Host metrics on the host card (load, disk, network, uptime)

[notrevetecnologia]

Hi! First off, thanks for Dozzle — it's excellent. I forked it to add host-level metrics that complement the per-container CPU/memory/network you already show, and I'd love to contribute it upstream if you're open to it.

What it adds

The host card currently shows CPU and Memory. I added four more facts for the host:

• Disk (used/total with a usage bar)
• Load (1m / 5m / 15m)
• Uptime
• Network (rx / tx totals)

Rendered as tiles matching the existing CPU/Memory cards. (I'll attach a screenshot in a follow-up comment.)

How it works

• Backend (Go): new fields on container.Host (memUsed, load1/5/15, uptime, diskTotal/diskFree, netRxTotal/netTxTotal), populated for the local host by reading /proc/loadavg, /proc/uptime, /proc/meminfo, /proc/net/dev, plus statfs for the root filesystem (reusing the existing statfs helper). The host is already serialized to the UI, so the fields flow through automatically.
• Frontend (Vue): a small tiles row in HostCard.vue.

Important caveat

To report the host's values (not the container's), the Dozzle container needs the host /proc and root mounted, e.g.:

volumes:
  - /proc:/host/proc:ro
  - /:/host/root:ro

Without those mounts it falls back to /proc (container values). So this would likely need to be opt-in and documented.

Open questions

1. Would you want this at all, or is host metrics out of scope for Dozzle?
2. If yes: opt-in via env flag, or always-on when the host mounts are present?
3. UI: tiles on the host card (what I did), or a different placement?
4. Scope: I only did the local host. Remote/agent hosts can be a follow-up through the agent protocol — fine to leave out of a first PR?
5. I'll follow your conventions (i18n, component tests, etc.) before opening the PR.

Happy to adjust the approach based on your preference. Thanks!

[amir20]

Can you add screenshot? I'll do a closer review tomorrow.

[amir20]

I responded to the PR. Here some of the answer to your question.

1. I think it would be cool to add this. I am mostly concerned about performance and the UI being too complex. Dozzle wins at being simple.
2. Most people are already mounting /data so that could be used for disk usage. I already alert on it actually. But the proc stuff should be optin IMO if the volume exists.
3. This is the one I provided a lot of feedback. I'd want this to be minimal.
4. Yea, that can be follow up.

[amir20]

Haven't heard back. Going to move this to discussion.

[amir20]

This is now merged.

[reslear]

Thanks for adding host metrics! Are there plans to show total host CPU, RAM and swap usage separately from container totals? For example, a backup running outside Docker can use most of the memory while containers look fine.

One more suggestion: could host monitoring also support webhook alerts for low disk space and unreachable agents?
For example, notify me when a disk stays over 90% full for 5 minutes, or an agent is unreachable for 2 minutes, then send a recovery notification when things return to normal. This would help catch problems without keeping Dozzle open.

[amir20]

This feature wasn't done by me. It was implemented by @notrevetecnologia . You can read more on what you can do by mounting /proc. https://dozzle.dev/guide/host-metrics#host-metrics

One more suggestion: could host monitoring also support webhook alerts for low disk space and unreachable agents?
For example, notify me when a disk stays over 90% full for 5 minutes, or an agent is unreachable for 2 minutes, then send a recovery notification when things return to normal. This would help catch problems without keeping Dozzle open.

1. I think disk space is already implemented. You just need to set it up.

2. Unreachable agents is an interesting idea. I am not sure where I would put that.

[marvinruder]

Thanks for implementing this feature. It appears there is something wrong with determining which file system is the Docker filesystem. My Dozzle container has the following volumes:

volumes:
  - /var/cache/dozzle:/data
  - /var/run/docker.sock:/var/run/docker.sock:ro
  - /proc:/host/proc:ro
  - /var/empty:/host/disks/sysroot:ro

The host has two main file systems, one for the system root directory (where also the /data directory is located), and another for /var/lib/docker. Therefore, a container with the same mounts shows the following df output:

docker run --rm -it -v /var/cache/dozzle:/data:ro -v /var/run/docker.sock:/var/run/docker.sock:ro -v /proc:/host/proc:ro -v /var/empty:/host/disks/sysroot:ro alpine
/ # df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda5             16777216   7961224   6619192  55% /
tmpfs                    65536         0     65536   0% /dev
shm                      65536         0     65536   0% /dev/shm
/dev/sda4             58654720  26964608  31690112  46% /data
/dev/sda5             16777216   7961224   6619192  55% /etc/resolv.conf
/dev/sda5             16777216   7961224   6619192  55% /etc/hostname
/dev/sda5             16777216   7961224   6619192  55% /etc/hosts
/dev/sda4             58654720  26964608  31690112  46% /host/disks/sysroot
tmpfs                  1579440      3500   1575940   0% /run/docker.sock
tmpfs                        4         0         4   0% /proc/acpi
tmpfs                    65536         0     65536   0% /proc/interrupts
tmpfs                    65536         0     65536   0% /proc/kcore
tmpfs                    65536         0     65536   0% /proc/keys
tmpfs                    65536         0     65536   0% /proc/latency_stats
tmpfs                        4         0         4   0% /proc/scsi
tmpfs                    65536         0     65536   0% /proc/timer_list
tmpfs                        4         0         4   0% /sys/firmware

Dozzle now incorrectly reports the stats of the system root filesystem as belonging to Docker:

Adding an explicit mount /var/lib/docker:/host/disks/Docker:ro only creates another Docker entry, but this time with the correct stats.

[amir20]

nice catch. the image has no /var/lib/docker, so disk fell back to /data, and your /data lives on the root disk. that's why the root fs showed up as Docker.

#5393 now measures through the container's /etc/hostname instead. docker keeps that file in its own data dir, so it always lands on Docker's disk no matter where /data is.

can you try amir20/dozzle:pr-5393? you can drop the /host/disks/Docker mount, the main reading should show sda5 on its own.

[marvinruder]

Yes, pr-5393 works great:

[amir20]

ok merging. I just released so it will be a couple days before I release again. You can use main for now.