GitLab.com settings

In this page you will find information about the settings that are used on GitLab.com.

SSH host keys fingerprints

Below are the fingerprints for GitLab.com's SSH host keys.

Algorithm	MD5	SHA256
DSA	`7a:47:81:3a:ee:89:89:64:33:ca:44:52:3d:30:d4:87`	`p8vZBUOR0XQz6sYiaWSMLmh0t9i8srqYKool/Xfdfqw`
ECDSA	`f1:d0:fb:46:73:7a:70:92:5a:ab:5d:ef:43:e2:1c:35`	`HbW3g8zUjNSksFbqTiUWPWg2Bq1x8xdGUrliXFzSnUw`
ED25519	`2e:65:6a:c8:cf:bf:b2:8b:9a:bd:6d:9f:11:5c:12:16`	`eUXGGm1YGsMAS7vkcx6JOJdOGHPem5gQp4taiCfCLB8`
RSA	`b6:03:0e:39:97:9e:d0:e7:24:ce:a3:77:3e:01:42:09`	`ROQFvPThGrW4RuWLoL9tq9I9zJ42fK4XywyRtbOz/EQ`

Mail configuration

GitLab.com sends emails from the mg.gitlab.com domain via Mailgun and has its own dedicated IP address (198.61.254.240).

Alternative SSH port

GitLab.com can be reached via a different SSH port for git+ssh.

Setting	Value
`Hostname`	`altssh.gitlab.com`
`Port`	`443`

An example ~/.ssh/config is the following:

Host gitlab.com
  Hostname altssh.gitlab.com
  User git
  Port 443
  PreferredAuthentications publickey
  IdentityFile ~/.ssh/gitlab

GitLab Pages

Below are the settings for GitLab Pages.

Setting	GitLab.com	Default
Domain name	`gitlab.io`	-
IP address	`35.185.44.232`	-
Custom domains support	yes	no
TLS certificates support	yes	no

The maximum size of your Pages site is regulated by the artifacts maximum size which is part of GitLab CI/CD.

GitLab CI/CD

Below are the current settings regarding GitLab CI/CD.

Setting	GitLab.com	Default
Artifacts maximum size	1G	100M
Artifacts expiry time	kept forever	deleted after 30 days unless otherwise specified

Repository size limit

The maximum size your Git repository is allowed to be, including LFS. If you are near or over the size limit, you can reduce your repository size with Git.

Setting	GitLab.com	Default
Repository size including LFS	10G	Unlimited

IP range

GitLab.com, CI/CD, and related services are deployed into Google Cloud Platform (GCP). Any IP based firewall can be configured by looking up all IP address ranges or CIDR blocks for GCP.

Static endpoints are being considered.

Shared Runners

Shared Runners on GitLab.com run in autoscale mode and powered by Google Cloud Platform. Autoscaling means reduced waiting times to spin up CI/CD jobs, and isolated VMs for each project, thus maximizing security. They're free to use for public open source projects and limited to 2000 CI minutes per month per group for private projects. More minutes can be purchased, if needed. Read about all GitLab.com plans.

All your CI/CD jobs run on n1-standard-1 instances with 3.75GB of RAM, CoreOS and the latest Docker Engine installed. Instances provide 1 vCPU and 25GB of HDD disk space. The default region of the VMs is US East1. Each instance is used only for one job, this ensures any sensitive data left on the system can't be accessed by other people their CI jobs.

Jobs handled by the shared Runners on GitLab.com (shared-runners-manager-X.gitlab.com), will be timed out after 3 hours, regardless of the timeout configured in a project. Check the issues 4010 and 4070 for the reference.

Below are the shared Runners settings.

Setting	GitLab.com	Default
GitLab Runner	Runner versions dashboard	-
Executor	`docker+machine`	-
Default Docker image	`ruby:2.5`	-
`privileged` (run Docker in Docker)	`true`	`false`

`config.toml`

The full contents of our config.toml are:

Google Cloud Platform

concurrent = X
check_interval = 1
metrics_server = "X"
sentry_dsn = "X"

[[runners]]
  name = "docker-auto-scale"
  request_concurrency = X
  url = "https://gitlab.com/"
  token = "SHARED_RUNNER_TOKEN"
  executor = "docker+machine"
  environment = [
    "DOCKER_DRIVER=overlay2",
    "DOCKER_TLS_CERTDIR="
  ]
  limit = X
  [runners.docker]
    image = "ruby:2.5"
    privileged = true
    volumes = [
      "/certs/client",
      "/dummy-sys-class-dmi-id:/sys/class/dmi/id:ro" # Make kaniko builds work on GCP.
    ]
  [runners.machine]
    IdleCount = 50
    IdleTime = 3600
    OffPeakPeriods = ["* * * * * sat,sun *"]
    OffPeakTimezone = "UTC"
    OffPeakIdleCount = 15
    OffPeakIdleTime = 3600
    MaxBuilds = 1 # For security reasons we delete the VM after job has finished so it's not reused.
    MachineName = "srm-%s"
    MachineDriver = "google"
    MachineOptions = [
      "google-project=PROJECT",
      "google-disk-size=25",
      "google-machine-type=n1-standard-1",
      "google-username=core",
      "google-tags=gitlab-com,srm",
      "google-use-internal-ip",
      "google-zone=us-east1-d",
      "engine-opt=mtu=1460", # Set MTU for container interface, for more information check https://gitlab.com/gitlab-org/gitlab-runner/issues/3214#note_82892928
      "google-machine-image=PROJECT/global/images/IMAGE",
      "engine-opt=ipv6", # This will create IPv6 interfaces in the containers.
      "engine-opt=fixed-cidr-v6=fc00::/7",
      "google-operation-backoff-initial-interval=2" # Custom flag from forked docker-machine, for more information check https://github.com/docker/machine/pull/4600
    ]
  [runners.cache]
    Type = "gcs"
    Shared = true
    [runners.cache.gcs]
      CredentialsFile = "/path/to/file"
      BucketName = "bucket-name"

