GCP forward proxy solution for whitelisting domain names on outbound traffic - google-cloud-platform

I use squid in my vpc as a forward proxy and to sanitize my outgoing traffic to only allow certain domains. Is there a cloud native solution in GCP that accomplishes the same thing? I just want to be able to whitelist certain domain names being requested from some of my instances.

A cloud-native solution is discrimiNAT though. It allows plugging in domain allowlists straight into GCP Firewall Rules, without the need to configure apps on the VM Instances to use an explicit proxy. The association of Firewall Rules with VM Instances by use of Network Tags (as is the GCP-way) then dictates which egress FQDN rules apply to which VM Instances.
It isn't a forward-proxy technically, but an NGFW accomplishing the specific requirement of filtering outbound traffic by FQDNs.
Disclosure: It's a marketplace product and I've written protocol parsers for them in Rust!

There is no native solution in that use case in GCP as of the moment, but you can check this documentation to help you harden your GCP infrastructure.
You can also file a feature request to give them an idea with your use case and possibly consider adding it in the future.

Related

Restrict access to some endpoints on Google Cloud

I have a k8s cluster that runs my app (gce as an ingress) and I want to restrict access to some endpoints "/test/*" but all other endpoints should be publically available. I don't want to restrict for specific IP's to have some flexibility and ability to access restricted endpoints from any device like phones.
I considered IAP but it restricts access to the full service when I need it only for some endpoints. Hence extra.
I have thought about VPN. But I don't understand how to set this up, or would it even resolve my issues.
I have heard about proxy but seems to me it can't fulfill my requirements (?)
I can't tell that solution should be super extensible or generic because only a few people will use this feature.
I want the solution to be light, flexible, simple, and fulfill my needs at the same time. So if you say that there are solutions but it's complex I would consider restricting access by the IP, but I worry about how the restricted IP's approach is viable in the real life. In a sense would it be too cumbersome to add the IP of my phone every time I change my location and so on?
You can use API Gateway for that. It approximatively meets your needs, it's not so flexible and simple.
But it's fully managed and can scale with your traffic.
For a more convenient solution, you have to use software proxy (or API Gateway), or go to the Bank and use Apigee
I set up OpenVPN.
It was not a tedious process because of the various small obstacles but I encourage you to do the same.
Get a host (machine, cluster, or whatever) with the static IP
Setup an OpenVPN instance. I do docker https://hub.docker.com/r/kylemanna/openvpn/ (follow instructions but update a host -u YOUR_IP)
Ensure that VPN setup works from your local machine
To the routes you need limit IP access to the VPN one. Nginx example
allow x.x.x.x;
deny all;
Make sure that nginx treats IP right. I had an issue that the nginx was having Load Balancer IP as client IP's, so I have to put some as trusted. http://nginx.org/en/docs/http/ngx_http_realip_module.html
Test the setup

How to expose a API that is running in a Pod and limit access?

I have an API running in a service in my GKE Cluster and it needs to be accessible for some other developers in my team. They are using a VPN so they have a static IP they can provide to me.
My idea was to just expose the service using a static external IP and restricting access to this IP using a Firewall rule so just the IP of my colleagues.
Unfortunately this just seems to be possible for Compute-VMs because only they can have tags.
Is there a way how I can simply deny all traffic to my service except for traffic from the specific IP?
I appreciate any hints to features, thank you
Well, you don't need tags, you can create your firewall rule to only allow access to the IP your developers provide you, just when you're creating your firewall rule, select all instances in the network for Targets and for source IP ranges specify the IP with the prefix /32 at the end.
You could provide them RBAC access to the pods in the required namespace and allow them to port forward. Assuming you don't want to set up a public end point and try secure it. This does require kubectl to be installed and cluster access and this will give access to all pods in the namespace.
https://medium.com/#ManagedKube/kubernetes-rbac-port-forward-4c7eb3951e28
Depends what level of security and permanency you need I guess.

Is it possible to create a firewall rule accepting calls from a Google Cloud Function [duplicate]

I would like to develop a Google Cloud Function that will subscribe to file changes in a Google Cloud Storage bucket and upload the file to a third party FTP site. This FTP site requires allow-listed IP addresses of clients.
As such, it is possible to get a static IP address for Google Cloud Functions containers?
Update: This feature is now available in GCP https://cloud.google.com/functions/docs/networking/network-settings#associate-static-ip
First of all this is not an unreasonable request, don't get gaslighted. AWS Lambdas already support this feature and have for awhile now. If you're interested in this feature please star this feature request: https://issuetracker.google.com/issues/112629904
Secondly, we arrived at a work-around which I also posted to that issue as well, maybe this will work for you too:
Setup a VPC Connector
Create a Cloud NAT on the VPC
Create a Proxy host which does not have a public IP, so the egress traffic is routed through Cloud NAT
Configure a Cloud Function which uses the VPC Connector, and which is configured to use the Proxy server for all outbound traffic
A caveat to this approach:
We wanted to put the proxy in a Managed Instance Group and behind a GCP Internal LB so that it would dynamically scale, but GCP Support has confirmed this is not possible because the GCP ILB basically allow-lists the subnet, and the Cloud Function CIDR is outside that subnet
I hope this is helpful.
Update: Just the other day, they announced an early-access beta for this exact feature!!
"Cloud Functions PM here. We actually have an early-access preview of this feature if you'd like to test it out.
Please complete this form so we can add you..."
The form can be found in the Issue linked above.
See answer below -- it took a number of years, but this is now supported.
https://cloud.google.com/functions/docs/networking/network-settings#associate-static-ip
For those wanting to associate cloud functions to a static IP address in order to whitelist the IP for an API or something of the sort I recommend checking out this step by step guide which helped me a lot:
https://dev.to/alvardev/gcp-cloud-functions-with-a-static-ip-3fe9 .
I also want to specify that this solution works for Google Cloud Functions and Firebase Functions (as it is based on GCP).
This functionality is now natively part of Google Cloud Functions (see here)
It's a two-step process according to the GCF docs:
Associating function egress with a static IP address In some cases,
you might want traffic originating from your function to be associated
with a static IP address. For example, this is useful if you are
calling an external service that only allows requests from whitelisted
IP addresses.
Route your function's egress through your VPC network. See the
previous section, Routing function egress through your VPC network.
Set up Cloud NAT and specify a static IP address. Follow the guides at
Specify subnet ranges for NAT and Specify IP addresses for NAT to set
up Cloud NAT for the subnet associated with your function's Serverless
VPC Access connector.
Refer to link below:
https://cloud.google.com/functions/docs/networking/network-settings#associate-static-ip
As per Google, the feature has been released check out the whole thread
https://issuetracker.google.com/issues/112629904
It's not possible to assign a static IP for Google Cloud Functions, as it's pretty much orthogonal to the nature of the architecture being 'serverless' i.e. allocate and deallocate servers on demand.
You can, however, leverage a HTTP proxy to achieve a similar effect. Setup a Google Compute Engine instance, assign it a static IP and install a proxy library such as https://www.npmjs.com/package/http-proxy. You can then route all your external API calls etc through this proxy.
However, this probably reduces scale and flexibility, but it might be a workaround.

