I am using Amazon's tutorial for installing a LAMP server. The first several instructions involve using yum, but every single way I have tried to do it has resulted in the same message. I have found a few other recent questions about the same issue, none of which change anything on my setup.
Here is the message:
Loaded plugins: priorities, update-motd, upgrade-helper
Could not retrieve mirrorlist http://repo.us-east-1.amazonaws.com/latest/main/mirror.list error was
12: Timeout on http://repo.us-east-1.amazonaws.com/latest/main/mirror.list: (28, 'Connection timed out after 10001 milliseconds')
One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:
1. Contact the upstream for the repository and get them to fix the problem.
2. Reconfigure the baseurl/etc. for the repository, to point to a working
upstream. This is most often useful if you are using a newer
distribution release than is supported by the repository (and the
packages for the previous distribution release still work).
3. Disable the repository, so yum won't use it by default. Yum will then
just ignore the repository until you permanently enable it again or use
--enablerepo for temporary usage:
yum-config-manager --disable <repoid>
4. Configure the failing repository to be skipped, if it is unavailable.
Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much
slower). If it is a very temporary problem though, this is often a nice
compromise:
yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true
Cannot find a valid baseurl for repo: amzn-main/latest
I have done this same thing before without running into any problems, using the same tutorial, but it was several months ago. I don't know what has changed but my meager experience is keeping me from figuring it out.
Looks like the host is having trouble contacting the yum server. Make sure the instance has outbound internet access (check security groups etc). If the instance is in a VPC and the security groups look good you may need to use a nat appliance or attach an elastic IP.
Good luck-
If you have an S3 endpoint on your VPC then this will cause yum to fail as repo file is stored in S3. To fix this add the following policy to S3 VPC endpoint:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": "*",
"Action": "*",
"Resource": [
"arn:aws:s3:::repo.eu-west-1.amazonaws.com",
"arn:aws:s3:::repo.eu-west-1.amazonaws.com/*"
]
}
]
}
Replace eu-west-1 with the relevant region code that your S3 endpoint is in.
A lot of first time users of Amazon EC2 run into this issue. In my experience, it's usually the result of not setting the allowed outgoing connections on their instance's security group. The tutorial that Amazon has for configuring Amazon Linux instances only mentions setting the Incoming connections so it's easy to forget that you never set the allowed outgoing ones. Simply allowing HTTP and HTTPS requests to any IP Address should fix the issue.
I have the same problem and was related to name resolution. I used the following to correct:
EC2 instance has no public DNS
This is the good explanation from Mat:
Go to console.aws.amazon.com
Go To Services -> VPC
Open Your VPCs
select your VPC connected to your EC2 and
Edit Summary ---> Change DNS hostnames: to YES
If you're using NACL on the subnet were the EC2 is located.
Quick fix
You will have to open inbound Ephemeral ports for this yum update.
For example adding the #100 inbound rule below:
Notice that this is still necessary even if the outbound rules allow all traffic:
Why did have to do this?
When yum opens an outbound connection on ports like 80/443 it comes back at a random high port (Ephemeral port).
Network ACLs are stateless (not like Security groups) and will not allow returned connection on the same port by default.
You can read more in here.
Check if your outbound entries are deleted/modified from assigned Security group. Normally Outbound entries are set to "All traffic" and allow any IP.
In my case, outbound was deleted. I again set to "All traffic" and it works.
just assign the default security group along with the one you may have created. This solved my problem. ;)
I had the same problem and the way I solved it, was by allowing inbound traffic for the HTTPS protocol port 443 on the security group of your NAT instance. Most of the repositories use HTTPS protocol. Make sure you haven't missed this.
I had the same problem, turns out another sysadmin decided to route outbound internet traffic through a proxy. I found this by noticing some wearied proxy env settings, dug a little deeper, and then noticed an entry in my /etc/yum.conf file.
Commented out the proxy= line and all worked again.
[main]
cachedir=/var/cache/yum/$basearch/$releasever
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
exactarch=1
obsoletes=1
gpgcheck=1
plugins=1
installonly_limit=5
bugtracker_url=http://bugs.centos.org/set_project.php?project_id=23&ref=http://bugs.centos.org/bug_report_page.php?category=yum
distroverpkg=centos-release
#proxy=http://pos-proxy-in-my-way-of-doing-actual-real-work:666
With chadneal's comment.
It is necessary to set the DNS Resolution to Yes.
