Ceph CRUSH Location lookup

crush-location-lookup.sh

#!/bin/bash

# Generates a CRUSH location based on the machine's hostname.
# This Gist was written for a customer who has mixed SSDs and HDDs in a a chassis.
# Hostname example in this case: dc2-rk01-ceph01 (Datacenter 2, rack 01, Ceph machine 01)
# It checks if the backing disk is a SSD or not and then comes up with the CRUSH location

while :; do
    case $1 in
        --cluster)
            CLUSTER=$2
            shift
            ;;
        --type)
            TYPE=$2
            shift
            ;;
        --id)
            ID=$2
            shift
            ;;
        *)
            break
    esac
    command shift
done

if [ -z "$CLUSTER" ]; then
    echo "No cluster was specified"
    exit 1
fi

if [ -z "$TYPE" ]; then
    echo "No type was specified"
    exit 1
fi

if [ -z "$ID" ]; then
    echo "No id was specified"
    exit 1
fi

HOST=$(hostname)
RACK=$(hostname|cut -d '-' -f 2)
DEV=$(df /var/lib/ceph/$TYPE/${CLUSTER}-${ID}|tail -1|awk '{print $1}'|cut -d '/' -f 3|sed -r 's/[0-9]{1,10}$//')
ROTATIONAL=$(cat /sys/block/$DEV/queue/rotational)

if [ $ROTATIONAL -eq 1 ]; then
    echo "root=hdd rack=${RACK}-hdd host=${HOST}-hdd"
else
    echo "root=ssd rack=${RACK}-ssd host=${HOST}-ssd"
fi