diff --git a/pkg/cmd/roachprod/flags.go b/pkg/cmd/roachprod/flags.go
index 54e42efa7adc..3e56c25d9fcb 100644
--- a/pkg/cmd/roachprod/flags.go
+++ b/pkg/cmd/roachprod/flags.go
@@ -43,18 +43,18 @@ var (
 		"COCKROACH_ENABLE_RPC_COMPRESSION=false",
 		"COCKROACH_UI_RELEASE_NOTES_SIGNUP_DISMISSED=true",
 	}
-	tag          string
-	external     = false
-	certsDir     string
-	adminurlOpen = false
-	adminurlPath = ""
-	adminurlIPs  = false
-	useTreeDist  = true
-	quiet        = false
-	sig          = 9
-	waitFlag     = false
-	createVMOpts = vm.DefaultCreateOpts()
-	startOpts    = install.StartOpts{
+	tag           string
+	external      = false
+	pgurlCertsDir string
+	adminurlOpen  = false
+	adminurlPath  = ""
+	adminurlIPs   = false
+	useTreeDist   = true
+	quiet         = false
+	sig           = 9
+	waitFlag      = false
+	createVMOpts  = vm.DefaultCreateOpts()
+	startOpts     = install.StartOpts{
 		Encrypt:    false,
 		Sequential: true,
 		SkipInit:   false,
@@ -152,7 +152,7 @@ func initFlags() {
 
 	pgurlCmd.Flags().BoolVar(&external,
 		"external", false, "return pgurls for external connections")
-	pgurlCmd.Flags().StringVar(&certsDir,
+	pgurlCmd.Flags().StringVar(&pgurlCertsDir,
 		"certs-dir", "./certs", "cert dir to use for secure connections")
 
 	pprofCmd.Flags().DurationVar(&pprofOptions.duration,
diff --git a/pkg/cmd/roachprod/main.go b/pkg/cmd/roachprod/main.go
index a7e365f5ebcc..f5a33dfde7a7 100644
--- a/pkg/cmd/roachprod/main.go
+++ b/pkg/cmd/roachprod/main.go
@@ -85,7 +85,7 @@ func wrap(f func(cmd *cobra.Command, args []string) error) func(cmd *cobra.Comma
 func clusterOpts() install.ClusterSettings {
 	return install.ClusterSettings{
 		Tag:            tag,
-		CertsDir:       certsDir,
+		PGUrlCertsDir:  pgurlCertsDir,
 		Secure:         secure,
 		Quiet:          quiet || !term.IsTerminal(int(os.Stdout.Fd())),
 		UseTreeDist:    useTreeDist,
diff --git a/pkg/roachprod/install/cluster_synced.go b/pkg/roachprod/install/cluster_synced.go
index 27297af58924..86d2d45dd88a 100644
--- a/pkg/roachprod/install/cluster_synced.go
+++ b/pkg/roachprod/install/cluster_synced.go
@@ -45,21 +45,10 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
-// ClusterImpl TODO(peter): document
-type ClusterImpl interface {
-	Start(c *SyncedCluster, opts StartOpts) error
-	CertsDir(c *SyncedCluster, index int) string
-	NodeDir(c *SyncedCluster, index, storeIndex int) string
-	LogDir(c *SyncedCluster, index int) string
-	NodeURL(c *SyncedCluster, host string, port int) string
-	NodePort(c *SyncedCluster, index int) int
-	NodeUIPort(c *SyncedCluster, index int) int
-}
-
 // ClusterSettings contains various knobs that affect operations on a cluster.
 type ClusterSettings struct {
 	Secure         bool
-	CertsDir       string
+	PGUrlCertsDir  string
 	Env            []string
 	Tag            string
 	UseTreeDist    bool
@@ -73,11 +62,11 @@ type ClusterSettings struct {
 // DefaultClusterSettings returns the default settings.
 func DefaultClusterSettings() ClusterSettings {
 	return ClusterSettings{
-		Tag:         "",
-		CertsDir:    "./certs",
-		Secure:      false,
-		Quiet:       false,
-		UseTreeDist: true,
+		Tag:           "",
+		PGUrlCertsDir: "./certs",
+		Secure:        false,
+		Quiet:         false,
+		UseTreeDist:   true,
 		Env: []string{
 			"COCKROACH_ENABLE_RPC_COMPRESSION=false",
 			"COCKROACH_UI_RELEASE_NOTES_SIGNUP_DISMISSED=true",
@@ -102,8 +91,6 @@ type SyncedCluster struct {
 
 	ClusterSettings
 
-	Impl ClusterImpl
-
 	Localities []string
 
 	// AuthorizedKeys is used by SetupSSH to add additional authorized keys.
@@ -120,7 +107,6 @@ func NewSyncedCluster(
 	c := &SyncedCluster{
 		Cluster:         *metadata,
 		ClusterSettings: settings,
-		Impl:            Cockroach{},
 	}
 	c.Localities = make([]string, len(c.VMs))
 	for i := range c.VMs {
@@ -166,14 +152,14 @@ func (c *SyncedCluster) localVMDir(nodeIdx int) string {
 	return local.VMDir(c.Name, nodeIdx)
 }
 
-// ServerNodes is the fully expanded, ordered list of nodes that any given
+// TargetNodes is the fully expanded, ordered list of nodes that any given
 // roachprod command is intending to target.
 //
 //  $ roachprod create local -n 4
 //  $ roachprod start local          # [1, 2, 3, 4]
 //  $ roachprod start local:2-4      # [2, 3, 4]
 //  $ roachprod start local:2,1,4    # [1, 2, 4]
-func (c *SyncedCluster) ServerNodes() []int {
+func (c *SyncedCluster) TargetNodes() []int {
 	return append([]int{}, c.Nodes...)
 }
 
