hostmetrics scraperhelper in Docker /etc/passwd not found errors

[ColaIan]

Docker Compose

services:
    opentelemetry-collector-contrib:
        container_name: otel-collector
        restart: unless-stopped
        network_mode: host
        pid: host
        volumes:
            - ./config.yaml:/etc/otelcol-contrib/config.yaml:ro
            - /:/hostfs:ro,rslave
        environment:
            - HOST_PROC=/hostfs/proc
            - HOST_SYS=/hostfs/sys
            - HOST_ETC=/hostfs/etc
            - HOST_VAR=/hostfs/var
            - HOST_RUN=/hostfs/run
            - HOST_DEV=/hostfs/dev
        image: otel/opentelemetry-collector-contrib:latest
        command: --config /etc/otelcol-contrib/config.yaml

Config

receivers:
  hostmetrics:
    collection_interval: 30s
    root_path: /hostfs
    scrapers:
      cpu:
        metrics:
          system.cpu.utilization:
            enabled: true
          # Lets OneUptime cache CPU core count on the host record
          # so the Hosts list and host detail page can show it
          # without re-aggregating metrics on every page load.
          system.cpu.logical.count:
            enabled: true
      memory:
        metrics:
          system.memory.utilization:
            enabled: true
      disk:
      filesystem:
        metrics:
          system.filesystem.utilization:
            enabled: true
      load:
      network:
      processes:
      paging:
      process:
        mute_process_name_error: true
        mute_process_exe_error: true
        mute_process_io_error: true
        metrics:
          process.cpu.utilization:
            enabled: true
          process.memory.utilization:
            enabled: true

processors:
  resourcedetection:
    detectors: [system, env]
    system:
      hostname_sources: [os]
      resource_attributes:
        host.name:
          enabled: true
        host.id:
          enabled: true
        host.arch:
          enabled: true
        # host.ip is opt-in in the system detector. OneUptime
        # surfaces it on the Host Network card, so enable it here.
        host.ip:
          enabled: true
        os.type:
          enabled: true
        os.description:
          enabled: true
  resource/oneuptime-labels:
    attributes:
      - key: oneuptime.label.env
        value: production
        action: upsert
  batch:

exporters:
  otlphttp/oneuptime:
    endpoint: https://redacted
    headers:
      x-oneuptime-token: redacted

service:
  pipelines:
    metrics:
      receivers: [hostmetrics]
      processors: [resourcedetection, resource/oneuptime-labels, batch]
      exporters: [otlphttp/oneuptime]

