Answers: <p>I had the same problem and I found that you have to specify the proxy address also in the curl command.</p>
  <p>So your Dockerfile become</p>
  <pre><code>FROM mcr.microsoft.com/windows/servercore:ltsc2019
  
  ENV HTTP_PROXY=$HTTP_PROXY
  ENV HTTPS_PROXY=$HTTPS_PROXY
  
  SHELL [&quot;cmd&quot;, &quot;/S&quot;, &quot;/C&quot;]
  
  RUN mkdir c:\temp \
      &amp;&amp; curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe --proxy %HTTP_PROXY%
  </code></pre>
  <p>and you will have to call the build command with this instruction</p>
  <pre><code>docker build --build-arg HTTP_PROXY --build-arg HTTPS_PROXY --tag=tswin .
  </code></pre>
  
Answers: CC BY-SA 4.0
Answers: 2022-02-03T07:23:07.380Z
Answers: 2022-02-03T07:23:07.380Z
Answers: nocino87
Body: <p>I'm using windows containers in windows 10. I've set proxy variables(HTTP_PROXY,HTTPS_PROXY) in environmental variable setup and using VPN. I also configured resources -&gt; Proxies.</p>
  <p>I was trying to build docker image with following Dockerfile content.</p>
  <pre><code>FROM mcr.microsoft.com/windows/servercore:ltsc2019
  SHELL [&quot;cmd&quot;, &quot;/S&quot;, &quot;/C&quot;]
  
  RUN mkdir c:\temp \
      &amp;&amp; curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe
  </code></pre>
  <p>When this docker image build command is executed it shows following error.</p>
  <pre><code>Step 5/5 : RUN mkdir c:\temp     &amp;&amp; curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe
   ---&gt; Running in 0c134b2d004a
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
    0     0    0     0    0     0      0      0 --:--:--  0:00:12 --:--:--     0curl: (6) Could not resolve host: aka.ms
  The command 'cmd /S /C mkdir c:\temp     &amp;&amp; curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe' returned a non-zero code: 6
  </code></pre>
  <p>I tried to build this with build arguments, and added dns: 8.8.8.8 in docker deamon config file</p>
  <pre><code>docker build --build-arg HTTP_PROXY --build-arg HTTPS_PROXY --tag=tswin .
  </code></pre>
  <p>But above mentioned error is not solved.</p>
  <p>When the same curl command is executed in Windows's CMD it is not throwing any error</p>
  <pre><code>C:\Users\mshanm6x&gt;curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
    0     0    0     0    0     0      0      0 --:--:--  0:00:01 --:--:--     0
  100 1432k  100 1432k    0     0   238k      0  0:00:06  0:00:06 --:--:--  332k
  </code></pre>
  <p>Also the same Dockerfile was able to built by without HTTP_PROXY, HTTPS_PROXY env variables and VPN off.</p>
  <p>What is the real issue. Why it is not working inside of container with proxy configuration.</p>
  
Tags: <docker><dockerfile>
Title: PROXY is not working inside windows container
UserDisplayName: imaheshwaran s
ThreadText: # PROXY is not working inside windows container
  
  (Asked by: username_0 on 2021-08-19)
  
  I'm using windows containers in windows 10. I've set proxy variables(HTTP\_PROXY,HTTPS\_PROXY) in environmental variable setup and using VPN. I also configured resources -> Proxies.
  
  I was trying to build docker image with following Dockerfile content.
  
  ```
  FROM mcr.microsoft.com/windows/servercore:ltsc2019
  SHELL ["cmd", "/S", "/C"]
  
  RUN mkdir c:\temp \
      && curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe
  
  ```
  
  When this docker image build command is executed it shows following error.
  
  ```
  Step 5/5 : RUN mkdir c:\temp     && curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe
   ---> Running in 0c134b2d004a
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
    0     0    0     0    0     0      0      0 --:--:--  0:00:12 --:--:--     0curl: (6) Could not resolve host: aka.ms
  The command 'cmd /S /C mkdir c:\temp     && curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe' returned a non-zero code: 6
  
  ```
  
  I tried to build this with build arguments, and added dns: 8.8.8.8 in docker deamon config file
  
  ```
  docker build --build-arg HTTP_PROXY --build-arg HTTPS_PROXY --tag=tswin .
  
  ```
  
  But above mentioned error is not solved.
  
  When the same curl command is executed in Windows's CMD it is not throwing any error
  
  ```
  C:\Users\mshanm6x>curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
    0     0    0     0    0     0      0      0 --:--:--  0:00:01 --:--:--     0
  100 1432k  100 1432k    0     0   238k      0  0:00:06  0:00:06 --:--:--  332k
  
  ```
  
  Also the same Dockerfile was able to built by without HTTP\_PROXY, HTTPS\_PROXY env variables and VPN off.
  
  What is the real issue. Why it is not working inside of container with proxy configuration.
  
  **Tags:** docker, dockerfile
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-02-03. Score: 1
  
  I had the same problem and I found that you have to specify the proxy address also in the curl command.
  
  So your Dockerfile become
  
  ```
  FROM mcr.microsoft.com/windows/servercore:ltsc2019
  
  ENV HTTP_PROXY=$HTTP_PROXY
  ENV HTTPS_PROXY=$HTTPS_PROXY
  
  SHELL ["cmd", "/S", "/C"]
  
  RUN mkdir c:\temp \
      && curl -SL --output c:\temp\vs_buildtools.exe https://aka.ms/vs/16/release/vs_buildtools.exe --proxy %HTTP_PROXY%
  
  ```
  
  and you will have to call the build command with this instruction
  
  ```
  docker build --build-arg HTTP_PROXY --build-arg HTTPS_PROXY --tag=tswin .
  
  ```
  
  
  ---
  
  