@@ -262,11 +248,6 @@ type StartOpts struct {
 	ExtraArgs  []string
 }
 
-// Start TODO(peter): document
-func (c *SyncedCluster) Start(startOpts StartOpts) error {
-	return c.Impl.Start(c, startOpts)
-}
-
 func (c *SyncedCluster) newSession(i int) (session, error) {
 	if c.IsLocal() {
 		return newLocalSession(), nil
@@ -306,7 +287,7 @@ func (c *SyncedCluster) Stop(sig int, wait bool) error {
     done
     echo "${pid}: dead" >> %[1]s/roachprod.log
   done`,
-				c.Impl.LogDir(c, c.Nodes[i]), // [1]
+				c.LogDir(c.Nodes[i]), // [1]
 			)
 		}
 
@@ -323,7 +304,7 @@ if [ -n "${pids}" ]; then
   kill -%[3]d ${pids}
 %[4]s
 fi`,
-			c.Impl.LogDir(c, c.Nodes[i]),    // [1]
+			c.LogDir(c.Nodes[i]),            // [1]
 			c.roachprodEnvRegex(c.Nodes[i]), // [2]
 			sig,                             // [3]
 			waitCmd,                         // [4]
@@ -442,7 +423,7 @@ type NodeMonitorInfo struct {
 // be emitted for them.
 func (c *SyncedCluster) Monitor(ignoreEmptyNodes bool, oneShot bool) chan NodeMonitorInfo {
 	ch := make(chan NodeMonitorInfo)
-	nodes := c.ServerNodes()
+	nodes := c.TargetNodes()
 	var wg sync.WaitGroup
 
 	for i := range nodes {
@@ -474,8 +455,8 @@ func (c *SyncedCluster) Monitor(ignoreEmptyNodes bool, oneShot bool) chan NodeMo
 			}{
 				OneShot:     oneShot,
 				IgnoreEmpty: ignoreEmptyNodes,
-				Store:       Cockroach{}.NodeDir(c, nodes[i], 1 /* storeIndex */),
-				Port:        Cockroach{}.NodePort(c, nodes[i]),
+				Store:       c.NodeDir(nodes[i], 1 /* storeIndex */),
+				Port:        c.NodePort(nodes[i]),
 				Local:       c.IsLocal(),
 			}
 
@@ -1377,7 +1358,7 @@ func (c *SyncedCluster) Logs(
 		if c.IsLocal() {
 			// This here is a bit of a hack to guess that the parent of the log dir is
 			// the "home" for the local node and that the srcBase is relative to that.
-			localHome := filepath.Dir(c.Impl.LogDir(c, idx))
+			localHome := filepath.Dir(c.LogDir(idx))
 			remote = filepath.Join(localHome, src) + "/"
 		} else {
 			logDir := src
@@ -1706,7 +1687,7 @@ func (c *SyncedCluster) pgurls(nodes []int) (map[int]string, error) {
 	}
 	m := make(map[int]string, len(hosts))
 	for node, host := range hosts {
-		m[node] = c.Impl.NodeURL(c, host, c.Impl.NodePort(c, node))
+		m[node] = c.NodeURL(host, c.NodePort(node))
 	}
 	return m, nil
 }
@@ -1942,19 +1923,16 @@ func (c *SyncedCluster) ParallelE(
 	return nil, nil
 }
 
-// Init initializes the cluster. It does it through node 1 (as per ServerNodes)
+// Init initializes the cluster. It does it through node 1 (as per TargetNodes)
 // to maintain parity with auto-init behavior of `roachprod start` (when
 // --skip-init) is not specified. The implementation should be kept in
-// sync with Cockroach.Start.
+// sync with Start().
 func (c *SyncedCluster) Init() error {
-	r := c.Impl.(Cockroach)
-	h := &crdbInstallHelper{c: c, r: r}
-
-	// See (Cockroach).Start. We reserve a few special operations for the first
-	// node, so we strive to maintain the same here for interoperability.
+	// See Start(). We reserve a few special operations for the first node, so we
+	// strive to maintain the same here for interoperability.
 	const firstNodeIdx = 0
 
-	vers, err := getCockroachVersion(c, c.ServerNodes()[firstNodeIdx])
+	vers, err := getCockroachVersion(c, c.TargetNodes()[firstNodeIdx])
 	if err != nil {
 		return errors.WithDetail(err, "install.Init() failed: unable to retrieve cockroach version.")
 	}
@@ -1963,8 +1941,8 @@ func (c *SyncedCluster) Init() error {
 		return errors.New("install.Init() failed: `roachprod init` only supported for v20.1 and beyond")
 	}
 
-	fmt.Printf("%s: initializing cluster\n", h.c.Name)
-	initOut, err := h.initializeCluster(firstNodeIdx)
+	fmt.Printf("%s: initializing cluster\n", c.Name)
+	initOut, err := c.initializeCluster(firstNodeIdx)
 	if err != nil {
 		return errors.WithDetail(err, "install.Init() failed: unable to initialize cluster.")
 	}
@@ -1972,8 +1950,8 @@ func (c *SyncedCluster) Init() error {
 		fmt.Println(initOut)
 	}
 
-	fmt.Printf("%s: setting cluster settings\n", h.c.Name)
-	clusterSettingsOut, err := h.setClusterSettings(firstNodeIdx)
+	fmt.Printf("%s: setting cluster settings\n", c.Name)
+	clusterSettingsOut, err := c.setClusterSettings(firstNodeIdx)
 	if err != nil {
 		return errors.WithDetail(err, "install.Init() failed: unable to set cluster settings.")
 	}
diff --git a/pkg/roachprod/install/cockroach.go b/pkg/roachprod/install/cockroach.go
index 8d653c571c06..c8f3ee9b2104 100644
--- a/pkg/roachprod/install/cockroach.go
+++ b/pkg/roachprod/install/cockroach.go
@@ -33,9 +33,6 @@ import (
 //go:embed scripts/start.sh
 var startScript string
 