Go to console.aws.amazon.com
Go To Services -> VPC
Open Your VPCs
Select your VPC connected to your EC2
Click Edit DNS Resolution and set it Yes
I was getting the same exact error message for yum as described in the question. In my case I had a NACL that allowed all outgoing traffic but restricted incoming traffic to HTTP/HTTPS, SSH and All ICMP. Since NACLS are stateless attempting to run yum failed as incoming ephemeral connections that yum uses were not explicitly allowed and were therefore dropped.
Loaded plugins: priorities, update-motd, upgrade-helper
Could not retrieve mirrorlist http://repo.us-east-1.amazonaws.com/latest/main/mirror.list error was
12: Timeout on http://repo.us-east-1.amazonaws.com/latest/main/mirror.list: (28, 'Connection timed out after 10001 milliseconds')
One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:
Contact the upstream for the repository and get them to fix the problem.
Reconfigure the baseurl/etc. for the repository, to point to a working
upstream. This is most often useful if you are using a newer
distribution release than is supported by the repository (and the
packages for the previous distribution release still work).
Disable the repository, so yum won't use it by default. Yum will then
just ignore the repository until you permanently enable it again or use
--enablerepo for temporary usage:
yum-config-manager --disable <repoid>
Configure the failing repository to be skipped, if it is unavailable.
Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much
slower). If it is a very temporary problem though, this is often a nice
compromise:
yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true
Cannot find a valid baseurl for repo: amzn-main/latest
Same error I was also having from last week tried almost everything but not able to install server and start httpd service.
Resolved it by just allowing all traffic IN/OUT to and From Security Group and NACL... try it it will be resolved defiantly.
Check internet connectivity on your EC2 instance by pinging
ping google.com
You will get response by if you have working internet there.
If not then go to etc/resolv.conf file and add below lines in that file:
nameserver 8.8.8.8
nameserver 1.1.1.1
nameserver 1.0.0.1
Now check if internet is working.
If yes, you can easily resume you work!!!!
Also, if you are unable to get any DNS working, check your DHCP options set. I had left an old one in place, and when I cleaned up a project involving active directory integrations, it broke. The answer is simply to change back to the original/saved options.
The problem can occur at both levels Security Groups and NACLs. In my case, I figured out that even after modifying the security group, the update failed. However, when the NACLs were modified.. the update was successful
I ran the following command with sudo (can't do yum alone if you're not root) and it fixed the issue.
yum-config-manager --save --setopt=dev.mysql.com_downloads_repo_yum_.skip_if_unavailable=true
I had the same problem. In my case, I mistakenly deleted the outbound rules of my security group. Adding outbound rule to allow all traffic solved the problem.
please follow the below step
Step 1 : go to AWS-VPC
Step 2 : find DHCP option
Step 3 : if you dont have any DHCP options create a new DHCP
Step 4 : add domaine name = ap-south-1.compute.internal (if your using other region please use other regionname)
Step 5 : add domain name server = AmazonProvidedDNS
Step 6 : then select your VPC --> actions -->edit your DHCP option set --> Select DHCP set which you just created --> Save
Step 7 : Then Reboot your Instance
Step 8 : Login Your Instance then Just type yum list installed --> It will defiantly give you the list of installed things
Thank you
don't worry this is simple error.
this is not connect internet also.
just to create new file with vi editor:
vi /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4
and then type this to quit vi:
:wq
I am using the default VPC and DNS host resolution is enabled by default; wasn't my issue. I followed the advice to add the default security group and that resolved my issue.
ACL in your vpc differs from the instances inbound or outbound rules. I see the vpc's acl get people every day multiple times.
check for private hosted zone such as "eu-west-1.s3.eu-west-1.amazonaws.com" and make sure the EC2 has internet , for instance if your EC2 instance is in a private subnet you need to make sure your routes point to a nat gateway or instance.
for me these helped, check
NACL
Security Groups
Routing table
this problem is usually caused by not being able to connect to the internet.
Do the following basic test: ping google.com (ping google), if the answer is no, if you are not pinging it is simple, your server is not connecting to the internet.
To solve this, edit the resolv.conf (nano /etc/resolv.conf) when you open the file you will see that it is empty, in my case here I wrote these lines here:
; generated by /usr/sbin/dhclient-script
search ec2.internal
timeout options:2 attempts:5
name server 172.31.0.2
Do this on yours, save the file, and test the ping again on google.com, if it responds normally, you can run yum update -y and it will work.
Hope this helps.
