get the prefered interactive shell in a given docker conatiner

doci

#!/bin/bash
set -eufo pipefail

SHELL_PREFERENCE=(
    'bash'
    'zsh'
    'sh'
)


function main()
{
    local container_id="${1:-}"

    if [ -z "${container_id}" ]; then
        error 255 \
            'No container name supplied'
    fi


    if ! is_container_exist "${container_id}"; then
        error 254 \
            "'${container_id}' is not valid container" \
            "$(list_containers)"
    fi

    for shell_cmd in "${SHELL_PREFERENCE[@]}"
    do
        if is_command_available_in_container "${container_id}" "${shell_cmd}"; then
            set -x
            exec docker exec -it "${container_id}" "${shell_cmd}"
        fi
    done

    error 253 \
        'There is no supported shell in the container'
}

function error()
{
    local exit_code="$1"; shift
    local messages=("$@")

    printf '%s\n' "${messages[@]}" >&2
    exit "${exit_code}"
}
function is_container_exist()
{
    local container_id="$1"

    list_containers \
        | grep -qw "$1"
}

function list_containers()
{
    docker container ls --format 'table {{.Names}}\t{{.ID}}'
}

function is_command_available_in_container()
{
    local container_id="$1"
    local command="$2"

    docker exec -t "${container_id}" which "$(printf '%q' "${command}")" \
        >/dev/null
}


main "$@"