kubectl-wait-wrapper.sh

#!/usr/bin/env bash

set -e
set -o pipefail

# This is a rather minimal example Argbash potential
# Example taken from http://argbash.readthedocs.io/en/stable/example.html
#
# ARG_OPTIONAL_SINGLE([namespace],[n],[namespace name])
# ARG_OPTIONAL_REPEATED([resource-type],[t],[resource type])
# ARG_OPTIONAL_REPEATED([params],[p],[kubectl parameters in quotes])
# ARG_OPTIONAL_SINGLE([retries],[r],[number of retries if the resource is not created yet],[30])
# ARG_OPTIONAL_SINGLE([wait],[w],[wait between retries],[5])
# ARG_OPTIONAL_BOOLEAN([debug],[d],[enable debug])
# ARGBASH_GO()
# needed because of Argbash --> m4_ignore([
### START OF CODE GENERATED BY Argbash v2.9.0 one line above ###
# Argbash is a bash code generator used to get arguments parsing right.
# Argbash is FREE SOFTWARE, see https://argbash.io for more info
# Generated online by https://argbash.io/generate


# # When called, the process ends.
# Args:
# 	$1: The exit message (print to stderr)
# 	$2: The exit code (default is 1)
# if env var _PRINT_HELP is set to 'yes', the usage is print to stderr (prior to $1)
# Example:
# 	test -f "$_arg_infile" || _PRINT_HELP=yes die "Can't continue, have to supply file as an argument, got '$_arg_infile'" 4
die()
{
	local _ret="${2:-1}"
	test "${_PRINT_HELP:-no}" = yes && print_help >&2
	echo "$1" >&2
	exit "${_ret}"
}


# Function that evaluates whether a value passed to it begins by a character
# that is a short option of an argument the script knows about.
# This is required in order to support getopts-like short options grouping.
begins_with_short_option()
{
	local first_option all_short_options='ntprwd'
	first_option="${1:0:1}"
	test "$all_short_options" = "${all_short_options/$first_option/}" && return 1 || return 0
}

# THE DEFAULTS INITIALIZATION - OPTIONALS
_arg_namespace=
_arg_resource_type=()
_arg_params=()
_arg_retries="30"
_arg_wait="5"
_arg_debug="off"


# Function that prints general usage of the script.
# This is useful if users asks for it, or if there is an argument parsing error (unexpected / spurious arguments)
# and it makes sense to remind the user how the script is supposed to be called.
print_help()
{
	printf 'Usage: %s [-n|--namespace <arg>] [-t|--resource-type <arg>] [-p|--params <arg>] [-r|--retries <arg>] [-w|--wait <arg>] [-d|--(no-)debug]\n' "$0"
	printf '\t%s\n' "-n, --namespace: namespace name (no default)"
	printf '\t%s\n' "-t, --resource-type: resource type (empty by default)"
	printf '\t%s\n' "-p, --params: kubectl parameters in quotes (empty by default)"
	printf '\t%s\n' "-r, --retries: number of retries if the resource is not created yet (default: '30')"
	printf '\t%s\n' "-w, --wait: wait between retries (default: '5')"
	printf '\t%s\n' "-d, --debug, --no-debug: enable debug (off by default)"
}