-// Cockroach TODO(peter): document
-type Cockroach struct{}
-
 func cockroachNodeBinary(c *SyncedCluster, node int) string {
 	if filepath.IsAbs(config.Binary) {
 		return config.Binary
@@ -123,20 +120,20 @@ func argExists(args []string, target string) int {
 	return -1
 }
 
-// Start implements the ClusterImpl.NodeDir interface, and powers `roachprod
-// start`. Starting the first node is special-cased quite a bit, it's used to
-// distribute certs, set cluster settings, and initialize the cluster. Also,
-// if we're only starting a single node in the cluster and it happens to be the
-// "first" node (node 1, as understood by SyncedCluster.ServerNodes), we use
+// Start the cockroach process on the cluster.
+//
+// Starting the first node is special-cased quite a bit, it's used to distribute
+// certs, set cluster settings, and initialize the cluster. Also, if we're only
+// starting a single node in the cluster and it happens to be the "first" node
+// (node 1, as understood by SyncedCluster.TargetNodes), we use
 // `start-single-node` (this was written to provide a short hand to start a
 // single node cluster with a replication factor of one).
-func (r Cockroach) Start(c *SyncedCluster, startOpts StartOpts) error {
-	h := &crdbInstallHelper{c: c, r: r}
-	if err := h.distributeCerts(); err != nil {
+func (c *SyncedCluster) Start(startOpts StartOpts) error {
+	if err := c.distributeCerts(); err != nil {
 		return err
 	}
 
-	nodes := c.ServerNodes()
+	nodes := c.TargetNodes()
 	var parallelism = 0
 	if startOpts.Sequential {
 		parallelism = 1
@@ -151,7 +148,7 @@ func (r Cockroach) Start(c *SyncedCluster, startOpts StartOpts) error {
 
 		// NB: if cockroach started successfully, we ignore the output as it is
 		// some harmless start messaging.
-		if _, err := h.startNode(nodeIdx, startOpts, vers); err != nil {
+		if _, err := c.startNode(nodeIdx, startOpts, vers); err != nil {
 			return nil, err
 		}
 
@@ -175,10 +172,10 @@ func (r Cockroach) Start(c *SyncedCluster, startOpts StartOpts) error {
 			return nil, nil
 		}
 
-		shouldInit := !h.useStartSingleNode(vers) && vers.AtLeast(version.MustParse("v20.1.0"))
+		shouldInit := !c.useStartSingleNode(vers) && vers.AtLeast(version.MustParse("v20.1.0"))
 		if shouldInit {
-			fmt.Printf("%s: initializing cluster\n", h.c.Name)
-			initOut, err := h.initializeCluster(nodeIdx)
+			fmt.Printf("%s: initializing cluster\n", c.Name)
+			initOut, err := c.initializeCluster(nodeIdx)
 			if err != nil {
 				return nil, errors.WithDetail(err, "unable to initialize cluster")
 			}
@@ -198,8 +195,8 @@ func (r Cockroach) Start(c *SyncedCluster, startOpts StartOpts) error {
 			// addressing #51897.
 			//
 			// TODO(irfansharif): Remove this once #51897 is resolved.
-			markBootstrap := fmt.Sprintf("touch %s/%s", h.c.Impl.NodeDir(h.c, nodes[nodeIdx], 1 /* storeIndex */), "cluster-bootstrapped")
-			cmdOut, err := h.run(nodeIdx, markBootstrap)
+			markBootstrap := fmt.Sprintf("touch %s/%s", c.NodeDir(nodes[nodeIdx], 1 /* storeIndex */), "cluster-bootstrapped")
+			cmdOut, err := c.run(nodeIdx, markBootstrap)
 			if err != nil {
 				return nil, errors.WithDetail(err, "unable to run cmd")
 			}
@@ -211,8 +208,8 @@ func (r Cockroach) Start(c *SyncedCluster, startOpts StartOpts) error {
 		// We're sure to set cluster settings after having initialized the
 		// cluster.
 
-		fmt.Printf("%s: setting cluster settings\n", h.c.Name)
-		clusterSettingsOut, err := h.setClusterSettings(nodeIdx)
+		fmt.Printf("%s: setting cluster settings\n", c.Name)
+		clusterSettingsOut, err := c.setClusterSettings(nodeIdx)
 		if err != nil {
 			return nil, errors.Wrap(err, "unable to set cluster settings")
 		}
@@ -223,44 +220,44 @@ func (r Cockroach) Start(c *SyncedCluster, startOpts StartOpts) error {
 	})
 }
 
-// NodeDir implements the ClusterImpl.NodeDir interface.
-func (Cockroach) NodeDir(c *SyncedCluster, index, storeIndex int) string {
+// NodeDir returns the data directory for the given node and store.
+func (c *SyncedCluster) NodeDir(nodeIndex, storeIndex int) string {
 	if c.IsLocal() {
 		if storeIndex != 1 {
-			panic("Cockroach.NodeDir only supports one store for local deployments")
+			panic("NodeDir only supports one store for local deployments")
 		}
-		return filepath.Join(c.localVMDir(index), "data")
+		return filepath.Join(c.localVMDir(nodeIndex), "data")
 	}
 	return fmt.Sprintf("/mnt/data%d/cockroach", storeIndex)
 }
 
-// LogDir implements the ClusterImpl.NodeDir interface.
-func (Cockroach) LogDir(c *SyncedCluster, index int) string {
+// LogDir returns the logs directory for the given node.
+func (c *SyncedCluster) LogDir(nodeIndex int) string {
 	if c.IsLocal() {
-		return filepath.Join(c.localVMDir(index), "logs")
+		return filepath.Join(c.localVMDir(nodeIndex), "logs")
 	}
 	return "logs"
 }
 
