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replace ip.cn

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Signed-off-by: Kang Huaishuai <khs1994@khs1994.com>
This commit is contained in:
Kang Huaishuai 2020-09-06 17:43:21 +08:00
parent 48785525e0
commit 5d91c5a39f
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2 changed files with 6 additions and 7 deletions
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1
.github/workflows/check-link.yml vendored
View File

@ -59,7 +59,6 @@ jobs:
"x.x.x.x/base",\
"x.x.x.x:9000/minio/",\
"https://www.freedesktop.org/wiki/Software/systemd/",\
"ip.cn",\
"www.aliyun.com" \
--allow-dupe \
--skip-save-results \

12
image/dockerfile/entrypoint.md
View File

@ -21,7 +21,7 @@ FROM ubuntu:18.04
RUN apt-get update \
&& apt-get install -y curl \
&& rm -rf /var/lib/apt/lists/*
CMD [ "curl", "-s", "http://ip.cn" ]
CMD [ "curl", "-s", "http://myip.ipip.net" ]
```
假如我们使用 `docker build -t myip .` 来构建镜像的话，如果我们需要查询当前公网 IP，只需要执行：
@ -38,12 +38,12 @@ $ docker run myip -i
docker: Error response from daemon: invalid header field value "oci runtime error: container_linux.go:247: starting container process caused \"exec: \\\"-i\\\": executable file not found in $PATH\"\n".
```
我们可以看到可执行文件找不到的报错，`executable file not found`。之前我们说过，跟在镜像名后面的是 `command`，运行时会替换 `CMD` 的默认值。因此这里的 `-i` 替换了原来的 `CMD`，而不是添加在原来的 `curl -s http://ip.cn` 后面。而 `-i` 根本不是命令，所以自然找不到。
我们可以看到可执行文件找不到的报错，`executable file not found`。之前我们说过，跟在镜像名后面的是 `command`，运行时会替换 `CMD` 的默认值。因此这里的 `-i` 替换了原来的 `CMD`，而不是添加在原来的 `curl -s http://myip.ipip.net` 后面。而 `-i` 根本不是命令，所以自然找不到。
那么如果我们希望加入 `-i` 这参数，我们就必须重新完整的输入这个命令：
```bash
$ docker run myip curl -s http://ip.cn -i
$ docker run myip curl -s http://myip.ipip.net -i
```
这显然不是很好的解决方案，而使用 `ENTRYPOINT` 就可以解决这个问题。现在我们重新用 `ENTRYPOINT` 来实现这个镜像：
@ -53,7 +53,7 @@ FROM ubuntu:18.04
RUN apt-get update \
&& apt-get install -y curl \
&& rm -rf /var/lib/apt/lists/*
ENTRYPOINT [ "curl", "-s", "http://ip.cn" ]
ENTRYPOINT [ "curl", "-s", "http://myip.ipip.net" ]
```
这次我们再来尝试直接使用 `docker run myip -i`：
@ -109,8 +109,8 @@ CMD [ "redis-server" ]
...
# allow the container to be started with `--user`
if [ "$1" = 'redis-server' -a "$(id -u)" = '0' ]; then
chown -R redis .
exec su-exec redis "$0" "$@"
find . \! -user redis -exec chown redis '{}' +
exec gosu redis "$0" "$@"
fi
exec "$@"