feat: add reactions (#1074)

reaction/action/action.go

@@ -0,0 +1,44 @@
+package action
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/SecurityBrewery/catalyst/reaction/action/python"
+	"github.com/SecurityBrewery/catalyst/reaction/action/webhook"
+)
+
+func Run(ctx context.Context, actionName, actionData, payload string) ([]byte, error) {
+	action, err := decode(actionName, actionData)
+	if err != nil {
+		return nil, err
+	}
+
+	return action.Run(ctx, payload)
+}
+
+type action interface {
+	Run(ctx context.Context, payload string) ([]byte, error)
+}
+
+func decode(actionName, actionData string) (action, error) {
+	switch actionName {
+	case "python":
+		var reaction python.Python
+		if err := json.Unmarshal([]byte(actionData), &reaction); err != nil {
+			return nil, err
+		}
+
+		return &reaction, nil
+	case "webhook":
+		var reaction webhook.Webhook
+		if err := json.Unmarshal([]byte(actionData), &reaction); err != nil {
+			return nil, err
+		}
+
+		return &reaction, nil
+	default:
+		return nil, fmt.Errorf("action %q not found", actionName)
+	}
+}

reaction/action/python/python.go

@@ -0,0 +1,105 @@
+package python
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+type Python struct {
+	Bootstrap string `json:"bootstrap"`
+	Script    string `json:"script"`
+}
+
+func (a *Python) Run(ctx context.Context, payload string) ([]byte, error) {
+	tempDir, err := os.MkdirTemp("", "catalyst_action")
+	if err != nil {
+		return nil, err
+	}
+
+	defer os.RemoveAll(tempDir)
+
+	if b, err := pythonSetup(ctx, tempDir); err != nil {
+		var ee *exec.ExitError
+		if errors.As(err, &ee) {
+			b = append(b, ee.Stderr...)
+		}
+
+		return nil, fmt.Errorf("failed to setup python, %w: %s", err, string(b))
+	}
+
+	if b, err := pythonRunBootstrap(ctx, tempDir, a.Bootstrap); err != nil {
+		var ee *exec.ExitError
+		if errors.As(err, &ee) {
+			b = append(b, ee.Stderr...)
+		}
+
+		return nil, fmt.Errorf("failed to run bootstrap, %w: %s", err, string(b))
+	}
+
+	b, err := pythonRunScript(ctx, tempDir, a.Script, payload)
+	if err != nil {
+		var ee *exec.ExitError
+		if errors.As(err, &ee) {
+			b = append(b, ee.Stderr...)
+		}
+
+		return nil, fmt.Errorf("failed to run script, %w: %s", err, string(b))
+	}
+
+	return b, nil
+}
+
+func pythonSetup(ctx context.Context, tempDir string) ([]byte, error) {
+	pythonPath, err := findExec("python", "python3")
+	if err != nil {
+		return nil, fmt.Errorf("python or python3 binary not found, %w", err)
+	}
+
+	// setup virtual environment
+	return exec.CommandContext(ctx, pythonPath, "-m", "venv", tempDir+"/venv").Output()
+}
+
+func pythonRunBootstrap(ctx context.Context, tempDir, bootstrap string) ([]byte, error) {
+	hasBootstrap := len(strings.TrimSpace(bootstrap)) > 0
+
+	if !hasBootstrap {
+		return nil, nil
+	}
+
+	bootstrapPath := tempDir + "/requirements.txt"
+
+	if err := os.WriteFile(bootstrapPath, []byte(bootstrap), 0o600); err != nil {
+		return nil, err
+	}
+
+	// install dependencies
+	pipPath := tempDir + "/venv/bin/pip"
+
+	return exec.CommandContext(ctx, pipPath, "install", "-r", bootstrapPath).Output()
+}
+
+func pythonRunScript(ctx context.Context, tempDir, script, payload string) ([]byte, error) {
+	scriptPath := tempDir + "/script.py"
+
+	if err := os.WriteFile(scriptPath, []byte(script), 0o600); err != nil {
+		return nil, err
+	}
+
+	pythonPath := tempDir + "/venv/bin/python"
+
+	return exec.CommandContext(ctx, pythonPath, scriptPath, payload).Output()
+}
+
+func findExec(name ...string) (string, error) {
+	for _, n := range name {
+		if p, err := exec.LookPath(n); err == nil {
+			return p, nil
+		}
+	}
+
+	return "", errors.New("no executable found")
+}

reaction/action/webhook/payload.go

@@ -0,0 +1,20 @@
+package webhook
+
+import (
+	"encoding/base64"
+	"io"
+	"unicode/utf8"
+)
+
+func EncodeBody(requestBody io.Reader) (string, bool) {
+	body, err := io.ReadAll(requestBody)
+	if err != nil {
+		return "", false
+	}
+
+	if utf8.Valid(body) {
+		return string(body), false
+	}
+
+	return base64.StdEncoding.EncodeToString(body), true
+}

reaction/action/webhook/payload_test.go

@@ -0,0 +1,49 @@
+package webhook
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+func TestEncodeBody(t *testing.T) {
+	type args struct {
+		requestBody io.Reader
+	}
+
+	tests := []struct {
+		name  string
+		args  args
+		want  string
+		want1 bool
+	}{
+		{
+			name: "utf8",
+			args: args{
+				requestBody: bytes.NewBufferString("body"),
+			},
+			want:  "body",
+			want1: false,
+		},
+		{
+			name: "non-utf8",
+			args: args{
+				requestBody: bytes.NewBufferString("body\xe0"),
+			},
+			want:  "Ym9keeA=",
+			want1: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, got1 := EncodeBody(tt.args.requestBody)
+			if got != tt.want {
+				t.Errorf("EncodeBody() got = %v, want %v", got, tt.want)
+			}
+
+			if got1 != tt.want1 {
+				t.Errorf("EncodeBody() got1 = %v, want %v", got1, tt.want1)
+			}
+		})
+	}
+}

reaction/action/webhook/response.go

@@ -0,0 +1,12 @@
+package webhook
+
+import (
+	"net/http"
+)
+
+type Response struct {
+	StatusCode      int         `json:"statusCode"`
+	Headers         http.Header `json:"headers"`
+	Body            string      `json:"body"`
+	IsBase64Encoded bool        `json:"isBase64Encoded"`
+}

reaction/action/webhook/webhook.go

@@ -0,0 +1,39 @@
+package webhook
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"strings"
+)
+
+type Webhook struct {
+	Headers map[string]string `json:"headers"`
+	URL     string            `json:"url"`
+}
+
+func (a *Webhook) Run(ctx context.Context, payload string) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, a.URL, strings.NewReader(payload))
+	if err != nil {
+		return nil, err
+	}
+
+	for key, value := range a.Headers {
+		req.Header.Set(key, value)
+	}
+
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	body, isBase64Encoded := EncodeBody(res.Body)
+
+	return json.Marshal(Response{
+		StatusCode:      res.StatusCode,
+		Headers:         res.Header,
+		Body:            body,
+		IsBase64Encoded: isBase64Encoded,
+	})
+}