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/pkg/labels/labels.go

@@ -0,0 +1,84 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package labels
+
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	SchemeHost   = "host"
+	SchemeDocker = "docker"
+)
+
+type Label struct {
+	Name   string
+	Schema string
+	Arg    string
+}
+
+func Parse(str string) (*Label, error) {
+	splits := strings.SplitN(str, ":", 3)
+	label := &Label{
+		Name:   splits[0],
+		Schema: "host",
+		Arg:    "",
+	}
+	if len(splits) >= 2 {
+		label.Schema = splits[1]
+	}
+	if len(splits) >= 3 {
+		label.Arg = splits[2]
+	}
+	if label.Schema != SchemeHost && label.Schema != SchemeDocker {
+		return nil, fmt.Errorf("unsupported schema: %s", label.Schema)
+	}
+	return label, nil
+}
+
+type Labels []*Label
+
+func (l Labels) RequireDocker() bool {
+	for _, label := range l {
+		if label.Schema == SchemeDocker {
+			return true
+		}
+	}
+	return false
+}
+
+func (l Labels) PickPlatform(runsOn []string) string {
+	platforms := make(map[string]string, len(l))
+	for _, label := range l {
+		switch label.Schema {
+		case SchemeDocker:
+			// "//" will be ignored
+			// TODO maybe we should use 'ubuntu-18.04:docker:node:16-buster' instead
+			platforms[label.Name] = strings.TrimPrefix(label.Arg, "//")
+		case SchemeHost:
+			platforms[label.Name] = "-self-hosted"
+		default:
+			// It should not happen, because Parse has checked it.
+			continue
+		}
+	}
+	for _, v := range runsOn {
+		if v, ok := platforms[v]; ok {
+			return v
+		}
+	}
+
+	// TODO: support multiple labels
+	// like:
+	//   ["ubuntu-22.04"] => "ubuntu:22.04"
+	//   ["with-gpu"] => "linux:with-gpu"
+	//   ["ubuntu-22.04", "with-gpu"] => "ubuntu:22.04_with-gpu"
+
+	// return default.
+	// So the runner receives a task with a label that the runner doesn't have,
+	// it happens when the user have edited the label of the runner in the web UI.
+	// TODO: it may be not correct, what if the runner is used as host mode only?
+	return "node:16-bullseye"
+}

internal/pkg/labels/labels_test.go

@@ -0,0 +1,64 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package labels
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"gotest.tools/v3/assert"
+)
+
+func TestParse(t *testing.T) {
+	tests := []struct {
+		args    string
+		want    *Label
+		wantErr bool
+	}{
+		{
+			args: "ubuntu:docker://node:18",
+			want: &Label{
+				Name:   "ubuntu",
+				Schema: "docker",
+				Arg:    "//node:18",
+			},
+			wantErr: false,
+		},
+		{
+			args: "ubuntu:host",
+			want: &Label{
+				Name:   "ubuntu",
+				Schema: "host",
+				Arg:    "",
+			},
+			wantErr: false,
+		},
+		{
+			args: "ubuntu",
+			want: &Label{
+				Name:   "ubuntu",
+				Schema: "host",
+				Arg:    "",
+			},
+			wantErr: false,
+		},
+		{
+			args:    "ubuntu:vm:ubuntu-18.04",
+			want:    nil,
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.args, func(t *testing.T) {
+			got, err := Parse(tt.args)
+			if tt.wantErr {
+				require.Error(t, err)
+				return
+			} else {
+				require.NoError(t, err)
+			}
+			assert.DeepEqual(t, got, tt.want)
+		})
+	}
+}