ci: Set Go version consistently via .go-version

Ensure Go version is determined consistently for CI and Docker builds
rather than spread across several different files.

The intent is to eventually replace this with use of the `toolchain`
directive in Go 1.21.

c.f. hashicorp/consul#20058

.github/workflows/build.yml

@@ -376,12 +376,7 @@ jobs:
       - uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
       - uses: actions/setup-go@fac708d6674e30b6ba41289acaab6d4b75aa0753 # v4.0.1
         with:
-          # pinning this to 1.20.5 because this issue in go-testcontainers occurs
-          # in 1.20.6 with the error "http: invalid Host header, host port waiting failed"
-          # https://github.com/testcontainers/testcontainers-go/issues/1359
-          # remove setting this when the above issue is fixed so that the job will
-          # just get the go version from .go-version.
-          go-version: 1.20.5
+          go-version: ${{ needs.get-go-version.outputs.go-version }}
       - id: run-tests
         run: cd integration-tests && go test -v -output-dir=./output -dataplane-image=hashicorppreview/${{env.repo}}:${{env.dev_tag}}-${{github.sha}} -server-image=${{matrix.server.image}} -server-version=${{matrix.server.version}}
         continue-on-error: true

.github/workflows/consul-dataplane-checks.yaml

@@ -42,12 +42,7 @@ jobs:
       - uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
       - uses: actions/setup-go@fac708d6674e30b6ba41289acaab6d4b75aa0753 # v4.0.1
         with:
-          # pinning this to 1.20.5 because this issue in go-testcontainers occurs
-          # in 1.20.6 with the error "http: invalid Host header, host port waiting failed"
-          # https://github.com/testcontainers/testcontainers-go/issues/1359
-          # remove setting this when the above issue is fixed so that the job will
-          # just get the go version from .go-version.
-          go-version: 1.20.5
+          go-version: ${{ needs.get-go-version.outputs.go-version }}
       - run: make docker
       #  Currently the server version below is set to 1.15-dev: integration-tests/main_test.go
       - run: echo "VERSION=$(make version)" >> $GITHUB_ENV

Dockerfile

@@ -33,6 +33,7 @@ FROM debian:bullseye-slim AS setcap-envoy-fips-binary
 ARG BIN_NAME=consul-dataplane
 ARG TARGETARCH
 ARG TARGETOS
+ARG GOLANG_VERSION
 
 COPY --from=envoy-fips-binary /usr/local/bin/envoy /usr/local/bin/
 COPY dist/$TARGETOS/$TARGETARCH/$BIN_NAME /usr/local/bin/
@@ -43,7 +44,7 @@ RUN setcap CAP_NET_BIND_SERVICE=+ep /usr/local/bin/$BIN_NAME
 
 # go-discover builds the discover binary (which we don't currently publish
 # either).
-FROM golang:1.20.12-alpine as go-discover
+FROM golang:${GOLANG_VERSION}-alpine as go-discover
 RUN CGO_ENABLED=0 go install github.com/hashicorp/go-discover/cmd/discover@214571b6a5309addf3db7775f4ee8cf4d264fd5f
 
 # Pull in dumb-init from alpine, as our distroless release image doesn't have a

Makefile

@@ -28,7 +28,7 @@ REVISION = $(shell git rev-parse HEAD)
 
 # Docker Stuff.
 export DOCKER_BUILDKIT=1
-BUILD_ARGS = BIN_NAME=$(BIN_NAME) PRODUCT_VERSION=$(VERSION) PRODUCT_REVISION=$(REVISION)
+BUILD_ARGS = BIN_NAME=$(BIN_NAME) PRODUCT_VERSION=$(VERSION) PRODUCT_REVISION=$(REVISION) GOLANG_VERSION=$(GOLANG_VERSION)
 TAG        = $(PRODUCT_NAME):$(VERSION)
 BA_FLAGS   = $(addprefix --build-arg=,$(BUILD_ARGS))
 FLAGS      = --target $(TARGET) --platform $(PLATFORM) --tag $(TAG) $(BA_FLAGS)