I have a Google Compute Engine instance which is uniquely identified:
name: updateservice
zone: us-central1-a
project: myproject
is there a way to access the instance via DNS name? Otherwise I need to whitelist it's IP everytime in Cloud SQL since it changes on reboot.
Compute Engine instances have a private DNS name within the VPC, but do not have a public DNS name. You must configure a DNS resource record for the instance at your DNS server if you want a public DNS name.
Otherwise I need to whitelist it's IP everytime in Cloud SQL since it
changes on reboot.
There are two solutions for Cloud SQL:
Assign a static IP address to the Compute Engine instance. link
Deploy the Cloud SQL Auth Proxy on the Compute Engine instance . link
Method #2 is the recommended method because IP addresses do not need to be whitelisted and authentication is encrypted.
If you SSH to the VM and run the command hostname -A it will show you the VM's internal DNS.
From the on-premise network, you can reach/ping the VM's internal DNS by setting up Cloud VPN.
Related
I was trying to find the IP Address of DNS server hosted in private zone in GCP to resolve some traffic routing related issue on the firewall. But i am not able to find it in Cloud DNS GUI console.
Cloud DNS Private zones require that you use the metadata server for name resolution. Compute Engine instances receive internal DNS resolution information as part of their DHCP leases. By default, the instance's metadata server (169.254.169.254) resolves internal DNS names. If you change the name server configuration for your instance, you cannot resolve records in Compute Engine internal DNS (the .internal zone) or in Cloud DNS managed private zones, forwarding zones, and peering zones unless your replacement DNS server forwards these queries to 169.254.169.254.
I want to access a Google Compute Engine instance by a permanent name. I found that there is supposed to be an internal DNS name for this like:
updateservice.us-central1-a.c.myproject.internal
however If I try to ping this instance from cloud shell I only receive:
ping: updateservice.us-central1-a.c.myproject.internal: Name or service not known
why is this? and how can I access updateservice via DNS name?
We cannot use Cloud Shell to access or ping internal DNS name for the reason that it is on a separate network. You can check this by running this command “ip -4 addr”.
Internal DNS can only resolved from VMs that are in the same network. You can check this link for more information.
For further understanding on how Private DNS works you can also follow this link on how to create Private DNS.
UPDATE
2022 - 12 - 07
It will depend on you on how you will access your domain name.
First if you are going to access it via internal connection that is the time that you need to use Private DNS. The connection will be from one VM instance to another in the same VPC network.
Using Cloud DNS and configuring Private DNS it will give you the option to have your own domain name. You can watch this link on how you can create a Private DNS and understand the internal connection between VM instances.
But based from this link there is already an internal DNS created for your vm instance but please dont be confused, the concept is the same with Private DNS. The only difference is Internal DNS is already created once a VM instance is created but it has a default domain name.
Unlike Private DNS configured under Cloud DNS, you have the option to have your own domain name. If you are using a linux server you can run this command “hostname -A” to get the default domain name of your VM instance.
What I discuss above is for internal access. Now the other way is external access, meaning you will access your VM instance outside your network. This will enter Public DNS. Before you create Public DNS you will need a domain name from a domain provider.
Once you already have a domain name from a domain provider, you can create Cloud DNS then configure Public DNS. Once it is created you need to add “A Record”. This is just one step from your GCP network in order to have access using your domain name from external access.
On creating an EC2 instance on AWS, you can access it via IP address or a domain name provided by Amazon out of the box:
Is there a similar thing available for Google Cloud out of the box? I'm on a network that blocks IP addresses, and wildcard DNS like xip.io, so I was curious to know about it. Also, is there a specific term this is called which I'm missing?
When you create a GCP Compute Engine instance (EC2 equivalent) you can declare that you want it to have a public IP address. This is an IP that you can use over the Internet to access your instance. GCP gives you two types of IP ... static (stable) or ephemeral. A static IP is yours until you explicitly release it. There is no charge for this as long as your compute engine is running. An ephemeral IP is one which is allocated to you dynamically and may change following a restart of your compute engine instance.
