vm/proxyapp: pass file data when running in tcp mode (#3648)

Instead of just passing the path to the file (on the local machine) to
the ProxyApp, we need to pass the file data. This applies for both calls
to Copy() and CreateInstance().

3 files changed, 68 insertions, 21 deletions

diff --git a/vm/proxyapp/init.go b/vm/proxyapp/init.go
index 8153cf031..467187f46 100644
--- a/vm/proxyapp/init.go
+++ b/vm/proxyapp/init.go
@@ -68,6 +68,9 @@ type Config struct {
 	// server_tls_cert points a TLS certificate used to authenticate the server.
 	// If not provided, the default system certificate pool will be used.
 	ServerTLSCert string `json:"server_tls_cert"`
+	// transfer_file_content will send the file content as a byte array in
+	// addition to the filename.
+	TransferFileContent bool `json:"transfer_file_content"`
 	// config is an optional remote plugin config
 	ProxyAppConfig json.RawMessage `json:"config"`
 }
diff --git a/vm/proxyapp/proxyappclient.go b/vm/proxyapp/proxyappclient.go
index 1e6d679ac..946556f24 100644
--- a/vm/proxyapp/proxyappclient.go
+++ b/vm/proxyapp/proxyappclient.go
@@ -11,10 +11,13 @@ import (
 	"crypto/x509"
 	"fmt"
 	"io"
+	"io/fs"
 	"net"
 	"net/rpc"
 	"net/rpc/jsonrpc"
 	"os"
+	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 
@@ -96,7 +99,9 @@ func (p *pool) init(params *proxyAppParams, cfg *Config) error {
 	if cfg.Command != "" {
 		p.proxy, err = runProxyApp(params, cfg.Command, usePipedRPC)
 	} else {
-		p.proxy = &ProxyApp{}
+		p.proxy = &ProxyApp{
+			transferFileContent: cfg.TransferFileContent,
+		}
 	}
 	if err != nil {
 		return fmt.Errorf("failed to run ProxyApp: %w", err)
@@ -170,11 +175,12 @@ func (p *pool) Close() error {
 
 type ProxyApp struct {
 	*rpc.Client
-	terminate        context.CancelFunc
-	onTerminated     chan bool
-	onLostConnection chan bool
-	stopLogPooling   chan bool
-	logPoolingDone   chan bool
+	transferFileContent bool
+	terminate           context.CancelFunc
+	onTerminated        chan bool
+	onLostConnection    chan bool
+	stopLogPooling      chan bool
+	logPoolingDone      chan bool
 }
 
 func initPipedRPCClient(cmd subProcessCmd) (*rpc.Client, []io.Closer, error) {
@@ -354,12 +360,40 @@ func (proxy *ProxyApp) CreatePool(config string, debug bool) (int, error) {
 
 func (proxy *ProxyApp) CreateInstance(workdir string, index int) (vmimpl.Instance, error) {
 	var reply proxyrpc.CreateInstanceResult
-	err := proxy.Call(
-		"ProxyVM.CreateInstance",
-		proxyrpc.CreateInstanceParams{
-			Workdir: workdir,
-			Index:   index},
-		&reply)
+
+	params := proxyrpc.CreateInstanceParams{
+		Workdir: workdir,
+		Index:   index,
+	}
+
+	if proxy.transferFileContent {
+		workdirData := make(map[string][]byte)
+
+		err := filepath.WalkDir(workdir, func(path string, d fs.DirEntry, e error) error {
+			if d.IsDir() {
+				return nil
+			}
+
+			name := strings.TrimPrefix(path, workdir)
+
+			data, err := os.ReadFile(path)
+			if err != nil {
+				return fmt.Errorf("read file on host: %s", err)
+			}
+
+			workdirData[name] = data
+
+			return nil
+		})
+
+		if err != nil {
+			return nil, fmt.Errorf("failed to walk workdir: %v", err)
+		}
+
+		params.WorkdirData = workdirData
+	}
+
+	err := proxy.Call("ProxyVM.CreateInstance", params, &reply)
 	if err != nil {
 		return nil, fmt.Errorf("failed to proxy.Call(\"ProxyVM.CreateInstance\"): %w", err)
 	}
@@ -379,13 +413,21 @@ type instance struct {
 // nolint: dupl
 func (inst *instance) Copy(hostSrc string) (string, error) {
 	var reply proxyrpc.CopyResult
-	err := inst.ProxyApp.Call(
-		"ProxyVM.Copy",
-		proxyrpc.CopyParams{
-			ID:      inst.ID,
-			HostSrc: hostSrc,
-		},
-		&reply)
+	params := proxyrpc.CopyParams{
+		ID:      inst.ID,
+		HostSrc: hostSrc,
+	}
+
+	if inst.ProxyApp.transferFileContent {
+		data, err := os.ReadFile(hostSrc)
+		if err != nil {
+			return "", fmt.Errorf("read file on host: %s", err)
+		}
+
+		params.Data = data
+	}
+
+	err := inst.ProxyApp.Call("ProxyVM.Copy", params, &reply)
 	if err != nil {
 		return "", err
 	}
diff --git a/vm/proxyapp/proxyrpc/proxyrpc.go b/vm/proxyapp/proxyrpc/proxyrpc.go
index d3fd606a4..95bc77ce0 100644
--- a/vm/proxyapp/proxyrpc/proxyrpc.go
+++ b/vm/proxyapp/proxyrpc/proxyrpc.go
@@ -27,8 +27,9 @@ type CreatePoolResult struct {
 }
 
 type CreateInstanceParams struct {
-	Workdir string
-	Index   int
+	Workdir     string
+	Index       int
+	WorkdirData map[string][]byte
 }
 
 type CreateInstanceResult struct {
@@ -38,6 +39,7 @@ type CreateInstanceResult struct {
 type CopyParams struct {
 	ID      string
 	HostSrc string
+	Data    []byte
 }
 
 type CopyResult struct {