Graylog centralized log server — deployment scripts

Deploys a Debian 12 LXC container on Proxmox VE with a Docker Compose stack (MongoDB + OpenSearch + Graylog) for collecting syslog from network equipment (Juniper, ZTE OLT, D-Link) and servers (RADIUS, accel-ppp).

Quick start

Run on the Proxmox host as claude-deploy (or any user with the same restricted sudo rights on pct/pveam for VMIDs 200-299):

./create-graylog-lxc.sh \
  --ip 10.254.254.202/24 \
  --gw 10.254.254.235 \
  --vlan 1254 \
  --external-uri http://93.171.241.5:9000/ \
  --discord-webhook "https://discord.com/api/webhooks/xxx/yyy"

This is the only command you need. It creates the container, installs Docker, applies the firewall (nftables: only 9000/tcp, 514+1514/udp, 5140/udp open), brings up the stack, creates the Syslog inputs, imports the pipeline rules, and prints the admin credentials at the end.

Both scripts are idempotent — re-running after a failure (or to apply an update) picks up from where it left off instead of duplicating work.

Step-by-step deployment from scratch

0. Prerequisites

• SSH access to the Proxmox host as a user with sudo rights on pct create/set/start/stop/exec/status/list and pveam update/list/download (does not need to be root - this whole toolkit was built and tested under exactly that restricted scope).
• A storage on the Proxmox host with content type vztmpl enabled, holding (or able to download) a debian-12-standard template - default assumed name: local-btrfs. Check with:

  sudo pveam list local-btrfs   # replace with your storage name
  

  If it errors with "storage is disabled" or "does not exist", find the right one (sudo pveam list <name> for candidates) and pass it via --template-storage.
• A storage for the container's root filesystem (default assumed: EX-Ceph) with enough free space for --disk (default 50GB).
• The IP address, gateway, and VLAN tag (if any) for the network the container will live on - i.e. the same network your RADIUS/NAS servers and network equipment can reach.
• If you need remote access to the Web UI from outside that network: a spare external port to DNAT to the container's 9000/tcp (see the "reaching the Web UI from outside" note below - port 9000 collided with an existing ClickHouse listener during initial testing, so don't assume any specific port is free).
• (Optional) A Discord webhook URL, if you want Critical alerts pushed to a channel.

1. Get the scripts onto the Proxmox host

From your workstation:

tar czf - -C /path/to/graylog-deploy . | ssh claude-deploy@<proxmox-host> \
  "mkdir -p ~/graylog-deploy && tar xzf - -C ~/graylog-deploy && chmod +x ~/graylog-deploy/*.sh"

(Or git clone/scp the directory if you keep it in a repo - any method that gets the whole folder, including rules/, pipelines/, streams/, alerts/, onto the host works.)

2. Decide your parameters

Pick, in advance:

You need	Example	Why
A free VMID in 200-299	210	or omit --vmid to auto-pick the first free one
Container IP + CIDR on the management network	10.254.254.220/24	must be reachable by every device that will send syslog
Gateway on that network	10.254.254.235
VLAN tag (if the bridge is trunked)	1254	omit --vlan if untagged
Public URL for the Web UI	http://<public-ip>:<port>/	used both in Graylog's config and in Discord alert links
Discord webhook (optional)	https://discord.com/api/webhooks/.../...	leave unset to skip Discord entirely

Check the IP is actually free first - a duplicate IP on this network silently causes ARP flapping and intermittent, hard-to-diagnose routing weirdness (this happened during initial testing: .201 turned out to already be in use, causing traffic to randomly land on the wrong host). A quick way to check without touching anything:

ssh claude-deploy@<proxmox-host> "sudo /usr/sbin/pct exec <any-running-vmid> -- ping -c2 -W1 <candidate-ip>"

If you get replies, that IP is taken - pick another.

