Proxmox Ve Template with HTTP Agent and Query fileds

[galvy]

Hi zabbix users
I have an issue related to the HTTP Agent and Proxmox VE HTTP. The problem is as follows: even if the query fields are empty, Zabbix still attempts to send the call to the server.

In the Proxmox template, if I remove the empty query fields, save, and reopen, an empty query field always reappears.
In the host associated with the template, I duplicated 'Get cluster status.' By doing so, during the test phase, I can remove the query field. However, if I close and reopen the item, Zabbix still adds an empty query field again.
I don't think the problem is related to the Proxmox template because I have other agents installed, and I've noticed that this behavior of adding an empty query field is systematic across all of them. However, I don't have this issue with the other APIs I monitor because, in the GET request, I simply discard any query fields, whereas the Proxmox APIs return a 400 error.


The problem started after migrating to zabbix 7

[gzdaniel]

I encountered the same problem， and I hope it can be resolved as soon as possible.

[Markku]

Unable to reproduce in Zabbix 7.0.1:

::ffff:192.168.7.80 - root@pam!Test [29/07/2024:10:23:01 +0300] "GET /api2/json/cluster/status HTTP/1.1" 200 121

Using the "Proxmox VE by HTTP" template that installed with 7.0.0.

Markku

[galvy]

Unable to reproduce in Zabbix 7.0.1:

::ffff:192.168.7.80 - root@pam!Test [29/07/2024:10:23:01 +0300] "GET /api2/json/cluster/status HTTP/1.1" 200 121

Using the "Proxmox VE by HTTP" template that installed with 7.0.0.

Markku

My Zabbix server was upgraded from version 6.4. After upgrading to 7.0.1, the problem appeared. I also tried both upgrading and downgrading the Proxmox template, but the issue persists.
Now, for testing, I will try creating a Docker instance just to see if the issue is related solely to the upgrade. Additionally, I will create an ASP.NET web API to check what the Zabbix server is requesting.

[Markku]

I also tested with a new host+HTTP item "http://127.0.0.1/test" (to connect to the web UI on the Zabbix server), didn't see any empty query parameters there either.

Markku

[galvy]

I also tested with a new host+HTTP item "http://127.0.0.1/test" (to connect to the web UI on the Zabbix server), didn't see any empty query parameters there either.

Markku

Is there a way to "grab" http request from server?

[Markku]

Yes, using tcpdump, when using non-encrypted http.

If testing on the local Zabbix web UI itself (using localhost = 127.0.0.1), this works:

sudo tcpdump -A -n -i lo port 80

GET /test HTTP/1.1
Host: 127.0.0.1
Accept: */*
Accept-Encoding: deflate, gzip, br, zstd

If using over network to remote host, capturing on the Zabbix server side, this works:

sudo tcpdump -A -n port 80 and host x.x.x.x
(where x.x.x.x = the IP address of the destination)

You can also use "-w filename.pcap" option to save the capture in a file and then inspect it better with Wireshark.

Markku

[galvy]

From a web api view point

Just to clarify
If I click "Remove" and test everything works as expected

But when click on "Update" and open it again an a empty query field appers

[Markku]

Are you only testing with the Test button or also by letting Zabbix to use the item? Asking because I saw the empty parameter with Test but not in the real item request.

Markku

[galvy]

Are you only testing with the Test button or also by letting Zabbix to use the item? Asking because I saw the empty parameter with Test but not in the real item request.

Markku

Zabbix is using the item, before the upgrade to 7.0.1 it was working with out problem

[Markku]

How about adding a dummy query parameter (foo=bar), saving the item, then opening item again and deleting the parameter, does it then still have an empty query parameter in the request?

Markku

[galvy]

How about adding a dummy query parameter (foo=bar), saving the item, then opening item again and deleting the parameter, does it then still have an empty query parameter in the request?

Markku

Did it, yes, same as before

[Markku]

Strange, in my 7.0.1 (btw 7.0.2 was just released) I can create new items without that problem, but in your setup creating new item always includes that empty query parameter.

Markku

[CharlieRoot]

Did it, yes, same as before

I can confirm we see the same behaviour. We do not use Query Fields but we see the ?= in the URL causing a 501 on our templates. I just updated to 7.0.2 this morning to see if that would resolve it, but that is sadly not the case.

Response code "501" did not match any of the required status codes "200" HTTP/1.1 301 Moved Permanently Location: https://xxxxxxx/Chassis/1/Power/?=/

[Markku]

You could open an issue at support.zabbix.com if you don't find a local reason, maybe they'll notice something that causes that in specific circumstances.

Markku