部署在 Azure 中的 nodejs 服务器正在输出内容长度

Question

My server.js looks like this:

var http = require('http');

var server = http.createServer(function (request, response) {

    const configs = {
        apiBaseUrl: 'http://myUrl'
    };

    const headers = {
        'Content-Type': 'application/json'
    };
    response.writeHead(200, headers);
    response.end(JSON.stringify(configs));
});

var port = process.env.PORT || 1337;
server.listen(port);

console.log("Server running at http://localhost:%d", port);

when i run this locally it outputs what it should:

{"apiBaseUrl":"http://myUrl"}

But when deployed to my Azure instance it behaves slightly different. It also outputs the number of chars:

29
{"apiBaseUrl":"http://myUrl"}
0

Any clue what could cause this issue?

Edit: i forgot to mention that i am deploying to Azure and have a web.config in place:

<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <clear />
                <rule name="Get dynamic configs in server environment" stopProcessing="true">
                    <match url="configs.json" ignoreCase="true"/>
                    <action type="Redirect" url="currentConfigs.js" redirectType="Permanent" appendQueryString="true" />
                </rule>
            </rules>
        </rewrite>
        <handlers>
            <add name="iisnode" path="currentConfigs.js" verb="*" modules="iisnode" />
        </handlers>
    </system.webServer>
</configuration>

Answer 1

I have made the following observation:

In Azure Portal i turned on Application Insights site extension by clicking the button.

This automatically created the following settings:

• APPINSIGHTS_INSTRUMENTATIONKEY
• APPINSIGHTS_PROFILERFEATURE_VERSION: 1.0.0
• APPINSIGHTS_SNAPSHOTFEATURE_VERSION: 1.0.0
• ApplicationInsightsAgent_EXTENSION_VERSION: ~2
• DiagnosticServices_EXTENSION_VERSION: ~3
• InstrumentationEngine_EXTENSION_VERSION: ~1
• SnapshotDebugger_EXTENSION_VERSION: ~1
• XDT_MicrosoftApplicationInsights_BaseExtensions: ~1
• XDT_MicrosoftApplicationInsights_Mode: recommended

The response of my node request is now:

29
{"apiBaseUrl":"http://myUrl"}
0

After playing around with those new values i found the value causing the issue:

• ApplicationInsightsAgent_EXTENSION_VERSION: ~2

Changing this to ~1 solved the issue and the response looked as desired:

• ApplicationInsightsAgent_EXTENSION_VERSION: ~1

response:

{"apiBaseUrl":"http://myUrl"}

I think this is a super strange behavior. I will create a github issue and link it.