MongoDB：连接到 MongoDB 的 resolv.conf 的 DNS 问题

我想从 MongoDB Atlas 导出一些数据。

如果我执行下面的命令，它会尝试连接localhost并导出数据。

mongoexport --uri="mongodb+srv://<username>:<password>@name-of-project-x2lpw.mongodb.net/test" --collection users --out /tmp/testusers.json

Note:如果您从 Windows CMD 运行此命令，效果很好 https://stackoverflow.com/a/60214558/3710490

在研究问题并在用户的帮助下，一切似乎都指向 DNS 问题和相关问题resolv.conf file.

低于原版/etc/resolv.conf:

# This file is managed by man:systemd-resolved(8). Do not edit.
#
# This is a dynamic resolv.conf file for connecting local clients to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
#
# Run "systemd-resolve --status" to see details about the uplink DNS servers
# currently in use.
#
# Third party programs must not access this file directly, but only through the
# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.

nameserver 127.0.0.53
options edns0
search name.com

一开始就导致连接失败，如下所示：

但是，如果我根据建议将该地址更改为以下公共可用地址这个帖子 https://stackoverflow.com/questions/55660134/cant-connect-to-mongo-cloud-mongodb-database-in-golang-on-ubuntu to 1.1.1.1连接成功，见下图：

# This file is managed by man:systemd-resolved(8). Do not edit.
#
# This is a dynamic resolv.conf file for connecting local clients to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
#
# Run "systemd-resolve --status" to see details about the uplink DNS servers
# currently in use.
#
# Third party programs must not access this file directly, but only through the
# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.

nameserver 1.1.1.1
options edns0
search name.com

结果连接成功，如下所示：

HOWEVER问题是，而不是显式连接到名称MongoDB集群，它将连接到localhost，这很奇怪，因为我成功地从真实连接中导出了我正在寻找的文件。意思是该机器已正确连接到数据库，但通过localhost.

一切似乎都在引导，也根据这个来源 https://datawookie.netlify.com/blog/2018/10/dns-on-ubuntu-18.04/并且here https://unix.stackexchange.com/questions/174349/what-overwrites-etc-resolv-conf-on-every-boot连接时出现 DNS 问题MongoDB通过终端导出集合。 现在，从最后一篇文章来看，出于多种原因，不建议手动更改此地址，因此在成功导出数据后立即使用DNS 1.1.1.1我把它改回原来的样子DNS 127.0.0.53。 但是，我认为这不应该是正确的行为，因为每次我需要导出数据时，我都必须不断地手动更改此地址。

这种奇怪行为的原因可能是什么？那么，如果不手动切换 DNS 地址，什么是长期解决方案呢？

感谢您为解决此问题指出了正确的方向。

看来您已经在您提到的链接中找到了答案。我会总结一下： https://unix.stackexchange.com/questions/174349/what-overwrites-etc-resolv-conf-on-every-boot

安装resolvconf（对于Ubuntuapt install resolvconf），添加行nameserver 8.8.8.8 to /etc/resolvconf/resolv.conf.d/base，然后运行sudo resolvconf -u并且可以肯定的是service resolvconf restart。 验证运行systemd-resolve --status.

您应该在第一行看到您的 DNS 服务器，如下所示：

         DNS Servers: 8.8.8.8
          DNS Domain: sa-east-1.compute.internal
          DNSSEC NTA: 10.in-addr.arpa
                      16.172.in-addr.arpa

此解决方案在重新启动之间仍然存在。