# Responsible for updating a supervisor configuration

update_supervisor_config.sh

#!/bin/bash

# Responsible for updating a supervisor configuration
# Usage: update_supervisor_config [service] [config] [new_value]
function update_supervisor_config() {
    local INPUT_FILE="${SUPERVISOR_CONFIG}"
    local SERVICE=$1
    local CONFIG=$2
    local NEW_VALUE=$3
    local TMP_FILE="/tmp/supervisor.conf"
    local SERVICE_MATCHED=0
    local LINE
    local CURRENT_VALUE

    # Removes temp file, if is exists
    if [[ -f "${TMP_FILE}" ]]; then
        rm -f "${TMP_FILE}"
    fi

    # Iterate over the files' lines
    while IFS= read -r LINE
    do
        # Check if its the selected service
        if [[ "${LINE}" =~ ^\[program\:$SERVICE\]$ ]]; then
            SERVICE_MATCHED=1
        elif [[ "${LINE}" =~ ^\[program\:.*\]$ ]]; then
            SERVICE_MATCHED=0
        fi

        # Check if its the selected config
        if [[ ${SERVICE_MATCHED} -eq 1 && ${LINE} =~ ^${CONFIG}=(.*)$ ]]; then
            # Gets the current value
            CURRENT_VALUE="${BASH_REMATCH[1]}"

            # Replace by the new one
            LINE=$(echo ${LINE} | sed "s/${CONFIG}=${CURRENT_VALUE}/${CONFIG}=${NEW_VALUE}/")
        fi
    echo ${LINE} >> ${TMP_FILE}
    done < "${INPUT_FILE}"

    # Overwrite input file and removes the temp one.
    cp "${TMP_FILE}" "${INPUT_FILE}"
    rm -f "${TMP_FILE}"
}