In my case I followed this troubleshooting (https://aws.amazon.com/premiumsupport/knowledge-center/ec2-troubleshoot-yum-errors-al1-al2/) and the file /etc/yum/vars/awsregion had invalid content. After set the correct region, yum worked fine.
I experienced the very same issue but the problem was not my Security Group or NACL.
Background:
I added a domain name via Route53.
The domain name continues to be hosted with DiscountASP.net.
The VPC was created manually (no wizard or default).
I created a DHCP Option Set with my domain name and the 4 servers IP addresses given to me by Route53.
Analysis:
First, I needed to prove that the problem was not the Security Group or the NACL.
I did this by attatching the default DHCP Option Set to my new VPC. It worked!
I could do the yum update and "curl http://www.google.com". No problem.
I then created a new DHCP Option Set using my domain name and the Google DNS Servers.
8.8.8.8 & 8.8.4.4
This also worked.
I then took 1 of the 4 DNS Servers IPs provided by Route 53 and used it with my domain name in a new DHCP Option Set.
I ran a test and it failed. I repeated the same test with 2 of the remaining 4 DNS Servers IPs, creating two separate DHCP Option Sets.
I ran tests and they both failed.
After checking the spelling of my domain name I could only conclude that the problem was the domain name servers.
Solution:
Amazon Virtual Private Cloud User Guide (PDF page 222)
Amazon DNS Server (Sub topic)
"When you create a VPC, we automatically create a set of DHCP options and associate them with the VPC. This set includes two options: domain-name-servers = AmazonProvidedDNS, and domain-name=domainname-for-your-region. AmazonProvidedDNS is an Amazon DNS server, and this option enables DNS
for instances that need to communicate over the VPC's Internet gateway. The string AmazonProvidedDNS maps to a DNS server running on a reserved IP address at the base of the VPC IPv4 network range, plus two. For example, the DNS Server on a 10.0.0.0/16 network is located at 10.0.0.2."
From page 221:
DHCP: domain-name-servers
Option Name Description
"The IP addresses of up to four domain name servers, or AmazonProvidedDNS. The default DHCP option set specifies AmazonProvidedDNS. If specifying more than one domain name server, separate them with commas."
The IP addresses that its referring to are for external domain name servers (excluding the possibility you have created a custom DNS).
So I created my final DHCP Option Set using my domain name and domain-name-servers=AmazonProvidedDNS. It worked!
By the way the VPC DNS Resolution = yes & DNS Hostname = no.
Go to the security group for which EC2 is configured.
And verify the below fields in its Inbound rules.If these below fields are not there then add it by clicking on button Edit inbound rules.
Type-: All traffic
Protocol-: All
Port range-: All
Destination-: 0.0.0.0/0
Hope this would resolve the issue.
Hay! Here is perfect answer i found
go to outbound rules add
All Traffic
That's it
Related
I have a site built on NodeJS, which I am currently trying to deploy on the free tier on AWS.
So far I have created an instance, launched it, I can connect via SSH (console) to my instance, and have successfully pulled my files from my Git repository. However, when I try to browse my public DNS, I get: http://ec2-13-234-136-30.ap-south-1.compute.amazonaws.com:2222 took too long to respond.
I have also had a look at the settings on security group (as recommended on a different post) and ensured that inbound and outbound 'HTTP' and 'HTTPS' traffic are allowed (screenshot below):
Inbound settings: Inbound settings
Outbound settings: enter image description here
Any ideas on what else could be causing this issue? I would greatly appreciate your help. Thanks.
Your security configuration is too permissive, please limit to the port and protocols you are using.
Given that your firewall is off, which you should definitely check to confirm,
I guess you start NodeJs server binding to hostname 127.0.0.1, which allows only local traffics from EC2 instance.
Try changing it to 0.0.0.0, which allows public traffic and see if that solves your problem.
I have been looking for help with this problem, and the answers just say to add inbound rules to the security group. Well, I have done those and I am still unable to access my website from the public DNS (just putting that into the url box and navigating to it). There are multiple port 22 inbound rules for the people accessing my server, and the outbound rule is just "All traffic".
I've had this problem running Wordpress on EC2 instances. Things I'd try:
Access the instance via ssh. Check out https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AccessingInstancesLinux.html
If you're accessing through ssh, maybe it's because your disk is full. To check this you can run df -h on your Amazon EC2 server.
