fix `artifactServerPath` and `artifactServerAddr` config for exec (#221)

fix exec logic to make `actions/download-artifact` and `actions/upload-artifact` can be used.

example result:

```YML
name: test-artifact
on:
  - push
  - pull_request

jobs:
  test-artifact-1:
    name: test 1
    runs-on: ubuntu-latest
    steps:
      - run: echo `date` | tee time.txt
      - name: cache build result
        uses: actions/upload-artifact@v3
        with:
          name: build-artifact
          path: time.txt
          retention-days: 1

  test-artifact-2:
    name: test 2
    needs: test-artifact-1
    runs-on: ubuntu-latest
    steps:
      - name: Retrieve saved build result
        uses: actions/download-artifact@v3
        with:
          name: build-artifact
          path: .
      - run: ls -lh
      - run: cat time.txt

```

![image](/attachments/5cad3b4a-930a-4d42-a1ae-45ac32e6bfc2)

Co-authored-by: Jason Song <i@wolfogre.com>
Reviewed-on: https://gitea.com/gitea/act_runner/pulls/221
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: a1012112796 <1012112796@qq.com>
Co-committed-by: a1012112796 <1012112796@qq.com>

internal/app/cmd/exec.go

@@ -357,6 +357,24 @@ func runExec(ctx context.Context, execArgs *executeArgs) func(cmd *cobra.Command
 		log.Infof("cache handler listens on: %v", handler.ExternalURL())
 		execArgs.cacheHandler = handler
 
+		if len(execArgs.artifactServerAddr) == 0 {
+			if ip := common.GetOutboundIP(); ip == nil {
+				return fmt.Errorf("unable to determine outbound IP address")
+			} else {
+				execArgs.artifactServerAddr = ip.String()
+			}
+		}
+
+		if len(execArgs.artifactServerPath) == 0 {
+			tempDir, err := os.MkdirTemp("", "gitea-act-")
+			if err != nil {
+				fmt.Println(err)
+			}
+			defer os.RemoveAll(tempDir)
+
+			execArgs.artifactServerPath = tempDir
+		}
+
 		// run the plan
 		config := &runner.Config{
 			Workdir:               execArgs.Workdir(),
@@ -381,6 +399,7 @@ func runExec(ctx context.Context, execArgs *executeArgs) func(cmd *cobra.Command
 			AutoRemove:         true,
 			ArtifactServerPath: execArgs.artifactServerPath,
 			ArtifactServerPort: execArgs.artifactServerPort,
+			ArtifactServerAddr: execArgs.artifactServerAddr,
 			NoSkipCheckout:     execArgs.noSkipCheckout,
 			// PresetGitHubContext:   preset,
 			// EventJSON:             string(eventJSON),
@@ -403,16 +422,6 @@ func runExec(ctx context.Context, execArgs *executeArgs) func(cmd *cobra.Command
 			return err
 		}
 
-		if len(execArgs.artifactServerPath) == 0 {
-			tempDir, err := os.MkdirTemp("", "gitea-act-")
-			if err != nil {
-				fmt.Println(err)
-			}
-			defer os.RemoveAll(tempDir)
-
-			execArgs.artifactServerPath = tempDir
-		}
-
 		artifactCancel := artifacts.Serve(ctx, execArgs.artifactServerPath, execArgs.artifactServerAddr, execArgs.artifactServerPort)
 		log.Debugf("artifacts server started at %s:%s", execArgs.artifactServerPath, execArgs.artifactServerPort)
 
@@ -459,6 +468,7 @@ func loadExecCmd(ctx context.Context) *cobra.Command {
 	execCmd.Flags().StringArrayVarP(&execArg.containerCapDrop, "container-cap-drop", "", []string{}, "kernel capabilities to remove from the workflow containers (e.g. --container-cap-drop SYS_PTRACE)")
 	execCmd.Flags().StringVarP(&execArg.containerOptions, "container-opts", "", "", "container options")
 	execCmd.PersistentFlags().StringVarP(&execArg.artifactServerPath, "artifact-server-path", "", ".", "Defines the path where the artifact server stores uploads and retrieves downloads from. If not specified the artifact server will not start.")
+	execCmd.PersistentFlags().StringVarP(&execArg.artifactServerAddr, "artifact-server-addr", "", "", "Defines the address where the artifact server listens")
 	execCmd.PersistentFlags().StringVarP(&execArg.artifactServerPort, "artifact-server-port", "", "34567", "Defines the port where the artifact server listens (will only bind to localhost).")
 	execCmd.PersistentFlags().StringVarP(&execArg.defaultActionsUrl, "default-actions-url", "", "https://gitea.com", "Defines the default url of action instance.")
 	execCmd.PersistentFlags().BoolVarP(&execArg.noSkipCheckout, "no-skip-checkout", "", false, "Do not skip actions/checkout")