Can't SSH into Google Cloud VM - google-cloud-platform

I was able to successfully SSH into the Google Cloud VM I had set up yesterday, but today for some reason I can't, and I didn't mess with any of the settings, especially not the Firewall settings. It keeps giving me these errors now:
Connection via Cloud Identity-Aware Proxy Failed
Code: 4003
Reason: failed to connect to backend
You may be able to connect without using the Cloud Identity-Aware Proxy.
Then when I click on "Connect without Identity-Aware Proxy" I get the following error:
Connection Failed
We are unable to connect to the VM on port 22. Learn more about possible causes of this issue.
I don't know what happened. Yesterday it was working fine and now it's not.

At first, try to disable Cloud Identity-Aware Proxy and connect to the VM instance via web Console.
After that, check logs:
Go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM -> at the VM instance details find section Logs and click on Serial port 1 (console)
Reboot your VM instance.
Check full boot log for any errors or/and warnings.
If your VM instance doesn't start up verify that your disk has a valid file system and a valid master boot record (MBR) by following the documentation General troubleshooting.
If you found errors/warning related to disk space you can try to resize it accordingly to the documentation Resizing a zonal persistent disk, also accordingly to the article Recovering an inaccessible instance or a full boot disk:
If an instance is completely out of disk space or if it is not running
a Linux guest environment, then automatically resizing your root
filesystem isn't possible, even after you've increased the size of the
persistent disk that backs it. If you can't connect to your instance,
or your boot disk is full and you can't resize it, you must create a
new instance and recreate the boot disk from a snapshot to resize it.
Otherwise try get access to your VM instance via serial console :
Enable serial console connection with gcloud command:
gcloud compute instances add-metadata NAME_OF_YOUR_VM_INSTANCE \
--metadata serial-port-enable=TRUE
or go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM_INSTANCE -> click on EDIT -> go to section Remote access and check Enable connecting to serial ports
Create temporary user and password to login: shutdown your VM and set a startup script by adding at the section Custom metadata key startup-script and value:
useradd --groups google_sudoers tempuser
echo "tempuser:password" | chpasswd
and then start your VM.
Connect to your VM via serial port with gcloud command:
gcloud compute connect-to-serial-port NAME_OF_YOUR_VM_INSTANCE
or go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM_INSTANCE -> and click on Connect to serial console
Check what went wrong.
Disable access via serial port with gcloud command:
gcloud compute instances add-metadata NAME_OF_YOUR_VM_INSTANCE \
--metadata serial-port-enable=FALSE
or go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM_INSTANCE -> click on EDIT -> go to section Remote access and uncheck Enable connecting to serial ports. Keep in mind that accordingly to the documentation Interacting with the serial console:
Caution: The interactive serial console does not support IP-based access
restrictions such as IP whitelists. If you enable the interactive
serial console on an instance, clients can attempt to connect to that
instance from any IP address. Anybody can connect to that instance if
they know the correct SSH key, username, project ID, zone, and
instance name. Use firewall rules to control access to your network
and specific ports.
If you weren't able to connect via serial console, try follow the documentation Troubleshooting SSH section Inspect the VM instance without shutting it down and inspect the disk of your VM on another VM. Same way you can transfer your data to another working VM instance.

I had had the same issue while running composer update.
In my case an rebooting of the VM-Instance has solved it.

Beased on these error messages, I guess that your project has Identity-Aware Proxy (IAP) enabled, which sometimes may affect the ability to SSH into an instance, depending on the configuration.
In order to rule out this, you may try the following:
Create the firewall rules for allowing IAP to connect to your instances
Grant the necessary permissions to use IAP
Tunnel the SSH connection through IAP