-// CertsDir implements the ClusterImpl.NodeDir interface.
-func (Cockroach) CertsDir(c *SyncedCluster, index int) string {
+// CertsDir returns the certificate directory for the given node.
+func (c *SyncedCluster) CertsDir(nodeIndex int) string {
 	if c.IsLocal() {
-		return filepath.Join(c.localVMDir(index), "certs")
+		return filepath.Join(c.localVMDir(nodeIndex), "certs")
 	}
 	return "certs"
 }
 
-// NodeURL implements the ClusterImpl.NodeDir interface.
-func (Cockroach) NodeURL(c *SyncedCluster, host string, port int) string {
+// NodeURL constructs a postgres URL.
+func (c *SyncedCluster) NodeURL(host string, port int) string {
 	var u url.URL
 	u.User = url.User("root")
 	u.Scheme = "postgres"
 	u.Host = fmt.Sprintf("%s:%d", host, port)
 	v := url.Values{}
 	if c.Secure {
-		v.Add("sslcert", c.CertsDir+"/client.root.crt")
-		v.Add("sslkey", c.CertsDir+"/client.root.key")
-		v.Add("sslrootcert", c.CertsDir+"/ca.crt")
+		v.Add("sslcert", c.PGUrlCertsDir+"/client.root.crt")
+		v.Add("sslkey", c.PGUrlCertsDir+"/client.root.key")
+		v.Add("sslrootcert", c.PGUrlCertsDir+"/ca.crt")
 		v.Add("sslmode", "verify-full")
 	} else {
 		v.Add("sslmode", "disable")
@@ -269,25 +266,31 @@ func (Cockroach) NodeURL(c *SyncedCluster, host string, port int) string {
 	return "'" + u.String() + "'"
 }
 
-// NodePort implements the ClusterImpl.NodeDir interface.
-func (Cockroach) NodePort(c *SyncedCluster, index int) int {
-	return c.VMs[index-1].SQLPort
+// NodePort returns the SQL port for the given node.
+func (c *SyncedCluster) NodePort(nodeIndex int) int {
+	return c.VMs[nodeIndex-1].SQLPort
 }
 
-// NodeUIPort implements the ClusterImpl.NodeDir interface.
-func (r Cockroach) NodeUIPort(c *SyncedCluster, index int) int {
-	return c.VMs[index-1].AdminUIPort
+// NodeUIPort returns the AdminUI port for the given node.
+func (c *SyncedCluster) NodeUIPort(nodeIndex int) int {
+	return c.VMs[nodeIndex-1].AdminUIPort
 }
 
-// SQL implements the ClusterImpl.NodeDir interface.
-func (r Cockroach) SQL(c *SyncedCluster, args []string) error {
+// SQL runs `cockroach sql`, which starts a SQL shell or runs a SQL command.
+//
+// In interactive mode, there must be exactly one node target (as per
+// TargetNodes).
+//
+// In non-interactive mode, a command specified via the `-e` flag is run against
+// all nodes.
+func (c *SyncedCluster) SQL(args []string) error {
 	if len(args) == 0 || len(c.Nodes) == 1 {
 		// If no arguments, we're going to get an interactive SQL shell. Require
 		// exactly one target and ask SSH to provide a pseudoterminal.
 		if len(args) == 0 && len(c.Nodes) != 1 {
 			return fmt.Errorf("invalid number of nodes for interactive sql: %d", len(c.Nodes))
 		}
-		url := r.NodeURL(c, "localhost", r.NodePort(c, c.Nodes[0]))
+		url := c.NodeURL("localhost", c.NodePort(c.Nodes[0]))
 		binary := cockroachNodeBinary(c, c.Nodes[0])
 		allArgs := []string{binary, "sql", "--url", url}
 		allArgs = append(allArgs, ssh.Escape(args))
@@ -315,7 +318,7 @@ func (r Cockroach) SQL(c *SyncedCluster, args []string) error {
 			cmd = fmt.Sprintf(`cd %s ; `, c.localVMDir(c.Nodes[nodeIdx]))
 		}
 		cmd += cockroachNodeBinary(c, c.Nodes[nodeIdx]) + " sql --url " +
-			r.NodeURL(c, "localhost", r.NodePort(c, c.Nodes[nodeIdx])) + " " +
+			c.NodeURL("localhost", c.NodePort(c.Nodes[nodeIdx])) + " " +
 			ssh.Escape(args)
 
 		out, err := sess.CombinedOutput(cmd)
@@ -343,22 +346,17 @@ func (r Cockroach) SQL(c *SyncedCluster, args []string) error {
 	return nil
 }
 
-type crdbInstallHelper struct {
-	c *SyncedCluster
-	r Cockroach
-}
-
-func (h *crdbInstallHelper) startNode(
+func (c *SyncedCluster) startNode(
 	nodeIdx int, startOpts StartOpts, vers *version.Version,
 ) (string, error) {
-	startCmd, err := h.generateStartCmd(nodeIdx, startOpts, vers)
+	startCmd, err := c.generateStartCmd(nodeIdx, startOpts, vers)
 	if err != nil {
 		return "", err
 	}
 
-	nodes := h.c.ServerNodes()
+	nodes := c.TargetNodes()
 	if err := func() error {
-		sess, err := h.c.newSession(nodes[nodeIdx])
+		sess, err := c.newSession(nodes[nodeIdx])
 		if err != nil {
 			return err
 		}
@@ -366,8 +364,8 @@ func (h *crdbInstallHelper) startNode(
 
 		sess.SetStdin(strings.NewReader(startCmd))
 		var cmd string
-		if h.c.IsLocal() {
-			cmd = fmt.Sprintf(`cd %s ; `, h.c.localVMDir(nodes[nodeIdx]))
+		if c.IsLocal() {
+			cmd = fmt.Sprintf(`cd %s ; `, c.localVMDir(nodes[nodeIdx]))
 		}
 		cmd += `cat > cockroach.sh && chmod +x cockroach.sh`
 		if out, err := sess.CombinedOutput(cmd); err != nil {
@@ -379,15 +377,15 @@ func (h *crdbInstallHelper) startNode(
 		return "", err
 	}
 