GCP does not (currently ... things could always change) create a DNS entry that will resolve to your IP address over the Internet. It does create a DNS entry that can be used inside your GCP VPC network to allow one compute engine to call another within the GCP environment.
If you want to reach your Compute Engine via a DNS name it is your responsibility to create a DNS "A" record in your own DNS server. If you don't have a DNS server that you can use, then you can obtain a domain name for a few dollars and then create an instance of a GCP Cloud DNS Server and add an "A" record for your compute engine to that server.
See also:
Cloud DNS
Internal DNS
Yes, you can forumate internal dns for instance using [INSTANCE_NAME].[ZONE].c.[PROJECT_ID].internal
See the following link for further information: https://cloud.google.com/compute/docs/internal-dns
Please ensure the ports are open.
You can visit the documentation as below for your reference, hope this helps.
https://cloud.google.com/vpc/docs/firewalls
I am taking the Google's GCP Fundamentals: Core Infrastructure course on Coursera. In the demonstration video of the Google Storage module, the presenter authorizes a compute engine instance to access a MySQL instance via it's external IP address.
Aren't these two resources part of the same VPC if they are part of the same project ? Why can't this authorization be done using the vm instance's internal IP address ?
Aren't these two resources part of the same VPC if they are part of
the same project ?
A Cloud SQL instance isn't created in one of your project's VPC network but in a Google-managed project, within its own network.
What happens when you enable private IP is that this network will be peered with the network of your choice in your project, where your Compute Engine instance resides:
You can then connect to the Cloud SQL instance from your VM via the internal IP address. The VM is considered trusted if your network configuration allows it to reach the Cloud SQL instance.
When you set an external IP address on the Cloud SQL instance, it means that the instance is accessible to the internet and the connection needs to be authorized. One way to do it is to whitelist the IP address of the caller as you mentioned. This works well if the caller's IP doesn't change. Another (easier) option is to connect via the cloud_sql_proxy, which handles authorization and encryption for you. You then don't need to whitelist the IP.
Does GCP support an internal DNS service? I don't need my zone to be public but I want my gce instances to use it for resolving internal services.
I am not very clear on your requirements, but if you just want two vm instances in a project VPC to communicate with each other then you can use internal dns, instead of using internal IP address which might change when a vm instance gets recreated.
GCP provides internal dns that can be used by two VM instances in the same VPC to communicate.
Note that vm instances in two different VPC can not communicate with each other across VPCs using this method (unless a VPN or other mechanism is configured to connect VPCs)
There are two ways to access/configure Internal DNS
Global DNS
Zonal DNS (Default for all organizations or standalone projects that have enabled the Compute Engine API after September 06, 2018.)
An internal fully qualified domain name (FQDN) for an instance has the following formats:
Instances using the default global DNS : [HOST_NAME] .c.[PROJECT_ID].internal
Instances enabled for Zonal DNS : [HOST_NAME].[ZONE].c.[PROJECT_ID].internal
You can address instances over the internal VPC network using this FQDN.
For example, if your instances are enabled for Zonal DNS, you can ping from one instance to another instance over the internal VPC network using the zonal fully qualified domain name:
ping example-instance.us-west1-c.c.example-project.internal -c 1
Yes, as of Oct 2018, Google Cloud DNS now supports Private DNS Zones.
You can create domains and DNS entries (pointing to whatever instances, load balancers, services) that will only be visible internally to the VPC networks you allow, and not available over the internet.
Announcement:
https://cloud.google.com/blog/products/networking/introducing-private-dns-zones-resolve-to-keep-internal-networks-concealed
Documentation:
https://cloud.google.com/dns/docs/quickstart#create_a_managed_private_zone
It appears based on this VPC doc that you would need to set up your own DNS server.
DNS server Each instance's metadata server acts as a DNS server. It
stores the DNS entries for all VPC network IP addresses in the local
VPC network and calls Google's public DNS server for entries outside
the VPC network. You cannot configure this DNS server, but you can set
up your own DNS server if you like and configure your instances to use
that server instead by editing the /etc/resolv.conf file.
EDIT:
As the more recent answers have pointed out, Cloud DNS now supports private zones.