3. Run create-graylog-lxc.sh

ssh claude-deploy@<proxmox-host>
cd ~/graylog-deploy
./create-graylog-lxc.sh \
  --vmid 210 \
  --ip 10.254.254.220/24 \
  --gw 10.254.254.235 \
  --vlan 1254 \
  --external-uri http://<public-ip>:<port>/ \
  --discord-webhook "https://discord.com/api/webhooks/xxx/yyy"

What happens, in order: template check/download → pct create → start the container → wait for network → copy this whole folder into the container at /opt/graylog-deploy/ → run install-graylog.sh inside it, which installs Docker, applies the firewall, brings up MongoDB/OpenSearch/Graylog, waits for it to report healthy, creates the Syslog inputs, imports the pipeline rules/pipelines/streams, and (if a webhook was given) creates the Discord notification and the three alert definitions.

If it stops with an AppArmor error (open sysctl net.ipv4.ip_unprivileged_port_start: permission denied), that's expected on some Proxmox setups and needs one manual step from the host's root account - see "Docker-in-unprivileged-LXC AppArmor block" below. Do that, then just run the exact same command again; everything already done is skipped automatically.

Total time for a clean run: a few minutes, mostly waiting for image pulls and for Graylog to report healthy.

4. Read the admin credentials

ssh claude-deploy@<proxmox-host> "sudo pct exec 210 -- cat /opt/graylog/.admin_credentials_ONE_TIME"

Copy the password into your password manager, then delete the file:

ssh claude-deploy@<proxmox-host> "sudo pct exec 210 -- rm /opt/graylog/.admin_credentials_ONE_TIME"

Log into http://<public-ip>:<port>/ with user admin and that password.

5. Reach the Web UI from outside the management network (if needed)

If the container's IP isn't directly reachable from where you browse, add a DNAT rule on your edge router/firewall for 9000/tcp:

-A PREROUTING -d <public-ip>/32 -p tcp -m tcp --dport <port> -j DNAT --to-destination <container-ip>:9000

Pick a port that's actually free - during initial setup, port 9000 turned out to already be serving ClickHouse on the same public IP, and the response (Port 9000 is for clickhouse-client program...) looked like a Graylog problem for a while before that was found. If you get a suspicious/unexpected response on the port you chose, suspect a pre-existing service on that port before suspecting Graylog.

6. Point real equipment at the server

Source	Port	Notes
Network equipment (switches, OLTs, routers)	514/udp	the standard syslog port - almost no gear lets you pick a different one (logging <host> on a typical switch always uses 514)
Network equipment that can target a custom port	1514/udp	kept as a secondary input, same stream as 514
Servers (RADIUS, accel-ppp, conntrack/kernel messages)	5140/udp

On each device, this is normally a one-line config change (e.g. on a Cisco-like CLI: logging <container-ip>). No Graylog-side config is needed per device - the inputs and streams already listen on all three ports.

7. Verify data is actually arriving

1. Web UI → System → Inputs: each input shows live "Traffic Last Minute". If it stays at 0 after a device should have sent something, the problem is network/firewall, not Graylog - confirm with tcpdump inside the container before touching any Graylog config:

   sudo pct exec 210 -- tcpdump -i eth0 -n udp port 514
   

2. Web UI → Search, widen the time range (top-left), click any message to expand it. If vendor / event_type fields are populated, a pipeline rule matched it. If a message arrives but those fields are empty, it reached Graylog fine but no rule recognizes its format yet - that's a sign a new device/vendor needs a new rule (see "What's still NOT included" below for the process).
3. Web UI → Streams: the "Throughput" column shows live msg/s per stream.

8. (Optional) Trigger a real test alert

See "Verifying a test alert" further down - send one of the known-critical log lines via logger from inside the container and watch it land in Discord within about a minute.

Parameters

All flags have an environment-variable equivalent (see the top of create-graylog-lxc.sh), so you can also export MEMORY_MB=16384 etc. instead of passing flags.

