JJandke's questions

I have the following scenario:

Service A

Service A is available under host:8080.

I have configured a reverse proxy in nginx to resolve servicea.domain to host:8080.

Here is my config-file (Location: /etc/nginx/sites-available/servicea)

server {
    listen 80;
    listen [::]:80;

    server_name servicea.domain.com;

    location / {
        proxy_pass http://host:8080/admin/;
        include proxy_params;

    proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Host $server_name;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_read_timeout 90;
        proxy_set_header X-Forwarded-Proto $scheme;

    set $xforwardedssl "off";
    if ($scheme = https) {
            set $xforwardedssl "on";
    }
    }
}

Service B

I would like to do the same with Service B (Grafana). This can be reached under host:3000. My nginx-config under /etc/nginx/sites-available/serviceb looks like this:

server {
    listen 80;
    listen [::]:80;

    server_name serviceb.domain.com;

    location / {
        proxy_pass http://host:3000/;
        include proxy_params;

    proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Host $server_name;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_read_timeout 90;
        proxy_set_header X-Forwarded-Proto $scheme;

    set $xforwardedssl "off";
    if ($scheme = https) {
            set $xforwardedssl "on";
    }
    }
}

• Both files are symlinked to /etc/nginx/sites-enabled/.
• Nginx starts successfully and does not complain.
• Everything works when calling servicea.domain.
• Ehen calling serviceb.domain I get a 400 error code in the browser.

When I use wget to load the page, I see that it does not actually resolve to host:3000 but to host:80.

╰─$ wget serviceb.domain.com
Will not apply HSTS. The HSTS database must be a regular and non-world-writable file.
ERROR: could not open HSTS store at '/home/config/.wget-hsts'. HSTS will be disabled.
--2024-04-08 12:17:00--  http://serviceb.domain.com/
Resolving serviceb.domain.com (serviceb.domain.com)... 10.25.25.34
Connecting to serviceb.domain.com (serviceb.domain.com)|10.25.25.34|:80... connected.
HTTP request sent, awaiting response... 400 Bad Request
2024-04-08 12:17:03 ERROR 400: Bad Request.

Why is that? I have the same configuration 1:1? A little proof that the config is the same. Here is the output of diff:

╰─$ diff serviceb servicea
5c5
<     server_name servicea.domain.com;
---
>     server_name serviceb.domain.com;
8c8
<         proxy_pass http://host:8080/admin/;
---
>         proxy_pass http://host:3000/;

Can anyone give me a hint where I can find settings that override my reverse proxy or otherwise impact name resolution? Let me know, if you need further information.

Thank you in advance!

To monitor a server we have imported a dashboard for Grafana. This uses Telegraf and InfluxDB as collector and database.

When certain graphs needed to be adjusted, I noticed that in the network speed queries, the bytes received (bytes_recv) are multiplied by 8, but the units on the graph itself are displayed in bits.

SELECT non_negative_derivative(mean(bytes_recv),1s)*8 as "in" FROM "net" WHERE host =~ /$server/ AND interface =~ /$netif/ AND $timeFilter GROUP BY time($interval), * fill(none)

According to my understanding is: 8Bit = 1Byte. According to this, if the data is available as bytes, it would have to be divided by 8 to get bits, if the graph should display bits.

Furthermore (if I am not mistaken): Megabit = Mb Mebibit = Mib Megabyte = MB Mebibyte = MiB

Refering to this, the unit on the graph seems to be megabit right? Do I understand something fundamentally wrong or was the "*" simply confused with the "/"?

Screenshot of the Grafana Dashboard