feat: implement worker

8 files changed, 432 insertions, 48 deletions

diff --git a/worker/Dockerfile b/worker/Dockerfile
index 1d1523d..2373f57 100644
--- a/worker/Dockerfile
+++ b/worker/Dockerfile
@@ -1,13 +1,21 @@
 FROM golang:1.22.3 AS builder
 
 WORKDIR /build
-COPY . /build
-RUN go build -o /build/server .
 
-################################################################################
-FROM golang:1.22.3
+RUN apt-get update && apt-get install -y curl xz-utils
+RUN curl https://wasmtime.dev/install.sh -sSf | bash -s -- --version v23.0.1
+
+COPY go.mod go.sum ./
+RUN go mod download
+COPY *.go /build
+RUN CGO_ENABLED=0 go build -o /build/server .
+
+# ################################################################################
+FROM ghcr.io/swiftwasm/swift:5.10-focal
 
 WORKDIR /app
+
+COPY --from=builder /root/.wasmtime/bin/wasmtime /usr/bin/wasmtime
 COPY --from=builder /build/server /app/server
 
 CMD ["/app/server"]
diff --git a/worker/Makefile b/worker/Makefile
index 4d6cf39..3c69e4b 100644
--- a/worker/Makefile
+++ b/worker/Makefile
@@ -5,3 +5,7 @@ fmt:
 .PHONY: check
 check:
 	go build -o /dev/null ./...
+
+.PHONY: lint
+lint:
+	go vet ./...
diff --git a/worker/exec.go b/worker/exec.go
new file mode 100644
index 0000000..2ef16fa
--- /dev/null
+++ b/worker/exec.go
@@ -0,0 +1,186 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"crypto/md5"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+const (
+	dataRootDir = "/app/data"
+	// Stores *.swift files.
+	dataSwiftRootDir = dataRootDir + "/swift"
+	// Stores *.wasm files.
+	dataWasmRootDir = dataRootDir + "/wasm"
+	// Stores *.cwasm files (compiled wasm generated by "wasmtime compile").
+	dataCwasmRootDir = dataRootDir + "/cwasm"
+
+	wasmMaxMemorySize = 10 * 1024 * 1024 // 10 MiB
+)
+
+func prepareDirectories() error {
+	if err := os.MkdirAll(dataSwiftRootDir, 0755); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(dataWasmRootDir, 0755); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(dataCwasmRootDir, 0755); err != nil {
+		return err
+	}
+	return nil
+}
+
+func calcHash(code string) string {
+	return fmt.Sprintf("%x", md5.Sum([]byte(code)))
+}
+
+func calcFilePath(hash, ext string) string {
+	return fmt.Sprintf("%s/%s/%s.%s", dataRootDir, ext, hash, ext)
+}
+
+func execCommandWithTimeout(
+	ctx context.Context,
+	maxDuration time.Duration,
+	makeCmd func(context.Context) *exec.Cmd,
+) (string, string, error) {
+	ctx, cancel := context.WithTimeout(ctx, maxDuration)
+	defer cancel()
+
+	cmd := makeCmd(ctx)
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	exitCh := make(chan error)
+	go func() {
+		exitCh <- cmd.Run()
+	}()
+
+	select {
+	case <-ctx.Done():