# The parsing of the command-line
parse_commandline()
{
	while test $# -gt 0
	do
		_key="$1"
		case "$_key" in
			# We support whitespace as a delimiter between option argument and its value.
			# Therefore, we expect the --namespace or -n value.
			# so we watch for --namespace and -n.
			# Since we know that we got the long or short option,
			# we just reach out for the next argument to get the value.
			-n|--namespace)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_namespace="$2"
				shift
				;;
			# We support the = as a delimiter between option argument and its value.
			# Therefore, we expect --namespace=value, so we watch for --namespace=*
			# For whatever we get, we strip '--namespace=' using the ${var##--namespace=} notation
			# to get the argument value
			--namespace=*)
				_arg_namespace="${_key##--namespace=}"
				;;
			# We support getopts-style short arguments grouping,
			# so as -n accepts value, we allow it to be appended to it, so we watch for -n*
			# and we strip the leading -n from the argument string using the ${var##-n} notation.
			-n*)
				_arg_namespace="${_key##-n}"
				;;
			# See the comment of option '--namespace' to see what's going on here - principle is the same.
			-t|--resource-type)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_resource_type+=("$2")
				shift
				;;
			# See the comment of option '--namespace=' to see what's going on here - principle is the same.
			--resource-type=*)
				_arg_resource_type+=("${_key##--resource-type=}")
				;;
			# See the comment of option '-n' to see what's going on here - principle is the same.
			-t*)
				_arg_resource_type+=("${_key##-t}")
				;;
			# See the comment of option '--namespace' to see what's going on here - principle is the same.
			-p|--params)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_params+=("$2")
				shift
				;;
			# See the comment of option '--namespace=' to see what's going on here - principle is the same.
			--params=*)
				_arg_params+=("${_key##--params=}")
				;;
			# See the comment of option '-n' to see what's going on here - principle is the same.
			-p*)
				_arg_params+=("${_key##-p}")
				;;
			# See the comment of option '--namespace' to see what's going on here - principle is the same.
			-r|--retries)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_retries="$2"
				shift
				;;
			# See the comment of option '--namespace=' to see what's going on here - principle is the same.
			--retries=*)
				_arg_retries="${_key##--retries=}"
				;;
			# See the comment of option '-n' to see what's going on here - principle is the same.
			-r*)
				_arg_retries="${_key##-r}"
				;;
			# See the comment of option '--namespace' to see what's going on here - principle is the same.
			-w|--wait)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_wait="$2"
				shift
				;;
			# See the comment of option '--namespace=' to see what's going on here - principle is the same.
			--wait=*)
				_arg_wait="${_key##--wait=}"
				;;
			# See the comment of option '-n' to see what's going on here - principle is the same.
			-w*)
				_arg_wait="${_key##-w}"
				;;
			# The debug argument doesn't accept a value,
			# we expect the --debug or -d, so we watch for them.
			-d|--no-debug|--debug)
				_arg_debug="on"
				test "${1:0:5}" = "--no-" && _arg_debug="off"
				;;
			# We support getopts-style short arguments clustering,
			# so as -d doesn't accept value, other short options may be appended to it, so we watch for -d*.
			# After stripping the leading -d from the argument, we have to make sure
			# that the first character that follows corresponds to a short option.
			-d*)
				_arg_debug="on"
				_next="${_key##-d}"
				if test -n "$_next" -a "$_next" != "$_key"
				then
					{ begins_with_short_option "$_next" && shift && set -- "-d" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
				fi
				;;
			*)
				_PRINT_HELP=yes die "FATAL ERROR: Got an unexpected argument '$1'" 1
				;;
		esac
		shift
	done
}

# Now call all the functions defined above that are needed to get the job done
parse_commandline "$@"

# OTHER STUFF GENERATED BY Argbash

### END OF CODE GENERATED BY Argbash (sortof) ### ])

[ "${_arg_debug}" == "on" ] && set -x

if [ "${_arg_namespace}" == "" ]; then
    printf "error: missing namespace parameter\n\n"
        print_help
    exit 1
fi

if [ ${#_arg_resource_type[@]} -eq 0 ]; then
    printf "error: missing params resource-type\n\n"
        print_help
    exit 1
fi

if [ ${#_arg_params[@]} -eq 0 ]; then
    printf "error: missing params parameter\n\n"
        print_help
    exit 1
fi

retries="${_arg_retries}"
echo "going to check for the resources creation ${retries} times before fail"
for i in "${_arg_resource_type[@]}"; do
	while [ "${retries}" != 0 ] ; do
		result="$(kubectl -n "${_arg_namespace}" get "${i}" 2>/dev/null || true)"
		if [ "${result}" == "No resources found in ${_arg_namespace} namespace." ] ; then \
			echo "#${retries} - No resources found yet. Waiting ${_arg_wait} seconds before next retry"
			retries=$((retries - 1))
			sleep "${_arg_wait}"
		else
			break
		fi
	done
done

retries="${_arg_retries}"
for j in "${_arg_params[@]}"; do
	while [ "${retries}" != 0 ] ; do
		read -r -a param_array <<< "${j}"
		result=$(kubectl wait -n "${_arg_namespace}" "${param_array[@]}" 2>&1 || true)
		if [ "${result}" == "error: no matching resources found" ]; then
			echo "#${retries} - No matching resources yet. Waiting ${_arg_wait} seconds before next retry"
			retries=$((retries - 1))
			sleep "${_arg_wait}"
		else
			echo "${result}"
			break
		fi
	done
done