Flag	Default	Notes
--ip	(required)	Static IP + CIDR for the container
--gw	(required)	Gateway IP
--external-uri	(required)	Public URL for the Graylog Web UI (used in GRAYLOG_HTTP_EXTERNAL_URI)
--vmid	first free 200-299
--hostname	graylog
--cores	4
--memory	8192 (MB)
--swap	512 (MB)
--disk	50 (GB)	rootfs size on --rootfs-storage
--bridge	vmbr0
--vlan	(none = untagged)
--nameserver	1.1.1.1
--searchdomain	(none)
--timezone	Europe/Kyiv
--template-storage	local-btrfs	must have content type vztmpl enabled
--rootfs-storage	EX-Ceph	container disk storage
--discord-webhook	(none)	passed through as DISCORD_WEBHOOK_URL to the in-container script

Dashboard

A "Network & RADIUS Monitoring" dashboard is created automatically (Dashboards → Network & RADIUS Monitoring), with five widgets over a default 7-day window:

• Messages Over Time by Stream - stacked bar, so you can see network equipment vs. server volume at a glance
• Vendor Breakdown - pie chart by the vendor field the pipeline rules set
• Top Event Types - table of event_type counts
• Critical Events by Type - the same, but filtered to severity_tag:critical - i.e. only what the three alerts above care about
• Top Sources - which devices/servers are sending the most volume

It's built via the Views API (dashboards/search.json + dashboards/view.json) rather than Graylog's own widget-builder UI - that UI turned out to be difficult to drive reliably via browser automation (React combobox widgets that don't respond to plain keyboard/click events without also triggering React's internal state update), while the REST API accepted the same structure cleanly on the first attempt once the shape was reverse engineered from an existing dashboard's JSON. If you want to add a widget, either use the Graylog UI directly (a human using a mouse doesn't hit the automation issue) and then optionally export the result back into these two JSON files, or extend dashboards/search.json/view.json by hand - each widget needs a matching search_types entry (in search.json) and widgets + widget_mapping + positions + titles.widget entry (in view.json) sharing the same ID.

Known environment quirks this script works around

• Docker-in-unprivileged-LXC AppArmor block: containers fail with open sysctl net.ipv4.ip_unprivileged_port_start: permission denied unless the Proxmox host admin adds a raw LXC config line. pct set does not expose this option, so it cannot be automated within the claude-deploy sudo scope. If you hit this, run as root on the host:

  echo "lxc.apparmor.profile: unconfined" >> /etc/pve/lxc/<VMID>.conf
  pct reboot <VMID>
  

  then re-run create-graylog-lxc.sh (idempotent, will continue from there).

• vm.max_map_count: OpenSearch requires >= 262144. This is a host-wide kernel parameter, not namespaced per LXC, so it can't be set from inside the container either. install-graylog.sh only verifies it and fails with instructions if it's too low — on this deployment it was already 262144 by default, so no action was needed.

• Docker Hub TLS over IPv6: on this network, IPv6 paths to registry-1.docker.io intermittently get intercepted and served a mismatched certificate (*.docker.com). The install script disables IPv6 inside the container to force IPv4-only egress. Image pulls also retry up to 5x since even IPv4 occasionally hits a bad edge node.

• MongoDB version: Graylog 7.1 requires MongoDB >= 7.0 (some older docs still reference 6.0.x — don't trust cached documentation over what the running server actually reports).

• Network gear sends syslog to port 514, not a custom port: most switches/OLTs (confirmed live with a BDCOM S5612) only support logging <host>, which always uses the standard UDP/514, with no way to point at a different port. There are therefore two "network equipment" inputs - 514 (what devices actually use) and 1514 (kept for any gear that can target a custom port) - both feeding the same "Network Equipment" stream (matching_type: OR). If you add new equipment and it doesn't show up, check with tcpdump -i eth0 udp port 514 inside the container before assuming the pipeline rules are wrong.

• nftables must never flush ruleset: an early version of this firewall step used flush ruleset, which also wipes Docker's own iptables-nft-managed nat/filter tables (DOCKER, DOCKER-USER, etc.), breaking container port publishing the next time docker compose up needs to add a rule (confirmed live - had to recover with a full docker compose down && up). nftables.conf here only ever does add table inet filter + flush table inet filter, which is scoped to just that one table and safe regardless of boot/service order relative to docker.service.