Logs

otel-collector  | 2026-05-25T14:06:31.228Z      error   scraperhelper@v0.152.0/obs_metrics.go:61        Error scraping metrics  {"resource": {"service.instance.id": "92f15bc8-08c0-499d-a648-037e068bf8c9", "service.name": "otelcol-contrib", "service.version": "0.152.1"}, "otelcol.component.id": "hostmetrics", "otelcol.component.kind": "receiver", "otelcol.signal": "metrics", "scraper": "process", "error": "error reading username for process \"systemd\" (pid 1): open /etc/passwd: no such file or directory; error reading username for process \"kthreadd\" (pid 2): open /etc/passwd: no such file or directory; error reading username for process \"pool_workqueue_release\" (pid 3): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-rcu_g\" (pid 4): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-rcu_p\" (pid 5): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-slub_\" (pid 6): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-netns\" (pid 7): open /etc/passwd: no such file or directory; error reading username for process \"kworker/0:0H-events_highpri\" (pid 10): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-mm_pe\" (pid 12): open /etc/passwd: no such file or directory; error reading username for process \"rcu_tasks_kthread\" (pid 13): open /etc/passwd: no such file or directory; error reading username for process \"rcu_tasks_rude_kthread\" (pid 14): open /etc/passwd: no such file or directory; error reading username for process \"rcu_tasks_trace_kthread\" (pid 15): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/0\" (pid 16): open /etc/passwd: no such file or directory; error reading username for process \"rcu_preempt\" (pid 17): open /etc/passwd: no such file or directory; error reading username for process \"migration/0\" (pid 18): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/0\" (pid 19): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/0\" (pid 20): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/1\" (pid 21): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/1\" (pid 22): open /etc/passwd: no such file or directory; error reading username for process \"migration/1\" (pid 23): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/1\" (pid 24): open /etc/passwd: no such file or directory; error reading username for process \"kworker/1:0H-events_highpri\" (pid 26): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/2\" (pid 27): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/2\" (pid 28): open /etc/passwd: no such file or directory; error reading username for process \"migration/2\" (pid 29): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/2\" (pid 30): open /etc/passwd: no such file or directory; error reading username for process \"kworker/2:0H-events_highpri\" (pid 32): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/3\" (pid 33): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/3\" (pid 34): open /etc/passwd: no such file or directory; error reading username for process \"migration/3\" (pid 35): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/3\" (pid 36): open /etc/passwd: no such file or directory; error reading username for process \"kworker/3:0H-events_highpri\" (pid 38): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/4\" (pid 39): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/4\" (pid 40): open /etc/passwd: no such file or directory; error reading username for process \"migration/4\" (pid 41): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/4\" (pid 42): open /etc/passwd: no such file or directory; error reading username for process \"kworker/4:0H-kblockd\" (pid 44): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/5\" (pid 45): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/5\" (pid 46): open /etc/passwd: no such file or directory; error reading username for process \"migration/5\" (pid 47): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/5\" (pid 48): open /etc/passwd: no such file or directory; error reading username for process \"kworker/5:0H-events_highpri\" (pid 50): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/6\" (pid 51): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/6\" (pid 52): open /etc/passwd: no such file or directory; error reading username for process \"migration/6\" (pid 53): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/6\" (pid 54): open /etc/passwd: no such file or directory; error reading username for process \"kworker/6:0H-events_highpri\" (pid 56): open /etc/passwd: no such file or directory; error reading username for process \"cpuhp/7\" (pid 57): open /etc/passwd: no such file or directory; error reading username for process \"idle_inject/7\" (pid 58): open /etc/passwd: no such file or directory; error reading username for process \"migration/7\" (pid 59): open /etc/passwd: no such file or directory; error reading username for process \"ksoftirqd/7\" (pid 60): open /etc/passwd: no such file or directory; error reading username for process \"kworker/7:0H-events_highpri\" (pid 62): open /etc/passwd: no such file or directory; error reading username for process \"kdevtmpfs\" (pid 63): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-inet_\" (pid 64): open /etc/passwd: no such file or directory; error reading username for process \"kauditd\" (pid 65): open /etc/passwd: no such file or directory; error reading username for process \"khungtaskd\" (pid 66): open /etc/passwd: no such file or directory; error reading username for process \"oom_reaper\" (pid 67): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-write\" (pid 69): open /etc/passwd: no such file or directory; error reading username for process \"kcompactd0\" (pid 71): open /etc/passwd: no such file or directory; error reading username for process \"ksmd\" (pid 72): open /etc/passwd: no such file or directory; error reading username for process \"khugepaged\" (pid 73): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-kinte\" (pid 74): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-kbloc\" (pid 75): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-blkcg\" (pid 76): open /etc/passwd: no such file or directory; error reading username for process \"irq/9-acpi\" (pid 77): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-tpm_d\" (pid 80): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-ata_s\" (pid 81): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-md\" (pid 82): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-md_bi\" (pid 83): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-edac-\" (pid 84): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-devfr\" (pid 85): open /etc/passwd: no such file or directory; error reading username for process \"watchdogd\" (pid 86): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-quota\" (pid 88): open /etc/passwd: no such file or directory; error reading username for process \"kworker/1:1H-kblockd\" (pid 89): open /etc/passwd: no such file or directory; error reading username for process \"kswapd0\" (pid 90): open /etc/passwd: no such file or directory; error reading username for process \"ecryptfs-kthread\" (pid 91): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-kthro\" (pid 92): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-acpi_\" (pid 93): open /etc/passwd: no such file or directory; error reading username for process \"scsi_eh_0\" (pid 94): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-scsi_\" (pid 95): open /etc/passwd: no such file or directory; error reading username for process \"scsi_eh_1\" (pid 96): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-scsi_\" (pid 97): open /etc/passwd: no such file or directory; error reading username for process \"scsi_eh_2\" (pid 98): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-scsi_\" (pid 99): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-mld\" (pid 104): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-ipv6_\" (pid 105): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-kstrp\" (pid 112): open /etc/passwd: no such file or directory; error reading username for process \"kworker/u17:0\" (pid 116): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-charg\" (pid 129): open /etc/passwd: no such file or directory; error reading username for process \"kworker/5:1H-kblockd\" (pid 152): open /etc/passwd: no such file or directory; error reading username for process \"kworker/4:1H-kblockd\" (pid 155): open /etc/passwd: no such file or directory; error reading username for process \"kworker/6:1H-kblockd\" (pid 157): open /etc/passwd: no such file or directory; error reading username for process \"kworker/3:1H-kblockd\" (pid 176): open /etc/passwd: no such file or directory; error reading username for process \"kworker/2:1H-kblockd\" (pid 177): open /etc/passwd: no such file or directory; error reading username for process \"jbd2/sda3-8\" (pid 237): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-ext4-\" (pid 238): open /etc/passwd: no such file or directory; error reading username for process \"psimon\" (pid 275): open /etc/passwd: no such file or directory; error reading username for process \"systemd-journald\" (pid 280): open /etc/passwd: no such file or directory; error reading username for process \"systemd-udevd\" (pid 347): open /etc/passwd: no such file or directory; error reading username for process \"psimon\" (pid 361): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-crypt\" (pid 405): open /etc/passwd: no such file or directory; error reading username for process \"jbd2/sda2-8\" (pid 462): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-ext4-\" (pid 463): open /etc/passwd: no such file or directory; error reading username for process \"systemd-networkd\" (pid 495): open /etc/passwd: no such file or directory; error reading username for process \"systemd-resolved\" (pid 577): open /etc/passwd: no such file or directory; error reading username for process \"systemd-timesyncd\" (pid 594): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-cfg80\" (pid 609): open /etc/passwd: no such file or directory; error reading username for process \"accounts-daemon\" (pid 629): open /etc/passwd: no such file or directory; error reading username for process \"cron\" (pid 630): open /etc/passwd: no such file or directory; error reading username for process \"dbus-daemon\" (pid 631): open /etc/passwd: no such file or directory; error reading username for process \"irqbalance\" (pid 636): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm7.4\" (pid 638): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.0\" (pid 640): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.1\" (pid 642): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.2\" (pid 645): open /etc/passwd: no such file or directory; error reading username for process \"redis-server\" (pid 650): open /etc/passwd: no such file or directory; error reading username for process \"snapd\" (pid 655): open /etc/passwd: no such file or directory; error reading username for process \"systemd-logind\" (pid 656): open /etc/passwd: no such file or directory; error reading username for process \"containerd\" (pid 689): open /etc/passwd: no such file or directory; error reading username for process \"rsyslogd\" (pid 690): open /etc/passwd: no such file or directory; error reading username for process \"polkitd\" (pid 695): open /etc/passwd: no such file or directory; error reading username for process \"unattended-upgr\" (pid 698): open /etc/passwd: no such file or directory; error reading username for process \"agetty\" (pid 702): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.2\" (pid 735): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.2\" (pid 736): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.0\" (pid 738): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.0\" (pid 739): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.1\" (pid 751): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.1\" (pid 752): open /etc/passwd: no such file or directory; error reading username for process \"dockerd\" (pid 774): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 788): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 789): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 790): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 791): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 792): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 793): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 794): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 796): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 797): open /etc/passwd: no such file or directory; error reading username for process \"containerd-shim-runc-v2\" (pid 1910): open /etc/passwd: no such file or directory; error reading username for process \"containerd-shim-runc-v2\" (pid 1917): open /etc/passwd: no such file or directory; error reading username for process \"containerd-shim-runc-v2\" (pid 1923): open /etc/passwd: no such file or directory; error reading username for process \"containerd-shim-runc-v2\" (pid 1946): open /etc/passwd: no such file or directory; error reading username for process \"dumb-init\" (pid 2049): open /etc/passwd: no such file or directory; error reading username for process \"dumb-init\" (pid 2051): open /etc/passwd: no such file or directory; error reading username for process \"s6-svscan\" (pid 2076): open /etc/passwd: no such file or directory; error reading username for process \"mysqld\" (pid 2083): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2241): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2248): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2257): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2265): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2273): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2282): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2290): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2298): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2306): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2315): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2322): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2331): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2338): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2345): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2352): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2359): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2365): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2374): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2381): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2390): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2411): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2418): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2453): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 2461): open /etc/passwd: no such file or directory; error reading username for process \"authentik\" (pid 2479): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 2501): open /etc/passwd: no such file or directory; error reading username for process \"python\" (pid 2515): open /etc/passwd: no such file or directory; error reading username for process \"gunicorn: master [authentik.root.asgi:application]\" (pid 3102): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-dio/o\" (pid 3836): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-dio/s\" (pid 3900): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4146): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4147): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4148): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4149): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4150): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4151): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4152): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4153): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4154): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4155): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4156): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4157): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4159): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4160): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4161): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4162): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4163): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4165): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4166): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4167): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4168): open /etc/passwd: no such file or directory; error reading username for process \"s6-supervise\" (pid 4169): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4170): open /etc/passwd: no such file or directory; error reading username for process \"cron\" (pid 4171): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4172): open /etc/passwd: no such file or directory; error reading username for process \"MainThread\" (pid 4174): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 4176): open /etc/passwd: no such file or directory; error reading username for process \"p0f\" (pid 4177): open /etc/passwd: no such file or directory; error reading username for process \"clamd\" (pid 4178): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4179): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4181): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4182): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4183): open /etc/passwd: no such file or directory; error reading username for process \"redis-server\" (pid 4185): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4186): open /etc/passwd: no such file or directory; error reading username for process \"s6-log\" (pid 4188): open /etc/passwd: no such file or directory; error reading username for process \"dovecot\" (pid 4189): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.2\" (pid 4204): open /etc/passwd: no such file or directory; error reading username