Shell Samples

Basic Shell Skeleton

#!/bin/sh
##
# Manage an imaginary build process.
##
. /path/to/shell


main() {
    safety_checks
    parse_options "$@"

    # Grab a lock
    lock acquire "$0" ||
            die 'Another process seems to be running.'

    # Wipe temp job cache, if present
    if [ -e '/tmp/razzle' ]; then
        log "$INFO" 'Incomplete job detected; deleting...'
        rm -rf '/tmp/razzle'
    fi

    log "$DEBUG" "Kicking things off at approx. $(date)."

    # Kick off CI/CD process
    run_cicd

    # Get build status
    build_status="$(get_cicd 'status')"
    if is_true "$build_status"; then
        log "$INFO" 'SUCCESS: Razzle dazzle, baby!'
        #[...]
    fi

    log "$DEBUG" "Ending things at exactly $(date)."

    # Release the lock
    lock destroy "$0"
}


safety_checks() {
    detect_release || die 'Unable to detect release.'

    # Check minimum helpers version
    helper_version '1.0.0' ||
            die 'Must have shell_helpers >= 1.0.0'

    # Check host
    is_release '20.04' '20.10' ||
            die 'Only *buntu 20.04 and 20.10 are supported.'

    # Check for expected binaries
    for cmd in 'strace' 'cicd_runner' 'grep'; do
        command_present "$cmd" || die "$cmd was not found"
    done
}


parse_options() {
    while getopts 'i:h' OPT; do
        case "$OPT" in
            i) export CICD_MAGIC_ID="$OPTARG";;
            h) show_help; exit 1;;
            *) die "Unexpected argument provided: '$OPT'";;
        esac
    done
}


show_help() {
    t="$(printf '\t')"
    cat <<-EOF
        Run a CICD build.

        Usage: script_name [options]

        Options:
          -i X${t}Exports CICD_MAGIC_ID for build process
          -h${t}Print this help text and exit
        EOF
}


run_cicd() {
    :
}


main "$@"