check_ping command not working on Alpine

[BE-Digital-Solutions-Bart]

I'm running the Alpine version of the container image, and the check_ping command is not working.
It always results in the output: Could not interpret output from ping command

This issue can be solved by executing:
chmod u+s /bin/ping
chmod u+s /bin/ping6

Since the check_ping command is a popular official Nagios plugin, please consider adding this fix in the Dockerfile directly.

[manios]

Hi @BE-Digital-Solutions-Bart !

I have tried the latest image and it works fine in my case: docker run -d -p 8080:80 --name nagios-amd64 manios/nagios:latest .

/opt/nagios # ./libexec/check_ping -H 192.168.1.1 -w 4000,80% -c 5000,85% -4 -p 
3
PING OK - Packet loss = 0%, RTA = 19.41 ms|rta=19.405001ms;4000.000000;5000.000000;0.000000 pl=0%;80;85;0

I get no error logs regarding the check_ping plugin. If you use the latest and you still see errors, then we need some more info:

Image information

Can you please give us some information about the image you are using? In order to achieve this, please post here the output of the command:

docker inspect --format='{{range $k,$v := .Config.Labels}}{{printf "* %s: " $k}}{{if not $v}}{{$v}}{{else}}{{$v}}{{end}}{{"\n"}}{{end}}'  manios/nagios:[TAG]

Example output:

* build: 5
* gitCommit: c34e48cb6866b1a2bb77adf4d69feeab534ecc84
* homepage: https://www.nagios.com/
* maintainer: Christos Manios <maniopaido@gmail.com>
* nagiosPluginsVersion: 2.3.3
* nagiosVersion: 4.4.6
* name: Nagios
* nrpeVersion: 4.0.3

Image architecture

What is the architecture your docker image is using? You can easily find out by executing this

docker exec -it [container-name] /bin/sh -c 'apk --print-arch'

in your running container.

Example output:

amd64

Relevant log output

Please copy and paste any relevant log output. This will be automatically formatted into code, so no need for markdown backticks.

For example, in order to view the last 200 log lines from the container you can run:

docker logs --tail 200 [container-name]

You can also append the Apache error or access logs by issuing the commands:

docker exec -it [container-name] /bin/sh -c 'cat /var/log/apache2/error.log'

# AND

docker exec -it [container-name] /bin/sh -c 'cat /var/log/apache2/access.log

Thanks,
Chris

[BE-Digital-Solutions-Bart]

Hi Chris,

Thank you far the fast reply!

I haven't been able to reproduce the error this week. I have no idea what caused the issue exactly.

--- Details ---

I had been running the 4.5.1 version of your container image on my Synology NAS (model DS 920+) since over a year without any issues.
(And to be precies, I'm actually I was running a docker image created from a private fork of this project, including Python & nmap in the container image, and exposing web ui on a different port: bedigitalsolutionsbart/nagios:build-2024-03-23 on Docker Hub)

Last weekend, I had upgraded to the 4.5.9 version by merging in the latest changes, and encountered a few things that didn't work. (bedigitalsolutionsbart/nagios:build-2025-04-19 on Docker Hub)
I installed bash to fix 1 of my custom Nagios commands, and started receiving lots of Nagios notifications in MS Teams, e.g.

PROBLEM: telenet-router is DOWN
CRITICAL - Could not interpret output from ping command

generated by:

define command {
command_name notify-host-by-teams
command_line /usr/bin/python3 /opt/Custom-Nagios-Plugins/notify-teams/notify-teams-workflow.py "$_CONTACTWEBHOOKURL$" "$NOTIFICATIONTYPE$: $HOSTALIAS$ is $HOSTSTATE$" "$HOSTOUTPUT$"
}

When connecting to the container console, I could reproduce this error message by executing the "./libexec/check_ping" command.

I could fix this by executing: chmod u+s /bin/ping
This change immediately resulted in lots of RECOVERY notifications in Teams, indicating successful ping output, e.g.

RECOVERY: telenet-router is UP
PING OK - Packet loss = 0%, RTA = 1.88 ms - 192.168.0.1

---

I haven't been able to reproduce the error when running a fresh container on my NAS from image: bedigitalsolutionsbart/nagios:build-2025-04-19
I also haven't been able to reproduce the error when running a fresh container on my NAS of your container image: manios/nagios:build-30

When opening the terminal with "/bin/sh" and executing "apk --print-arch" results in:
x86_64

Thank you for the support, and feel free to close this issue.

Bart

[pygoubet]

Hi,
I am experiencing the same problem with image manios/nagios:4.5.9 for linux/arm64 architecture. Within the container, as nagios user, the ping command fails. chmod u+s /bin/ping fixes it.

/opt/nagios # su -s /bin/sh - nagios -c "ping 192.168.1.1"
PING 192.168.1.1 (192.168.1.1): 56 data bytes
ping: permission denied (are you root?)