for process \"anvil\" (pid 4292): open /etc/passwd: no such file or directory; error reading username for process \"log\" (pid 4294): open /etc/passwd: no such file or directory; error reading username for process \"config\" (pid 4295): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.2\" (pid 4296): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.2\" (pid 4297): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4384): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4385): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4386): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4387): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4388): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4389): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4390): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4391): open /etc/passwd: no such file or directory; error reading username for process \"rspamd\" (pid 4392): open /etc/passwd: no such file or directory; error reading username for process \"python\" (pid 4419): open /etc/passwd: no such file or directory; error reading username for process \"python\" (pid 4461): open /etc/passwd: no such file or directory; error reading username for process \"python\" (pid 4462): open /etc/passwd: no such file or directory; error reading username for process \"python\" (pid 4463): open /etc/passwd: no such file or directory; error reading username for process \"stats\" (pid 4479): open /etc/passwd: no such file or directory; error reading username for process \"sshd\" (pid 4676): open /etc/passwd: no such file or directory; error reading username for process \"containerd-shim-runc-v2\" (pid 65850): open /etc/passwd: no such file or directory; error reading username for process \"containerd-shim-runc-v2\" (pid 65853): open /etc/passwd: no such file or directory; error reading username for process \"redis-server\" (pid 65896): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 65901): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 65957): open /etc/passwd: no such file or directory; error reading username for process \"docker-proxy\" (pid 65964): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66028): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66029): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66031): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66032): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66033): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66040): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66041): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66042): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 66043): open /etc/passwd: no such file or directory; error reading username for process \"MainThread\" (pid 441970): open /etc/passwd: no such file or directory; error reading username for process \"kworker/R-tls-s\" (pid 1272959): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1483922): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1483927): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593427): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593428): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593429): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593430): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593431): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593432): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593433): open /etc/passwd: no such file or directory; error reading username for process \"nginx\" (pid 1593434): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1622620): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1622621): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1714279): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1714281): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1714282): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1714284): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1714287): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1714294): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1714303): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1714308): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1714313): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1714318): open /etc/passwd: no such file or directory; error reading username for process \"kworker/0:1H-kblockd\" (pid 1740362): open /etc/passwd: no such file or directory; error reading username for process \"kworker/2:2-events\" (pid 1741782): open /etc/passwd: no such file or directory; error reading username for process \"sshd\" (pid 1741847): open /etc/passwd: no such file or directory; error reading username for process \"systemd\" (pid 1741867): open /etc/passwd: no such file or directory; error reading username for process \"(sd-pam)\" (pid 1741868): open /etc/passwd: no such file or directory; error reading username for process \"sshd\" (pid 1741897): open /etc/passwd: no such file or directory; error reading username for process \"bash\" (pid 1741900): open /etc/passwd: no such file or directory; error reading username for process \"sudo\" (pid 1741981): open /etc/passwd: no such file or directory; error reading username for process \"sudo\" (pid 1741982): open /etc/passwd: no such file or directory; error reading username for process \"bash\" (pid 1741983): open /etc/passwd: no such file or directory; error reading username for process \"kworker/1:0-events\" (pid 1753434): open /etc/passwd: no such file or directory; error reading username for process \"kworker/5:1-events\" (pid 1789955): open /etc/passwd: no such file or directory; error reading username for process \"kworker/7:2H-kblockd\" (pid 1825278): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1841217): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1841220): open /etc/passwd: no such file or directory; error reading username for process \"gunicorn: worker [authentik.root.asgi:application]\" (pid 1863164): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 