php copy 找不到文件,docker 为什么找不到 copy 的文件？

dockerfile 中有一句：

COPY supervisord.conf /etc/supervisord.conf

构建成功，但是进入容器却找不到这个文件，为什么？

另外，这个容器为什么不能用 docker-compose exec php-worker bash 进入，而要用 docker-compose exec php-worker sh？

完整的 dockerfile 如下：

#

#--------------------------------------------------------------------------

# Image Setup

#--------------------------------------------------------------------------

#

FROM php:7.1-alpine

MAINTAINER Mahmoud Zalt

RUN apk --update add wget \

curl \

git \

build-base \

libmemcached-dev \

libmcrypt-dev \

libxml2-dev \

zlib-dev \

autoconf \

cyrus-sasl-dev \

libgsasl-dev \

supervisor

RUN docker-php-ext-install mysqli mbstring pdo pdo_mysql mcrypt tokenizer xml

RUN pecl channel-update pecl.php.net && pecl install memcached-3.0.4 && docker-php-ext-enable memcached

# Install PostgreSQL drivers:

ARG INSTALL_PGSQL=false

RUN if [ ${INSTALL_PGSQL} = true ]; then \

apk --update add postgresql-dev \

&& docker-php-ext-install pdo_pgsql \

;fi

RUN rm /var/cache/apk/* \

&& mkdir -p /var/www

#

#--------------------------------------------------------------------------

# Optional Supervisord Configuration

#--------------------------------------------------------------------------

#

# Modify the ./supervisor.conf file to match your App's requirements.

# Make sure you rebuild your container with every change.

#

COPY supervisord.conf /etc/supervisord.conf

ENTRYPOINT ["/usr/bin/supervisord", "-n", "-c", "/etc/supervisord.conf"]

#

#--------------------------------------------------------------------------

# Optional Software's Installation

#--------------------------------------------------------------------------

#

# If you need to modify this image, feel free to do it right here.

#

# -- Your awesome modifications go here -- #

#

#--------------------------------------------------------------------------

# Final Touch

#--------------------------------------------------------------------------

#

WORKDIR /etc/supervisor/conf.d/