Add IPMI fan control scripts, reading credentials from conf/

ipmi-fancontrol.service pins the fans to a fixed speed on start and hands
control back to the BMC's automatic curve on stop, to quiet the chassis.

BMC credentials are read from conf/ipmi-fancontrol.conf, resolved relative
to the scripts themselves so the tree stays self-contained whether it is run
from a checkout or from /opt/ergosteur. See conf/ipmi-fancontrol.conf.example.

Use ipmitool -E rather than -P so the password is passed via the environment
instead of argv, where any local user could read it out of ps.

docker-idrac.sh is the alternative temperature-aware controller.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

conf/ipmi-fancontrol.conf.example

@@ -0,0 +1,17 @@
+# Credentials for the BMC user driving ipmi-fancontrol-manual / ipmi-fancontrol-auto.
+#
+# Copy to conf/ipmi-fancontrol.conf next to the scripts and lock it down:
+#   cp conf/ipmi-fancontrol.conf.example conf/ipmi-fancontrol.conf
+#   chmod 0600 conf/ipmi-fancontrol.conf
+#
+# The scripts look for it relative to their own location, so this works both in a
+# checkout and deployed at /opt/ergosteur. Override with IPMI_FANCONTROL_CONFIG.
+
+IPMI_HOST=169.254.0.1
+IPMI_USER=fancontrol
+
+# Read by ipmitool -E, so it never appears in the process table.
+IPMI_PASSWORD=changeme
+
+# Fan speed applied in manual mode, as a raw hex byte (0x15 = 21%).
+FAN_SPEED=0x15

docker-idrac.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+docker run -d \
+  --name Dell_iDRAC_fan_controller \
+  --restart=unless-stopped \
+  -e IDRAC_HOST=local \
+  -e FAN_SPEED=24 \
+  -e CPU_TEMPERATURE_THRESHOLD=70 \
+  -e CHECK_INTERVAL=60 \
+  -e DISABLE_THIRD_PARTY_PCIE_CARD_DELL_DEFAULT_COOLING_RESPONSE=true \
+  --device=/dev/ipmi0:/dev/ipmi0:rw \
+  tigerblue77/dell_idrac_fan_controller:latest

ipmi-fancontrol-auto

@@ -0,0 +1,25 @@
+#!/bin/sh
+# Hand fan control back to the BMC's automatic curve.
+# Paired with ipmi-fancontrol-manual via ipmi-fancontrol.service.
+set -eu
+
+SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+CONFIG=${IPMI_FANCONTROL_CONFIG:-$SCRIPT_DIR/conf/ipmi-fancontrol.conf}
+
+if [ ! -r "$CONFIG" ]; then
+    echo "Error: cannot read $CONFIG" >&2
+    echo "Copy conf/ipmi-fancontrol.conf.example there and fill in the BMC credentials." >&2
+    exit 1
+fi
+
+. "$CONFIG"
+
+: "${IPMI_HOST:?not set in $CONFIG}"
+: "${IPMI_USER:?not set in $CONFIG}"
+: "${IPMI_PASSWORD:?not set in $CONFIG}"
+
+# ipmitool -E reads the password from IPMI_PASSWORD, keeping it out of argv.
+export IPMI_PASSWORD
+
+# Re-enable automatic fan control.
+ipmitool -I lanplus -H "$IPMI_HOST" -U "$IPMI_USER" -E raw 0x30 0x30 0x01 0x01

ipmi-fancontrol-manual

@@ -0,0 +1,29 @@
+#!/bin/sh
+# Put the BMC into manual fan control and pin the fans to a fixed speed.
+# Paired with ipmi-fancontrol-auto via ipmi-fancontrol.service.
+set -eu
+
+SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+CONFIG=${IPMI_FANCONTROL_CONFIG:-$SCRIPT_DIR/conf/ipmi-fancontrol.conf}
+
+if [ ! -r "$CONFIG" ]; then
+    echo "Error: cannot read $CONFIG" >&2
+    echo "Copy conf/ipmi-fancontrol.conf.example there and fill in the BMC credentials." >&2
+    exit 1
+fi
+
+. "$CONFIG"
+
+: "${IPMI_HOST:?not set in $CONFIG}"
+: "${IPMI_USER:?not set in $CONFIG}"
+: "${IPMI_PASSWORD:?not set in $CONFIG}"
+: "${FAN_SPEED:=0x15}"
+
+# ipmitool -E reads the password from IPMI_PASSWORD, keeping it out of argv.
+export IPMI_PASSWORD
+
+# Disable the BMC's automatic fan curve.
+ipmitool -I lanplus -H "$IPMI_HOST" -U "$IPMI_USER" -E raw 0x30 0x30 0x01 0x00
+
+# Apply the fixed speed to all fans.
+ipmitool -I lanplus -H "$IPMI_HOST" -U "$IPMI_USER" -E raw 0x30 0x30 0x02 0xff "$FAN_SPEED"

systemd-system/ipmi-fancontrol.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=IPMI Fan Control silencing
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/opt/ergosteur/ipmi-fancontrol-manual
+ExecStop=/opt/ergosteur/ipmi-fancontrol-auto
+[Install]
+WantedBy=multi-user.target