(t, client, user.OrganizationID, &echo.Responses{
+				Parse:           echo.ParseComplete,
+				ProvisionDryRun: provisionResponse,
+				Provision:       provisionResponse,
+			})
+			coderdtest.AwaitTemplateVersionJob(t, client, version.ID)
+			template := coderdtest.CreateTemplate(t, client, user.OrganizationID, version.ID)
+			workspace := coderdtest.CreateWorkspace(t, client, user.OrganizationID, template.ID)
+			coderdtest.AwaitWorkspaceBuildJob(t, client, workspace.LatestBuild.ID)
+
+			sshConfigFile, _ := sshConfigFileNames(t)
+
+			cmd, root := clitest.New(t, "config-ssh", "--ssh-config-file", sshConfigFile)
+			clitest.SetupConfig(t, client, root)
+			doneChan := make(chan struct{})
+			pty := ptytest.New(t)
+			cmd.SetIn(pty.Input())
+			cmd.SetOut(pty.Output())
+			go func() {
+				defer close(doneChan)
+				err := cmd.Execute()
+				assert.NoError(t, err)
+			}()
+
+			matches := []struct {
+				match, write string
+			}{
+				{match: "Continue?", write: "yes"},
+			}
+			for _, m := range matches {
+				pty.ExpectMatch(m.match)
+				pty.WriteLine(m.write)
+			}
+
+			<-doneChan
+
+			var expectedHosts []string
+			for _, hostnamePattern := range tt.expected {
+				hostname := strings.ReplaceAll(hostnamePattern, "@", workspace.Name)
+				expectedHosts = append(expectedHosts, hostname)
+			}
+
+			hosts := sshConfigFileParseHosts(t, sshConfigFile)
+			require.ElementsMatch(t, expectedHosts, hosts)
+		})
+	}
+}
+
+// sshConfigFileParseHosts reads a file in the format of .ssh/config and extracts
+// the hostnames that are listed in "Host" directives.
+func sshConfigFileParseHosts(t *testing.T, name string) []string {
+	t.Helper()
+	b, err := os.ReadFile(name)
+	require.NoError(t, err)
+
+	var result []string
+	lineScanner := bufio.NewScanner(bytes.NewBuffer(b))
+	for lineScanner.Scan() {
+		line := lineScanner.Text()
+		line = strings.TrimSpace(line)
+
+		tokenScanner := bufio.NewScanner(bytes.NewBufferString(line))
+		tokenScanner.Split(bufio.ScanWords)
+		ok := tokenScanner.Scan()
+		if ok && tokenScanner.Text() == "Host" {
+			for tokenScanner.Scan() {
+				result = append(result, tokenScanner.Text())
+			}
+		}
+	}
+
+	return result
+}