-	sess, err := h.c.newSession(nodes[nodeIdx])
+	sess, err := c.newSession(nodes[nodeIdx])
 	if err != nil {
 		return "", err
 	}
 	defer sess.Close()
 
 	var cmd string
-	if h.c.IsLocal() {
-		cmd = fmt.Sprintf(`cd %s ; `, h.c.localVMDir(nodes[nodeIdx]))
+	if c.IsLocal() {
+		cmd = fmt.Sprintf(`cd %s ; `, c.localVMDir(nodes[nodeIdx]))
 	}
 	cmd += "./cockroach.sh"
 	out, err := sess.CombinedOutput(cmd)
@@ -397,11 +395,11 @@ func (h *crdbInstallHelper) startNode(
 	return strings.TrimSpace(string(out)), nil
 }
 
-func (h *crdbInstallHelper) generateStartCmd(
+func (c *SyncedCluster) generateStartCmd(
 	nodeIdx int, startOpts StartOpts, vers *version.Version,
 ) (string, error) {
 
-	args, advertiseFirstIP, err := h.generateStartArgs(nodeIdx, startOpts, vers)
+	args, advertiseFirstIP, err := c.generateStartArgs(nodeIdx, startOpts, vers)
 	if err != nil {
 		return "", err
 	}
@@ -409,25 +407,25 @@ func (h *crdbInstallHelper) generateStartCmd(
 	// For a one-node cluster, use `start-single-node` to disable replication.
 	// For everything else we'll fall back to using `cockroach start`.
 	var startCmd string
-	if h.useStartSingleNode(vers) {
+	if c.useStartSingleNode(vers) {
 		startCmd = "start-single-node"
 	} else {
 		startCmd = "start"
 	}
-	nodes := h.c.ServerNodes()
+	nodes := c.TargetNodes()
 	return execStartTemplate(startTemplateData{
-		LogDir: h.c.Impl.LogDir(h.c, nodes[nodeIdx]),
-		KeyCmd: h.generateKeyCmd(nodeIdx, startOpts),
+		LogDir: c.LogDir(nodes[nodeIdx]),
+		KeyCmd: c.generateKeyCmd(nodeIdx, startOpts),
 		EnvVars: append(append([]string{
-			fmt.Sprintf("ROACHPROD=%s", h.c.roachprodEnvValue(nodes[nodeIdx])),
+			fmt.Sprintf("ROACHPROD=%s", c.roachprodEnvValue(nodes[nodeIdx])),
 			"GOTRACEBACK=crash",
 			"COCKROACH_SKIP_ENABLING_DIAGNOSTIC_REPORTING=1",
-		}, h.c.Env...), h.getEnvVars()...),
-		Binary:           cockroachNodeBinary(h.c, nodes[nodeIdx]),
+		}, c.Env...), getEnvVars()...),
+		Binary:           cockroachNodeBinary(c, nodes[nodeIdx]),
 		StartCmd:         startCmd,
 		Args:             args,
 		MemoryMax:        config.MemoryMax,
-		Local:            h.c.IsLocal(),
+		Local:            c.IsLocal(),
 		AdvertiseFirstIP: advertiseFirstIP,
 	})
 }
@@ -461,14 +459,14 @@ func execStartTemplate(data startTemplateData) (string, error) {
 	return buf.String(), nil
 }
 
-func (h *crdbInstallHelper) generateStartArgs(
+func (c *SyncedCluster) generateStartArgs(
 	nodeIdx int, startOpts StartOpts, vers *version.Version,
 ) (_ []string, _advertiseFirstIP bool, _ error) {
 	var args []string
-	nodes := h.c.ServerNodes()
+	nodes := c.TargetNodes()
 
-	if h.c.Secure {
-		args = append(args, `--certs-dir`, h.c.Impl.CertsDir(h.c, nodes[nodeIdx]))
+	if c.Secure {
+		args = append(args, `--certs-dir`, c.CertsDir(nodes[nodeIdx]))
 	} else {
 		args = append(args, "--insecure")
 	}
@@ -476,7 +474,7 @@ func (h *crdbInstallHelper) generateStartArgs(
 	var storeDirs []string
 	if idx := argExists(startOpts.ExtraArgs, "--store"); idx == -1 {
 		for i := 1; i <= startOpts.StoreCount; i++ {
-			storeDir := h.c.Impl.NodeDir(h.c, nodes[nodeIdx], i)
+			storeDir := c.NodeDir(nodes[nodeIdx], i)
 			storeDirs = append(storeDirs, storeDir)
 			// Place a store{i} attribute on each store to allow for zone configs
 			// that use specific stores.
@@ -498,7 +496,7 @@ func (h *crdbInstallHelper) generateStartArgs(
 		}
 	}
 
-	logDir := h.c.Impl.LogDir(h.c, nodes[nodeIdx])
+	logDir := c.LogDir(nodes[nodeIdx])
 	if vers.AtLeast(version.MustParse("v21.1.0-alpha.0")) {
 		// Specify exit-on-error=false to work around #62763.
 		args = append(args, "--log", `file-defaults: {dir: '`+logDir+`', exit-on-error: false}`)
@@ -508,7 +506,7 @@ func (h *crdbInstallHelper) generateStartArgs(
 
 	if vers.AtLeast(version.MustParse("v1.1.0")) {
 		cache := 25
-		if h.c.IsLocal() {
+		if c.IsLocal() {
 			cache /= len(nodes)
 			if cache == 0 {
 				cache = 1
@@ -517,7 +515,7 @@ func (h *crdbInstallHelper) generateStartArgs(
 		args = append(args, fmt.Sprintf("--cache=%d%%", cache))
 		args = append(args, fmt.Sprintf("--max-sql-memory=%d%%", cache))
 	}
-	if h.c.IsLocal() {
+	if c.IsLocal() {
 		// This avoids annoying firewall prompts on Mac OS X.
 		if vers.AtLeast(version.MustParse("v2.1.0")) {
 			args = append(args, "--listen-addr=127.0.0.1")
@@ -527,16 +525,16 @@ func (h *crdbInstallHelper) generateStartArgs(
 	}
 
