moby/hack/make/.binary
Sebastiaan van Stijn 53d1b12bc0
hack/make/.binary: don't use "netgo" when building Windows binaries
Starting with go1.19, the Go runtime on Windows now supports the `netgo` build-
flag to use a native Go DNS resolver. Prior to that version, the build-flag
only had an effect on non-Windows platforms. When using the `netgo` build-flag,
the Windows's host resolver is not used, and as a result, custom entries in
`etc/hosts` are ignored, which is a change in behavior from binaries compiled
with older versions of the Go runtime.

From the go1.19 release notes: https://go.dev/doc/go1.19#net

> Resolver.PreferGo is now implemented on Windows and Plan 9. It previously
> only worked on Unix platforms. Combined with Dialer.Resolver and Resolver.Dial,
> it's now possible to write portable programs and be in control of all DNS name
> lookups when dialing.
>
> The net package now has initial support for the netgo build tag on Windows.
> When used, the package uses the Go DNS client (as used by Resolver.PreferGo)
> instead of asking Windows for DNS results. The upstream DNS server it discovers
> from Windows may not yet be correct with complex system network configurations,
> however.

Our Windows binaries are compiled with the "static" (`make/binary-daemon`)
script, which has the `netgo` option set by default. This patch unsets the
`netgo` option when cross-compiling for Windows.

Co-authored-by: Bjorn Neergaard <bjorn.neergaard@docker.com>
Signed-off-by: Bjorn Neergaard <bjorn.neergaard@docker.com>
2023-05-24 09:16:41 -06:00

92 lines
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Bash

#!/usr/bin/env bash
set -e
# a helper to provide ".exe" when it's appropriate
binary_extension() {
if [ "$(go env GOOS)" = 'windows' ]; then
echo -n '.exe'
fi
}
BINARY_EXTENSION="$(binary_extension)"
BINARY_FULLNAME="$BINARY_NAME$BINARY_EXTENSION"
source "${MAKEDIR}/.go-autogen"
(
export GOGC=${DOCKER_BUILD_GOGC:-1000}
if [ "$(go env GOOS)/$(go env GOARCH)" != "$(go env GOHOSTOS)/$(go env GOHOSTARCH)" ]; then
# must be cross-compiling!
if [ "$(go env GOOS)/$(go env GOARCH)" = "linux/arm" ]; then
# specify name of the target ARM architecture
case "$(go env GOARM)" in
5)
export CGO_CFLAGS="-march=armv5t"
export CGO_CXXFLAGS="-march=armv5t"
;;
6)
export CGO_CFLAGS="-march=armv6"
export CGO_CXXFLAGS="-march=armv6"
;;
7)
export CGO_CFLAGS="-march=armv7-a"
export CGO_CXXFLAGS="-march=armv7-a"
;;
esac
fi
fi
# -buildmode=pie is not supported on Windows arm64 and Linux mips*, ppc64be
# https://github.com/golang/go/blob/go1.19.4/src/cmd/internal/sys/supported.go#L125-L132
if ! [ "$DOCKER_STATIC" = "1" ]; then
# -buildmode=pie not supported when -race is enabled
if [[ " $BUILDFLAGS " != *" -race "* ]]; then
case "$(go env GOOS)/$(go env GOARCH)" in
windows/arm64 | linux/mips* | linux/ppc64) ;;
*)
BUILDFLAGS+=("-buildmode=pie")
;;
esac
fi
fi
# XXX: Disable netgo on Windows and use Window's system resolver instead.
#
# go1.19 and newer added support for netgo on Windows (https://go.dev/doc/go1.19#net),
# which won't ask Windows for DNS results, and hence may be ignoring
# custom "C:\Windows\System32\drivers\etc\hosts".
# See https://github.com/moby/moby/issues/45251#issuecomment-1561001817
# https://github.com/moby/moby/issues/45251, and
# https://go-review.googlesource.com/c/go/+/467335
if [ "$(go env GOOS)" = "windows" ]; then
BUILDFLAGS=("${BUILDFLAGS[@]/netgo/}")
fi
# only necessary for non-sandboxed invocation where TARGETPLATFORM is empty
PLATFORM_NAME=$TARGETPLATFORM
if [ -z "$PLATFORM_NAME" ]; then
PLATFORM_NAME="$(go env GOOS)/$(go env GOARCH)"
if [ -n "$(go env GOARM)" ]; then
PLATFORM_NAME+="/v$(go env GOARM)"
elif [ -n "$(go env GOAMD64)" ] && [ "$(go env GOAMD64)" != "v1" ]; then
PLATFORM_NAME+="/$(go env GOAMD64)"
fi
fi
# This is a workaround to have buildinfo with deps embedded in the binary. We
# need to create a go.mod file before building with -modfile=vendor.mod,
# otherwise it fails with: "-modfile cannot be used to set the module root directory."
if [ ! -f "go.mod" ]; then
printf '%s\n\n%s' 'module github.com/docker/docker' 'go 1.19' > "go.mod"
trap 'rm -f go.mod' EXIT
fi
echo "Building $([ "$DOCKER_STATIC" = "1" ] && echo "static" || echo "dynamic") $DEST/$BINARY_FULLNAME ($PLATFORM_NAME)..."
if [ -n "$DOCKER_DEBUG" ]; then
set -x
fi
GO111MODULE=on go build -mod=vendor -modfile=vendor.mod -o "$DEST/$BINARY_FULLNAME" "${BUILDFLAGS[@]}" -ldflags "$LDFLAGS $LDFLAGS_STATIC $DOCKER_LDFLAGS" ${GO_PACKAGE}
)
echo "Created binary: $DEST/$BINARY_FULLNAME"