Related

Cannot access GCP VM instance

I've been trying to connect to a VM instance for the past couple of days now. Here's what I've tried:
Trying to SSH into it returns username#ipaddress: Permission denied (publickey).
Using the Google Cloud SDK returns this:
No zone specified. Using zone [us-central1-a] for instance: [instancename].
Updating project ssh metadata...done.
Waiting for SSH key to propagate.
SFATAL ERROR: No supported authentication methods available (server sent: publickey)
ERROR: (gcloud.compute.ssh) Could not SSH into the instance. It is possible that your SSH key has not propagated to theinstance yet. Try running this command again. If you still cannot connect, verify that the firewall and instance are set to accept ssh traffic.
Using the browser SSH just gets stuck on "Transferring SSH keys to the VM."
Using PuTTy also results in No supported authentication methods available (server sent: publickey)
I checked the serial console and found this:
systemd-hostnamed.service: Failed to run 'start' task: No space left on device
I did recently resize the disk and did restart the VM, but this error still occurs.
Access to port 22 is allowed in the firewall rules. What can I do to fix this?
After increasing the disk size you need to reboot the instance so the filesystem can be resized, just in this specific case because you already ran out of space.
If you have not already done so, create a snapshot of the VM's boot disk.
Try to restart the VM.
If you still can't access the VM, do the following:
Stop the VM:
gcloud compute instances stop VM_NAME
Replace VM_NAME with the name of your VM.
Increase the size the boot disk:
gcloud compute disks resize BOOT_DISK_NAME --size DISK_SIZE
Replace the following:
BOOT_DISK_NAME: the name of your VM's boot disk
DISK_SIZE: the new larger size, in gigabytes, for the boot disk
Start the VM:
gcloud compute instances start VM_NAME
Reattempt to SSH to the VM.

Lost access to Mongo running on Google Cloud VM and can't ssh to it

I have a mongo instance running on a google cloud VM and my application lost access to it overnight. I'm not being able to SSH to it and Cloud console is looking weird.
VM Image: bitnami-mongodb-3-2-1-1-r04-linux-debian-7-x86-64
It first says I don't have permission to access the instance console page. Eventhough I'm the owner of the project and I can see it once I close the modal.
Then when I try to SSH using the built-in SSH tool I first get the following message. I see I have a VPC setup so I'm not really sure if that is actually expected or not.
If I try the alternative method I then get the following:
Does anyone has any hint on what could be the issue?
UPDATE:
VPC Firewall settings are set to allow SSH and the target project is set for it this rule:
I also have an external static IP set for this VM.
Just yesterday I could connect to my mongo instance through port 27017 and it stoped working without touching any GPC configuration.
Based on the information you have provided, it would seem that your GCE VM instance is currently utilizing IAP (Identity-Aware Proxy).
With this in mind, any overviewing the error message you are receiving, it would seem that your firewall rules aren't allowing connections on the SSH port. There should be an ingress rule to allow traffic to the instance on TCP port 22 (SSH) on that VPC network.
Generally, this is automatically created by GCP, on the default network it is typically called "default-allow-ssh", but you can also manually create it in the VPC Network -> Firewall rules tab. Make sure it applies to the instance in question (either through "All targets" or a target tag that matches the instance). You can read more about GCP firewall rules in the documentation.
Likewise, make sure you have an external IP or that you are following one of the options described here.

