[gentoo-dev] Re: [PATCH] go-module.eclass: add functions for use in custom src_unpack phase

[Zac Medico]

On 5/19/21 1:45 PM, Zac Medico wrote:
>> +# @FUNCTION: go-module_setup_proxy
>> +# @DESCRIPTION:
>> +# If your ebuild redefines src_unpack and uses EGO_SUM you need to call
>> +# this function in src_unpack.
>> +# It sets up the go module proxy in the appropriate location and exports
>> +# the GOPROXY environment variable so that go calls will be able to
>> +# locate the proxy directory.
>> +go-module_setup_proxy() {
>> +	# shellcheck disable=SC2120
>> +	debug-print-function "${FUNCNAME}" "$@"
>> +
>> +	if [[ ! ${_GO_MODULE_SET_GLOBALS_CALLED} ]]; then
>> +		die "go-module_set_globals must be called in global scope"
>> +	fi
>> +
>> +	local goproxy_dir="${T}/go-proxy"
>> +	mkdir -p "${goproxy_dir}" || die
>> +
>> +	# For each Golang module distfile, look up where it's supposed to go and
>> +	# symlink it into place.
>> +	local f
>> +	local goproxy_mod_dir
>> +	for f in ${A}; do
>> +		goproxy_mod_path="${_GOMODULE_GOSUM_REVERSE_MAP["${f}"]}"
>> +		if [[ -n "${goproxy_mod_path}" ]]; then
>> +			debug-print-function "Populating go proxy for ${goproxy_mod_path}"
>> +			# Build symlink hierarchy
>> +			goproxy_mod_dir=$( dirname "${goproxy_dir}"/"${goproxy_mod_path}" )
>> +			mkdir -p "${goproxy_mod_dir}" || die
>> +			ln -sf "${DISTDIR}"/"${f}" "${goproxy_dir}/${goproxy_mod_path}" ||
>> +				die "Failed to ln"
>> +			local v=${goproxy_mod_path}
>> +			v="${v%.mod}"
>> +			v="${v%.zip}"
>> +			v="${v//*\/}"
>> +			_go-module_gosum_synthesize_files "${goproxy_mod_dir}" "${v}"
>> +		fi
>> +	done
>> +	export GOPROXY="file://${goproxy_dir}"
>> +
>> +	# Validate the gosum now
>> +	_go-module_src_unpack_verify_gosum
>> +}
>> +
>>  # @FUNCTION: go-module_src_unpack
>>  # @DESCRIPTION:
>>  # If EGO_SUM is set, unpack the base tarball(s) and set up the
>>
>
> The go-module_setup_proxy function solves bug 790851 nicely, since
> sys-cluster/k3s ebuilds can call that instead of go-module_src_unpack.

I do have one criticism of the go-module_setup_proxy, which is that it
relies on the side-effect of the GOPROXY export for its operation. We
can instead echo the GOPROXY value to stdout and force the caller to
export it themselves, and provide a convenience wrapper function which
works based on side-effects.
-- 
Thanks,
Zac