Statically built Client Library sample does not work when containerized

[DazWilkin]

Perplexed but anxious that this is a trivial or obvious solution. The working Docker container (#3) is 1GB and expensive to move around. If it worked, it would be more convenient, to use Docker container (#2) as this is only 12MB.

1. Statically built sample -- works
2. Containerize getting-started/bookshelf: use MDL UI library #1 -- doesn't work (but only 11.9MB) -- blocks (indefinitely)
3. Containerize using golang|go-wrapper -- works (but 1.02GB!)

Took this Golang sample:
https://github.com/GoogleCloudPlatform/golang-samples/blob/master/pubsub/pubsub_quickstart/main.go
https://cloud.google.com/pubsub/docs/reference/libraries

Extended it trivially to (a) reference environment variables; (b) publish a message too:
https://gist.github.com/DazWilkin/bd8300af9f3f9be0954573304775639b

1. Static build no container

CGO_ENABLED=0 \
GOOS=linux \
GOARCH=amd64 \
go build -ldflags '-extldflags "-static"' -o pubsub pubsub.go

Then:

PROJECT_ID=${PROJECT} \
PUBSUB_TOPIC=${PUB} \
GOOGLE_APPLICATION_CREDENTIALS=./key.json \
./pubsub

and:

2017/11/26 11:45:25 Topic '${PUB}' exists no need to recreate
2017/11/26 11:45:26 Message ID: 175704661496913

2. Containerize it

Dockerfile.scratch

FROM scratch
ADD pubsub /
ENTRYPOINT ["/pubsub"]

and:

docker build \
--tag=${IMAGE}:${TAG} \
--file=Dockerfile.scratch \
.

docker run \
--interactive \
--tty \
--rm \
--env=PROJECT_ID=$PROJECT \
--env=PUBSUB_TOPIC=$PUB \
--env=GOOGLE_APPLICATION_CREDENTIALS=/config/key.json \
--volume=$PWD:/config \
$IMAGE:$TAG

and appears to just block indefinitely on pubsub.NewClient(...)

3. Containerize using golang|go-wrapper

Dockerfile.golang

FROM golang:1.9

WORKDIR /go/src/app
COPY . .

RUN go-wrapper download   # "go get -d -v ./..."
RUN go-wrapper install    # "go install -v ./..."

CMD ["go-wrapper", "run"] # ["app"]

and build using the above and same run:

docker build \
--tag=${IMAGE}:${TAG} \
--file=Dockerfile.golang \
.

docker run \
--interactive \
--tty \
--rm \
--env=PROJECT_ID=$PROJECT \
--env=PUBSUB_TOPIC=$PUB \
--env=GOOGLE_APPLICATION_CREDENTIALS=/config/key.json \
--volume=$PWD:/config \
$IMAGE:$TAG

Generates:

+ exec app
2017/11/26 19:53:19 Topic $PUB' exists no need to recreate
2017/11/26 19:53:19 Message ID: 175706135054686

[DazWilkin]

My colleague pointed me to Distroless.

I'm going to try that out as it appears to be my solution.

https://github.com/GoogleCloudPlatform/distroless

[DazWilkin]

Distroless worked!

Dockerfile.distroless

FROM golang:1.8 as build

WORKDIR /go/src/app
COPY pubsub.go .

RUN go-wrapper download   # "go get -d -v ./..."
RUN go-wrapper install

FROM gcr.io/distroless/base
COPY --from=build /go/bin/app /
CMD ["/app"]

build and run as before:

2017/11/27 17:32:06 Topic '$PUB' exists no need to recreate
2017/11/27 17:32:06 Message ID: 175919015426938