Google Cloud Platform fix SSH

I have a problem with SSH access on my google compute engine. I made a server, set up the application on it and configured the domain and everything works. After a few days when I wanted to approach her to make changes my SSH didn’t work. I have one assumption I was turning on firewall and I didn't add a rule for SSH, maybe that's a problem? But how to access the machine now and enable it?
Thanks in advance .
To solve your issue you can connect to your VM instance via serial console. Before connecting to the VM via serial console check if you enabled connections to your VM instance at GCP Firewall.
Please have a look at the step by step instructions below:
Enable serial console connection with gcloud command:
gcloud compute instances add-metadata NAME_OF_YOUR_VM_INSTANCE \
--metadata serial-port-enable=TRUE
or go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM_INSTANCE -> click on EDIT -> go to section Remote access and check Enable connecting to serial ports
Create temporary user and password to login: shutdown your VM and set a startup script by adding at the section Custom metadata key startup-script and value:
#!/bin/bash
useradd --groups google_sudoers tempuser
echo "tempuser:password" | chpasswd
and then start your VM.
Connect to your VM via serial port with gcloud command:
gcloud compute connect-to-serial-port NAME_OF_YOUR_VM_INSTANCE
or go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM_INSTANCE -> and click on Connect to serial console
Check what went wrong.
Disable access via serial port with gcloud command:
gcloud compute instances add-metadata NAME_OF_YOUR_VM_INSTANCE \
--metadata serial-port-enable=FALSE
or go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM_INSTANCE -> click on EDIT -> go to section Remote access and uncheck Enable connecting to serial ports. Keep in mind that accordingly to the documentation Interacting with the serial console:
Caution: The interactive serial console does not support IP-based access
restrictions such as IP whitelists. If you enable the interactive
serial console on an instance, clients can attempt to connect to that
instance from any IP address. Anybody can connect to that instance if
they know the correct SSH key, username, project ID, zone, and
instance name. Use firewall rules to control access to your network
and specific ports.
In addition, have a look at 3rd party example Resolving getting locked out of a Compute Engine.
If you weren't able to connect via serial console check logs:
Go to Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM -> at the VM instance details find section Logs and click on Serial port 1 (console)
Reboot your VM instance again.
Check full boot log for any errors or/and warnings.
If you found errors/warning related to disk space you can try to resize it accordingly to the documentation Resizing a zonal persistent disk, also accordingly to the article Recovering an inaccessible instance or a full boot disk:
If nothing helped, try to follow other recommendations from the documentation Troubleshooting SSH and update your question with your attempts.

Cannot access google cloud VM via SSH client through browser after VM restart

I created GCP VM for one month and connect VM instance through GCP console via browser.It worked fine for past one month until VM restart. I did not create ssh key/edit metadata and very thing so far is used default setting. I cannot establish connection after VM restart. The browser kept prompt me cannot establish the connection. I can ping this VM from another VM through VPC. any advise on it. Thank in advance.
There are several ways to connect a Linux instance via the SSH. You can connect to an instance via the terminal. You can connect via the Cloud Console Web UI which is in general the most convenient way to connect to an instance. Also, you can use Google Cloud SDK and run below command to connect to an instance via SSH:
$ gcloud compute ssh [INSTANCE_NAME]
You can also use Cloud Shell to connect your instance from the Cloud Console web UI by using the same command as above. You can connect via the serial console using the Google Cloud Platform Console, the gcloud command-line tool, or a third-party SSH client.
The serial console authenticates users with SSH keys. Specifically, you must add your public SSH key to the project or instance metadata, and store your private key on the local machine from which you want to connect. There are other advanced methods to connect to an instance which you can find at this link.
By default, the gcloud compute command-line tool uses the $USER variable to add users to the /etc/passwd file for connecting to virtual machine instances using SSH. You can specify a different user using the --ssh-key-file PRIVATE_KEY_FILE flag when running the gcloud compute ssh command. Depending on your use case and convenience, you can use any method consistently.
If you fail to connect to your instance upon following these methods then I would suggest to check this troubleshooting page for SSH and follow the instruction that matches your use case.

Google Cloud Instances Firewall Unable to Login SSH

I logged to my ssh in google cloud Linux Machine by mistake i changed firewall rule and i lost ssh connection. now i am not able login to ssh(22), Is there any way to recover that ?
I know I can take shanpshots of my machine and create new instances using that snapshot. but is there anyway to get again ssh login in same machine or i have to delete it.
Try connecting to the instance via the serial console: https://cloud.google.com/compute/docs/instances/interacting-with-serial-console. From there you should be able to repair the firewall rules.
pjhsea I tried your steps and it is connecting to serial port but it asks passphrase. I was not sure where I have given this passphrase. If you try to access serial port on gcloud console then it always asks for passphrase.
So I tried below steps and I was able to connect to serial port to change firewall setting on my ubuntu VM.
Goto Compute Engine -> VM Instances fro left side menu.
Click on name of the VM you are facing issue connecting using SSH.
It will open VM Instance details page.
On details tab under VM name there will be two dropdown for remote access.
SSH and Connect to serial console.
Click on serial console and select serial port 1(console)
This connect to serial console without any passphrase and I was able to change my firewall rules using below command.
ufw allow 22
Now you should be able to connect using SSH.