/opt/nagios # chmod u+s /bin/ping
/opt/nagios # su -s /bin/sh - nagios -c "ping 192.168.1.1"
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: seq=0 ttl=62 time=1.041 ms
64 bytes from 192.168.1.1: seq=1 ttl=62 time=0.727 ms

As workaround, I have changed the container entrypoint command to: sh -c 'chmod u+s /bin/ping; /usr/local/bin/start_nagios'.

[manios]

Hi @pygoubet , @BE-Digital-Solutions-Bart !

I have tried again today in both amd64 and arm64 flavours of the image with build-30 and I cannot reproduce the issue. Ping command works normally as you can see:

# Run qemu to emulate ARM architecture in an x64 PC
sudo docker run --rm --privileged multiarch/qemu-user-static --reset -p yes

# Create a docker network which support IPv6
docker network create --ipv6 ip6net

# Run the arm64 Nagios Docker image with the IPv6 enabled network
sudo docker run -d -p 8082:80 --name nagios-arm64  --rm --platform=linux/arm64 --network ip6net  manios/nagios:4.5.9

# Test ping command
sudo docker exec  nagios-arm64   /bin/sh -c "ping 192.168.1.1"
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: seq=0 ttl=63 time=2.241 ms
64 bytes from 192.168.1.1: seq=1 ttl=63 time=2.248 ms

# Test ping6 command
sudo docker exec  nagios-arm64   /bin/sh -c "ping6 ipv6.google.com"
PING ipv6.google.com (2a00:1450:4001:800::200e): 56 data bytes
64 bytes from 2a00:1450:4001:800::200e: seq=0 ttl=110 time=52.374 ms
64 bytes from 2a00:1450:4001:800::200e: seq=1 ttl=110 time=50.312 ms

Can you please try again and check if you are using the latest image version build-30 by running this command?

docker inspect --format='{{range $k,$v := .Config.Labels}}{{printf "* %s: " $k}}{{if not $v}}{{$v}}{{else}}{{$v}}{{end}}{{"\n"}}{{end}}'    manios/nagios:4.5.9

Thank you,
Chris

[pygoubet]

Hi @manios
Thank you for taking the time to test on (emulated) ARM64 architecture.
I do confirm that ping command works for root user but it does not for nagios.

# as root
root@nagios:~/compose# docker exec -it nagios /bin/sh -c "ping -c 1 192.168.1.1"
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: seq=0 ttl=63 time=0.873 ms

--- 192.168.1.1 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.873/0.873/0.873 ms

# as nagios
root@nagios:~/compose# docker exec -it nagios su nagios -s /bin/sh -c "ping -c 1 192.168.1.1"
PING 192.168.1.1 (192.168.1.1): 56 data bytes
ping: permission denied (are you root?)

docker exec -it nagios chmod u+s /bin/ping fix remains needed.

Pierre-Yves

[manios]

Hi @pygoubet !

I have tested again in a real aarch64 Arm64 hardware (Raspberry Pi 4 Model B) and I cannot reproduce the issue. As you can see even if I run the ping command with nagios user, it works properly. Also the check_ping command plugin tool works.

pi@raspberrypi:~ $ uname -a
Linux raspberrypi 6.12.47+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1 (2025-09-16) aarch64 GNU/Linux
pi@raspberrypi:~ $ uname -m
aarch64
pi@raspberrypi:~ $ sudo lsb_release -a
No LSB modules are available.
Distributor ID:	Raspbian
Description:	Raspbian GNU/Linux 13 (trixie)
Release:	13
Codename:	trixie
pi@raspberrypi:~ $ docker run -d --ulimit nofile=65535:65535  -p 8080:80 --name nagios manios/nagios
d7d4c4e5596dba33f56a5bcc3ef143669b1eae26afba668a713f8c6e169b7ada

####
# Run ping command with nagios user
pi@raspberrypi:~ $ docker exec -it nagios su nagios -s /bin/sh -c "ping -c 1 192.168.1.1"
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: seq=0 ttl=42 time=4.751 ms

--- 192.168.1.1 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 4.751/4.751/4.751 ms

####
# Run check_ping plugin with nagios user
pi@raspberrypi:~ $ docker exec -it nagios su nagios -s /bin/sh -c "./libexec/check_ping -H 192.168.1.1 -w 4000,80% -c 5000,85% -4 -p 3"
PING OK - Packet loss = 0%, RTA = 4.35 ms|rta=4.350000ms;4000.000000;5000.000000;0.000000 pl=0%;80;85;0

Can you please run this command in your arm64 machine and post the output?

docker inspect --format='{{range $k,$v := .Config.Labels}}{{printf "* %s: " $k}}{{if not $v}}{{$v}}{{else}}{{$v}}{{end}}{{"\n"}}{{end}}'  manios/nagios:<the-tag-that-you-use>

Thank you,
Chris