I tried accessing my newly setup AWS EC2 Instance and I had this same issue, I later realised I was accessing the public DNS via HTTPS which had not been set up. when I changed the url to use HTTP it worked. Ensure to configure HTTP in the security group.
When I try to update EC2 Amazon Linux instance, I get following error:
Loaded plugins: extras_suggestions, langpacks, priorities, update-motd
Could not retrieve mirrorlist http://amazonlinux.ap-south-1.amazonaws.com/2/core /latest/x86_64/mirror.list error was
12: Timeout on http://amazonlinux.ap-south-1.amazonaws.com/2/core/latest/x86_64/ mirror.list: (28, 'Connection timed out after 5000 milliseconds')
One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:
1. Contact the upstream for the repository and get them to fix the problem.
2. Reconfigure the baseurl/etc. for the repository, to point to a working
upstream. This is most often useful if you are using a newer
distribution release than is supported by the repository (and the
packages for the previous distribution release still work).
3. Run the command with the repository temporarily disabled
yum --disablerepo=<repoid> ...
4. Disable the repository permanently, so yum won't use it by default. Yum
will then just ignore the repository until you permanently enable it
again or use --enablerepo for temporary usage:
yum-config-manager --disable <repoid>
or
subscription-manager repos --disable=<repoid>
5. Configure the failing repository to be skipped, if it is unavailable.
Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much
slower). If it is a very temporary problem though, this is often a nice
compromise:
yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true
Cannot find a valid baseurl for repo: amzn2-core/2/x86_64
Any help would be much appreciated.
Your instance does not have access to internet.
You can resolve this in following ways:
If your instance is running in a public subnet make sure it has a public ip attached. Also check if the route table for the public subnet is associated with this subnet and has a route 0.0.0.0/0 pointing to internet gateway.
If you are running your instance in private make sure you have created the NAT Gateway in a public subnet. Check the route table has a route 0.0.0.0/0 pointing to NAT and the subnet is associated with the private route table.
Check if the security group associated with instance has outbound traffic enabled.
You are probably in a private subnet (ie a subnet without a 0.0.0.0/0 route to the outside world).
If you want to connect to the outside world, you need a NAT gatway in a public subnet, which has a route to an Internet Gateway.
EC2 -> NAT -> IGW
This is the best AWS troubleshooting page I've found (early 2021)
If you don't want to connect to the outside world, you need a VPC endpoint which allows connectivity to specific AWS services from a private subnet. I have never got this to work.
Verify that the security group attached to the instance is allowing all inbound and outbound connections.
I don't know what specific network protocol is needed for these updates, but public SSH, HTTP, and HTTPS weren't enough for me. So I simply allowed all traffic for a brief time to run the updates.
(I'm guessing it might have simply needed an FTP port open, but I didn't experiment long enough to find out. Feel free to edit this answer if you know specifically which ports are needed for yum updates on EC2 instances.)
If you have an S3 endpoint on your subnet route table then this will cause yum to fail. To fix this please try to add the following policy to the S3 endpoint:
{
"Statement": [
{
"Sid": "Amazon Linux AMI Repository Access",
"Principal": "*",
"Action": [
"s3:GetObject"
],
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::packages.*.amazonaws.com/*",
"arn:aws:s3:::repo.*.amazonaws.com/*"
]
}
]
}
I am trying to install docker on my EC2 instance in private subnet which I have SSH using Jumpbox. I even tried to allow ALL TRAFFIC in my security group, but still didnot happen.
sudo yum update -y
Loaded plugins: priorities, update-motd, upgrade-helper
Could not retrieve mirrorlist http://repo.us-west-1.amazonaws.com/latest/main/mirror.list error was
12: Timeout on http://repo.us-west-1.amazonaws.com/latest/main/mirror.list: (28, 'Connection timed out after 5001 milliseconds')
One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:
1. Contact the upstream for the repository and get them to fix the problem.
2. Reconfigure the baseurl/etc. for the repository, to point to a working
upstream. This is most often useful if you are using a newer
distribution release than is supported by the repository (and the
packages for the previous distribution release still work).
3. Disable the repository, so yum won't use it by default. Yum will then
just ignore the repository until you permanently enable it again or use
--enablerepo for temporary usage:
yum-config-manager --disable <repoid>
4. Configure the failing repository to be skipped, if it is unavailable.
Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much
slower). If it is a very temporary problem though, this is often a nice
compromise:
yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true
Cannot find a valid baseurl for repo: amzn-main/latest
An Amazon EC2 instance in a private subnet cannot directly communicate with the Internet. This is intentional, since it is a private subnet.
