Slack launched GovSlack in July 2022. With GovSlack, authorities companies, and people they work with, can allow their groups to seamlessly collaborate of their digital headquarters, whereas holding safety and compliance on the forefront. Utilizing GovSlack consists of the next advantages:
- Helps key authorities safety requirements, corresponding to FedRAMP Excessive, DoD IL4, and ITAR
- Runs in AWS GovCloud information facilities
- Permits exterior collaboration with different GovSlack-using organizations by means of Slack Join
- Supplies entry to your individual set of encryption keys for superior auditing and logging controls
- Permits permission and entry controls at scale by means of Slack’s enterprise-grade admin dashboard
- Features a listing of curated functions (together with DLP and eDiscovery apps) that may combine with Slack
- Maintained and supported by US personnel
Earlier than the large launch, the Cloud Foundations group spent virtually two quarters establishing the infrastructure wanted to run GovSlack.
GovSlack is the very first service Slack launched on AWS Gov infrastructure. Due to this fact we needed to spend a major period of time studying the variations between customary and Gov AWS and making adjustments to our tooling and the platform to have the ability to run on Gov AWS.
On this weblog publish, we’re going to take a look at how we constructed the AWS infrastructure wanted for GovSlack and challenges we confronted. In case you’re interested by constructing a brand new service on AWS GovCloud, this publish is for you.
How are GovCloud accounts associated to industrial accounts?
Not way back, Slack began transferring from a single AWS account to baby accounts. As a part of this mission, we additionally made important adjustments to our international community infrastructure. You may learn extra about this within the weblog posts Constructing the Subsequent Evolution of Cloud Networks at Slack and Constructing the Subsequent Evolution of Cloud Networks at Slack – A Retrospective. We have been capable of make the most of most of our learnings into constructing the GovSlack community infrastructure.
Initially, AWS Gov accounts should not have any billing functionality. The sources within the Gov accounts will propagate their billing right into a linked shell industrial AWS account. Whenever you request a Gov AWS account, a linked shell industrial AWS account is routinely created. Due to this fact the very first thing we needed to do was to request a Gov root AWS account utilizing our root payer industrial account. This was a prolonged course of, however not as a result of it was a technically tough factor to do—it was so simple as clicking a button on our root industrial AWS account. Nevertheless including the Gov Accounts to our present agreements with AWS did take just a few weeks. As soon as we had our Gov root account, we have been capable of request extra GovCloud accounts for our service groups. It’s price mentioning that GovCloud baby accounts nonetheless have to be requested utilizing the industrial AWS API utilizing the create-gov-cloud-account name.
When a brand new GovCloud baby account is created, you possibly can assume the OrganizationAccountAccessRole within the baby account by way of the GovCloud root account’s OrganizationAccountAccessRole (this position title might differ should you override the title utilizing –role-name flag).
Let’s take a look at what are these hyperlinks appear to be in a diagram:
As we are able to see above, all our GovCloud sources prices are propagated to our root industrial AWS account.
How did we create GovCloud accounts?
As we mentioned above, we use the AWS organizations API and the create-gov-cloud-account name to request a brand new GovCloud baby account. This course of creates two new accounts: the GovCloud account and the linked industrial AWS account. We use a pipeline on the industrial aspect for this portion of the method. Then the linked industrial AWS account is moved to a extremely restricted OU, so it’s blocked from creating any AWS sources in it.
We use a Jenkins pipeline within the AWS Gov partition to configure the GovCloud baby account. We are able to assume the OrganizationAccountAccessRole of the brand new baby account from the GovCloud root account as quickly as it’s created. Nevertheless our Gov Jenkins providers are situated in a devoted baby account. Due to this fact there’s a step on this pipeline that can replace the kid account’s OrganizationAccountAccessRole’s belief coverage, so it may be assumed by the Jenkins employees. This step should be accomplished first earlier than we are able to transfer on to different steps of the kid account configuration course of.
How will we separate GovDev and GovProd?
As talked about beforehand, one of many core compliance necessities for a GovCloud setting was that solely US individuals could be licensed to the manufacturing setting. With this requirement in thoughts we made the choice to face up two Gov environments, one being the manufacturing Gov setting, recognized internally as “GovProd”, and a second setting, generally known as “GovDev”. The GovDev setting could be accessed by anybody and check their providers earlier than being deployed to GovProd by US personnel.
To make sure now we have full isolation between these environments, now we have approached the construct out utilizing a full shared-nothing paradigm, which permits the environments to function in fully totally different AWS organizations. The layer 3 networking mesh we use (Nebula) is totally disconnected, that means the networks are solely segregated from each other.
To archive this, we created two AWS organizations in GovCloud, and beneath every of those organizations, an an identical set of kid accounts to launch our providers within the Dev and Prod environments.
Is that this actually remoted?
When a brand new baby account is created, we have to use the Gov root account for assuming the OrganizationAccountAccessRole’s into it for the primary portion of the provisioning as we mentioned right here. Since solely US personnel can entry the Gov prod accounts, solely US personnel are capable of entry the Gov root account, as this account has entry to imagine the OrganizationAccountAccessRole within the baby accounts. Due to this fact the preliminary provisioning of dev accounts additionally should run on Gov prod Jenkins, and US personnel are required to be engaged to kick off the preliminary a part of GovDev accounts creation.
Different challenges
GovProd additionally lacks some AWS providers, corresponding to CloudFront and public zones in Route53. Moreover, after we are utilizing the AWS CLI in GovCloud, we should go within the –area flag or set the AWS_DEFAULT_REGION setting variable with a Gov area because the AWS CLI all the time defaults to a industrial area for API calls.
