Configure the GitLab chart with GitLab Geo

GitLab Geo provides the ability to have geographically distributed application deployments.

While external database services can be used, these documents focus on the use of the Linux package for PostgreSQL to provide the most platform agnostic guide, and make use of the automation included in gitlab-ctl.

In this guide, both clusters have the same external URL. This feature is supported by the chart since version 7.3. See Set up a Unified URL for Geo sites. You can optionally configure a separate URL for the secondary site.

note
See the defined terms to describe all aspects of Geo (mainly the distinction between site and node).

Requirements

To use GitLab Geo with the GitLab Helm chart, the following requirements must be met:

  • The use of external PostgreSQL services, as the PostgresSQL included with the chart is not exposed to outside networks, and doesn’t have WAL support required for replication.
  • The supplied database must:
    • Support replication.
    • The primary database must be reachable by the primary site, and all secondary database nodes (for replication).
    • Secondary databases only need to be reachable by the secondary sites.
    • Support SSL between primary and secondary database nodes.
  • The primary site must be reachable via HTTP(S) by all secondary sites. Secondary sites must be accessible to the primary site via HTTP(S).
  • See requirements for running Geo for the full list of requirements.

Limitations

See Geo limitations for a complete list of limitations.

Overview

This guide uses 2 database nodes created by using the Linux package, configuring only the PostgreSQL services needed, and 2 deployments of the GitLab Helm chart. It is intended to be the minimal required configuration. This documentation does not include SSL from application to database, support for other database providers, or promoting a secondary site to primary.

The outline below should be followed in order:

  1. Set up Linux package database nodes
  2. Set up Kubernetes clusters
  3. Collect information
  4. Configure Primary database
  5. Deploy chart as Geo Primary site
  6. Set the Geo Primary site
  7. Configure Secondary database
  8. Copy secrets from the primary site to the secondary site
  9. Deploy chart as Geo Secondary site
  10. Add Secondary Geo site via Primary
  11. Confirm Operational Status
  12. Configure a separate URL for the secondary site (Optional)
  13. Registry
  14. Cert-manager and unified URL

Set up Linux package database nodes

For this process, two nodes are required. One is the Primary database node, the other the Secondary database node. You may use any provider of machine infrastructure, on-premise or from a cloud provider.

Bear in mind that communication is required:

  • Between the two database nodes for replication.
  • Between each database node and their respective Kubernetes deployments:
    • The primary needs to expose TCP port 5432.
    • The secondary needs to expose TCP ports 5432 & 5431.

Install an operating system supported by the Linux package, and then install the Linux package onto it. Do not provide the EXTERNAL_URL environment variable when installing, as we’ll provide a minimal configuration file before reconfiguring the package.

After you have installed the operating system, and the GitLab package, configuration can be created for the services that will be used. Before we do that, information must be collected.

Set up Kubernetes clusters

For this process, two Kubernetes clusters should be used. These can be from any provider, on-premise or from a cloud provider.

Bear in mind that communication is required:

  • To the respective database nodes:
    • Primary outbound to TCP 5432.
    • Secondary outbound to TCP 5432 and 5431.
  • Between both Kubernetes Ingress via HTTPS.

Each cluster that is provisioned should have:

Collect information

To continue with the configuration, the following information needs to be collected from the various sources. Collect these, and make notes for use through the rest of this documentation.

  • Primary database:
    • IP address
    • hostname (optional)
  • Secondary database:
    • IP address
    • hostname (optional)
  • Primary cluster:
    • External URL
    • Internal URL
    • IP addresses of nodes
  • Secondary cluster:
    • Internal URL
    • IP addresses of nodes
  • Database Passwords (must pre-decide the passwords):
    • gitlab (used in postgresql['sql_user_password'], global.psql.password)
    • gitlab_geo (used in geo_postgresql['sql_user_password'], global.geo.psql.password)
    • gitlab_replicator (needed for replication)
  • Your GitLab license file

The Internal URL of each cluster must be unique to the cluster, so that all clusters can make requests to all other clusters. For example:

  • External URL of all clusters: https://gitlab.example.com
  • Primary cluster’s Internal URL: https://london.gitlab.example.com
  • Secondary cluster’s Internal URL: https://shanghai.gitlab.example.com

This guide does not cover setting up DNS.

