Golang DBTx.Query方法代碼示例

// migrateProcessData populates ProcessType.Volumes if ProcessType.Data is set
func migrateProcessData(tx *postgres.DBTx) error {
	type Release struct {
		ID string

		// use map[string]interface{} for process types so we can just
		// update Volumes and Data and leave other fields untouched
		Processes map[string]map[string]interface{}
	}

	var releases []Release
	rows, err := tx.Query("SELECT release_id, processes FROM releases")
	if err != nil {
		return err
	}
	defer rows.Close()
	for rows.Next() {
		var release Release
		if err := rows.Scan(&release.ID, &release.Processes); err != nil {
			return err
		}
		releases = append(releases, release)
	}
	if err := rows.Err(); err != nil {
		return err
	}

	for _, release := range releases {
		for typ, proc := range release.Processes {
			v, ok := proc["data"]
			if !ok {
				continue
			}
			data, ok := v.(bool)
			if !ok || !data {
				continue
			}
			proc["volumes"] = []struct {
				Path string `json:"path"`
			}{
				{Path: "/data"},
			}
			delete(proc, "data")
			release.Processes[typ] = proc
		}

		// save the processes back to the db
		if err := tx.Exec("UPDATE releases SET processes = $1 WHERE release_id = $2", release.Processes, release.ID); err != nil {
			return err
		}
	}
	return nil
}

// migrateProcessArgs sets ProcessType.Args from Entrypoint / Cmd for every
// release, and also prepends an explicit entrypoint for system and slug apps
// (they will no longer use the Dockerfile Entrypoint as they have some args
// like `scheduler` for the controller scheduler and `start web` for slugs).
func migrateProcessArgs(tx *postgres.DBTx) error {
	type Release struct {
		ID      string
		AppName *string
		AppMeta map[string]string
		Meta    map[string]string

		// use map[string]interface{} for process types so we can
		// just update Args and leave other fields untouched
		Processes map[string]map[string]interface{}
	}

	// get all the releases with the associated app name if set
	var releases []Release
	rows, err := tx.Query("SELECT r.release_id, r.meta, r.processes, a.name, a.meta FROM releases r LEFT JOIN apps a ON a.release_id = r.release_id")
	if err != nil {
		return err
	}
	for rows.Next() {
		var release Release
		if err := rows.Scan(&release.ID, &release.Meta, &release.Processes, &release.AppName, &release.AppMeta); err != nil {
			rows.Close()
			return err
		}
		releases = append(releases, release)
	}
	if err := rows.Err(); err != nil {
		return err
	}

	for _, release := range releases {
		for typ, proc := range release.Processes {
			// if the release is for a system app which has a Cmd,
			// explicitly set the Entrypoint
			var cmd []interface{}
			if v, ok := proc["cmd"]; ok {
				cmd = v.([]interface{})
			}
			if release.AppName != nil && release.AppMeta["flynn-system-app"] == "true" && len(cmd) > 0 {
				switch *release.AppName {
				case "postgres":
					proc["entrypoint"] = []interface{}{"/bin/start-flynn-postgres"}
				case "controller":
					proc["entrypoint"] = []interface{}{"/bin/start-flynn-controller"}
				case "redis":
					proc["entrypoint"] = []interface{}{"/bin/start-flynn-redis"}
				case "mariadb":
					proc["entrypoint"] = []interface{}{"/bin/start-flynn-mariadb"}
				case "mongodb":
					proc["entrypoint"] = []interface{}{"/bin/start-flynn-mongodb"}
				case "router":
					proc["entrypoint"] = []interface{}{"/bin/flynn-router"}
				case "logaggregator":
					proc["entrypoint"] = []interface{}{"/bin/logaggregator"}
				default:
					if strings.HasPrefix(*release.AppName, "redis-") {
						proc["entrypoint"] = []interface{}{"/bin/start-flynn-redis"}
					} else {
						panic(fmt.Sprintf("migration failed to set entrypoint for system app %s", *release.AppName))
					}
				}
			}

			// git releases use the slugrunner which need an Entrypoint
			if release.Meta["git"] == "true" {
				proc["entrypoint"] = []interface{}{"/runner/init"}
			}

			// construct Args by appending Cmd to Entrypoint
			var args []interface{}
			if v, ok := proc["entrypoint"]; ok {
				args = v.([]interface{})
			}
			proc["args"] = append(args, cmd...)
			release.Processes[typ] = proc
		}

		// save the processes back to the db
		if err := tx.Exec("UPDATE releases SET processes = $1 WHERE release_id = $2", release.Processes, release.ID); err != nil {
			return err
		}
	}
	return nil
}