Docker - 高山映像上的 WORKDIR 问题（多阶段构建）

Question

我的 Dockerfile 有第二阶段：

############################################ MULTI STAGE BUILD PART 2 ##############################################

# Start from alpine image
FROM alpine

# Creating work directory
WORKDIR /service

# Copy the certificats and executable into new Docker image
COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
COPY --from=builder /service/main /service/
COPY --from=builder /service/.credentials /service/.credentials/

# Expose port
EXPOSE ${GRPC_PORT}
EXPOSE ${REST_PORT}

## Get required ARGs and put them into ENVs variables
ARG ENVIRONMENT
ARG NAMESPACE
ARG GRPC_PORT
ARG REST_PORT
ENV _ENVIRONMENT=${ENVIRONMENT}
ENV _NAMESPACE=${NAMESPACE}
ENV _GRPC_PORT=${GRPC_PORT}
ENV _REST_PORT=${REST_PORT}

### HERE YOU CAN TEST WITH ANY OF THE FOLLOWING ENTRYPOINT

# The One I need
ENTRYPOINT /main "ENVIRONMENT=${_ENVIRONMENT}" "NAMESPACE=${_NAMESPACE}" "GRPC_PORT=${_GRPC_PORT}" "REST_PORT=${_REST_PORT}"

# This one isn't able to resolve ENVs variables, but I use it as an example for my ISSUE
ENTRYPOINT [ "/main" ]

如您所见，WORKDIR 设置为 /service

但是，如果您使用第一个入口点运行映像，您会得到：

/bin/sh: /main: not found

如果你使用第二个入口点运行，你会得到：

docker: Error response from daemon: OCI runtime create failed: container_linux.go:346: starting container process caused "exec: \"/main\": stat /main: no such file or directory": unknown.

注意：另一个有趣的地方是 COPY --from=builder ... 我需要将 dest 设置为 /service/ 否则我的文件会被复制进去/ 目录

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根据documentation：

WORKDIR 指令为任何 RUN、CMD、 ENTRYPOINT、COPY 和 ADD 指令在 Dockerfile。

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有什么想法吗？真的与我或 Docker/alpine 有关吗？

Answer 1

Entrypoint 必须是 ./main。

/main 是一个绝对路径，它将引用您根目录上的主目录。

因为你在/service，你需要一个相对路径。你想要./main，它指向/service/main。