The gitlab and gitlab_geo database user passwords must exist in two forms: bare password, and PostgreSQL hashed password. To obtain the hashed form, perform the following commands on one of the Linux package installation instances, which asks you to enter and confirm the password before outputting an appropriate hash value for you to make note of.

  1. gitlab-ctl pg-password-md5 gitlab
  2. gitlab-ctl pg-password-md5 gitlab_geo

Configure Primary database

This section is performed on the Primary Linux package installation database node.

To configure the Primary database node’s Linux package installation, work from this example configuration: 

### Geo Primary
external_url 'http://gitlab.example.com'
roles ['geo_primary_role']
# The unique identifier for the Geo node.
gitlab_rails['geo_node_name'] = 'London Office'
gitlab_rails['auto_migrate'] = false
## turn off everything but the DB
sidekiq['enable']=false
puma['enable']=false
gitlab_workhorse['enable']=false
nginx['enable']=false
geo_logcursor['enable']=false
grafana['enable']=false
gitaly['enable']=false
redis['enable']=false
gitlab_kas['enable']=false
prometheus_monitoring['enable'] = false
## Configure the DB for network
postgresql['enable'] = true
postgresql['listen_address'] = '0.0.0.0'
postgresql['sql_user_password'] = 'gitlab_user_password_hash'
# !! CAUTION !!
# This list of CIDR addresses should be customized
# - primary application deployment
# - secondary database node(s)
postgresql['md5_auth_cidr_addresses'] = ['0.0.0.0/0']

We must replace several items:

  • external_url must be updated to reflect the host name of our Primary site.
  • gitlab_rails['geo_node_name'] must be replaced with a unique name for your site. See the Name field in Common settings.
  • gitlab_user_password_hash must be replaced with the hashed form of the gitlab password.
  • postgresql['md5_auth_cidr_addresses'] can be update to be a list of explicit IP addresses, or address blocks in CIDR notation.

The md5_auth_cidr_addresses should be in the form of [ '127.0.0.1/24', '10.41.0.0/16']. It is important to include 127.0.0.1 in this list, as the automation in the Linux package connects using this. The addresses in this list should include the IP address (not hostname) of your Secondary database, and all nodes of your primary Kubernetes cluster. This can be left as ['0.0.0.0/0'], however it is not best practice.

After the configuration above is prepared:

  1. Place the content into /etc/gitlab/gitlab.rb
  2. Run gitlab-ctl reconfigure. If you experience any issues in regards to the service not listening on TCP, try directly restarting it with gitlab-ctl restart postgresql.
  3. Run gitlab-ctl set-replication-password to set the password for the gitlab_replicator user.

  4. Retrieve the Primary database node’s public certificate, this is needed for the Secondary database to be able to replicate (save this output): 

    cat ~gitlab-psql/data/server.crt

Deploy chart as Geo Primary site

This section is performed on the Primary site’s Kubernetes cluster.

To deploy this chart as a Geo Primary, start from this example configuration:

  1. Create a secret containing the database password for the chart to consume. Replace PASSWORD below with the password for the gitlab database user: 

    kubectl --namespace gitlab create secret generic geo --from-literal=postgresql-password=PASSWORD

  2. Create a primary.yaml file based on the example configuration and update the configuration to reflect the correct values: 

    ### Geo Primary
global:
  # See docs.gitlab.com/charts/charts/globals
  # Configure host & domain
  hosts:
    domain: example.com
    # optionally configure a static IP for the default LoadBalancer
    # externalIP: 
    # optionally configure a static IP for the Geo LoadBalancer
    # externalGeoIP:
  # configure DB connection
  psql:
    host: geo-1.db.example.com
    port: 5432
    password:
      secret: geo
      key: postgresql-password
  # configure geo (primary)
  geo:
    nodeName: London Office
    enabled: true
    role: primary
# configure Geo Nginx Controller for internal Geo site traffic
nginx-ingress-geo:
  enabled: true
gitlab:
  webservice:
    # Use the Geo NGINX controller.
    ingress:
      useGeoClass: true
    # Configure an Ingress for internal Geo traffic
    extraIngress:
      enabled: true
      hostname: gitlab.london.example.com
      useGeoClass: true
# External DB, disable
postgresql:
  install: false

  3. Deploy the chart using this configuration: 

    helm upgrade --install gitlab-geo gitlab/gitlab --namespace gitlab -f primary.yaml
    note
    This assumes you are using the gitlab namespace. If you want to use a different namespace, you should also replace it in --namespace gitlab throughout the rest of this document.