 	args = append(args,
-		fmt.Sprintf("--port=%d", h.r.NodePort(h.c, nodes[nodeIdx])),
-		fmt.Sprintf("--http-port=%d", h.r.NodeUIPort(h.c, nodes[nodeIdx])),
+		fmt.Sprintf("--port=%d", c.NodePort(nodes[nodeIdx])),
+		fmt.Sprintf("--http-port=%d", c.NodeUIPort(nodes[nodeIdx])),
 	)
-	if locality := h.c.locality(nodes[nodeIdx]); locality != "" {
+	if locality := c.locality(nodes[nodeIdx]); locality != "" {
 		if idx := argExists(startOpts.ExtraArgs, "--locality"); idx == -1 {
 			args = append(args, "--locality="+locality)
 		}
 	}
 
-	if !h.useStartSingleNode(vers) {
+	if !c.useStartSingleNode(vers) {
 		// --join flags are unsupported/unnecessary in `cockroach
 		// start-single-node`. That aside, setting up --join flags is a bit
 		// precise. We have every node point to node 1. For clusters running
@@ -545,14 +543,14 @@ func (h *crdbInstallHelper) generateStartArgs(
 		// node 1 also points to itself, and an explicit `cockroach init` is
 		// needed.
 		if nodes[nodeIdx] != 1 || vers.AtLeast(version.MustParse("v20.1.0")) {
-			args = append(args, fmt.Sprintf("--join=%s:%d", h.c.host(1), h.r.NodePort(h.c, 1)))
+			args = append(args, fmt.Sprintf("--join=%s:%d", c.host(1), c.NodePort(1)))
 		}
 	}
 
 	var advertiseFirstIP bool
-	if h.shouldAdvertisePublicIP() {
-		args = append(args, fmt.Sprintf("--advertise-host=%s", h.c.host(nodeIdx+1)))
-	} else if !h.c.IsLocal() {
+	if c.shouldAdvertisePublicIP() {
+		args = append(args, fmt.Sprintf("--advertise-host=%s", c.host(nodeIdx+1)))
+	} else if !c.IsLocal() {
 		// Explicitly advertise by IP address so that we don't need to
 		// deal with cross-region name resolution. The `hostname -I`
 		// prints all IP addresses for the host and then we'll select
@@ -566,7 +564,7 @@ func (h *crdbInstallHelper) generateStartArgs(
 		node: nodes[nodeIdx],
 	}
 	for _, arg := range startOpts.ExtraArgs {
-		expandedArg, err := e.expand(h.c, arg)
+		expandedArg, err := e.expand(c, arg)
 		if err != nil {
 			return nil, false, err
 		}
@@ -576,11 +574,11 @@ func (h *crdbInstallHelper) generateStartArgs(
 	return args, advertiseFirstIP, nil
 }
 
-func (h *crdbInstallHelper) initializeCluster(nodeIdx int) (string, error) {
-	nodes := h.c.ServerNodes()
-	initCmd := h.generateInitCmd(nodeIdx)
+func (c *SyncedCluster) initializeCluster(nodeIdx int) (string, error) {
+	nodes := c.TargetNodes()
+	initCmd := c.generateInitCmd(nodeIdx)
 
-	sess, err := h.c.newSession(nodes[nodeIdx])
+	sess, err := c.newSession(nodes[nodeIdx])
 	if err != nil {
 		return "", err
 	}
@@ -593,11 +591,11 @@ func (h *crdbInstallHelper) initializeCluster(nodeIdx int) (string, error) {
 	return strings.TrimSpace(string(out)), nil
 }
 
-func (h *crdbInstallHelper) setClusterSettings(nodeIdx int) (string, error) {
-	nodes := h.c.ServerNodes()
-	clusterSettingCmd := h.generateClusterSettingCmd(nodeIdx)
+func (c *SyncedCluster) setClusterSettings(nodeIdx int) (string, error) {
+	nodes := c.TargetNodes()
+	clusterSettingCmd := c.generateClusterSettingCmd(nodeIdx)
 
-	sess, err := h.c.newSession(nodes[nodeIdx])
+	sess, err := c.newSession(nodes[nodeIdx])
 	if err != nil {
 		return "", err
 	}
@@ -610,22 +608,22 @@ func (h *crdbInstallHelper) setClusterSettings(nodeIdx int) (string, error) {
 	return strings.TrimSpace(string(out)), nil
 }
 
-func (h *crdbInstallHelper) generateClusterSettingCmd(nodeIdx int) string {
-	nodes := h.c.ServerNodes()
+func (c *SyncedCluster) generateClusterSettingCmd(nodeIdx int) string {
+	nodes := c.TargetNodes()
 	license := envutil.EnvOrDefaultString("COCKROACH_DEV_LICENSE", "")
 	if license == "" {
 		fmt.Printf("%s: COCKROACH_DEV_LICENSE unset: enterprise features will be unavailable\n",
-			h.c.Name)
+			c.Name)
 	}
 
 	var clusterSettingCmd string
-	if h.c.IsLocal() {
-		clusterSettingCmd = fmt.Sprintf(`cd %s ; `, h.c.localVMDir(1))
+	if c.IsLocal() {
+		clusterSettingCmd = fmt.Sprintf(`cd %s ; `, c.localVMDir(1))
 	}
 
