docker : ERROR: unsatisfiable constraints

Question

我正在尝试从 https://docs.docker.com/compose/gettingstarted/ 构建 docker 镜像示例。我收到了这个错误

Building web
Step 1/9 : FROM python:3.7-alpine
 ---> e854017db514
Step 2/9 : WORKDIR /code
 ---> Using cache
 ---> e15b6e62d8af
Step 3/9 : ENV FLASK_APP app.py
 ---> Using cache
 ---> 759c4bc8b254
Step 4/9 : ENV FLASK_RUN_HOST 0.0.0.0
 ---> Using cache
 ---> 6d40793f3089
Step 5/9 : RUN apk add --no-cache gcc musl-dev linux-headers
 ---> Running in 5e40bd670f1b
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz
WARNING: Ignoring http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz: Permission denied
WARNING: Ignoring http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz: Permission denied
ERROR: unsatisfiable constraints:
  gcc (missing):
    required by: world[gcc]
  linux-headers (missing):
    required by: world[linux-headers]
  musl-dev (missing):
    required by: world[musl-dev]
ERROR: Service 'web' failed to build: The command '/bin/sh -c apk add --no-cache gcc musl-dev linux-headers' returned a non-zero code: 3

这是我的 Dockfile

FROM python:3.7-alpine
WORKDIR /code
ENV FLASK_APP app.py
ENV FLASK_RUN_HOST 0.0.0.0
RUN apk add --no-cache gcc musl-dev linux-headers
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY . .
CMD ["flask", "run"]

有人可以帮我解决这个错误吗？谢谢大家!!!

Answer 1

您想要安装的软件包是否已移至其他注册表？

有时，正在安装的软件包是从不同的注册表分支移动的。默认的 Docker Alpine 镜像仅设置了某些注册表。添加额外的注册表可以扩展您的安装选项 (YMMV)；我无法谈论与不同注册表分支相关的稳定性、安全性和/或风险。 This thread helped me.

失败的尝试和错误消息:

❯ docker run -it alpine sh                                                                                                                                                                 
/ # apk update
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz
v3.12.0-175-g8b3334c57c [http://dl-cdn.alpinelinux.org/alpine/v3.12/main]
v3.12.0-178-gb27c83e867 [http://dl-cdn.alpinelinux.org/alpine/v3.12/community]
OK: 12749 distinct packages available
/ # apk add cowsay
ERROR: unsatisfiable constraints:
  cowsay (missing):
    required by: world[cowsay]
/ # 

1. 我们从输出中得到的第一条线索

ERROR: unsatisfiable constraints:
       cowsay (missing):
       required by: world[cowsay]

输出中的第二条线索

日志前面

fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz

解决方案

在 DuckDuckGo 上搜索 package <package name>

• 引导我访问 URL:https://pkgs.org/download/cowsay

我使用哪种类型的内存？

• 答案可以在线索#2中找到。x86_64

在包页面上选择正确的链接。所以就我而言:

• Alpine 测试 x86_64 > cowsay-3.04-r0.apk

阅读该页面上的信息，我发现在下载下，该软件包的二进制文件目前位于

• http://dl-cdn.alpinelinux.org/alpine/edge/testing/x86_64/cowsay-3.04-r0.apk

将其与线索 #2 进行比较，我发现 alpine 容器没有使用我想要安装的二进制文件引用注册表。

成功 & TL;DR;

通过向 docker alpine 容器添加额外的注册表，将以前未找到的包添加到 alpine。

我将添加查找我想要安装的软件包所需的注册表(步骤#3)。在下面的代码块中，可以看到第三个注册表与第 3 部分中完成的研究中的 URL 的初始部分相匹配。我不想替换现有的注册表(线索#2)，所以我再次设置了它们。我不知道这是否有必要，但我还是这么做了。

$ docker run -it alpine sh
/# apk update && apk add cowsay \
        --update-cache \
        --repository https://alpine.global.ssl.fastly.net/alpine/edge/community \
        --repository https://alpine.global.ssl.fastly.net/alpine/edge/main \
        --repository https://dl-3.alpinelinux.org/alpine/edge/testing
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz
v3.12.0-175-g8b3334c57c [http://dl-cdn.alpinelinux.org/alpine/v3.12/main]
v3.12.0-178-gb27c83e867 [http://dl-cdn.alpinelinux.org/alpine/v3.12/community]
OK: 12749 distinct packages available
fetch https://dl-3.alpinelinux.org/alpine/edge/testing/x86_64/APKINDEX.tar.gz
fetch https://alpine.global.ssl.fastly.net/alpine/edge/main/x86_64/APKINDEX.tar.gz
fetch https://alpine.global.ssl.fastly.net/alpine/edge/community/x86_64/APKINDEX.tar.gz
(1/3) Installing libbz2 (1.0.8-r1)
(2/3) Installing perl (5.30.3-r2)
(3/3) Installing cowsay (3.04-r0)
Executing busybox-1.31.1-r16.trigger
OK: 43 MiB in 17 packages
/ #

Dockerfile 示例

FROM alpine
RUN apk update && apk add cowsay \
        --update-cache \
        --repository https://alpine.global.ssl.fastly.net/alpine/edge/community \
        --repository https://alpine.global.ssl.fastly.net/alpine/edge/main \
        --repository https://dl-3.alpinelinux.org/alpine/edge/testing
CMD ["cowsay", "hi stackoverflow"]

构建此文件后:

 ❯ docker run cowsay                                                                                                                                                                        [13:13:45]
 __________________ 
< hi stackoverflow >
 ------------------ 
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||