GitLab Platform Module

Terraform module for deploying GitLab CI/CD platform to Kubernetes. Provides a complete DevOps platform including source control, CI/CD pipelines, container registry, and package registry with Auth0 SSO and MinIO object storage integration.

Note: GitLab only supports AMD64 architecture. This module is automatically skipped on ARM64 clusters.

Architecture

flowchart TB
    subgraph external [External]
        User[Developer]
        Auth0[Auth0 IdP]
    end

    subgraph k8s [Kubernetes Cluster]
        subgraph ingress [Ingress Layer]
            Nginx[NGINX Ingress]
        end

        subgraph ns [Namespace: gitlab]
            subgraph webservice [Webservice]
                WebUI[GitLab UI]
                API[GitLab API]
            end

            subgraph sidekiq [Background Jobs]
                Sidekiq[Sidekiq Workers]
            end

            subgraph gitaly [Git Storage]
                Gitaly[Gitaly]
                GitalyPVC[(Gitaly PVC)]
            end

            subgraph registry [Container Registry]
                Registry[Registry]
            end

            subgraph runner [CI/CD]
                Runner[GitLab Runner]
            end

            subgraph data [Data Stores]
                PostgreSQL[(CloudNativePG - PostgreSQL 17)]
                Valkey[(Valkey)]
                PGSQLPVC[(PostgreSQL PVC)]
                ValkeyPVC[(Valkey PVC)]
            end

            Shell[GitLab Shell]
            Toolbox[Toolbox]
        end

        subgraph minio_ns [Namespace: minio-tenant]
            MinIO[(MinIO Object Storage)]
        end
    end

    User -->|HTTPS| Nginx
    Nginx --> WebUI
    Nginx --> Registry
    User -->|SSH| Shell

    WebUI --> PostgreSQL
    WebUI --> Valkey
    WebUI --> Gitaly
    Sidekiq --> PostgreSQL
    Sidekiq --> Valkey
    Registry --> PostgreSQL

    Registry --> MinIO
    Toolbox -->|backups| MinIO
    Runner -->|cache| MinIO

    WebUI -->|OIDC| Auth0

CI/CD Pipeline Flow

sequenceDiagram
    participant Dev as Developer
    participant GitLab as GitLab Webservice
    participant Runner as GitLab Runner
    participant Registry as Container Registry
    participant MinIO as MinIO Storage

    Dev->>GitLab: Push code
    GitLab->>Runner: Trigger pipeline
    Runner->>MinIO: Restore cache
    Runner->>Runner: Execute jobs
    Runner->>Registry: Push container image
    Runner->>MinIO: Save artifacts
    Runner->>MinIO: Update cache
    Runner-->>GitLab: Report status
    GitLab-->>Dev: Pipeline complete

Resources Created

Namespace and Secrets

• kubernetes_namespace.gitlab - Dedicated namespace
• kubernetes_secret.initial_root_password - Root admin password
• kubernetes_secret.valkey_password - Valkey authentication, key named default per the ACL user
• kubernetes_secret.postgresql_password - PostgreSQL credentials
• kubernetes_secret.rails_secret - Rails encryption keys
• kubernetes_secret.gitlab_shell_secret - Shell authentication
• kubernetes_secret.gitaly_secret - Gitaly authentication
• kubernetes_secret.gitlab_shell_host_keys - SSH host keys
• kubernetes_secret.gitlab_object_store_connection - MinIO connection
• kubernetes_secret.gitlab_registry_httpsecret - Registry secret
• kubernetes_secret.gitlab_registry_storage_secret - Registry MinIO config
• kubernetes_secret.gitlab_runner_s3_access - Runner S3 credentials
• kubernetes_secret.gitlab_toolbox_s3cmd - Backup toolbox config
• kubernetes_secret.gitlab_auth0_provider - Auth0 OIDC config

Storage

• kubernetes_storage_class_v1.gitlab_backup_ephemeral - Delete-reclaim class for the nightly backup's ephemeral volume

Helm Release

• helm_release.gitlab - GitLab Helm chart
• helm_release.cloudnative_pg - CloudNativePG operator
• helm_release.valkey - Valkey, replacing the removed bundled Redis
• kubectl_manifest.gitlab_postgres - CNPG Cluster, replacing the removed bundled PostgreSQL

Databases

Chart 10.0 removed the bundled PostgreSQL, Redis and MinIO subcharts, and the chart refuses to render if postgresql.install or redis.install is present and truthy. MinIO was already external via stage2/minio-object-storage; PostgreSQL and Redis moved here.

GitLab 19.0 sets MINIMUM_POSTGRES_VERSION = 17, so imageName is pinned deliberately: the CNPG operator's own default is an 18.x image, and omitting the field silently provisions PostgreSQL 18.

Service	Endpoint	Credentials
PostgreSQL	gitlab-pg-rw.gitlab.svc.cluster.local:5432	secret postgresql-password, key postgresql-password
Registry metadata DB	same host, database registry	secret registry-database-password
Valkey	gitlab-valkey.gitlab.svc.cluster.local:6379	secret valkey-password, key default

The Valkey secret key is default rather than password because the chart looks up auth.aclUsers.<user>.passwordKey, which defaults to the username, and AUTH <password> with no username authenticates as the default ACL user.

The CNPG Cluster

Defined in postgres-cluster.tf, which carries the rationale for the monolith import type and the pinned imageName. bootstrap.initdb.import runs only once, at bootstrap: re-importing means deleting the Cluster and its PVC first. externalClusters is consulted only during that import and is inert afterward.

postImportApplicationSQL is unsupported with monolith, so extensions must be added by hand after an import.

