Docker Compose 用于 Java 后端和 Python 前端应用程序。

huangapple
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英文:

Docker compose for java backend and python frontend application

问题

以下是翻译好的内容：

我有一个简单的Spring Boot Java后端应用程序，可以从列表中获取元素（端点/get/{id}）并将元素添加到列表中（端点/add/{product}）：

  1. @RestController
  2. public class DemoController {
  4.     List<String> products = Arrays.asList("test");
  6.     @PostMapping(path="/add/{product}")
  7.     public int addProduct(@PathVariable final String product){
  8.         products.add(product);
  9.         return products.size()-1;
  10.     }
  12.     @GetMapping(path="/get/{id}")
  13.     public String getValue(@PathVariable final int id){
  14.         return products.get(id);
  15.     }
  16. }

我为此创建了Dockerfile，如下所示：

  1. FROM openjdk:11
  3. # 将打包的jar文件复制到我们的Docker镜像中
  4. COPY target/demo-0.0.1-SNAPSHOT.jar /demo.jar
  6. EXPOSE 8080/tcp
  8. # 设置启动命令以执行jar文件
  9. CMD ["java", "-jar", "/demo.jar"]

现在我可以构建镜像（docker build -t java_backend .）并运行应用程序（docker run --rm -p 8080:8080 java_backend）。

因此，在localhost:8080/get/0下，我得到了"test"，在localhost:8080/add/something下，我可以添加元素。一切正常。

作为前端，我有一个简单的Python应用程序，如下所示：

  1. from flask import Flask, request
  2. import requests as r
  3. import os
  4. app = Flask(__name__)
  6. @app.route("/")
  7. def renderProduct():
  8.     return """
  9.             <html>
  10.                 <head>
  11.                     <title>""" + os.environ["title"] + """</title>
  12.                 </head>    
  13.                 <form id="1" method="POST">
  14.                     <input name="getID"/>
  15.                     <br>
  16.                     <input name="addID">
  17.                     <input type="submit">
  18.                 </form>
  19.                 </html>
  20.                 """
  22. @app.route("/", methods=["POST"])
  23. def queryAndRender():
  24.     builded = "<html>"
  25.     if request.form["getID"] is not None:
  26.         resp = r.get("http://localhost:8080/get/" + request.form["getID"])
  27.         builded = builded + "PRODUCT:" + resp.text + "<br>"
  29.     if request.form["addID"] is not None:
  30.         resp = r.get("http://localhost:8080/add/" + request.form["addID"])
  31.         builded = builded + "ADDED ID:" + resp.text + "<br>"
  33.     builded = builded + """<html>
  34.                             <head>
  35.                                 <title>""" + os.environ["title"] + """</title>
  36.                             </head>
  37.                             <form id="1" method="POST">
  38.                                 <input name="getID"/>
  39.                                 <br>
  40.                                 <input name="addID">
  41.                                 <input type="submit">
  42.                             </form>
  43.                             </html>
  44.                             """
  45.     return builded;
  48. if __name__ == "__main__":
  49.     app.run()

Dockerfile如下：

  1. ARG version=3.8.5-alpine3.11
  2. FROM python:${version}
  4. ENV title="Hello world"
  5. ENV test testspacja
  6. ENV FLASK_APP=/main.py
  8. RUN pip install Flask==1.1.2
  9. RUN pip install requests==2.22.0
  11. COPY main.py /
  12. RUN sed -i 's/localhost:8080/backend/g' /main.py
  14. EXPOSE 80/tcp
  16. ENTRYPOINT ["flask", "run"]
  17. CMD ["-h", "0.0.0.0", "-p", "80"]

最后，我创建了docker-compose.yml文件来运行它们两个：

  1. version: '3.3'
  2. services:
  3.     backend:
  4.         image: java_backend
  5.         ports:
  6.              - "8080:8080"
  8.     frontend:
  9.         image: frontend
  10.         ports:
  11.             - "8081:80"

现在我尝试启动docker-compose up --build backend frontend。

前端和后端是独立工作的，因此如果我尝试在localhost:8080/get/0中放置localhost:8080/get/0，我会得到"test"，如果我转到localhost:8081，我会看到我的前端。但是，如果我在文本框中输入一些值并单击提交，我会收到500 Internal Server Error。因此，服务之间没有连接。您能告诉我为什么吗？

英文:

I have simple spring boot java backend application which get element from the list (endpoint /get/{id}) and add element to the list (endpoint /add/{product}):

  1. @RestController
  2. public class DemoController {
  4.     List&lt;String&gt; products = Arrays.asList(&quot;test&quot;);
  6.     @PostMapping(path=&quot;/add/{product}&quot;)
  7.     public int addProduct(@PathVariable final String product){
  8.         products.add(product);
  9.         return products.size()-1;
  10.     }
  12.     @GetMapping(path=&quot;/get/{id}&quot;)
  13.     public String getValue(@PathVariable final int id){
  14.         return products.get(id);
  15.     }
  16. }

I created Dockerfile for this like:

  1. FROM openjdk:11
  3. # copy the packaged jar file into our docker image
  4. COPY target/demo-0.0.1-SNAPSHOT.jar /demo.jar
  6. EXPOSE 8080/tcp
  8. # set the startup command to execute the jar
  9. CMD [&quot;java&quot;, &quot;-jar&quot;, &quot;/demo.jar&quot;]

Now I can build image (docker build -t java_backend .) and run application (docker run --rm -p 8080:8080 java_backend).

Thus, under localhost:8080/get/0 I got &quot;test&quot;, under localhost:8080/add/something I can add element. Everything is fine.

