Error during downloading metadata for repository appstream

I had installed a minimalist CentOS 8 on one of my servers. Installation went successful, however, when I tried to update the system using yum update I see this error message: Failed to download metadata for repo. Below is the complete error.

[root@autocontroller ~]# yum update
CentOS-8 - AppStream 70 B/s | 38 B 00:00
Error: Failed to download metadata for repo 'AppStream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

Output from the /var/log/dnf.log for more DEBUG information:

2022-02-02T11:39:36Z DEBUG error: Curl error (6): Couldn't resolve host name for http://mirrorlist.centos.org/?release=8&arch=x86_64&repo=AppStream&infra=stock [Could not resolve host: mirrorlist.centos.org] (http://mirrorlist.centos.org/?release=8&arch=x86_64&repo=AppStream&infra=stock).
2022-02-02T11:39:36Z WARNING Errors during downloading metadata for repository 'AppStream':
- Curl error (6): Couldn't resolve host name for http://mirrorlist.centos.org/?release=8&arch=x86_64&repo=AppStream&infra=stock [Could not resolve host: mirrorlist.centos.org]
2022-02-02T11:39:36Z DDEBUG Cleaning up.
2022-02-02T11:39:36Z SUBDEBUG
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/dnf/repo.py", line 573, in load
ret = self._repo.load()
File "/usr/lib64/python3.6/site-packages/libdnf/repo.py", line 394, in load
return _repo.Repo_load(self)
RuntimeError: Failed to download metadata for repo 'AppStream': Cannot prepare internal mirrorlist: Curl error (6): Couldn't resolve host name for http://mirrorlist.centos.org/?release=8&arch=x86_64&repo=AppStream&infra=stock [Could not resolve host: mirrorlist.centos.org]

But, then verified with the internet connection and DNS and it works just fine as below:

[root@autocontroller ~]# ping google.com
PING google.com (172.217.166.206) 56(84) bytes of data.
64 bytes from del03s13-in-f14.1e100.net (172.217.166.206): icmp_seq=1 ttl=115 ti me=43.5 ms
--- google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 43.508/43.508/43.508/0.000 ms

So how did I fix the issue? Here it is.

CentOS Linux 8 had reached the End Of Life (EOL) on December 31st, 2021. It means that CentOS 8 will no longer receive development resources from the official CentOS project. After Dec 31st, 2021, if you need to update your CentOS, you need to change the mirrors to vault.centos.org where they will be archived permanently. Alternatively, you may want to upgrade to CentOS Stream.

Step 1: Go to the /etc/yum.repos.d/ directory.

[root@autocontroller ~]# cd /etc/yum.repos.d/

Step 2: Run the below commands

[root@autocontroller ~]# sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*

[root@autocontroller ~]# sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*

Step 3: Now run the yum update

[root@autocontroller ~]# yum update -y

That’s it!

If you, for one reason or the other, are still actively using CentOS 8, you might probably have encountered the following error when trying to update your system or simply install a package.

“Error: Failed to download metadata for repo ‘appstream’: Cannot prepare internal mirrorlist: No URLs in mirrorlist”

For example, in the screenshot that follows, I was trying to install the fio package and run into it.

What is the Cause of This Error?

You may well be aware that CentOS Linux 8 died a premature death, it reached the End Of Life (EOL) on December 31st, 2021, thus it no longer receives development resources from the official CentOS project.

This means that after Dec 31st, 2021, to update your CentOS installation, you are required to change the mirrors to CentOS Vault Mirror, where they will be archived permanently.

Fix Error: Failed to Download Metadata for Repo ‘AppStream’

To fix the above error, open your terminal or login via ssh, and run the following commands to change the repo URL to point to vault.centos.org, from the official CentOS repos.

Here we use the sed command to edit the required directives or parameters in the repo configuration files:

# sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
# sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*

Alternatively, you can also point to the Cloudflare-based vault repository, by running the following commands:

# sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-Linux-*
# sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.epel.cloud|g' /etc/yum.repos.d/CentOS-Linux-*

Now you should be able to update CentOS or install packages without any error:

If you wish to migrate from CentOS 8 to Rock Linux 8 or AlamLinux 8, check these guides:

• How to Migrate from CentOS 8 to Rocky Linux 8
• How to Migrate from CentOS 8 to AlmaLinux 8.5

That’s all! We hope that this guide helped you fix the above-aforementioned error. Use the comment form below to share feedback with us, you can ask questions as well.

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Если вы столкнулись со следующей ошибкой в CentOS 8 при попытке обновить пакеты с помощью dnf update или yum update в этом руководстве мы исправим эту проблему.

Исправление  в CentOS 8: “Ошибка: Failed to download metadata for repo appstream”

Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

Исправление: Переход на CentOS Stream 8 или альтернативный дистрибутив

Пользователи CentOS переходят на альтернативные дистрибутивы CentOS, потому что CentOS перешла на Stream – дистрибутив Linux, который находится на полпути между разработкой Fedora и разработкой RHEL.

Другие перешли на CentOS Stream 8, чтобы остаться с CentOS.

Оба этих варианта позволят вам обновить CentOS 8, несмотря на то, что вы не можете этого сделать напрямую.

Переход с CentOS 8 на CentOS Stream 8:

dnf --disablerepo '*' --enablerepo=extras swap centos-linux-repos centos-stream-repos

In this article, we’ll get to know, how to fix the error, “Failed to download metadata for repo AppStream” in CentOS 8.
For example, you have installed a minimalist CentOS 8 on one of the servers. The entire process of installation goes smoothly and is successful.

But, while updating the system, using the yum update, you’re likely to get the error message, “Failed to download metadata for repo”

Here is the error you’ll get:

Now the output from the /var/log/dnf.log for more debug information:

If you verify the internet connection and DNS, it works alright as given below:

Now, how to fix this issue? Let’s see in the below steps:

FIXING THE ERROR: FAILED TO DOWNLOAD METADATA FOR REPO

On 31st December 2021, CentOS Linux 9 had reached its End of Life (EOL). This means, it will not receive any development updates from the official CentOS project. Thereafter, 31st December 2021, for updating your CentOS, you will first need to change the mirrors to vault.centos.org. Here they will be archived for all time. Instead, you may also need to upgrade to CentOS stream.

Here are the steps: Step 1:

First go to the /etc/yum.repos.d/ directory.

Step2: Now, run the commands given below:

Step 3: After this, run the yum update:

And that’s all!

By following the above steps, you can easily fix the error, “Failed to Download Metadata for Repo ‘AppStream’.