Alerting and Discord notifications

Three CRITICAL-only alerts are wired up out of the box (everything else stays quiet on purpose - routine auth failures, single dropped-session events, etc. are parsed and searchable but never page anyone):

Alert	Fires on	Priority
RADIUS server unreachable	radius: server(N) not responding or radius: no available servers (verified strings from accel-ppp source, radius/req.c)	High
conntrack table full (packet loss)	nf_conntrack: table full, dropping packet (standard Linux kernel message - active, ongoing packet loss)	High
Unrecognized critical-severity syslog	Any message (any vendor, either stream) with RFC5424/3164 syslog severity Emergency/Alert/Critical (0-2) that no specific pipeline rule already classified	Medium

That third one is the "universal network equipment problem" catch-all: it doesn't depend on knowing any vendor's specific message format, just the standard syslog severity level every reasonable device already sends.

Also parsed (searchable, but not alerted on since they're routine/expected volume, not incidents by themselves):

• accel-ppp: PPP authentication failed (ppp_auth.c)
• Standalone FreeRADIUS: Auth: (n) Login OK: [user] (from client X port P) / Auth: Login incorrect: [user] (from client X port P) (default auth_log format)

To wire up Discord, pass --discord-webhook (or set DISCORD_WEBHOOK_URL) when running create-graylog-lxc.sh. Under the hood this uses Graylog's built-in Slack notification type pointed at <your-webhook-url>/slack - Discord's Slack-compatibility endpoint - so no extra converter service is needed. The message template shows the event title/description plus the source and raw text of every matched message:

*${event_definition_title}*
${event_definition_description}
${if backlog}${foreach backlog message}• `${message.source}`: ${message.message}
${end}${end}

Verifying a test alert

# from inside the container, simulating each trigger:
docker exec -it graylog-server bash
logger -n 127.0.0.1 -P 5140 -d 'radius: server(1) not responding'
logger -n 127.0.0.1 -P 5140 -d 'kernel: nf_conntrack: table full, dropping packet'

The scheduler checks every 60s, so the Discord message can take up to a minute to arrive. Check Graylog's Alerts page and the configured Discord channel.

What's still NOT included

• D-Link switch parsing — no sample logs were available.
• ZTE OLT ONU online/offline + optical power alarms — no sample logs were available (only BDCOM OLT-style CLI logs were provided: privilege-mode/logout/ARP-move/config-write, which are parsed).
• Plain RADIUS Access-Accept/Reject from a specific real deployment — the standalone-FreeRADIUS rule above is based on FreeRADIUS's documented default log format, not a sample from this network's actual RADIUS boxes (no SSH access to them was available; the pattern is well-established upstream, but verify it against a real log line when one is available).

To fill these gaps: provide a few real raw log lines per source (D-Link syslog, ZTE OLT ONU up/down + optical alarms) and the equivalent rules/*.json + alert definitions can be added the same way the existing ones were built.

File layout

create-graylog-lxc.sh   # run on the Proxmox host
install-graylog.sh      # run inside the container (invoked automatically)
docker-compose.yml      # MongoDB + OpenSearch + Graylog stack definition
nftables.conf            # firewall ruleset applied inside the container
rules/*.json             # Graylog Pipeline Rule definitions (imported via API)
pipelines/*.json         # Graylog Pipeline definitions referencing the rules
streams/*.json           # Graylog Stream definitions (routes by input port)

Inside the container, everything lives under /opt/graylog/ (docker-compose.yml, .env with secrets) and /opt/graylog-deploy/ (a copy of this repo, used for re-running the install idempotently).

Credentials

install-graylog.sh generates GRAYLOG_PASSWORD_SECRET and a random admin password on first run, writing the admin password once to /opt/graylog/.admin_credentials_ONE_TIME inside the container — read it, store it in your password manager, then delete the file:

pct exec <VMID> -- cat /opt/graylog/.admin_credentials_ONE_TIME
pct exec <VMID> -- rm /opt/graylog/.admin_credentials_ONE_TIME