Previous step failed in CI because the bare alloy container had no
/var/log/journal, no docker.sock, etc., so loki.source.journal +
discovery.docker exited the process — and --rm wiped the container
before logs could be inspected.
Now: drop --rm, mount the same host paths the prod compose uses, plus
an empty /var/log/journal stand-in. Capture logs unconditionally and
fail only on config-level patterns ('unknown component',
'undefined reference', 'syntax error', etc.). Runtime/component
failures against dummy endpoints are tolerated.
alloy-docker-compose
One-file Grafana Alloy setup that ships host (linux) and container (docker) telemetry to Grafana Cloud, plus pulls remote config from Grafana Fleet Management.
- Single container running both
node_exporter(host) andcadvisor(containers) collectors. - Config embedded inline via Compose
configs:— no sidecarconfig.alloyfile on disk. - Env-driven — nine shell variables, no
.envfile. - Remote config via
remotecfgblock (Grafana Fleet Management).
What it collects
| Source | Component | Notes |
|---|---|---|
| Host metrics | prometheus.exporter.unix |
CPU, memory, load, disk I/O, filesystem, network, uname, boot time |
| Container metrics | prometheus.exporter.cadvisor |
CPU, memory, fs usage/limit, network, last_seen |
| Container logs | loki.source.docker |
all running containers, labeled with container, stream, instance |
| System logs | loki.source.journal (via journal_module) |
systemd journal with unit, boot_id, transport, level labels |
| Remote config | remotecfg |
polls Grafana Fleet Management every 60s |
keep-filter on metric names trims the firehose down to the standard Grafana Cloud integration dashboards (node-exporter + docker).
Quick start
export ALLOY_HOSTNAME=miti-jp # also used as Loki/Prometheus instance label
export REMOTECFG_URL=https://fleet-management-prod-013.grafana.net
export REMOTECFG_ID=miti-jp # fleet-management agent id
export REMOTECFG_USER=1431677 # fleet-management user id
export PROM_URL=https://prometheus-prod-XX-<region>.grafana.net/api/prom/push
export PROM_USER=<prometheus-user-id>
export LOKI_URL=https://logs-prod-XXX.grafana.net/loki/api/v1/push
export LOKI_USER=<loki-user-id>
export GRAFANA_TOKEN=glc_... # one Cloud Access Policy token, scopes: metrics:write + logs:write + fleet-management:read
docker compose up -d
Find the PROM_* / LOKI_* / REMOTECFG_* values under Grafana Cloud → your stack → Details on each data source / Fleet Management. The same token is reused for remotecfg, Prometheus, and Loki basic-auth.
Any unset required variable makes docker compose up fail fast.
Multi-host
Same compose file on every host — change ALLOY_HOSTNAME and REMOTECFG_ID per host. Filter in Grafana with instance=~"...".
Security note
Runs privileged: true + network_mode: host, matching the upstream Grafana Cloud docker integration. network_mode: host is required so prometheus.exporter.unix reports the host's real network interfaces (eth0…) instead of the alloy container's veth pair. If you need least-privilege, see the upstream Alloy docker integration docs and tighten capabilities.
Mounts
| Mount | Why |
|---|---|
/proc:/rootproc:ro |
node-exporter cpu/mem/load (referenced via procfs_path) |
/sys:/sys:ro |
node-exporter + cadvisor cgroups |
/:/rootfs:ro |
filesystem collector (referenced via rootfs_path) |
/dev/disk/:/dev/disk:ro |
node-exporter diskstats device labels |
/var/run/docker.sock |
discovery.docker + loki.source.docker |
/var/lib/docker:ro |
cadvisor container metadata |
/var/log/journal:ro |
loki.source.journal |
/etc/machine-id:ro |
stable host id for the journal reader |
alloy-data (named volume) |
WAL + remotecfg cache |
License
Apache 2.0 — see LICENSE.