+		return stdout.String(), stderr.String(), ctx.Err()
+	case err := <-exitCh:
+		return stdout.String(), stderr.String(), err
+	}
+}
+
+func convertCommandErrorToResultType(err error) string {
+	if err != nil {
+		if err == context.DeadlineExceeded {
+			return resultTimeout
+		} else {
+			return resultFailure
+		}
+	} else {
+		return resultSuccess
+	}
+}
+
+func execSwiftCompile(
+	ctx context.Context,
+	code string,
+	maxDuration time.Duration,
+) swiftCompileResponseData {
+	hash := calcHash(code)
+	inPath := calcFilePath(hash, "swift")
+	outPath := calcFilePath(hash, "wasm")
+
+	if err := os.WriteFile(inPath, []byte(code), 0644); err != nil {
+		return swiftCompileResponseData{
+			Result: resultInternalError,
+			Stdout: "",
+			Stderr: err.Error(),
+		}
+	}
+
+	stdout, stderr, err := execCommandWithTimeout(
+		ctx,
+		maxDuration,
+		func(ctx context.Context) *exec.Cmd {
+			return exec.CommandContext(
+				ctx,
+				"swiftc",
+				"-target", "wasm32-unknown-wasi",
+				"-o", outPath,
+				inPath,
+			)
+		},
+	)
+
+	return swiftCompileResponseData{
+		Result: convertCommandErrorToResultType(err),
+		Stdout: stdout,
+		Stderr: stderr,
+	}
+}
+
+func execWasmCompile(
+	ctx context.Context,
+	code string,
+	maxDuration time.Duration,
+) wasmCompileResponseData {
+	hash := calcHash(code)
+	inPath := calcFilePath(hash, "wasm")
+	outPath := calcFilePath(hash, "cwasm")
+
+	stdout, stderr, err := execCommandWithTimeout(
+		ctx,
+		maxDuration,
+		func(ctx context.Context) *exec.Cmd {
+			return exec.CommandContext(
+				ctx,
+				"wasmtime", "compile",
+				"-O", "opt-level=0",
+				"-C", "cache=n",
+				"-W", fmt.Sprintf("max-memory-size=%d", wasmMaxMemorySize),
+				"-o", outPath,
+				inPath,
+			)
+		},
+	)
+
+	return wasmCompileResponseData{
+		Result: convertCommandErrorToResultType(err),
+		Stdout: stdout,
+		Stderr: stderr,
+	}
+}
+
+func execTestRun(
+	ctx context.Context,
+	code string,
+	stdin string,
+	maxDuration time.Duration,
+) testRunResponseData {
+	hash := calcHash(code)
+	inPath := calcFilePath(hash, "cwasm")
+
+	stdout, stderr, err := execCommandWithTimeout(
+		ctx,
+		maxDuration,
+		func(ctx context.Context) *exec.Cmd {
+			cmd := exec.CommandContext(
+				ctx,
+				"wasmtime", "run",
+				"--allow-precompiled",
+				inPath,
+			)
+			cmd.Stdin = strings.NewReader(stdin)
+			return cmd
+		},
+	)
+
+	return testRunResponseData{
+		Result: convertCommandErrorToResultType(err),
+		Stdout: stdout,
+		Stderr: stderr,
+	}
+}
diff --git a/worker/go.mod b/worker/go.mod
index 007435d..1d01907 100644
--- a/worker/go.mod
+++ b/worker/go.mod
@@ -1,3 +1,23 @@
 module github.com/nsfisis/iosdc-japan-2024-albatross/worker
 