Sidekiq

GitLab.com runs Sidekiq with arguments --timeout=4 --concurrency=4 and the following environment variables:

Setting	GitLab.com	Default
`SIDEKIQ_MEMORY_KILLER_MAX_RSS`	`1000000`	`2000000`
`SIDEKIQ_MEMORY_KILLER_SHUTDOWN_SIGNAL`	`SIGKILL`	-
`SIDEKIQ_LOG_ARGUMENTS`	`1`	-

Cron jobs

Periodically executed jobs by Sidekiq, to self-heal GitLab, do external synchronizations, run scheduled pipelines, etc.:

Setting	GitLab.com	Default
`pipeline_schedule_worker`	`19 * * * *`	`19 * * * *`

PostgreSQL

GitLab.com being a fairly large installation of GitLab means we have changed various PostgreSQL settings to better suit our needs. For example, we use streaming replication and servers in hot-standby mode to balance queries across different database servers.

The list of GitLab.com specific settings (and their defaults) is as follows:

Setting	GitLab.com	Default
archive_command	`/usr/bin/envdir /etc/wal-e.d/env /opt/wal-e/bin/wal-e wal-push %p`	empty
archive_mode	on	off
autovacuum_analyze_scale_factor	0.01	0.01
autovacuum_max_workers	6	3
autovacuum_vacuum_cost_limit	1000	-1
autovacuum_vacuum_scale_factor	0.01	0.02
checkpoint_completion_target	0.7	0.9
checkpoint_segments	32	10
effective_cache_size	338688MB	Based on how much memory is available
hot_standby	on	off
hot_standby_feedback	on	off
log_autovacuum_min_duration	0	-1
log_checkpoints	on	off
log_line_prefix	`%t [%p]: [%l-1]`	empty
log_min_duration_statement	1000	-1
log_temp_files	0	-1
maintenance_work_mem	2048MB	16 MB
max_replication_slots	5	0
max_wal_senders	32	0
max_wal_size	5GB	1GB
shared_buffers	112896MB	Based on how much memory is available
shared_preload_libraries	pg_stat_statements	empty
shmall	30146560	Based on the server's capabilities
shmmax	123480309760	Based on the server's capabilities
wal_buffers	16MB	-1
wal_keep_segments	512	10
wal_level	replica	minimal
statement_timeout	15s	60s
idle_in_transaction_session_timeout	60s	60s

Some of these settings are in the process being adjusted. For example, the value for shared_buffers is quite high and as such we are looking into adjusting it. More information on this particular change can be found at https://gitlab.com/gitlab-com/infrastructure/issues/1555. An up to date list of proposed changes can be found at https://gitlab.com/gitlab-com/infrastructure/issues?scope=all&utf8=%E2%9C%93&state=opened&label_name[]=database&label_name[]=change.

Unicorn

GitLab.com adjusts the memory limits for the unicorn-worker-killer gem.

Base default:

memory_limit_min = 750MiB
memory_limit_max = 1024MiB

Web front-ends:

memory_limit_min = 1024MiB
memory_limit_max = 1280MiB

GitLab.com-specific rate limits

NOTE: Note: See Rate limits for administrator documentation.

IP blocks usually happen when GitLab.com receives unusual traffic from a single IP address that the system views as potentially malicious based on rate limit settings. After the unusual traffic ceases, the IP address will be automatically released depending on the type of block, as described below.

If you receive a 403 Forbidden error for all requests to GitLab.com, please check for any automated processes that may be triggering a block. For assistance, contact GitLab Support with details, such as the affected IP address.

HAProxy API throttle

GitLab.com responds with HTTP status code 429 to API requests that exceed 10 requests per second per IP address.

The following example headers are included for all API requests:

RateLimit-Limit: 600
RateLimit-Observed: 6
RateLimit-Remaining: 594
RateLimit-Reset: 1563325137
RateLimit-ResetTime: Wed, 17 Jul 2019 00:58:57 GMT

Source:

Search for rate_limit_http_rate_per_minute and rate_limit_sessions_per_second in GitLab.com's current HAProxy settings.

Rack Attack initializer

Details of rate limits enforced by Rack Attack.

Protected paths throttle

GitLab.com responds with HTTP status code 429 to POST requests at protected paths that exceed 10 requests per minute per IP address.

See the source below for which paths are protected. This includes user creation, user confirmation, user sign in, and password reset.

This header is included in responses to blocked requests:

Retry-After: 60

Source:

Search for rate_limit_requests_per_period, rate_limit_period, and rack_attack_protected_paths in GitLab.com's current Rails app settings.

Git and container registry failed authentication ban

GitLab.com responds with HTTP status code 403 for 1 hour, if 30 failed authentication requests were received in a 3-minute period from a single IP address.

This applies only to Git requests and container registry (/jwt/auth) requests (combined).

This limit is reset by requests that authenticate successfully. For example, 29 failed authentication requests followed by 1 successful request, followed by 29 more failed authentication requests would not trigger a ban.

No response headers are provided.

Admin Area settings

GitLab.com does not currently use these settings.

GitLab.com at scale

In addition to the GitLab Enterprise Edition Omnibus install, GitLab.com uses the following applications and settings to achieve scale. All settings are located publicly available chef cookbooks.