1863166): open /etc/passwd: no such file or directory; error reading username for process \"kworker/1:1\" (pid 1877883): open /etc/passwd: no such file or directory; error reading username for process \"kworker/0:0-events\" (pid 1904162): open /etc/passwd: no such file or directory; error reading username for process \"gunicorn: worker [authentik.root.asgi:application]\" (pid 1910624): open /etc/passwd: no such file or directory; error reading username for process \"kworker/4:2-mm_percpu_wq\" (pid 1913234): open /etc/passwd: no such file or directory; error reading username for process \"kworker/u16:2-ext4-rsv-conversion\" (pid 1931033): open /etc/passwd: no such file or directory; error reading username for process \"kworker/6:0-events\" (pid 1944336): open /etc/passwd: no such file or directory; error reading username for process \"kworker/2:1-mm_percpu_wq\" (pid 1944857): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1952417): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1952422): open /etc/passwd: no such file or directory; error reading username for process \"kworker/7:3-events\" (pid 1958529): open /etc/passwd: no such file or directory; error reading username for process \"imap-login\" (pid 1959941): open /etc/passwd: no such file or directory; error reading username for process \"imap\" (pid 1959964): open /etc/passwd: no such file or directory; error reading username for process \"kworker/5:0-events\" (pid 1960585): open /etc/passwd: no such file or directory; error reading username for process \"kworker/3:0-cgroup_free\" (pid 1976625): open /etc/passwd: no such file or directory; error reading username for process \"kworker/4:0-mm_percpu_wq\" (pid 1979814): open /etc/passwd: no such file or directory; error reading username for process \"kworker/u16:4-events_power_efficient\" (pid 1985698): open /etc/passwd: no such file or directory; error reading username for process \"kworker/u16:5-ext4-rsv-conversion\" (pid 1986542): open /etc/passwd: no such file or directory; error reading username for process \"kworker/3:1-mm_percpu_wq\" (pid 1986984): open /etc/passwd: no such file or directory; error reading username for process \"kworker/6:1-mm_percpu_wq\" (pid 1991395): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm8.2\" (pid 1991434): open /etc/passwd: no such file or directory; error reading username for process \"kworker/0:2-events\" (pid 1992053): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm7.4\" (pid 1992318): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm7.4\" (pid 1993470): open /etc/passwd: no such file or directory; error reading username for process \"kworker/u16:0-events_power_efficient\" (pid 1994129): open /etc/passwd: no such file or directory; error reading username for process \"kworker/7:1-mm_percpu_wq\" (pid 1995176): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 1996291): open /etc/passwd: no such file or directory; error reading username for process \"php-fpm7.4\" (pid 1997010): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 1998176): open /etc/passwd: no such file or directory; error reading username for process \"kworker/u16:1-events_power_efficient\" (pid 1998394): open /etc/passwd: no such file or directory; error reading username for process \"kworker/0:1\" (pid 1998957): open /etc/passwd: no such file or directory; error reading username for process \"kworker/3:2-events\" (pid 1998964): open /etc/passwd: no such file or directory; error reading username for process \"containerd-shim-runc-v2\" (pid 1998994): open /etc/passwd: no such file or directory; error reading username for process \"otelcol-contrib\" (pid 1999019): open /etc/passwd: no such file or directory; error reading username for process \"postgres\" (pid 1999654): open /etc/passwd: no such file or directory; error reading username for process \"sshd\" (pid 1999701): open /etc/passwd: no such file or directory; error reading username for process \"sshd\" (pid 1999702): open /etc/passwd: no such file or directory"}
otel-collector  | go.opentelemetry.io/collector/scraper/scraperhelper.wrapObsMetrics.func1
otel-collector  |       go.opentelemetry.io/collector/scraper/scraperhelper@v0.152.0/obs_metrics.go:61
otel-collector  | go.opentelemetry.io/collector/scraper.ScrapeMetricsFunc.ScrapeMetrics
otel-collector  |       go.opentelemetry.io/collector/scraper@v0.152.0/metrics.go:24
otel-collector  | go.opentelemetry.io/collector/scraper/scraperhelper.scrapeMetrics
otel-collector  |       go.opentelemetry.io/collector/scraper/scraperhelper@v0.152.0/controller.go:172
otel-collector  | go.opentelemetry.io/collector/scraper/scraperhelper.NewMetricsController.func1
otel-collector  |       go.opentelemetry.io/collector/scraper/scraperhelper@v0.152.0/controller.go:143
otel-collector  | go.opentelemetry.io/collector/scraper/scraperhelper/internal/controller.(*Controller[...]).startScraping.func1
otel-collector  |       go.opentelemetry.io/collector/scraper/scraperhelper@v0.152.0/internal/controller/controller.go:125
otel-collector  | sync.(*WaitGroup).Go.func1
otel-collector  |       sync/waitgroup.go:258

[vincere-mori]

This looks like the process scraper, not the root_path mapping itself. Your root_path: /hostfs is already the right setting for the hostmetrics receiver.

The actual error is username resolution:

open /etc/passwd: no such file or directory

That path is the collector container's /etc/passwd, not /hostfs/etc/passwd. The process scraper is trying to turn host UIDs into usernames and failing there.

Add the missing mute flag:

receivers:
  hostmetrics:
    root_path: /hostfs
    scrapers:
      process:
        mute_process_name_error: true
        mute_process_exe_error: true
        mute_process_io_error: true
        mute_process_user_error: true

If you actually need process usernames, the other option is to make the host passwd/group database visible to the collector, e.g. bind-mount /etc/passwd and /etc/group read-only. For most hostmetrics setups, just muting process_user_error is the simpler fix.