util.sh

#!/bin/bash

########################
# Print to STDERR
# Arguments:
#   Message to print
# Returns:
#   None
#########################
stderr_print() {
    # 'is_boolean_yes' is defined in libvalidations.sh, but depends on this file so we cannot source it
    local bool="${BITNAMI_QUIET:-false}"
    # comparison is performed without regard to the case of alphabetic characters
    shopt -s nocasematch
    if ! [[ "$bool" = 1 || "$bool" =~ ^(yes|true)$ ]]; then
        printf "%b\\n" "${*}" >&2
    fi
}

########################
# Replace a regex in a file
# Arguments:
#   $1 - filename
#   $2 - match regex
#   $3 - substitute regex
#   $4 - use POSIX regex. Default: true
# Returns:
#   None
#########################
replace_in_file() {
    local filename="${1:?filename is required}"
    local match_regex="${2:?match regex is required}"
    local substitute_regex="${3:?substitute regex is required}"
    local posix_regex=${4:-true}

    local result

    # We should avoid using 'sed in-place' substitutions
    # 1) They are not compatible with files mounted from ConfigMap(s)
    # 2) We found incompatibility issues with Debian10 and "in-place" substitutions
    del=$'\001' # Use a non-printable character as a 'sed' delimiter to avoid issues
    if [[ $posix_regex = true ]]; then
        result="$(sed -E "s${del}${match_regex}${del}${substitute_regex}${del}g" "$filename")"
    else
        result="$(sed "s${del}${match_regex}${del}${substitute_regex}${del}g" "$filename")"
    fi
    echo "$result" > "$filename"
}

########################
# Set a configuration setting value to a file
# Globals:
#   None
# Arguments:
#   $1 - file
#   $2 - key
#   $3 - values (array)
# Returns:
#   None
#########################
kafka_common_conf_set() {
    local file="${1:?missing file}"
    local key="${2:?missing key}"
    shift
    shift
    local values=("$@")

    if [[ "${#values[@]}" -eq 0 ]]; then
        stderr_print "missing value"
        return 1
    elif [[ "${#values[@]}" -ne 1 ]]; then
        for i in "${!values[@]}"; do
            kafka_common_conf_set "$file" "${key[$i]}" "${values[$i]}"
        done
    else
        value="${values[0]}"
        # Check if the value was set before
        if grep -q "^[#\\s]*$key\s*=.*" "$file"; then
            # Update the existing key
            replace_in_file "$file" "^[#\\s]*${key}\s*=.*" "${key}=${value}" false
        else
            # Add a new key
            printf '\n%s=%s' "$key" "$value" >>"$file"
        fi
    fi
}

########################
# Set a configuration setting value to server.properties
# Globals:
#   KAFKA_CONF_FILE
# Arguments:
#   $1 - key
#   $2 - values (array)
# Returns:
#   None
#########################
kafka_server_conf_set() {
    kafka_common_conf_set "$KAFKA_CONF_FILE" "$@"
}