  4. Wait for the deployment to complete, and the application to come online. When the application is reachable, log in.

  5. Sign in to GitLab, and activate your GitLab subscription.

    note
    This step is required for Geo to function.

Set the Geo Primary site

Now that the chart has been deployed, and a license uploaded, we can configure this as the Primary site. We will do this via the Toolbox Pod.

  1. Find the Toolbox Pod 

    kubectl --namespace gitlab get pods -lapp=toolbox

  2. Run gitlab-rake geo:set_primary_node with kubectl exec: 

    kubectl --namespace gitlab exec -ti gitlab-geo-toolbox-XXX -- gitlab-rake geo:set_primary_node

  3. Set the primary site’s Internal URL with a Rails runner command. Replace https://primary.gitlab.example.com with the actual Internal URL: 

    kubectl --namespace gitlab exec -ti gitlab-geo-toolbox-XXX -- gitlab-rails runner "GeoNode.primary_node.update!(internal_url: 'https://primary.gitlab.example.com')"

  4. Check the status of Geo configuration: 

    kubectl --namespace gitlab exec -ti gitlab-geo-toolbox-XXX -- gitlab-rake gitlab:geo:check

    You should see output similar to below: 

    WARNING: This version of GitLab depends on gitlab-shell 10.2.0, but you're running Unknown. Please update gitlab-shell.
Checking Geo ...

GitLab Geo is available ... yes
GitLab Geo is enabled ... yes
GitLab Geo secondary database is correctly configured ... not a secondary node
Database replication enabled? ... not a secondary node
Database replication working? ... not a secondary node
GitLab Geo HTTP(S) connectivity ... not a secondary node
HTTP/HTTPS repository cloning is enabled ... yes
Machine clock is synchronized ... Exception: getaddrinfo: Servname not supported for ai_socktype
Git user has default SSH configuration? ... yes
OpenSSH configured to use AuthorizedKeysCommand ... no
  Reason:
  Cannot find OpenSSH configuration file at: /assets/sshd_config
  Try fixing it:
  If you are not using our official docker containers,
  make sure you have OpenSSH server installed and configured correctly on this system
  For more information see:
  doc/administration/operations/fast_ssh_key_lookup.md
GitLab configured to disable writing to authorized_keys file ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... yes

Checking Geo ... Finished
    • Don’t worry about Exception: getaddrinfo: Servname not supported for ai_socktype, as Kubernetes containers don’t have access to the host clock. This is OK.
    • OpenSSH configured to use AuthorizedKeysCommand ... no is expected. This Rake task is checking for a local SSH server, which is actually present in the gitlab-shell chart, deployed elsewhere, and already configured appropriately.

Configure Secondary database

This section is performed on the Secondary Linux package installation database node.

To configure the Secondary database node’s Linux package installation, work from this example configuration: 