-	binary := cockroachNodeBinary(h.c, nodes[nodeIdx])
-	path := fmt.Sprintf("%s/%s", h.c.Impl.NodeDir(h.c, nodes[nodeIdx], 1 /* storeIndex */), "settings-initialized")
-	url := h.r.NodeURL(h.c, "localhost", h.r.NodePort(h.c, 1))
+	binary := cockroachNodeBinary(c, nodes[nodeIdx])
+	path := fmt.Sprintf("%s/%s", c.NodeDir(nodes[nodeIdx], 1 /* storeIndex */), "settings-initialized")
+	url := c.NodeURL("localhost", c.NodePort(1))
 
 	// We ignore failures to set remote_debugging.mode, which was
 	// removed in v21.2.
@@ -640,17 +638,17 @@ func (h *crdbInstallHelper) generateClusterSettingCmd(nodeIdx int) string {
 	return clusterSettingCmd
 }
 
-func (h *crdbInstallHelper) generateInitCmd(nodeIdx int) string {
-	nodes := h.c.ServerNodes()
+func (c *SyncedCluster) generateInitCmd(nodeIdx int) string {
+	nodes := c.TargetNodes()
 
 	var initCmd string
-	if h.c.IsLocal() {
-		initCmd = fmt.Sprintf(`cd %s ; `, h.c.localVMDir(1))
+	if c.IsLocal() {
+		initCmd = fmt.Sprintf(`cd %s ; `, c.localVMDir(1))
 	}
 
-	path := fmt.Sprintf("%s/%s", h.c.Impl.NodeDir(h.c, nodes[nodeIdx], 1 /* storeIndex */), "cluster-bootstrapped")
-	url := h.r.NodeURL(h.c, "localhost", h.r.NodePort(h.c, nodes[nodeIdx]))
-	binary := cockroachNodeBinary(h.c, nodes[nodeIdx])
+	path := fmt.Sprintf("%s/%s", c.NodeDir(nodes[nodeIdx], 1 /* storeIndex */), "cluster-bootstrapped")
+	url := c.NodeURL("localhost", c.NodePort(nodes[nodeIdx]))
+	binary := cockroachNodeBinary(c, nodes[nodeIdx])
 	initCmd += fmt.Sprintf(`
 		if ! test -e %[1]s ; then
 			COCKROACH_CONNECT_TIMEOUT=0 %[2]s init --url %[3]s && touch %[1]s
@@ -658,16 +656,16 @@ func (h *crdbInstallHelper) generateInitCmd(nodeIdx int) string {
 	return initCmd
 }
 
-func (h *crdbInstallHelper) generateKeyCmd(nodeIdx int, startOpts StartOpts) string {
+func (c *SyncedCluster) generateKeyCmd(nodeIdx int, startOpts StartOpts) string {
 	if !startOpts.Encrypt {
 		return ""
 	}
 
-	nodes := h.c.ServerNodes()
+	nodes := c.TargetNodes()
 	var storeDirs []string
 	if idx := argExists(startOpts.ExtraArgs, "--store"); idx == -1 {
 		for i := 1; i <= startOpts.StoreCount; i++ {
-			storeDir := h.c.Impl.NodeDir(h.c, nodes[nodeIdx], i)
+			storeDir := c.NodeDir(nodes[nodeIdx], i)
 			storeDirs = append(storeDirs, storeDir)
 		}
 	} else {
@@ -687,37 +685,36 @@ func (h *crdbInstallHelper) generateKeyCmd(nodeIdx int, startOpts StartOpts) str
 	return keyCmd.String()
 }
 
-func (h *crdbInstallHelper) useStartSingleNode(vers *version.Version) bool {
-	return len(h.c.VMs) == 1 && vers.AtLeast(version.MustParse("v19.2.0"))
+func (c *SyncedCluster) useStartSingleNode(vers *version.Version) bool {
+	return len(c.VMs) == 1 && vers.AtLeast(version.MustParse("v19.2.0"))
 }
 
-// distributeCerts, like the name suggests, distributes certs if it's a secure
-// cluster and we're starting n1.
-func (h *crdbInstallHelper) distributeCerts() error {
-	for _, node := range h.c.ServerNodes() {
-		if node == 1 && h.c.Secure {
-			if err := h.c.DistributeCerts(); err != nil {
-				return err
-			}
-			break
+// distributeCerts distributes certs if it's a secure cluster and we're
+// starting n1.
+func (c *SyncedCluster) distributeCerts() error {
+	for _, node := range c.TargetNodes() {
+		if node == 1 && c.Secure {
+			return c.DistributeCerts()
 		}
 	}
 	return nil
 }
 
-func (h *crdbInstallHelper) shouldAdvertisePublicIP() bool {
+func (c *SyncedCluster) shouldAdvertisePublicIP() bool {
 	// If we're creating nodes that span VPC (e.g. AWS multi-region or
 	// multi-cloud), we'll tell the nodes to advertise their public IPs
 	// so that attaching nodes to the cluster Just Works.
-	for i := range h.c.VMs {
-		if i > 0 && h.c.VMs[i].VPC != h.c.VMs[0].VPC {
+	for i := range c.VMs {
+		if i > 0 && c.VMs[i].VPC != c.VMs[0].VPC {
 			return true
 		}
 	}
 	return false
 }
 
-func (h *crdbInstallHelper) getEnvVars() []string {
+// getEnvVars returns all COCKROACH_* environment variables, in the form
+// "key=value".
+func getEnvVars() []string {
 	var sl []string
 	for _, v := range os.Environ() {
 		if strings.HasPrefix(v, "COCKROACH_") {
@@ -727,10 +724,10 @@ func (h *crdbInstallHelper) getEnvVars() []string {
 	return sl
 }
 
-func (h *crdbInstallHelper) run(nodeIdx int, cmd string) (string, error) {
-	nodes := h.c.ServerNodes()
+func (c *SyncedCluster) run(nodeIdx int, cmd string) (string, error) {
+	nodes := c.TargetNodes()
 
