Refactor to new framework (#98)

- Adjust directory structure
```text
├── internal
│   ├── app
│   │   ├── artifactcache
│   │   ├── cmd
│   │   ├── poll
│   │   └── run
│   └── pkg
│       ├── client
│       ├── config
│       ├── envcheck
│       ├── labels
│       ├── report
│       └── ver
└── main.go
```
- New pkg `labels` to parse label
- New pkg `report` to report logs to Gitea
- Remove pkg `engine`, use `envcheck` to check if docker running.
- Rewrite `runtime` to `run`
- Rewrite `poller` to `poll`
- Simplify some code and remove what's useless.

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/98
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Jason Song <i@wolfogre.com>
Co-committed-by: Jason Song <i@wolfogre.com>

internal/app/artifactcache/util.go

@@ -0,0 +1,100 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package artifactcache
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/go-chi/render"
+	"xorm.io/xorm"
+)
+
+func responseJson(w http.ResponseWriter, r *http.Request, code int, v ...any) {
+	render.Status(r, code)
+	if len(v) == 0 || v[0] == nil {
+		render.JSON(w, r, struct{}{})
+	} else if err, ok := v[0].(error); ok {
+		logger.Errorf("%v %v: %v", r.Method, r.RequestURI, err)
+		render.JSON(w, r, map[string]any{
+			"error": err.Error(),
+		})
+	} else {
+		render.JSON(w, r, v[0])
+	}
+}
+
+func parseContentRange(s string) (int64, int64, error) {
+	// support the format like "bytes 11-22/*" only
+	s, _, _ = strings.Cut(strings.TrimPrefix(s, "bytes "), "/")
+	s1, s2, _ := strings.Cut(s, "-")
+
+	start, err := strconv.ParseInt(s1, 10, 64)
+	if err != nil {
+		return 0, 0, fmt.Errorf("parse %q: %w", s, err)
+	}
+	stop, err := strconv.ParseInt(s2, 10, 64)
+	if err != nil {
+		return 0, 0, fmt.Errorf("parse %q: %w", s, err)
+	}
+	return start, stop, nil
+}
+
+func getOutboundIP() (net.IP, error) {
+	// FIXME: It makes more sense to use the gateway IP address of container network
+	if conn, err := net.Dial("udp", "8.8.8.8:80"); err == nil {
+		defer conn.Close()
+		return conn.LocalAddr().(*net.UDPAddr).IP, nil
+	}
+	if ifaces, err := net.Interfaces(); err == nil {
+		for _, i := range ifaces {
+			if addrs, err := i.Addrs(); err == nil {
+				for _, addr := range addrs {
+					var ip net.IP
+					switch v := addr.(type) {
+					case *net.IPNet:
+						ip = v.IP
+					case *net.IPAddr:
+						ip = v.IP
+					}
+					if ip.IsGlobalUnicast() {
+						return ip, nil
+					}
+				}
+			}
+		}
+	}
+	return nil, fmt.Errorf("no outbound IP address found")
+}
+
+// engine is a wrapper of *xorm.Engine, with a lock.
+// To avoid racing of sqlite, we don't care performance here.
+type engine struct {
+	e *xorm.Engine
+	m sync.Mutex
+}
+
+func (e *engine) Exec(f func(*xorm.Session) error) error {
+	e.m.Lock()
+	defer e.m.Unlock()
+
+	sess := e.e.NewSession()
+	defer sess.Close()
+
+	return f(sess)
+}
+
+func (e *engine) ExecBool(f func(*xorm.Session) (bool, error)) (bool, error) {
+	e.m.Lock()
+	defer e.m.Unlock()
+
+	sess := e.e.NewSession()
+	defer sess.Close()
+
+	return f(sess)
+}