### Geo Secondary
# external_url must match the Primary cluster's external_url
external_url 'http://gitlab.example.com'
roles ['geo_secondary_role']
gitlab_rails['enable'] = true
# The unique identifier for the Geo node.
gitlab_rails['geo_node_name'] = 'Shanghai Office'
gitlab_rails['auto_migrate'] = false
geo_secondary['auto_migrate'] = false
## turn off everything but the DB
sidekiq['enable']=false
puma['enable']=false
gitlab_workhorse['enable']=false
nginx['enable']=false
geo_logcursor['enable']=false
grafana['enable']=false
gitaly['enable']=false
redis['enable']=false
prometheus_monitoring['enable'] = false
gitlab_kas['enable']=false
## Configure the DBs for network
postgresql['enable'] = true
postgresql['listen_address'] = '0.0.0.0'
postgresql['sql_user_password'] = 'gitlab_user_password_hash'
# !! CAUTION !!
# This list of CIDR addresses should be customized
# - secondary application deployment
# - secondary database node(s)
postgresql['md5_auth_cidr_addresses'] = ['0.0.0.0/0']
geo_postgresql['listen_address'] = '0.0.0.0'
geo_postgresql['sql_user_password'] = 'gitlab_geo_user_password_hash'
# !! CAUTION !!
# This list of CIDR addresses should be customized
# - secondary application deployment
# - secondary database node(s)
geo_postgresql['md5_auth_cidr_addresses'] = ['0.0.0.0/0']
gitlab_rails['db_password']='gitlab_user_password'

We must replace several items:

  • gitlab_rails['geo_node_name'] must be replaced with a unique name for your site. See the Name field in Common settings.
  • gitlab_user_password_hash must be replaced with the hashed form of the gitlab password.
  • postgresql['md5_auth_cidr_addresses'] should be updated to be a list of explicit IP addresses, or address blocks in CIDR notation.
  • gitlab_geo_user_password_hash must be replaced with the hashed form of the gitlab_geo password.
  • geo_postgresql['md5_auth_cidr_addresses'] should be updated to be a list of explicit IP addresses, or address blocks in CIDR notation.
  • gitlab_user_password must be updated, and is used here to allow the Linux package to automate the PostgreSQL configuration.

The md5_auth_cidr_addresses should be in the form of [ '127.0.0.1/24', '10.41.0.0/16']. It is important to include 127.0.0.1 in this list, as the automation in the Linux package connects using this. The addresses in this list should include the IP addresses of all nodes of your Secondary Kubernetes cluster. This can be left as ['0.0.0.0/0'], however it is not best practice.

After configuration above is prepared:

  1. Check TCP connectivity to the primary site’s PostgreSQL node: 

    openssl s_client -connect <primary_node_ip>:5432 </dev/null

    The output should show the following: 

    CONNECTED(00000003)
write:errno=0
    note
    If this step fails, you may be using the wrong IP address, or a firewall may be preventing access to the server. Check the IP address, paying close attention to the difference between public and private addresses and ensure that, if a firewall is present, the secondary PostgreSQL node is permitted to connect to the primary PostgreSQL node on TCP port 5432.
  2. Place the content into /etc/gitlab/gitlab.rb
  3. Run gitlab-ctl reconfigure. If you experience any issues in regards to the service not listening on TCP, try directly restarting it with gitlab-ctl restart postgresql.
  4. Place the Primary PostgreSQL node’s certificate content from above into primary.crt

  5. Set up PostgreSQL TLS verification on the secondary PostgreSQL node:

    Install the primary.crt file: 

    install \
   -D \
   -o gitlab-psql \
   -g gitlab-psql \
   -m 0400 \
   -T primary.crt ~gitlab-psql/.postgresql/root.crt

    PostgreSQL will now only recognize that exact certificate when verifying TLS connections. The certificate can only be replicated by someone with access to the private key, which is only present on the primary PostgreSQL node.

  6. Test that the gitlab-psql user can connect to the primary site’s PostgreSQL (the default Linux package database name is gitlabhq_production): 

    sudo \
   -u gitlab-psql /opt/gitlab/embedded/bin/psql \
   --list \
   -U gitlab_replicator \
   -d "dbname=gitlabhq_production sslmode=verify-ca" \
   -W \
   -h <primary_database_node_ip>

    When prompted enter the password collected earlier for the gitlab_replicator user. If all worked correctly, you should see the list of primary PostgreSQL node’s databases.

    A failure to connect here indicates that the TLS configuration is incorrect. Ensure that the contents of ~gitlab-psql/data/server.crt on the primary PostgreSQL node match the contents of ~gitlab-psql/.postgresql/root.crt on the secondary PostgreSQL node.

