System Requirements
This document is intended for system administrators of self-hosted installations of CircleCI Server.
This section defines the system and port access requirements for installing CircleCI v2.19.1.
Services Machine
The Services machine hosts the core of our Server product, including the user-facing website, API engine, datastores, and Nomad job scheduler. It is best practice to use an isolated machine.
The following table defines the Services machine CPU, RAM, and disk space requirements:
| Number of daily active CircleCI users | CPU | RAM | Disk space | NIC speed |
|---|---|---|---|---|
<50 |
8 cores |
32GB |
100GB |
1Gbps |
50-250 |
12 cores |
64GB |
200GB |
1Gbps |
251-1000 |
16 cores |
128GB |
500GB |
10Gbps |
1001-5000 |
20 cores |
256GB |
1TB |
10Gbps |
5000+ |
24 cores |
512GB |
2TB |
10Gbps |
Nomad Clients
Nomad client machines run the CircleCI jobs that are scheduled by the Nomad Server on the Services machine. Following are the Minimum CPU, RAM, and disk space requirements per client:
-
CPU: 4 cores
-
RAM: 32GB
-
Disk space: 100GB
-
NIC speed: 1Gbps
The following table defines the number of Nomad clients to make available as a best practice. Scale up and down according to demand on your system:
| Number of daily active CircleCI users | Number of Nomad client machines |
|---|---|
<50 |
1-5 |
50-250 |
5-10 |
250-1000 |
10-15 |
5000+ |
15+ |
Server Ports
Below all ports required by a CircleCI 2.0 installation are listed for each machine type.
Services Machine
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
80 |
TCP |
Inbound |
End users |
HTTP web app traffic |
|
443 |
TCP |
Inbound |
End users |
HTTPS web app traffic |
|
7171 |
TCP |
Inbound |
End users |
Artifacts access |
|
8081 |
TCP |
Inbound |
End users |
Artifacts access |
|
22 |
TCP |
Inbound |
Administrators |
SSH |
|
8800 |
TCP |
Inbound |
Administrators |
Admin console |
|
8125 |
UDP |
Inbound |
Nomad Clients |
Metrics |
|
8125 |
UDP |
Inbound |
Nomad Servers |
Metrics |
Only if using externalized Nomad Servers |
8125 |
UDP |
Inbound |
All Database Servers |
Metrics |
Only if using externalised databases |
4647 |
TCP |
Bi-directional |
Nomad Clients |
Internal communication |
|
8585 |
TCP |
Bi-directional |
Nomad Clients |
Internal communication |
|
7171 |
TCP |
Bi-directional |
Nomad Clients |
Internal communication |
|
3001 |
TCP |
Bi-directional |
Nomad Clients |
Internal communication |
|
80 |
TCP |
Bi-directional |
GitHub Enterprise / GitHub.com (whichever applies) |
Webhooks / API access |
|
443 |
TCP |
Bi-directional |
GitHub Enterprise / GitHub.com (whichever applies) |
Webhooks / API access |
|
80 |
TCP |
Outbound |
AWS API endpoints |
API access |
Only if running on AWS |
443 |
TCP |
Outbound |
AWS API endpoints |
API access |
Only if running on AWS |
5432 |
TCP |
Outbound |
PostgreSQL Servers |
PostgreSQL database connection |
Only if using externalised databases. Port is user-defined, assuming the default PostgreSQL port. |
27017 |
TCP |
Outbound |
MongoDB Servers |
MongoDB database connection |
Only if using externalized databases. Port is user-defined, assuming the default MongoDB port. |
5672 |
TCP |
Outbound |
RabbitMQ Servers |
RabbitMQ connection |
Only if using externalized RabbitMQ |
6379 |
TCP |
Outbound |
Redis Servers |
Redis connection |
Only if using externalized Redis |
4647 |
TCP |
Outbound |
Nomad Servers |
Nomad Server connection |
Only if using externalized Nomad Servers |
443 |
TCP |
Outbound |
CloudWatch Endpoints |
Metrics |
Only if using AWS CloudWatch |
Nomad Clients
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
64535-65535 |
TCP |
Inbound |
End users |
SSH into builds feature |
|
80 |
TCP |
Inbound |
Administrators |
CircleCI Admin API access |
|
443 |
TCP |
Inbound |
Administrators |
CircleCI Admin API access |
|
22 |
TCP |
Inbound |
Administrators |
SSH |
|
22 |
TCP |
Outbound |
GitHub Enterprise / GitHub.com (whichever applies) |
Download Code From GitHub. |
|
4647 |
TCP |
Bi-directional |
Services Machine |
Internal communication |
|
8585 |
TCP |
Bi-directional |
Services Machine |
Internal communication |
|
7171 |
TCP |
Bi-directional |
Services Machine |
Internal communication |
|
3001 |
TCP |
Bi-directional |
Services Machine |
Internal communication |
|
443 |
TCP |
Outbound |
Cloud Storage Provider |
Artifacts storage |
Only if using external artifacts storage |
53 |
UDP |
Outbound |
Internal DNS Server |
DNS resolution |
This is to make sure that your jobs can resolve all DNS names that are needed for their correct operation. |
GitHub Enterprise / GitHub.com
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
22 |
TCP |
Inbound |
Services Machine |
Git access |
|
22 |
TCP |
Inbound |
Nomad Clients |
Git access |
|
80 |
TCP |
Inbound |
Nomad Clients |
API access |
|
443 |
TCP |
Inbound |
Nomad Clients |
API access |
|
80 |
TCP |
Bi-directional |
Services Machine |
Webhooks / API access |
PostgreSQL Servers
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
5432 |
TCP |
Bi-directional |
PostgreSQL Servers |
PostgreSQL replication |
Only if using externalized databases. Port is user-defined, assuming the default PostgreSQL port. |
MongoDB Servers
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
27017 |
TCP |
Bi-directional |
MongoDB Servers |
MongoDB replication |
Only if using externalized databases. Port is user-defined, assuming the default MongoDB port. |
RabbitMQ Servers
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
5672 |
TCP |
Inbound |
Services Machine |
RabbitMQ connection |
Only if using externalized RabbitMQ |
5672 |
TCP |
Bi-directional |
RabbitMQ Servers |
RabbitMQ mirroring |
Only if using externalized RabbitMQ |
Redis Servers
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
6379 |
TCP |
Inbound |
Services Machine |
Redis connection |
Only if using externalized Redis |
6379 |
TCP |
Bi-directional |
Redis Servers |
Redis replication |
Only if using externalized Redis, and using Redis replication (optional) |
Nomad Servers
| Port number | Protocol | Direction | Source / destination | Use | Notes |
|---|---|---|---|---|---|
4646 |
TCP |
Inbound |
Services Machine |
Nomad Server connection |
Only if using externalized Nomad Servers |
4647 |
TCP |
Inbound |
Services Machine |
Nomad Server connection |
Only if using externalized Nomad Servers |
4648 |
TCP |
Bi-directional |
Nomad Servers |
Nomad Servers internal communication |
Only if using externalized Nomad Servers |