UpdateController/log_helpers

#!/bin/bash
# set -x 

if [ "${log_helpers_sourced:-1}" = "1" ]; then    # include only once
    readonly log_helpers_sourced=${BASH_SOURCE[0]}

    readonly log_file=/var/log/update_controller.log
    if ! [ -f "$log_file" ]; then
        touch $log_file
    fi

    readonly DEBUG=0
    readonly INFO=1
    readonly WARN=2
    readonly CRIT=3
    readonly ERROR=4
    readonly FATAL=5
    readonly MAX_DEBUG_LEVEL=6

    log_level=$INFO
    FATAL_FAILURE=false

    set_dbg_level () {
        if [ $1 < $MAX_DEBUG_LEVEL ]; then
            log_level=$1
        fi
    }

    dbg_level () {
        return $log_level
    }

    log_to_file() {
        if [[ $(("$(wc -l < $log_file)")) -ge $((100000)) ]]; then
            # remove first line
            sed -e 1d -i $log_file
        fi
        local msg="$(date +'%Y-%m-%d_%T'): $*"
        echo "$msg" >> $log_file
    }

    log() {
        local msg="$(date +'%Y-%m-%d_%T'): $*"
        echo "log:$msg" >&2
    }

    log_debug() {
        log_to_file "DEBUG $*"
        if [ $log_level -le $DEBUG ]; then
            log "DEBUG $*"
        fi
    }

    log_info() {
        log_to_file "INFO $*"
        if [ $log_level -le $INFO ]; then
            log "INFO  $*"
        fi
    }

    log_warn() {
        log_to_file "WARN $*"
        if [ $log_level -le $WARN ]; then
            log "WARN  $*"
        fi
    }

    log_crit() {
        log_to_file "CRIT $*"
        if [ $log_level -le $CRIT ]; then
            log "CRIT  $*"
        fi
    }

    log_error() {
        log_to_file "ERROR $*"
        if [ $log_level -le $ERROR ]; then
            log "ERROR  $*"
        fi
    }

    log_fatal() {
        log_to_file "FATAL $*"
        if [ $log_level -le $FATAL ]; then
            log "FATAL  $*"
            log "exiting ..."
            FATAL_FAILURE=true
            exit 1
        fi
    }
###############################################################################
fi ### include guard