  7. Replicate the databases. Replace PRIMARY_DATABASE_HOST with the IP or hostname of your Primary PostgreSQL node: 

    gitlab-ctl replicate-geo-database --slot-name=geo_2 --host=PRIMARY_DATABASE_HOST --sslmode=verify-ca

  8. After replication has finished, we must reconfigure the Linux package one last time to ensure pg_hba.conf is correct for the secondary PostgreSQL node: 

    gitlab-ctl reconfigure

Copy secrets from the primary site to the secondary site

Now copy a few secrets from the Primary site’s Kubernetes deployment to the Secondary site’s Kubernetes deployment:

  • gitlab-geo-gitlab-shell-host-keys
  • gitlab-geo-rails-secret
  • gitlab-geo-registry-secret, if Registry replication is enabled.
  1. Change your kubectl context to that of your Primary.

  2. Collect these secrets from the Primary deployment: 

    kubectl get --namespace gitlab -o yaml secret gitlab-geo-gitlab-shell-host-keys > ssh-host-keys.yaml
kubectl get --namespace gitlab -o yaml secret gitlab-geo-rails-secret > rails-secrets.yaml
kubectl get --namespace gitlab -o yaml secret gitlab-geo-registry-secret > registry-secrets.yaml
  3. Change your kubectl context to that of your Secondary.

  4. Apply these secrets: 

    kubectl --namespace gitlab apply -f ssh-host-keys.yaml
kubectl --namespace gitlab apply -f rails-secrets.yaml
kubectl --namespace gitlab apply -f registry-secrets.yaml

Next create a secret containing the database passwords. Replace the passwords below with the appropriate values: 

kubectl --namespace gitlab create secret generic geo \
   --from-literal=postgresql-password=gitlab_user_password \
   --from-literal=geo-postgresql-password=gitlab_geo_user_password

Deploy chart as Geo Secondary site

This section is performed on the Secondary site’s Kubernetes cluster.

To deploy this chart as a Geo Secondary site, start from this example configuration.

  1. Create a secondary.yaml file based on the example configuration and update the configuration to reflect the correct values: 

    ## Geo Secondary
global:
  # See docs.gitlab.com/charts/charts/globals
  # Configure host & domain
  hosts:
    domain: shanghai.example.com
    # use a unified URL (same external URL as the primary site)
    gitlab:
      name: gitlab.example.com
  # configure DB connection
  psql:
    host: geo-2.db.example.com
    port: 5432
    password:
      secret: geo
      key: postgresql-password
  # configure geo (secondary)
  geo:
    enabled: true
    role: secondary
    nodeName: Shanghai Office
    psql:
      host: geo-2.db.example.com
      port: 5431
      password:
        secret: geo
        key: geo-postgresql-password
gitlab:
  webservice:
    # Configure a Ingress for internal Geo traffic
    extraIngress:
      enabled: true
      hostname: shanghai.gitlab.example.com
# External DB, disable
postgresql:
  install: false

  2. Deploy the chart using this configuration: 

    helm upgrade --install gitlab-geo gitlab/gitlab --namespace gitlab -f secondary.yaml

  3. Wait for the deployment to complete, and the application to come online.

Add Secondary Geo site via Primary

Now that both databases are configured and applications are deployed, we must tell the Primary site that the Secondary site exists:

  1. Visit the primary site.
  2. On the left sidebar, at the bottom, select Admin Area.
  3. Select Geo > Add site.
  4. Add the secondary site. Use the full GitLab URL for the URL.
  5. Enter a Name with the global.geo.nodeName of the Secondary site. These values must always match exactly, character for character.
  6. Enter Internal URL, for example https://shanghai.gitlab.example.com.
  7. Optionally, choose which groups or storage shards should be replicated by the secondary site. Leave blank to replicate all.
  8. Select Add node.

After the secondary site is added to the administration panel, it automatically starts replicating missing data from the primary site. This process is known as “backfill”. Meanwhile, the primary site starts to notify each secondary site of any changes, so that the secondary site can replicate those changes promptly.

Confirm Operational Status

The final step is to double check the Geo configuration on the secondary site once fully configured, via the Toolbox Pod.

