用modelbox server启动流程图，暴露Restful接口

背景

假设你已经搭建了modelbox开发容器，能够使用webUI构建流程图。如果没有请参考昇腾npu上构建modelbox webUI开发容器教程。

现在，本文会说明，如何在终端用命令的方式将流程图暴露为服务，并能够在本地用postman访问。

本文参考ModelBox运行的"通过modelbox命令启动"一节

主要流程

首先，假设我们编写了如图的程序，其中foobar阶段会固定输出一个字符串。

foobar.py内容如下，固定会输出"Hello world!"

import _flowunit as modelbox

class FoobarFlowUnit(modelbox.FlowUnit):
    # Derived from modelbox.FlowUnit
    def __init__(self):
        super().__init__()

    def open(self, config):
        # Open the flowunit to obtain configuration information
        return modelbox.Status.StatusCode.STATUS_SUCCESS

    def process(self, data_context):
        # Process the data
        # input data
        in_data = data_context.input("in_data")
        # output data
        out_data = data_context.output("out_data")

        # Example process code.
        # Remove the following code and add your own code here.
        for buffer in in_data:
            add_buffer = modelbox.Buffer(self.get_bind_device(), "Hello world!")
            out_data.push_back(add_buffer)

        return modelbox.Status.StatusCode.STATUS_SUCCESS

    def close(self):
        # Close the flowunit
        return modelbox.Status()

    def data_pre(self, data_context):
        # Before streaming data starts
        return modelbox.Status()

    def data_post(self, data_context):
        # After streaming data ends
        return modelbox.Status()

mnist_response.py的代码逻辑也很简单，固定输出上一步骤的字符串，内容如下：

import _flowunit as modelbox
import numpy as np
import json

class MnistResponseFlowUnit(modelbox.FlowUnit):
    def __init__(self):
        super().__init__()

    def open(self, config):
        return modelbox.Status.StatusCode.STATUS_SUCCESS

    def process(self, data_context):
        in_data = data_context.input("in_data")
        out_data = data_context.output("out_data")

        for buffer in in_data:
            add_buffer = modelbox.Buffer(self.get_bind_device(), buffer.as_object())
            out_data.push_back(add_buffer)

        return modelbox.Status.StatusCode.STATUS_SUCCESS

    def close(self):
        return modelbox.Status()

    def data_pre(self, data_context):
        return modelbox.Status()

    def data_post(self, data_context):
        return modelbox.Status()

    def data_group_pre(self, data_context):
        return modelbox.Status()

    def data_group_post(self, data_context):
        return modelbox.Status()

然后，在项目路径内graph/下的.toml文件内，修改暴露的端口，如下文显示端口暴露在8190

…
digraph mnist_sample {
node [shape=Mrecord]
httpserver_sync_receive [ type=flowunit flowunit=httpserver_sync_receive device=cpu time_out_ms=“5000” endpoint=“http://0.0.0.0:8190” max_requests=“100” ]
…

那么，如何不用webUI，将流程图启动暴露为Restful服务呢？

进入modelbox开发容器
进入目录/root/modelbox-service/conf
编辑modelbox.conf配置文件。把flow_path 属性指向你的项目的graph目录，比如在本文的mnist项目，流程图存储在/root/projects/mnist/src/graph目录下。内容如下：
```
[server]
ip = "0.0.0.0"
port = "1104"
flow_path = "/root/projects/mnist/src/graph/"

# 后续略...
```
执行modelbox -c ./modelbox-service/conf/modelbox.conf -fV。如果在子目录下则执行modelbox -c ./modelbox.conf -fV

然后，能看到终端输出日志：

[root@devserver-com conf]$ modelbox -c ./modelbox.conf -fV
[2023-12-06 20:35:17,711][ INFO][          main.cc:385 ] modelbox config path : ./modelbox.conf
[2023-12-06 20:35:17,711][ INFO][        server.cc:129 ] plugin list:
[2023-12-06 20:35:17,711][ INFO][        server.cc:131 ]  /usr/local/lib64/modelbox-plugin.so
[2023-12-06 20:35:17,711][ INFO][        server.cc:131 ]  /usr/local/lib64/modelbox-plugin-editor.so
[2023-12-06 20:35:17,712][ INFO][modelbox_plugin.cc:68  ] create modelbox plugin
[2023-12-06 20:35:17,712][ INFO][modelbox_plugin.cc:51  ] modelbox plugin init
[2023-12-06 20:35:17,712][ INFO][modelbox_plugin.cc:61  ] run modelbox plugin on http://0.0.0.0:1104
[2023-12-06 20:35:17,712][ INFO][modelbox_plugin.cc:73  ] modelbox plugin register handlers
[2023-12-06 20:35:17,712][ INFO][modelbox_plugin.cc:74  ] regist url : /v1/modelbox/job
[2023-12-06 20:35:17,712][ INFO][modelbox_plugin.cc:148 ] create local job
[2023-12-06 20:35:17,712][ INFO][modelbox_plugin.cc:192 ] Create local job /root/projects/mnist/src/graph//CMakeLists.txt
[2023-12-06 20:35:17,712][ERROR][          flow.cc:473 ] read config from  toml:/root/projects/mnist/src/graph//CMakeLists.txtfailed, err :Load config file failed, detail: [error] toml::parse_key_value_pair: missing key-value separator `=`
 --> /root/projects/mnist/src/graph//CMakeLists.txt
    |
 16 | cmake_minimum_required(VERSION 3.10)
    |                       ^--- should be `=`
[2023-12-06 20:35:17,712][ERROR][           job.cc:65  ] flow init failed: code: Fault, errmsg: Load config file failed, detail: [error] toml::parse_key_value_pair: missing key-value separator `=`
 --> /root/projects/mnist/src/graph//CMakeLists.txt
 ...
 [2023-12-06 20:35:18,824][ INFO][ editor_plugin.cc:126 ] create modelbox editor plugin
[2023-12-06 20:35:18,824][ INFO][ editor_plugin.cc:104 ] modelbox editor plugin init
[2023-12-06 20:35:18,824][ INFO][ editor_plugin.cc:119 ] run editor on http://0.0.0.0:1104
[2023-12-06 20:35:18,824][ INFO][        server.cc:59  ] app server start
[2023-12-06 20:35:18,825][ INFO][   http_helper.cc:438 ] Start listen at 0.0.0.0:1104

然后用postman访问那个服务器IP的8190端口，并按预定的接口填写参数，即可发出Restful请求。如下图所示，返回了字符串，与预期一致。