To allow such connectivity:
Create a NAT Gateway in a public subnet in the same VPC
Modify the Route Table for the private subnet to direct traffic destination 0.0.0.0/0 to the NAT Gateway
When the EC2 instance tries to access the Internet, its request will be sent to the NAT Gateway. The NAT Gateway will make the request on behalf of the instance and will send the response back to the instance. This allows outbound connectivity to the Internet while protecting the instance from inbound connectivity.
It is not strictly necessary to use private subnets. Security Groups can perform a similar function at the instance level rather than at the subnet level.
In this situation, when EC2 is inside VPC and we want to allow EC2 to connect outside world through internet. We need to add outbound rules to EC2.
For eg, I wanted to download Docker on EC2 from amazom repository. I have added HTTP rules in below snapshot
So, I've been working locally in a vagrant ubuntu box for the past month: I've spent a lot of time working on customizing it and installing exactly all the software I want on it. I started all of this through the normal vagrant tutorial (aka, nothing special). I packaged my local vagrant box into a package.box file. Now, I want to move my development environment (e.g. package.box file) to an Amazon EC2 instance on AWS. I know I'm not supposed to ask for software recommendations, but my question is basically: is this possible to do and, if it is, could you point me to some examples of people doing it? I've read that packer might be an option, but it looks to me (a very inexperienced perspective) that maybe I should have started with that instead of trying to use it now. Any help would be appreciated - I don't want to spend a couple weeks setting up a new environment when I have one locally set up.
Edit:
Progress! I followed #error2007s link and followed the tutorial. I'm at the point where I've uploaded the VMDK image to s3 and provisioned an instance using it (all done automatically with the ec2-import-instance command on the CLI). However, I don't see a Public IP to access the new instance after I start it up.
I think this is related to cloud-init somehow, but I'm not sure what that is really. I tried it with both the /etc/cloud/cloud.cfg file that came with the box as well as the one listed here and neither of the two boxes I uploaded gave me a Public IP to access.
Edit 2:
Here are some things I see in the Console (They all seem right to me, but a more experienced eye might see something wrong):
subnet info:
Auto-assign Public IP: yes
Network ACL:
VPC info:
DNS resolution: yes
DNS hostnames: yes
ClassicLink DNS Support: no
VPC CIDR: 172.31.0.0/16
DHCP Option Set:
Options: domain-name = ec2.internal domain-name-servers = AmazonProvidedDNS
From my perspective, those all look right, or am I missing something?
I assigned an Elastic IP per these instructions, but when I ssh ec2-user#<elastic-ip>, it says ssh: connect to host <elastic-ip> port 22: Connection refused. The security group assigned to the instance is set to allow all protocols on all ports. Also, this is the first time I encounter a Elastic IP and I'm unsure what exactly it is doing.
Amazon enables you to transfer your Vm to AWS as a EC2 instance. Check this tutorial this is more simple.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/UsingVirtualMachinesinAmazonEC2.html
You want to use the Vagrant AWS provider found here:
https://github.com/mitchellh/vagrant-aws
This is a Vagrant 1.2+ plugin that adds an AWS provider to Vagrant,
allowing Vagrant to control and provision machines in EC2 and VPC.
This will allow you to provision your AWS instances using Vagrant, allowing you to migrate the same local development environment to an AWS EC2 instance.
There is a good tutorial here:
https://nurmrony.wordpress.com/2015/03/15/vagrant-deploy-and-provisioning-an-amazon-ec2-instance/
Hi I have found these articles but I have not yet tested them myself. Im still in the middle of organizing my personal notes and identifying my technology stack. I intend to have a Homestead vagrant box be replicated as an EC2 instance, so I wont have to configure the instance(s) manually.
https://nurmrony.wordpress.com/2015/03/15/vagrant-deploy-and-provisioning-an-amazon-ec2-instance/
https://www.tothenew.com/blog/using-vagrant-to-deploy-aws-ec2-instances/
https://foxutech.com/how-to-deploy-on-amazon-ec2-with-vagrant/
https://blog.scottlowe.org/2016/09/15/using-vagrant-with-aws/
https://devops.com/devops-primer-using-vagrant-with-aws/
I find their approaches similar. The only thing that I am worried at is the "vagrant add box" part.
I asked myselft, what if I had to do this setup again for familiarization purposes, what will happen since I already added a vagrant box (the dummy one, as instructed in the tutorials) previously.