 go 1.22.3
+
+require (
+	github.com/labstack/echo-jwt/v4 v4.2.0
+	github.com/labstack/echo/v4 v4.12.0
+)
+
+require (
+	github.com/golang-jwt/jwt v3.2.2+incompatible // indirect
+	github.com/golang-jwt/jwt/v5 v5.2.1 // indirect
+	github.com/labstack/gommon v0.4.2 // indirect
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/valyala/bytebufferpool v1.0.0 // indirect
+	github.com/valyala/fasttemplate v1.2.2 // indirect
+	golang.org/x/crypto v0.22.0 // indirect
+	golang.org/x/net v0.24.0 // indirect
+	golang.org/x/sys v0.19.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	golang.org/x/time v0.5.0 // indirect
+)
diff --git a/worker/go.sum b/worker/go.sum
new file mode 100644
index 0000000..26616a1
--- /dev/null
+++ b/worker/go.sum
@@ -0,0 +1,39 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang-jwt/jwt v3.2.2+incompatible h1:IfV12K8xAKAnZqdXVzCZ+TOjboZ2keLg81eXfW3O+oY=
+github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I=
+github.com/golang-jwt/jwt/v5 v5.2.1 h1:OuVbFODueb089Lh128TAcimifWaLhJwVflnrgM17wHk=
+github.com/golang-jwt/jwt/v5 v5.2.1/go.mod h1:pqrtFR0X4osieyHYxtmOUWsAWrfe1Q5UVIyoH402zdk=
+github.com/labstack/echo-jwt/v4 v4.2.0 h1:odSISV9JgcSCuhgQSV/6Io3i7nUmfM/QkBeR5GVJj5c=
+github.com/labstack/echo-jwt/v4 v4.2.0/go.mod h1:MA2RqdXdEn4/uEglx0HcUOgQSyBaTh5JcaHIan3biwU=
+github.com/labstack/echo/v4 v4.12.0 h1:IKpw49IMryVB2p1a4dzwlhP1O2Tf2E0Ir/450lH+kI0=
+github.com/labstack/echo/v4 v4.12.0/go.mod h1:UP9Cr2DJXbOK3Kr9ONYzNowSh7HP0aG0ShAyycHSJvM=
+github.com/labstack/gommon v0.4.2 h1:F8qTUNXgG1+6WQmqoUWnz8WiEU60mXVVw0P4ht1WRA0=
+github.com/labstack/gommon v0.4.2/go.mod h1:QlUFxVM+SNXhDL/Z7YhocGIBYOiwB0mXm1+1bAPHPyU=
+github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
+github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
+github.com/valyala/fasttemplate v1.2.2 h1:lxLXG0uE3Qnshl9QyaK6XJxMXlQZELvChBOCmQD0Loo=
+github.com/valyala/fasttemplate v1.2.2/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
+golang.org/x/crypto v0.22.0 h1:g1v0xeRhjcugydODzvb3mEM9SQ0HGp9s/nh3COQ/C30=
+golang.org/x/crypto v0.22.0/go.mod h1:vr6Su+7cTlO45qkww3VDJlzDn0ctJvRgYbC2NvXHt+M=
+golang.org/x/net v0.24.0 h1:1PcaxkF854Fu3+lvBIx5SYn9wRlBzzcnHZSiaFFAb0w=
+golang.org/x/net v0.24.0/go.mod h1:2Q7sJY5mzlzWjKtYUEXSlBWCdyaioyXzRB2RtU8KVE8=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.19.0 h1:q5f1RH2jigJ1MoAWp2KTp3gm5zAGFUTarQZ5U386+4o=
+golang.org/x/sys v0.19.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
+golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/time v0.5.0 h1:o7cqy6amK/52YcAKIPlM3a+Fpj35zvRj2TP+e1xFSfk=
+golang.org/x/time v0.5.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/worker/handlers.go b/worker/handlers.go
new file mode 100644
index 0000000..e7ceef6
--- /dev/null
+++ b/worker/handlers.go
@@ -0,0 +1,67 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/labstack/echo/v4"
+)
+
+func newBadRequestError(err error) *echo.HTTPError {
+	return echo.NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Invalid request: %s", err.Error()))
+}
+
+func handleSwiftCompile(c echo.Context) error {
+	var req swiftCompileRequestData
+	if err := c.Bind(&req); err != nil {
+		return newBadRequestError(err)
+	}
+	if err := req.validate(); err != nil {
+		return newBadRequestError(err)
+	}
+
+	res := execSwiftCompile(
+		c.Request().Context(),
+		req.Code,
+		req.maxDuration(),
+	)
+
+	return c.JSON(http.StatusOK, res)
+}
+
+func handleWasmCompile(c echo.Context) error {
+	var req wasmCompileRequestData
+	if err := c.Bind(&req); err != nil {
+		return newBadRequestError(err)
+	}
+	if err := req.validate(); err != nil {
+		return newBadRequestError(err)
+	}
+
+	res := execWasmCompile(
+		c.Request().Context(),
+		req.Code,
+		req.maxDuration(),
+	)
+
+	return c.JSON(http.StatusOK, res)
+}
+
+func handleTestRun(c echo.Context) error {
+	var req testRunRequestData
+	if err := c.Bind(&req); err != nil {
+		return newBadRequestError(err)
+	}
+	if err := req.validate(); err != nil {
+		return newBadRequestError(err)
+	}
+
+	res := execTestRun(
+		c.Request().Context(),
+		req.Code,
+		req.Stdin,
+		req.maxDuration(),
+	)
+
+	return c.JSON(http.StatusOK, res)
+}
diff --git a/worker/main.go b/worker/main.go
index 0a52b0e..8134a56 100644
--- a/worker/main.go
+++ b/worker/main.go
@@ -1,57 +1,33 @@
 package main
 