Operating it

amcheck is required by GitLab but absent from a fresh monolith import. Recreate it after any re-import:

kubectl -n gitlab exec gitlab-pg-1 -- psql -U postgres -d gitlabhq_production \
  -c "CREATE EXTENSION IF NOT EXISTS amcheck;"

Before re-importing, scale sidekiq, webservice, registry and kas to zero. KAS writes to the database and is easy to overlook; confirm with pg_stat_activity, not the pod list. Then delete the Cluster and re-apply.

backup-utility does not cover the registry database: Rails' database.yml declares only the main and ci connections, both on gitlabhq_production, and gitlab-backup iterates those connections. Dump registry separately before any migration. Restores also abort on a version mismatch. lib/backup/restore/preconditions.rb compares the backup's GitLab version to the running one by exact string equality, so a backup is only usable against the exact version that produced it.

Variables

Host Configuration

Name	Description	Default
gitlab_global_hosts_domain	Base domain for GitLab	chrislee.local
gitlab_global_hosts_host_suffix	Subdomain suffix	""
gitlab_global_hosts_https	Use HTTPS	true
gitlab_global_hosts_external_ip	External LoadBalancer IP	""
gitlab_time_zone	GitLab application timezone	Australia/Melbourne

Ingress Configuration

Name	Description	Default
gitlab_global_ingress_provider	Ingress provider	nginx
gitlab_global_ingress_class	Ingress class	nginx
gitlab_global_ingress_enable_tls	Enable TLS	true
gitlab_certmanager_issuer_email	Let's Encrypt email	""

MinIO Object Storage

Name	Description	Default
gitlab_minio_host	MinIO hostname	minio.chrislee.local
gitlab_minio_endpoint	MinIO endpoint URL	http://minio.chrislee.local
gitlab_minio_use_https	Use HTTPS for MinIO	False
gitlab_minio_access_key	MinIO access key	minio-user
gitlab_minio_secret_key	MinIO secret key	(from minio module, sensitive)

Persistence

Name	Description	Default
gitlab_persistence_storage_class_name	Storage class	longhorn
gitlab_toolbox_backups_cron_persistence_size	Backup staging volume size, per-pod ephemeral	30Gi
gitlab_toolbox_persistence_size	Toolbox PVC size	20Gi
gitlab_postgres_storage_size	CloudNativePG cluster data volume size	20Gi
gitlab_valkey_persistence_size	Valkey data volume size	2Gi
gitlab_gitaly_persistence_size	Gitaly PVC size	50Gi

CI/CD Runner

Name	Description	Default
gitlab_runner_authentication_token	Runner auth token	"" (sensitive)

Auth0 SSO

Name	Description	Default
gitlab_auth0_client_id	Auth0 client ID	""
gitlab_auth0_client_secret	Auth0 client secret	"" (sensitive)
gitlab_auth0_domain	Auth0 domain	chrislee.auth0.com

Usage

1. Configure Auth0 Application

1. Create a Regular Web Application in Auth0
2. Set Allowed Callback URLs: https://gitlab.chrislee.local/users/auth/auth0/callback
3. Copy Client ID and Client Secret

2. Configure Variables

TF_VAR_gitlab_global_hosts_domain="chrislee.local"
TF_VAR_gitlab_auth0_domain="your-tenant.auth0.com"
TF_VAR_gitlab_auth0_client_id="your-client-id"
TF_VAR_gitlab_auth0_client_secret="your-client-secret"

3. Deploy

task stage2:terraform:apply

4. Get Root Password

kubectl -n gitlab get secret initial-root-password -o jsonpath="{.data.password}" | base64 -d

5. Access GitLab

Navigate to https://gitlab.chrislee.local

• Username: root
• Password: (from step 4)

6. Configure Runner Token

1. Go to Admin > CI/CD > Runners
2. Create a new instance runner
3. Copy the authentication token
4. Set TF_VAR_gitlab_runner_authentication_token
5. Run task stage2:terraform:apply

Helm Chart

Property	Value
Repository	https://charts.gitlab.io/
Chart	gitlab

Endpoints

Service	URL
GitLab UI	https://gitlab.chrislee.local
Container Registry	https://registry.chrislee.local
SSH	ssh://git@gitlab.chrislee.local:22

MinIO Buckets Used

Bucket	Purpose
registry	Container images
git-lfs	Git LFS objects
runner-cache	CI runner cache
gitlab-uploads	User uploads
gitlab-artifacts	CI artifacts
gitlab-backups	Automated backups
gitlab-packages	Package registry

Backup and Restore

Manual Backup

kubectl -n gitlab exec -it $(kubectl -n gitlab get pod -l app=toolbox -o name) -- backup-utility

Scheduled Backups

Backups are configured to run via CronJob and stored in MinIO gitlab-backups bucket.

Each run stages its tarball on its own generic ephemeral volume, garbage-collected with the pod, so no shared claim can wedge the schedule. That volume uses a dedicated Delete-reclaim StorageClass (backup-storageclass.tf); the shared longhorn class is Retain and would strand a volume nightly.

Jobs are capped at 3h (activeDeadlineSeconds: 10800), generous against a healthy run. Without a deadline a stuck backup runs indefinitely, and concurrencyPolicy: Replace then deletes it on the next schedule, leaving no failed job behind to notice.

Troubleshooting

Registry Storage Full

Expand MinIO PVCs:

kubectl edit -n minio-tenant pvc data0-minio-tenant-pool-0-0

Check Component Status

kubectl -n gitlab get pods
kubectl -n gitlab logs deployment/gitlab-webservice-default

References

• GitLab Helm Chart Documentation
• GitLab Installation Secrets
• GitLab Runner Helm Chart
• Auth0 OmniAuth Provider