feat: automatically configure vendor mode

When a vendor folder is seen, we need to disable the go module mode,
instead we need to use GOPATH mode. This is a simple toggle of one
env variable, using a script means that users do not need to set any
build args.

Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>

Author: LucasRoesler

template/golang-http/Dockerfile

@@ -20,20 +20,24 @@ ARG GO111MODULE="on"
 ARG GOPROXY=""
 ARG GOFLAGS=""
 ARG CGO_ENABLED=0
-ENV CGO_ENABLED=${CGO_ENABLED}
+ARG DEBUG=0
 
+ENV DEBUG=${DEBUG}
+ENV CGO_ENABLED=${CGO_ENABLED}
+ENV GOOS=${TARGETOS}
+ENV GOARCH=${TARGETARCH}
+ENV GO=/go/src/handler/go.sh
 
 # Run a gofmt and exclude all vendored code.
 RUN test -z "$(gofmt -l $(find . -type f -name '*.go' -not -path "./vendor/*" -not -path "./function/vendor/*"))" || { echo "Run \"gofmt -s -w\" on your Golang code"; exit 1; }
 
 WORKDIR /go/src/handler/function
 RUN mkdir -p /go/src/handler/function/static
 
-RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} go test ./... -cover
+RUN ${GO} test ./... -cover
 
 WORKDIR /go/src/handler
-RUN CGO_ENABLED=${CGO_ENABLED} GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
-    go build --ldflags "-s -w" -a -installsuffix cgo -o handler .
+RUN ${GO} build --ldflags "-s -w" -a -installsuffix cgo -o handler .
 
 FROM --platform=${TARGETPLATFORM:-linux/amd64} alpine:3.15
 # Add non root user and certs

template/golang-http/go.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+# go.sh is a wrapper for the Go command that will
+# automatically set the required module related flags
+# when a vendor folder is detected.
+#
+# Currently, in Go 1.18, Go Workspaces are incompatible
+# with vendored modules. As a result, we must disable
+# Go modules and use GOPATH mode.
+
+# We use this bash script to wrap Go commands because
+# there is no clear way to set an env variable from the
+# a script in a Dockerfile.
+# It is possible to use  `go env -w` but, but env varaibles
+# have precedence and if it is set as an arg/env variable,
+# then it will be ignored by the `go env -w`.
+
+# if the function/vendor folder exists
+# then we set the env variables for
+# GO111MODULE=off
+if [ -d "/go/src/handler/function/vendor" ]; then
+    echo "Setting vendor mode env variables"
+    export GO111MODULE=off
+fi
+
+# if DEBUG env is 1, print the go env
+if [ "${DEBUG:-0}" = "1" ]; then
+    go env
+fi
+
+go "$@"

template/golang-middleware/Dockerfile

@@ -20,19 +20,24 @@ ARG GO111MODULE="on"
 ARG GOPROXY=""
 ARG GOFLAGS=""
 ARG CGO_ENABLED=0
+ARG DEBUG=0
+
+ENV DEBUG=${DEBUG}
 ENV CGO_ENABLED=${CGO_ENABLED}
+ENV GOOS=${TARGETOS}
+ENV GOARCH=${TARGETARCH}
+ENV GO=/go/src/handler/go.sh
 
 # Run a gofmt and exclude all vendored code.
 RUN test -z "$(gofmt -l $(find . -type f -name '*.go' -not -path "./vendor/*" -not -path "./function/vendor/*"))" || { echo "Run \"gofmt -s -w\" on your Golang code"; exit 1; }
 
 WORKDIR /go/src/handler/function
 RUN mkdir -p /go/src/handler/function/static
 
-RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} go test ./... -cover
+RUN ${GO} test ./... -cover
 
 WORKDIR /go/src/handler
-RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
-    go build --ldflags "-s -w" -a -installsuffix cgo -o handler .
+RUN ${GO} build --ldflags "-s -w" -a -installsuffix cgo -o handler .
 
 FROM --platform=${TARGETPLATFORM:-linux/amd64} alpine:3.15 as ship
 

template/golang-middleware/go.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+# go.sh is a wrapper for the Go command that will
+# automatically set the required module related flags
+# when a vendor folder is detected.
+#
+# Currently, in Go 1.18, Go Workspaces are incompatible
+# with vendored modules. As a result, we must disable
+# Go modules and use GOPATH mode.
+
+# We use this bash script to wrap Go commands because
+# there is no clear way to set an env variable from the
+# a script in a Dockerfile.
+# It is possible to use  `go env -w` but, but env varaibles
+# have precedence and if it is set as an arg/env variable,
+# then it will be ignored by the `go env -w`.
+
+# if the function/vendor folder exists
+# then we set the env variables for
+# GO111MODULE=off
+if [ -d "/go/src/handler/function/vendor" ]; then
+    echo "Setting vendor mode env variables"
+    export GO111MODULE=off
+fi
+
+# if DEBUG env is 1, print the go env
+if [ "${DEBUG:-0}" = "1" ]; then
+    go env
+fi
+
+go "$@"