 import (
-	"encoding/json"
+	"log"
 	"net/http"
-	"strconv"
-	"time"
-)
-
-type RequestBody struct {
-	Code  string `json:"code"`
-	Stdin string `json:"stdin"`
-}
 
-type ResponseBody struct {
-	Result string `json:"result"`
-	Stdout string `json:"stdout"`
-	Stderr string `json:"stderr"`
-}
-
-func doExec(code string, stdin string, maxDuration time.Duration) ResponseBody {
-	_ = code
-	_ = stdin
-	_ = maxDuration
+	echojwt "github.com/labstack/echo-jwt/v4"
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
+)
 
-	return ResponseBody{
-		Result: "success",
-		Stdout: "42",
-		Stderr: "",
+func main() {
+	if err := prepareDirectories(); err != nil {
+		log.Fatal(err)
 	}
-}
 
-func execHandler(w http.ResponseWriter, r *http.Request) {
-	maxDurationStr := r.URL.Query().Get("max_duration")
-	maxDuration, err := strconv.Atoi(maxDurationStr)
-	if err != nil || maxDuration <= 0 {
-		http.Error(w, "Invalid max_duration parameter", http.StatusBadRequest)
-		return
-	}
+	e := echo.New()
 
-	var reqBody RequestBody
-	err = json.NewDecoder(r.Body).Decode(&reqBody)
-	if err != nil {
-		http.Error(w, "Invalid request body", http.StatusBadRequest)
-		return
-	}
+	e.Use(middleware.Logger())
+	e.Use(middleware.Recover())
 
-	resBody := doExec(reqBody.Code, reqBody.Stdin, time.Duration(maxDuration)*time.Second)
+	e.Use(echojwt.WithConfig(echojwt.Config{
+		SigningKey: []byte("TODO"),
+	}))
 
-	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(resBody)
-}
+	e.POST("/api/swiftc", handleSwiftCompile)
+	e.POST("/api/wasmc", handleWasmCompile)
+	e.POST("/api/testrun", handleTestRun)
 
-func main() {
-	http.HandleFunc("/api/exec", execHandler)
-	http.ListenAndServe(":80", nil)
+	if err := e.Start(":80"); err != http.ErrServerClosed {
+		log.Fatal(err)
+	}
 }
diff --git a/worker/models.go b/worker/models.go
new file mode 100644
index 0000000..b838fe0
--- /dev/null
+++ b/worker/models.go
@@ -0,0 +1,84 @@
+package main
+
+import (
+	"errors"
+	"time"
+)
+
+const (
+	resultSuccess       = "success"
+	resultFailure       = "failure"
+	resultTimeout       = "timeout"
+	resultInternalError = "internal_error"
+)
+
+var (
+	errInvalidMaxDuration = errors.New("'max_duration_ms' must be positive")
+)
+
+type swiftCompileRequestData struct {
+	MaxDurationMilliseconds int    `json:"max_duration_ms"`
+	Code                    string `json:"code"`
+}
+
+func (req *swiftCompileRequestData) maxDuration() time.Duration {
+	return time.Duration(req.MaxDurationMilliseconds) * time.Millisecond
+}
+
+func (req *swiftCompileRequestData) validate() error {
+	if req.MaxDurationMilliseconds <= 0 {
+		return errInvalidMaxDuration
+	}
+	return nil
+}
+
+type swiftCompileResponseData struct {
+	Result string `json:"result"`
+	Stdout string `json:"stdout"`
+	Stderr string `json:"stderr"`
+}
+
+type wasmCompileRequestData struct {
+	MaxDurationMilliseconds int    `json:"max_duration_ms"`
+	Code                    string `json:"code"`
+}
+
+type wasmCompileResponseData struct {
+	Result string `json:"result"`
+	Stdout string `json:"stdout"`
+	Stderr string `json:"stderr"`
+}
+
+func (req *wasmCompileRequestData) maxDuration() time.Duration {
+	return time.Duration(req.MaxDurationMilliseconds) * time.Millisecond
+}
+
+func (req *wasmCompileRequestData) validate() error {
+	if req.MaxDurationMilliseconds <= 0 {
+		return errInvalidMaxDuration
+	}
+	return nil
+}
+
+type testRunRequestData struct {
+	MaxDurationMilliseconds int    `json:"max_duration_ms"`
+	Code                    string `json:"code"`
+	Stdin                   string `json:"stdin"`
+}
+
+func (req *testRunRequestData) maxDuration() time.Duration {
+	return time.Duration(req.MaxDurationMilliseconds) * time.Millisecond
+}
+
+func (req *testRunRequestData) validate() error {
+	if req.MaxDurationMilliseconds <= 0 {
+		return errInvalidMaxDuration
+	}
+	return nil
+}
+
+type testRunResponseData struct {
+	Result string `json:"result"`
+	Stdout string `json:"stdout"`
+	Stderr string `json:"stderr"`
+}