feat: Add UI for awaiting agent connections (#578)

* feat: Add stage to build logs

This adds a stage property to logs, and refactors the job logs
cliui.

It also adds tests to the cliui for build logs!

* feat: Add stage to build logs

This adds a stage property to logs, and refactors the job logs
cliui.

It also adds tests to the cliui for build logs!

* feat: Add config-ssh and tests for resiliency

* Rename "Echo" test to "ImmediateExit"

* Fix Terraform resource agent association

* Fix logs post-cancel

* Fix select on Windows

* Remove terraform init logs

* Move timer into it's own loop

* Fix race condition in provisioner jobs

* Fix requested changes

agent/agent_test.go

@@ -39,7 +39,10 @@ func TestAgent(t *testing.T) {
 		t.Cleanup(func() {
 			_ = conn.Close()
 		})
-		client := agent.Conn{conn}
+		client := agent.Conn{
+			Negotiator: api,
+			Conn:       conn,
+		}
 		sshClient, err := client.SSHClient()
 		require.NoError(t, err)
 		session, err := sshClient.NewSession()
@@ -65,7 +68,10 @@ func TestAgent(t *testing.T) {
 		t.Cleanup(func() {
 			_ = conn.Close()
 		})
-		client := &agent.Conn{conn}
+		client := &agent.Conn{
+			Negotiator: api,
+			Conn:       conn,
+		}
 		sshClient, err := client.SSHClient()
 		require.NoError(t, err)
 		session, err := sshClient.NewSession()

agent/conn.go

@@ -8,11 +8,15 @@ import (
 	"golang.org/x/xerrors"
 
 	"github.com/coder/coder/peer"
+	"github.com/coder/coder/peerbroker/proto"
 )
 
 // Conn wraps a peer connection with helper functions to
 // communicate with the agent.
 type Conn struct {
+	// Negotiator is responsible for exchanging messages.
+	Negotiator proto.DRPCPeerBrokerClient
+
 	*peer.Conn
 }
 
@@ -48,3 +52,8 @@ func (c *Conn) SSHClient() (*ssh.Client, error) {
 	}
 	return ssh.NewClient(sshConn, channels, requests), nil
 }
+
+func (c *Conn) Close() error {
+	_ = c.Negotiator.DRPCConn().Close()
+	return c.Conn.Close()
+}