repo-init

#!/bin/bash
#
# Bash code to initialize the environment / repo settings for deploying on a specific stack,
# for which the config is stored in the repo containing this script.
#
# This script assumes there is for each ${STACK_NAME} a corresponding:
#  1. ./group_vars/${STACK_NAME}/vars.yml        Ansible variables for this stack, which defines the {{ stack_prefix }} Ansible variable.
#  2. ./static_inventories/${STACK_NAME}.yml     Ansible inventory file.
#
# Once this code was sourced (not executed!) like this:
#     $> . ./repo-init
# You can call the repo-config function for a specific stack prefix. E.g.:
#     $> repo-config tl
#

#
##
### Environment and bash sanity.
##
#
export REPO_DIR="$( cd -P "$( dirname "${BASH_SOURCE:-}" )" && pwd )"

#
##
### Main.
##
#

function repo-config() {
	local _previous_opt_nounset_state
	if [[ -o nounset ]]; then
		_previous_opt_nounset_state='-u'
	else
		_previous_opt_nounset_state='+u'
	fi
	set -u
	#
	# Check if Python venv was initialized.
	#
	if [[ -z "${VIRTUAL_ENV:-}" ]]; then
		printf 'ERROR: ${VIRTUAL_ENV} is empty.\n'
		printf 'FATAL: The code from this repo requires Ansible and its dependencies installed in a Python virtual environment.\n'
		printf 'FATAL: See the README.md for instructions.\n'
		set "${_previous_opt_nounset_state}"
		return 1
	fi
	#
	# Ensure we have a .vault dir with sane, safe permissions.
	#
	mkdir -p -m 700 "${REPO_DIR}/.vault"
	chmod -R go-rwx "${REPO_DIR}/.vault"
	#
	# Get and check input.
	#
	local _stack_prefix="${1-}"
	if [[ -z "${_stack_prefix:-}" ]]; then
		printf '%s\n' 'ERROR: must specify an infra stack prefix.'
		set "${_previous_opt_nounset_state}"
		return 1
	fi
	local _group_vars="$(grep "^stack_prefix: ['\"]*${_stack_prefix}['\"]*$" "${REPO_DIR}/group_vars/"*/vars.yml | sed 's|:.*||')"
	if [[ -z "${_group_vars:-}" ]]; then
		printf '%s\n' "ERROR: cannot find group_vars/*/vars.yml for infra stack prefix ${_stack_prefix}."
		set "${_previous_opt_nounset_state}"
		return 1
	fi
	local _stack_name="$(basename "$(dirname "${_group_vars}")")"
	declare -a _required_paths=(
		"${REPO_DIR}/group_vars/${_stack_name}/"
		"${REPO_DIR}/static_inventories/${_stack_name}.yml"
		"${REPO_DIR}/.vault/vault_pass.txt.all"
	)
	local _required_path
	for _required_path in "${_required_paths[@]}"; do
		if [[ ! -e "${_required_path}" ]]; then
			printf '%s\n' "ERROR: ${_required_path} does not exist for infra stack prefix ${_stack_prefix}."
			set "${_previous_opt_nounset_state}"
			return 1
		fi
	done
	#
	# Get jumphost from inventory file.
	#
	# ToDo: this is rather brittle code;
	# install something like https://github.com/mikefarah/yq
	# for proper parsing of YAML files.
	#
	local _jumphost_block=$(fgrep -A1 'jumphost' "${REPO_DIR}/static_inventories/${_stack_name}.yml" | head -2 | tail -1 | tr -d ' :')
	if [[ "${_jumphost_block:-}" == 'hosts' ]]; then
		local _jumphost=$(fgrep -A2 'jumphost' "${REPO_DIR}/static_inventories/${_stack_name}.yml" | head -3 | tail -1 | tr -d ' :')
	fi
	#
	# Init and report current setup.
	#
	cd "${REPO_DIR}"
	if [[ -n "${_jumphost:-}" ]]; then
		export AI_PROXY="${_jumphost}"
	else
		unset AI_PROXY
	fi
	export ANSIBLE_INVENTORY="static_inventories/${_stack_name}.yml"
	export ANSIBLE_VAULT_IDENTITY_LIST="all@.vault/vault_pass.txt.all"
	export ANSIBLE_ROLES_PATH="${VIRTUAL_ENV}/ansible/ansible_roles/:"
	export ANSIBLE_COLLECTIONS_PATHS="${VIRTUAL_ENV}/ansible/:"
	printf 'INFO: Current working directory is:      %s\n' "$(pwd)"
	printf 'INFO: Using ANSIBLE_INVENTORY:           %s\n' "${ANSIBLE_INVENTORY}"
	printf 'INFO: Using AI_PROXY:                    %s\n' "${AI_PROXY:-None: no jumphost specified in ANSIBLE_INVENTORY}"
	printf 'INFO: Using ANSIBLE_VAULT_IDENTITY_LIST: %s\n' "${ANSIBLE_VAULT_IDENTITY_LIST}"
	printf 'INFO: Using ANSIBLE_ROLES_PATH:          %s\n' "${ANSIBLE_ROLES_PATH}"
	printf 'INFO: Using ANSIBLE_COLLECTIONS_PATHS:   %s\n' "${ANSIBLE_COLLECTIONS_PATHS}"
	#
	# Enable ansible_mitogen strategy plugin for improved speed of plays when available.
	#
	_ansible_mitogen_search_path='.*/lib/python.*/site-packages/ansible_mitogen/plugins/strategy'
	_ansible_mitogen_path=$(find ${VIRTUAL_ENV:-.} -regex "${_ansible_mitogen_search_path}" | sort -V | tail -1)
	if [[ -n "${_ansible_mitogen_path}" ]]; then
		export ANSIBLE_STRATEGY_PLUGINS="${_ansible_mitogen_path}"
		export ANSIBLE_STRATEGY='mitogen_linear'
		printf 'INFO: Found Mitogen strategy plugin in:  %s\n' "${ANSIBLE_STRATEGY_PLUGINS}"
		printf 'INFO: Using Ansible strategy:            %s.\n' "${ANSIBLE_STRATEGY}"
	else
		printf 'WARNING: Could not find Mitogen strategy plugin in %s\n' "${_ansible_mitogen_search_path}"
		printf 'INFO: Mitogen strategy plugin is:        %s.\n' 'disabled (default)'
	fi
	set "${_previous_opt_nounset_state}"
}