  1. Find the Toolbox Pod: 

    kubectl --namespace gitlab get pods -lapp=toolbox

  2. Attach to the Pod with kubectl exec: 

    kubectl --namespace gitlab exec -ti gitlab-geo-toolbox-XXX -- bash -l

  3. Check the status of Geo configuration: 

    gitlab-rake gitlab:geo:check

    You should see output similar to below: 

    WARNING: This version of GitLab depends on gitlab-shell 10.2.0, but you're running Unknown. Please update gitlab-shell.
Checking Geo ...

GitLab Geo is available ... yes
GitLab Geo is enabled ... yes
GitLab Geo secondary database is correctly configured ... yes
Database replication enabled? ... yes
Database replication working? ... yes
GitLab Geo HTTP(S) connectivity ...
* Can connect to the primary node ... yes
HTTP/HTTPS repository cloning is enabled ... yes
Machine clock is synchronized ... Exception: getaddrinfo: Servname not supported for ai_socktype
Git user has default SSH configuration? ... yes
OpenSSH configured to use AuthorizedKeysCommand ... no
  Reason:
  Cannot find OpenSSH configuration file at: /assets/sshd_config
  Try fixing it:
  If you are not using our official docker containers,
  make sure you have OpenSSH server installed and configured correctly on this system
  For more information see:
  doc/administration/operations/fast_ssh_key_lookup.md
GitLab configured to disable writing to authorized_keys file ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... yes

Checking Geo ... Finished
    • Don’t worry about Exception: getaddrinfo: Servname not supported for ai_socktype, as Kubernetes containers do not have access to the host clock. This is OK.
    • OpenSSH configured to use AuthorizedKeysCommand ... no is expected. This Rake task is checking for a local SSH server, which is actually present in the gitlab-shell chart, deployed elsewhere, and already configured appropriately.

Configure a separate URL for the secondary site (Optional)

A single, unified URL for the primary and secondary site is usually more convenient for users. For example, you can:

  • Place both sites behind a load balancer.
  • Route users to the closest site using your cloud provider’s DNS features.

In some cases, you may want to give users control over which site they visit. For this purpose, you can configure the secondary Geo site to use a unique external URL. For example:

  • Primary cluster’s External URL: https://gitlab.example.com
  • Secondary cluster’s External URL: https://shanghai.gitlab.example.com

  1. Edit secondary.yaml and update the secondary cluster’s external URL so that the webservice chart can process those requests: 

    global:
  # See docs.gitlab.com/charts/charts/globals
  # Configure host & domain
  hosts:
    domain: example.com
    # use a unique external URL for the secondary site
    gitlab:
      name: shanghai.gitlab.example.com
  2. Update the secondary site’s External URL in GitLab so that it can use the URL wherever it’s needed:
    • Using the Admin UI:
      1. Visit the primary site.
      2. On the left sidebar, at the bottom, select Admin Area.
      3. Select Geo > Sites.
      4. Select the pencil icon to Edit the secondary site.
      5. Edit the External URL, for example https://shanghai.gitlab.example.com.
      6. Select Save changes.
    • Using a Rails runner command:

      1. In a toolbox container in the primary site: 

        kubectl --namespace gitlab exec -ti gitlab-geo-toolbox-XXX -- gitlab-rails runner "GeoNode.secondary_nodes.last.update!(url: 'https://shanghai.gitlab.example.com')"

  3. Redeploy the secondary site’s chart: 

    helm upgrade --install gitlab-geo gitlab/gitlab --namespace gitlab -f secondary.yaml
  4. Wait for the deployment to complete, and the application to come online.

Registry

To sync the secondary registry with the primary registry you can configure registry replication using a notification secret.

Cert-manager and unified URL

Geo’s unified URL is often used with geolocation-aware routing (for example, using Amazon Route 53 or Google Cloud DNS), which can cause problems if the HTTP01 challenge is used to validate that the domain name is under your control.

When you request a certificate for one Geo site, Let’s Encrypt must resolve the DNS name to the requesting Geo site. If the DNS resolves to a different Geo site, the certificate for the unified URL will not be issued or refreshed.

To reliably create and refresh certificates with cert-manager, either set the challenge nameserver to a server that is known to resolve the unified hostname to the Geo sites IP address or configure a DNS01 Issuer.