NATS Go Dockerfile + Go mod workflow

Dockerfile

FROM golang:1.16-alpine AS builder

WORKDIR $GOPATH/src/github.com/nats-io/nats-server

MAINTAINER Waldemar Quevedo <wally@synadia.com>

RUN apk add --update git

COPY . .

RUN CGO_ENABLED=0 GO111MODULE=off go build -v -a -tags netgo -installsuffix netgo -ldflags "-s -w -X github.com/nats-io/nats-server/server.gitCommit=`git rev-parse --short HEAD`" -o /nats-server

FROM alpine:latest

RUN apk add --update ca-certificates && mkdir -p /nats/bin && mkdir /nats/conf

COPY docker/nats-server.conf /nats/conf/nats-server.conf
COPY --from=builder /nats-server /nats/bin/nats-server

# NOTE: For backwards compatibility, we add a symlink to /gnatsd which is
# where the binary from the scratch container image used to be located.
RUN ln -ns /nats/bin/nats-server /bin/nats-server && ln -ns /nats/bin/nats-server /nats-server && ln -ns /nats/bin/nats-server /gnatsd

# Expose client, cluster, monitoring, leafnode, gateway ports
EXPOSE 4222 6222 8222 7422 7522

ENTRYPOINT ["/bin/nats-server"]
CMD ["-c", "/nats/conf/nats-server.conf"]

go-mod.sh

# Start: go.mod does not include test dependencies, only those for binary.

# Create go.sum that does not include test dependencies.
go build -mod=mod -modfile=go.mod

# Updates the vendoring directory:
# 
# - May bring test deps and update both `vendor/modules.txt' and `go.sum'
# 
go mod vendor

# Builds the binary with what is in vendor folder only, not network access required, better for Docker, etc...
go build

# (Implicitly this is what is happening since there is a vendor folder)
go build -mod=vendor -modfile=go.mod

# DEV: Running tests updating dependencies if needed.
go test ./... -mod=mod -modfile go_test.mod -run TestJetStreamPushConsumersPullError -v

# Cleanup entries in go_test.sum
go mod tidy -mod=mod -modfile=go_test.mod

# CI:  Run the tests without modifying deps.
go test ./... -mod=readonly -modfile go_test.mod -v