install

#!/bin/sh
# vi:et lbr noet sw=2 ts=2 tw=79 wrap
# Copyright 2023-2025 David Rabkin
# Uses Unix shell framework shellbase:
#  https://github.com/rdavid/shellbase/
# shellcheck disable=SC2034,SC3043 # Uses local variables, appears unused.
readonly \
	BASE_APP_VERSION=0.9.20250122 \
	BASE_MIN_VERSION=0.9.20230606 \
	DST=/usr/local/bin \
	GOR=0.9.20240303 \
	PKG="\
curl \
dci-ansible \
dci-openshift-agent \
dci-openshift-app-agent \
jq \
python3-dciclient \
tar \
which" \
	SHR=0.9.20241111 \
	USR=dci-openshift-app-agent \
	YQR=4.45.1
readonly \
	GO=https://github.com/rdavid/gento/archive/refs/tags/v$GOR.tar.gz \
	OC=https://mirror.openshift.com/pub/openshift-v4/x86_64/clients/ocp/stable-4.14/openshift-client-linux.tar.gz \
	SH=https://github.com/rdavid/shellbase/archive/refs/tags/v$SHR.tar.gz \
	YQ=https://github.com/mikefarah/yq/releases/download/v$YQR/yq_linux_amd64

# Downloads an archive, extracts, and puts a single file to the destination.
# The first parameter is an package name, the second is an URL of an archive,
# the lasted arguments are a position of a file inside the archive to extract
# and install.
install_arc() {
	local pkg="$1" url="$2"
	shift 2
	curl --location --silent "$url" |
		tar --directory $DST --extract --gzip "$@" ||
		die Failed to download and extract "$pkg".
	log "$pkg" is installed or upgraded.
}

# Installs or updates needful RHEL packages. dnf upgrade does not fail if
# multiple packages are listed, and a single package succeeds, hence upgrade
# packages one by one.
install_dnf() {
	local out pkg
	for pkg in $PKG; do
		out="$(dnf install --assumeyes --best --quiet "$pkg" 2>&1)" ||
			die "Failed to install or upgrade $pkg. $out"
		log "$pkg" is installed or upgraded.
	done
}

# Downloads the executable to the destination.
install_yq() {
	curl --location --output $DST/yq --silent $YQ ||
		die Unable to install $YQ.
	chmod +x $DST/yq || die Unable to add execute permission to $DST/yq.
	log yq is installed or upgraded.
}

# Validates the environment and installs the software.
main() {
	validate
	install_arc gento $GO --strip-components=2 gento-$GOR/app/gento
	install_arc oc $OC oc
	install_arc shellbase $SH --strip-components=2 shellbase-$SHR/lib/base.sh
	install_dnf
	install_yq
}

# Installs shellbase to the current shell session. Packages curl and tar are
# required.
shellbase() {
	local err pkg
	for pkg in curl tar; do
		command -v $pkg >/dev/null 2>&1 || {
			err=$?
			printf >&2 Install\ %s.\\n $pkg
			exit $err
		}
	done
	curl --fail --head --output /dev/null --silent $SH || {
		err=$?
		printf >&2 '%s is unavailable.\n' $SH
		exit $err
	}
	eval "$(
		curl --location --silent $SH |
			tar --extract --gzip --to-stdout shellbase-$SHR/lib/base.sh
	)"
	[ -n "${BASE_VERSION+x}" ] || {
		printf >&2 No\ shellbase.\\n
		exit 1
	}
	log shellbase "$BASE_VERSION" is installed to the current shell session.
}

# Uses functions of shellbase to validate the environment.
validate() {
	local dir uid

	# shellcheck disable=SC1091,SC2015 # File not following, A && B || C.
	[ -r $DST/base.sh ] && . $DST/base.sh || shellbase
	beroot
	validate_cmd curl dnf install tar
	iswritable $DST || die $DST is not writable.
	url_exists $GO $OC $SH $YQ || die
	user_exists $USR || die $USR: Not such user.

	# Verifies that XDG_RUNTIME_DIR exists and accessible by
	# dci-openshift-app-agent.
	uid="$(id -u $USR 2>&1)" || die "$uid"
	dir=/run/user/"$uid"
	install --directory --group $USR --mode 0700 --owner $USR "$dir" ||
		die Unable to create "$dir".
}

# Starting point.
main "$@"