Route53 and ACM
A few of our Gov providers use AWS ACM for the load balancer SSL certifications. We keep away from utilizing e mail certificates validation as this doesn’t permit us to auto-renew expiring certificates. ACM DNS helps auto-renewal however requires public DNS information to take action. Due to this fact, we use the identical devoted industrial DNS account for validating our ACM certificates as nicely. Entry to this industrial DNS account is restricted to US personnel.
Route53
AWS GovCloud doesn’t assist public Route53 zones. Nevertheless personal zones are allowed. We created a GovDev and Gov Prod DNS account for internet hosting personal Route53 zones. The Cloud Foundations group creates VPCs in a set of accounts managed by us, then we use AWS Transit gateways to attach totally different areas collectively and construct a world community mesh. Lastly these VPCs are shared into baby accounts to summary the complexity of establishing networks from software groups. You may learn extra about how we do that in our different two weblog posts Constructing the Subsequent Evolution of Cloud Networks at Slack and Constructing the Subsequent Evolution of Cloud Networks at Slack – A Retrospective
The personal Route53 zones we create are hooked up to the shared VPCs, in order quickly as a report is added to those zones, it may be resolved inside our VPCs.
Nevertheless since GovCloud doesn’t assist public DNS, we have to create these information on the industrial aspect. Due to this fact, we created a devoted industrial AWS account for internet hosting public GovSlack DNS information. Entry to this industrial DNS account is restricted to US personnel.
How will we switch artefacts between industrial and GovCloud?
AWS doesn’t assist assuming roles between AWS customary and AWS GovCloud partitions. Due to this fact we created a mechanism to compliantly go objects to GovCloud.
This mechanism ensures the objects are pulled into AWS GovCloud partition from the usual partition utilizing AWS IAM credentials. Credentials to entry the usual partition for pulling these objects are saved securely on the AWS GovCloud partition.
Terraform modules
We use Terraform modules for constructing our infrastructure as a group of interdependent sources corresponding to VPCs, Web Gateways, Transit Gateways, and route tables. We wished to make use of the identical modules for constructing our Gov infrastructure so we are able to hold these patterns constant between AWS Gov and customary partitions. One key distinction between the industrial and Gov AWS sources are the sources ARNs. Business ARNs begin with arn:aws versus Gov ARNs begin with arn:aws-us-gov.
Due to this fact we needed to construct a quite simple Terraform module referred to as aws_partition. Utilizing outputs of this module, we are able to programmatically construct ARNs and uncover which AWS partition we’re in.
Let’s take a look at the aws_partition module,
information "aws_caller_identity" "present"
information "aws_arn" "arn_details"
arn = information.aws_caller_identity.present.arn
output "partition"
worth = information.aws_arn.arn_details.partition
output "is_govcloud"
worth = substitute(information.aws_arn.arn_details.partition, "gov", "") != information.aws_arn.arn_details.partition ? true : false
Now let’s take a look at a instance utilization,
module "aws_partition"
supply = "../modules/aws/aws_partition"
information "aws_iam_policy_document" "instance"
assertion
impact = "Enable"
actions = [
"s3:GetObject",
]
sources = [
"arn:$module.aws_partition.partition:iam::*:role/some-role",
]
useful resource "aws_config_config_rule" "instance"
depend = module.aws_partition.is_govcloud ? 1 : 0
title = "example-rule"
supply
proprietor = "AWS"
source_identifier = "S3_BUCKET_SERVER_SIDE_ENCRYPTION_ENABLED"
VPC endpoints
Over the past three years Slack has been working very onerous to utilize AWS’ VPC endpoints for accessing native AWS providers in our industrial setting. They cut back the latency and improve the resiliency of our programs, whereas additionally lowering our networking prices.
With all these benefits, it’s very simple to imagine that it’s a easy transfer, however one obvious challenge that now we have present in each the industrial and GovCloud transfer to VPC endpoints is that AWS doesn’t all the time assist all providers in all AZs. Very often now we have discovered that we have to assist the power for programs to entry AWS providers each with and with out VPC endpoints, which at instances can create summary edge instances that may be onerous to account for.
Whereas AWS is continually releasing these VPC endpoints at a AZ degree, we nonetheless haven’t reached 100% of providers enabled for 100% of the areas/AZs we run our service in.
AWS-SSO
Whereas we have been constructing out the Gov setting, we began by utilizing IAM customers to bootstrap the Gov setting, however this was solely ever going to be a short-term resolution. AWS not too long ago launched the AWS-SSO resolution into their industrial setting and much more not too long ago of their Gov setting. As this was a whole greenfield buildout it was alternative to experiment with new applied sciences and enhance our present implementation.
In contrast to AWS’ customary IAM roles, AWS-SSO permission units are an org-wide international (throughout all the org, versus an account) useful resource, and this adjustments how we construct and deploy them.
Since deploying AWS-SSO within the GovCloud setting, now we have taken the learnings and back-ported it into our industrial setting. Whereas we already had an present SSO system in place for entry to the whole lot of our industrial AWS setting, utilizing AWS-SSO has made this course of so much smoother and simpler.
So what have we realized?
Rebuilding our whole community infrastructure gave us the power to check our tooling, processes, and Terraform modules, and gave us the chance to make enhancements. We have been capable of clear up a mess of hardcoded values and alter issues to be extra reusable. We have been additionally capable of take a step again and have a deep dive into our processes, instruments, AWS footprint and achieve a better understanding of our platform as this entire course of gave us a possibility to rebuild Slack from scratch.