-	sess, err := h.c.newSession(nodes[nodeIdx])
+	sess, err := c.newSession(nodes[nodeIdx])
 	if err != nil {
 		return "", err
 	}
diff --git a/pkg/roachprod/install/expander.go b/pkg/roachprod/install/expander.go
index f2ce1c4ca5ca..3962b6e7a77a 100644
--- a/pkg/roachprod/install/expander.go
+++ b/pkg/roachprod/install/expander.go
@@ -153,7 +153,7 @@ func (e *expander) maybeExpandPgPort(c *SyncedCluster, s string) (string, bool,
 	if e.pgPorts == nil {
 		e.pgPorts = make(map[int]string, len(c.VMs))
 		for _, i := range allNodes(len(c.VMs)) {
-			e.pgPorts[i] = fmt.Sprint(c.Impl.NodePort(c, i))
+			e.pgPorts[i] = fmt.Sprint(c.NodePort(i))
 		}
 	}
 
@@ -171,7 +171,7 @@ func (e *expander) maybeExpandUIPort(c *SyncedCluster, s string) (string, bool,
 	if e.uiPorts == nil {
 		e.uiPorts = make(map[int]string, len(c.VMs))
 		for _, i := range allNodes(len(c.VMs)) {
-			e.uiPorts[i] = fmt.Sprint(c.Impl.NodeUIPort(c, i))
+			e.uiPorts[i] = fmt.Sprint(c.NodeUIPort(i))
 		}
 	}
 
@@ -184,7 +184,7 @@ func (e *expander) maybeExpandStoreDir(c *SyncedCluster, s string) (string, bool
 	if !storeDirRe.MatchString(s) {
 		return s, false, nil
 	}
-	return c.Impl.NodeDir(c, e.node, 1 /* storeIndex */), true, nil
+	return c.NodeDir(e.node, 1 /* storeIndex */), true, nil
 }
 
 // maybeExpandLogDir is an expanderFunc for "{log-dir}"
@@ -192,7 +192,7 @@ func (e *expander) maybeExpandLogDir(c *SyncedCluster, s string) (string, bool,
 	if !logDirRe.MatchString(s) {
 		return s, false, nil
 	}
-	return c.Impl.LogDir(c, e.node), true, nil
+	return c.LogDir(e.node), true, nil
 }
 
 // maybeExpandCertsDir is an expanderFunc for "{certs-dir}"
@@ -200,5 +200,5 @@ func (e *expander) maybeExpandCertsDir(c *SyncedCluster, s string) (string, bool
 	if !certsDirRe.MatchString(s) {
 		return s, false, nil
 	}
-	return c.Impl.CertsDir(c, e.node), true, nil
+	return c.CertsDir(e.node), true, nil
 }
diff --git a/pkg/roachprod/roachprod.go b/pkg/roachprod/roachprod.go
index f90d8775db4d..ef6dc04850df 100644
--- a/pkg/roachprod/roachprod.go
+++ b/pkg/roachprod/roachprod.go
@@ -366,11 +366,7 @@ func SQL(name string, clusterOpts install.ClusterSettings, cmdArray []string) er
 	if err != nil {
 		return err
 	}
-	cockroach, ok := c.Impl.(install.Cockroach)
-	if !ok {
-		return errors.New("sql is only valid on cockroach clusters")
-	}
-	return cockroach.SQL(c, cmdArray)
+	return c.SQL(cmdArray)
 }
 
 // IP gets the ip addresses of the nodes in a cluster.
@@ -380,7 +376,7 @@ func IP(name string, clusterOpts install.ClusterSettings, external bool) ([]stri
 		return nil, err
 	}
 
-	nodes := c.ServerNodes()
+	nodes := c.TargetNodes()
 	ips := make([]string, len(nodes))
 
 	if external {
@@ -700,7 +696,7 @@ func PgURL(name string, clusterOpts install.ClusterSettings, external bool) erro
 	if err != nil {
 		return err
 	}
-	nodes := c.ServerNodes()
+	nodes := c.TargetNodes()
 	ips := make([]string, len(nodes))
 
 	if external {
@@ -722,7 +718,7 @@ func PgURL(name string, clusterOpts install.ClusterSettings, external bool) erro
 		if ip == "" {
 			return errors.Errorf("empty ip: %v", ips)
 		}
-		urls = append(urls, c.Impl.NodeURL(c, ip, c.Impl.NodePort(c, nodes[i])))
+		urls = append(urls, c.NodeURL(ip, c.NodePort(nodes[i])))
 	}
 	fmt.Println(strings.Join(urls, " "))
 	if len(urls) != len(nodes) {
@@ -743,7 +739,7 @@ func AdminURL(
 		return err
 	}
 
-	for i, node := range c.ServerNodes() {
+	for i, node := range c.TargetNodes() {
 		host := vm.Name(c.Name, node) + "." + gce.Subdomain
 
 		// verify DNS is working / fallback to IPs if not.
@@ -757,7 +753,7 @@ func AdminURL(
 		if adminurlIPs {
 			host = c.VMs[node-1].PublicIP
 		}
-		port := c.Impl.NodeUIPort(c, node)
+		port := c.NodeUIPort(node)
 		scheme := "http"
 		if c.Secure {
 			scheme = "https"
@@ -812,9 +808,9 @@ func Pprof(
 
 	httpClient := httputil.NewClientWithTimeout(timeout)
 	startTime := timeutil.Now().Unix()
-	failed, err := c.ParallelE(description, len(c.ServerNodes()), 0, func(i int) ([]byte, error) {
+	failed, err := c.ParallelE(description, len(c.TargetNodes()), 0, func(i int) ([]byte, error) {
 		host := c.VMs[i].PublicIP
-		port := c.Impl.NodeUIPort(c, i)
+		port := c.NodeUIPort(i)
 		scheme := "http"
 		if c.Secure {
 			scheme = "https"