As frontend I have simple python application like:

  1. from flask import Flask, request
  2. import requests as r
  3. import os
  4. app = Flask(__name__)
  6. @app.route(&quot;/&quot;)
  7. def renderProduct():
  8.     return &quot;&quot;&quot;
  9.             &lt;html&gt;
  10.                 &lt;head&gt;
  11.                     &lt;title&gt;&quot;&quot;&quot; + os.environ[&quot;title&quot;] + &quot;&quot;&quot;&lt;/title&gt;
  12.                 &lt;/head&gt;    
  13.                 &lt;form id=&quot;1&quot; method=&quot;POST&quot;&gt;
  14.                     &lt;input name=&quot;getID&quot;/&gt;
  15.                     &lt;br&gt;
  16.                     &lt;input name=&quot;addID&quot;&gt;
  17.                     &lt;input type=&quot;submit&quot;&gt;
  18.                 &lt;/form&gt;
  19.                 &lt;/html&gt;
  20.                 &quot;&quot;&quot;
  22. @app.route(&quot;/&quot;, methods=[&quot;POST&quot;])
  23. def queryAndRender():
  24.     builded = &quot;&lt;html&gt;&quot;
  25.     if request.form[&quot;getID&quot;] is not None:
  26.         resp = r.get(&quot;http://localhost:8080/get/&quot; + request.form[&quot;getID&quot;])
  27.         builded = builded + &quot;PRODUCT:&quot; + resp.text + &quot;&lt;br&gt;&quot;
  29.     if request.form[&quot;addID&quot;] is not None:
  30.         resp = r.get(&quot;http://localhost:8080/add/&quot; + request.form[&quot;addID&quot;])
  31.         builded = builded + &quot;ADDED ID:&quot; + resp.text + &quot;&lt;br&gt;&quot;
  33.     builded = builded + &quot;&quot;&quot;&lt;html&gt;
  34.                             &lt;head&gt;
  35.                                 &lt;title&gt;&quot;&quot;&quot; + os.environ[&quot;title&quot;] + &quot;&quot;&quot;&lt;/title&gt;
  36.                             &lt;/head&gt;
  37.                             &lt;form id=&quot;1&quot; method=&quot;POST&quot;&gt;
  38.                                 &lt;input name=&quot;getID&quot;/&gt;
  39.                                 &lt;br&gt;
  40.                                 &lt;input name=&quot;addID&quot;&gt;
  41.                                 &lt;input type=&quot;submit&quot;&gt;
  42.                             &lt;/form&gt;
  43.                             &lt;/html&gt;
  44.                             &quot;&quot;&quot;
  46.     return builded;
  49. if __name__ == &quot;__main__&quot;:
  50.     app.run()

And Dockerfile:

  1. ARG version=3.8.5-alpine3.11
  2. FROM python:${version}
  4. ENV title=&quot;Hello world&quot;
  5. ENV test testspacja
  6. ENV FLASK_APP=/main.py
  8. RUN pip install Flask==1.1.2
  9. RUN pip install requests==2.22.0
  11. COPY main.py /
  12. RUN sed -i &#39;s/localhost:8080/backend/g&#39; /main.py
  14. EXPOSE 80/tcp
  16. ENTRYPOINT [&quot;flask&quot;, &quot;run&quot;]
  17. CMD [&quot;-h&quot;, &quot;0.0.0.0&quot;, &quot;-p&quot;, &quot;80&quot;]

At the end I created docker-compose.yml file to run both of them:

  1. version: &#39;3.3&#39;
  2. services:
  3.         backend:
  4.                 image: java_backend
  5.                 ports:
  6.                          - &quot;8080:8080&quot;
  8.         frontend:
  9.                 image: frontend
  10.                 ports:
  11.                         - &quot;8081:80&quot;

Now I try to start docker-compose up --build backend frontend.

Frontend and backend are working independent, hence if I try put localhost:8080/get/0 I am getting &quot;test&quot;, If I go to localhost:8081 I see my frontend. But if I put some values in textboxes and click submit then I got 500 Internal Server Error. So services are not connected. Could you please tell me why?

答案1

得分: 0

我认为你在意外地擦除了后端端口。尝试将以下内容替换为：

  1. RUN sed -i &#39;s/localhost:8080/backend:8080/g&#39; /main.py
英文:

I think you are accidentally erasing the backend port. Try replacing

  1. RUN sed -i &#39;s/localhost:8080/backend/g&#39; /main.py

with

  1. RUN sed -i &#39;s/localhost:8080/backend:8080/g&#39; /main.py

答案2

得分: 0

我有一个额外的问题。假设我想从容器中启动前端，但只从我的本地IDE（IntelliJ）启动后端。

当然，RUN sed -i 's/localhost:8080/backend/g' /main.py 这一行被注释了，所以前端调用的是 http://localhost:8080 下的端点。

在这种情况下，前端位于 http://localhost:8081，后端位于 http://localhost:8080（两个端点 - /get/{id} 和 /add/{product}）。但为什么在容器中运行的前端无法“看到”我的后端呢？

英文:

I have one additional question for this. Let's suppose that I would like start frontend from container but backend only from the my local IDE (IntelliJ).

Of course line RUN sed -i &#39;s/localhost:8080/backend/g&#39; /main.py is commented so frontent is calling endpoints under http://localhost:8080.

In this case frontend is under http://localhost:8081 and backend under http://localhost:8080 (two endpoints - /get/{id} and /add/{product}). But why frontend which is running in container doesn't "see" my backend?

huangapple
  • 本文由 发表于 2020年9月20日 23:59:20
  • 转载请务必保留本文链接：https://go.coder-hub.com/63980939.html
  • docker
  • docker-compose
  • java
  • python
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