ERROR: dockerfile parse error invalid field ' '-CodePudding

I am trying to containerize Go Developer environment. Blogs I am referring: https://www.docker.com/blog/containerize-your-go-developer-environment-part-1/

I am getting an error:

failed to solve with frontend dockerfile.v0: failed to solve with frontend gateway.v0: rpc error: code = Unknown desc = invalid field '' must be a key=value pair Makefile:8: recipe for target 'bin/example' failed make: *** [bin/example] Error 1

My Dockerfile:

# syntax = docker/dockerfile:1-experimental

FROM --platform=${BUILDPLATFORM} golang:1.17.8-alpine AS base
WORKDIR /src
ENV CGO_ENABLED=0
COPY go.* .
RUN --mount=type=cache, target=/go/pkg/mod go mod download

FROM base AS build
ARG TARGETOS
ARG TARGETARCH
RUN --mount=target=. --mount=type=cache, target=/go/pkg/mod --mount=type=cache, target=/root/.cache/go-build GOOS=${TARGETOS} GOARCH=${TARGETARCH} go build -o /out/example .

FROM base AS unit-test
RUN --mount=target=. --mount=type=cache, target=/go/pkg/mod --mount=type=cache, target=/root/.cache/go-build go test -v .

FROM golangci/golangci-lint:v1.43-alpine AS lint-base

FROM base AS lint
RUN --mount=target=. --mount=from=lint-base, src=/usr/bin/golangci-lint, target=/usr/bin/golangci-lint --mount=type=cache, target=/go/pkg/mod --mount=type=cache, target=/root/.cache/go-build --mount=type=cache, target=/root/.cache/golangci-lint golangci-lint run --timeout 10m0s ./...

FROM scratch AS bin-unix
COPY --from=build /out/example /

FROM bin-unix AS bin-linux
FROM bin-unix AS bin-darwin

FROM scratch AS bin-windows
COPY --from=build /out/example /example.exe

FROM bin-${TARGETOS} AS bin

Makefile is as follows:

all: bin/example
test: lint unit-test

PLATFORM=linux/amd64

.PHONY: bin/example
bin/example:
    @docker build . --target bin --output bin/ --platform ${PLATFORM}

.PHONY: unit-test
unit-test:
    @docker build . --target unit-test

.PHONY: lint
lint:
    @docker build . --target lint

In terminal:

atin@atin-VirtualBox:~/Desktop/container-go-dev$ export DOCKER_BUILDKIT=1
atin@atin-VirtualBox:~/Desktop/container-go-dev$ make
[ ] Building 23.2s (5/5) FINISHED                                               
 => [internal] load build definition from Dockerfile                       1.6s
 => => transferring dockerfile: 38B                                        0.4s
 => [internal] load .dockerignore                                          1.3s
 => => transferring context: 34B                                           0.3s
 => resolve image config for docker.io/docker/dockerfile:1-experimental   10.3s
 => [auth] docker/dockerfile:pull token for registry-1.docker.io           0.0s
 => CACHED docker-image://docker.io/docker/dockerfile:1-experimental@sha2  0.0s
failed to solve with frontend dockerfile.v0: failed to solve with frontend gateway.v0: rpc error: code = Unknown desc = failed to create LLB definition: dockerfile parse error line 7: invalid field '' must be a key=value pair
Makefile:8: recipe for target 'bin/example' failed
make: *** [bin/example] Error 1

CodePudding user response：

This is line #7 of your docker file:

RUN --mount=type=cache, target=/go/pkg/mod go mod download

I'm certainly not an expert at dockerfiles but that syntax does not look right to me. I have no idea what program in your image the RUN command is invoking, but I question whether there should be a comma here, and should there be an equals sign between "mount" and "type", or should it be a dash? And, does it even work to pass an option here with "--"?

CodePudding user response：

You have a lot of invalid whitespace throughout your file, including the syntax line up top (likely resulting in it being ignored) and in the --mount options:

RUN --mount=type=cache, target=/go/pkg/mod go mod download

Should be

RUN --mount=type=cache,target=/go/pkg/mod go mod download