Several firewalls when creating Google Cloud Platform instance. Which to use?

I created a Google Cloud Platform Ubuntu 16.04 instance. It seems the GCP has several places where traffic can be filtered:
The Instances section of the GCP console lets me allow or disallow
HTTP and HTTPS traffic.
In the Networking section I can create additional firewall rules which limit access to the network.
Finally, in the Ubuntu instance itself I can configure UFW to block/allow certain ports.
Should I configure all of these? Would it be better to just configure one and allow all in the others?
As a note, this instance will serve a website, so I would only allow HTTP/HTTPS traffic.
The complete answer is that it depends.
For number one, the only thing that happens is that the default-allow-http rule gets applied to that instance.
The networking section is where you define your own rules that what to be applied to instances. It becomes easier to maintain all your networking configs in Google Cloud if you start having multiple instances and load balancers. You can share apply a single rule to some machines and you can compose them.
Finally, I would use ufw/iptables only as a last resort config. For example I have a some machines behind a load balancer and one of them is doing something weird. I would ssh into it and block port 80 and investigate it.

Possible to get static IP address for Google Cloud Functions?

I would like to develop a Google Cloud Function that will subscribe to file changes in a Google Cloud Storage bucket and upload the file to a third party FTP site. This FTP site requires allow-listed IP addresses of clients.
As such, it is possible to get a static IP address for Google Cloud Functions containers?
Update: This feature is now available in GCP https://cloud.google.com/functions/docs/networking/network-settings#associate-static-ip
First of all this is not an unreasonable request, don't get gaslighted. AWS Lambdas already support this feature and have for awhile now. If you're interested in this feature please star this feature request: https://issuetracker.google.com/issues/112629904
Secondly, we arrived at a work-around which I also posted to that issue as well, maybe this will work for you too:
Setup a VPC Connector
Create a Cloud NAT on the VPC
Create a Proxy host which does not have a public IP, so the egress traffic is routed through Cloud NAT
Configure a Cloud Function which uses the VPC Connector, and which is configured to use the Proxy server for all outbound traffic
A caveat to this approach:
We wanted to put the proxy in a Managed Instance Group and behind a GCP Internal LB so that it would dynamically scale, but GCP Support has confirmed this is not possible because the GCP ILB basically allow-lists the subnet, and the Cloud Function CIDR is outside that subnet
I hope this is helpful.
Update: Just the other day, they announced an early-access beta for this exact feature!!
"Cloud Functions PM here. We actually have an early-access preview of this feature if you'd like to test it out.
Please complete this form so we can add you..."
The form can be found in the Issue linked above.
See answer below -- it took a number of years, but this is now supported.
https://cloud.google.com/functions/docs/networking/network-settings#associate-static-ip
For those wanting to associate cloud functions to a static IP address in order to whitelist the IP for an API or something of the sort I recommend checking out this step by step guide which helped me a lot:
https://dev.to/alvardev/gcp-cloud-functions-with-a-static-ip-3fe9 .
I also want to specify that this solution works for Google Cloud Functions and Firebase Functions (as it is based on GCP).
This functionality is now natively part of Google Cloud Functions (see here)
It's a two-step process according to the GCF docs:
Associating function egress with a static IP address In some cases,
you might want traffic originating from your function to be associated
with a static IP address. For example, this is useful if you are
calling an external service that only allows requests from whitelisted
IP addresses.
Route your function's egress through your VPC network. See the
previous section, Routing function egress through your VPC network.
Set up Cloud NAT and specify a static IP address. Follow the guides at
Specify subnet ranges for NAT and Specify IP addresses for NAT to set
up Cloud NAT for the subnet associated with your function's Serverless
VPC Access connector.
Refer to link below:
https://cloud.google.com/functions/docs/networking/network-settings#associate-static-ip
As per Google, the feature has been released check out the whole thread
https://issuetracker.google.com/issues/112629904
It's not possible to assign a static IP for Google Cloud Functions, as it's pretty much orthogonal to the nature of the architecture being 'serverless' i.e. allocate and deallocate servers on demand.
You can, however, leverage a HTTP proxy to achieve a similar effect. Setup a Google Compute Engine instance, assign it a static IP and install a proxy library such as https://www.npmjs.com/package/http-proxy. You can then route all your external API calls etc through this proxy.
However, this probably reduces scale and flexibility, but it might be a workaround.