#!/bin/bash

# - VAR

# - Bash info
APPNAME=$(basename $0)
NAME="Check ESXi vCenter"
AUTHOR="Kalarumeth"
VERSION="v1.0"
URL="https://github.com/Kalarumeth/ESXi-Monitoring"

# - Default settings for connection
COMMUNITY="public"
HOST_NAME="localhost"
SNMPVERSION="2c"

# - State Variables
STATE_OK=0
STATE_WARN=1
STATE_CRIT=2
STATE_UNK=3
STATE=$STATE_OK

eWarning=0
eCritical=0
eUnknown=0

# - OID

ESXi.OIDS() {
    OID_osName=".1.3.6.1.2.1.47.1.2.1.1.2.1"
    OID_fwRev=".1.3.6.1.2.1.47.1.1.1.1.9.1"
    OID_serviceTag=".1.3.6.1.2.1.47.1.1.1.1.11.1"
    OID_sysManufacturer=".1.3.6.1.2.1.47.1.1.1.1.12.1"
    OID_sysModel=".1.3.6.1.2.1.47.1.1.1.1.13.1"
    OID_prodName=".1.3.6.1.4.1.6876.1.1.0"
    OID_prodVersion=".1.3.6.1.4.1.6876.1.2.0"
    OID_prodBuild=".1.3.6.1.4.1.6876.1.4.0"
    OID_prodUpdate=".1.3.6.1.4.1.6876.1.5.0"
    OID_prodPatch=".1.3.6.1.4.1.6876.1.6.0"
    OID_vmName=".1.3.6.1.4.1.6876.2.1.1.2"
}

# - MAIN CODE

Source.HostAlive() {
    for server in $HOST_NAME; do
        ping -c1 -W1 -q $server &>/dev/null
        if [[ $? != 0 ]] ; then
            printf "%s\n" "$server is unreachable"
            exit $STATE_UNK
        fi
    done
}

Source.SNMP() {    
    snmpwalk -v $SNMPVERSION -r 1 -t 10 -Oe -c $COMMUNITY $HOST_NAME $1
}

Source.vSpheredb.Host() {
    for host in $HOST_NAME; do
        icingacli vspheredb check host --name $host
        exit $?
    done
}

Source.vSpheredb.Vm() {
    for vm in $1; do 
        icingacli vspheredb check vm --name $vm
        Source.e
    done
}

Source.e() {
    case $? in
        1) eWarning=$(($eWarning + 1)) ;;
        2) eCritical=$(($eCritical + 1)) ;;
        3) eUnknown=$(($eUnknown + 1)) ;;
    esac
}

# - ESXi vCenter Health Check

ESXi.Main() {
    Source.HostAlive
    
    case $1 in
        host)
            Source.vSpheredb.Host
            exit $? ;;
        info)
            ESXi.Info
            exit $STATE ;;
        vm)
            ESXi.VmList
            exit $? ;;
        *)
            echo "Unknown check!"
            Help.Function
            exit $STATE_UNK ;;
    esac
}

ESXi.GetData() {
    ESXi.OIDS

    case $1 in
        info)   osName=$(Source.SNMP $OID_osName | cut -d '"' -f 2)
                fwRev=$(Source.SNMP $OID_fwRev | cut -d '"' -f 2)
                serviceTag=$(Source.SNMP $OID_serviceTag | cut -d '"' -f 2)
                sysManufacturer=$(Source.SNMP $OID_sysManufacturer | cut -d '"' -f 2)
                sysModel=$(Source.SNMP $OID_sysModel | cut -d '"' -f 2)
                prodName=$(Source.SNMP $OID_prodName | cut -d '"' -f 2)
                prodVersion=$(Source.SNMP $OID_prodVersion | cut -d '"' -f 2)
                prodBuild=$(Source.SNMP $OID_prodBuild | cut -d '"' -f 2)
                prodUpdate=$(Source.SNMP $OID_prodUpdate | cut -d '"' -f 2)
                prodPatch=$(Source.SNMP $OID_prodPatch | cut -d '"' -f 2) ;;
        vm)     vmList=($(Source.SNMP $OID_vmName | cut -d '"' -f 2)) ;;
    esac
}

ESXi.Info() {
    ESXi.GetData info

    printf "%s\n" "$osName Rev. $fwRev" "$sysManufacturer" "Model: $sysModel" "Service Tag: $serviceTag" "$prodName $prodVersion" "Build: $prodBuild" "Update: $prodUpdate" "Patch: $prodPatch"
}

ESXi.VmList() {
    ESXi.GetData vm

    if [[ $? != 0 ]] ; then
        printf "%s\n" "$server is unreachable"
        exit $STATE_UNK
    else
        for((i=0; i<${#vmList[@]}; i++))
        do
            printf "%s\n" "$(($i+1)) - ${vmList[$i]}"
            Source.vSpheredb.Vm ${vmList[$i]}
            printf "\n"
        done
        
        if [[ $eWarning != 0 ]] && [[ $eCritical == 0 ]] ; then
            exit $STATE_WARN
        elif [[ $eCritical != 0 ]] && [[ $eUnknown != 0 ]] ; then
            exit $STATE_CRIT
        fi
    fi
}

# - Help 

Help.Main() {
    echo "Check ESXi Status"
    echo ''
    Help.Usage
    echo ''
    Help.Option
    echo ''
    Help.Info
    echo ''
    exit $STATE_UNK
}

Help.Usage() {
    printf "%s\n" "Method to compose the execution string"
    printf "%s\n" "./$APPNAME -c <SNMP community> -h <host> -t [host/info/vm]"
}

Help.Option() {
    printf "%s\n" "OPTIONS:"
    printf "%s\t%s\t%s\n\t\t\t%s\n" "-c" "--community" "SNMP v2 community string with Read access." " Default is $COMMUNITY."
    printf "%s\t%s\t\t%s\n\t\t\t%s\n" "-h" "--host" "Host name or IP address to check." " Default is $HOST_NAME."
    printf "%s\t%s\t\t%s\n" "-t" "--type" "Argument for check function"
    printf "%s\t%s\t\t%s\n" "-H" "--help" "Show script help"
    printf "%s\t%s\t%s\n" "-V" "--version" "Show script version"
}

Help.Function() {
    printf "\n%s\n\n" "ESXi vCenter Check Function"
    printf "%s\t%s\n\n" "Check" "Description"
    printf "%s\t%s\n" "host" "Get Host check from vsphere plugin."
    printf "%s\t%s\n" "info" "Get Information from snmpwalk."
    printf "%s\t%s\n" "vm" "Get Virtual Machine from vsphere plugin."
}

Help.Info() {
    printf "%s\t%s\t%s\n" "INFO:" "$NAME" "$VERSION" "" "$AUTHOR" "$URL"
}

# - COMMAND LINE ENCODER

while test -n "$1"; do
    case "$1" in
        --host | -h)
            HOST_NAME=$2
            shift ;;
        --comunity | -c)
            COMMUNITY=$2
            shift ;;
        --type | -t)
            ESXi.Main $2
            shift ;;
        --help | -H)
            Help.Main ;;
        --version | -V)
            Help.Info
            exit $STATE ;;
        *)
            echo "Unknown argument: $1"
            print_help
            exit $STATE_UNK ;;
        esac
    shift
done