`docker build` 显示 `RUN` 的输出

Question

我有这个Dockerfile，我在其中运行命令RUN，并且我想在运行时查看其输出docker build：

FROM alpine:3.14
COPY . .
RUN echo "here are some numbers: $(seq 10)"

当我运行时docker build .，它不显示上述命令的输出：

[+] Building 2.8s (8/8) FINISHED                                                                                                           
 => [internal] load build definition from Dockerfile                                                                                  0.0s
 => => transferring dockerfile: 36B                                                                                                   0.0s
 => [internal] load .dockerignore                                                                                                     0.0s
 => => transferring context: 2B                                                                                                       0.0s
 => [internal] load metadata for docker.io/library/alpine:3.14                                                                        1.2s
 => [internal] load build context                                                                                                     0.1s
 => => transferring context: 188.24kB                                                                                                 0.1s
 => CACHED [1/3] FROM docker.io/library/alpine:3.14@sha256:234cb88d3020898631af0ccbbcca9a66ae7306ecd30c9720690858c1b007d2a0           0.0s
 => [2/3] COPY . .                                                                                                                    0.4s
 => [3/3] RUN echo "here are some numbers: $(seq 10)"                                                                                 0.2s
 => exporting to image                                                                                                                0.8s
 => => exporting layers                                                                                                               0.8s
 => => writing image sha256:7e0bf9ff04a7b4a3a53395d430ddd950500be9a53733cce22a1da1929cae1a0a                                          0.0s 
                                                                                                                                           
Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them.

我如何查看输出是什么？

码头工人版本：

$ docker --version
Docker version 20.10.6, build 370c289

Answer 1

这就是你要找的吗？

$ docker build --progress=plain .

Sending build context to Docker daemon  4.096kB
Step 1/3 : FROM alpine:3.14
3.14: Pulling from library/alpine
5843afab3874: Pull complete 
Digest: sha256:234cb88d3020898631af0ccbbcca9a66ae7306ecd30c9720690858c1b007d2a0
Status: Downloaded newer image for alpine:3.14
 ---> d4ff818577bc
Step 2/3 : COPY . .
 ---> 106aa79185ae
Step 3/3 : RUN echo "here are some numbers: $(seq 10)"
 ---> Running in 30a81b6d5035
here are some numbers: 1
2
3
4
5
6
7
8
9
10
Removing intermediate container 30a81b6d5035
 ---> 3c059c9b6150
Successfully built 3c059c9b6150

$ docker --version
Docker version 19.03.8, build afacb8b