Ado Pipelines Ops

ADO Pipelines Operations & Infrastructure

When to Use

• Setting up self-hosted agent pools and registering agents
• Creating and managing service connections (Azure, GitHub, Docker, etc.)
• Managing variable groups and secure files (Library)
• Configuring deployment environments with approvals and checks
• Auditing and governing pipeline resource access

Core Jobs

1. Agent Pool Management

# List agent pools
az pipelines agent pool list --org https://dev.azure.com/MyOrg --output table

# List agents in pool
az pipelines agent list \
  --pool-id 5 \
  --org https://dev.azure.com/MyOrg \
  --output table

Self-hosted agent registration:

# Download agent, then configure
./config.sh \
  --url https://dev.azure.com/MyOrg \
  --auth pat \
  --token $PAT \
  --pool "SelfHosted-Linux" \
  --agent "agent-01" \
  --unattended

# Install as service
sudo ./svc.sh install
sudo ./svc.sh start

Agent pool types:

• Microsoft-hosted — managed, fresh VM per job, no maintenance, costs per parallel job
• Self-hosted — your VMs, full control, pre-installed tools, behind firewall access, no per-minute cost
• Scale set agents — Azure VMSS auto-scales based on demand (best of both)

2. Service Connections

# Create Azure Resource Manager service connection
az devops service-endpoint azurerm create \
  --azure-rm-service-principal-id $SP_ID \
  --azure-rm-subscription-id $SUB_ID \
  --azure-rm-subscription-name "Production" \
  --azure-rm-tenant-id $TENANT_ID \
  --name "Azure-Production" \
  --project MyProject

# List service connections
az devops service-endpoint list --project MyProject --output table

Service connection types and use cases:

Security: Grant "Project Collection Build Service" only — not broad contributor access.

3. Library — Variable Groups & Secure Files

# Create variable group
az pipelines variable-group create \
  --name "Production-Config" \
  --variables ENV=prod DB_HOST=prod.db.company.com \
  --project MyProject

# Add secret variable
az pipelines variable-group variable create \
  --group-id 5 \
  --name "DB_PASSWORD" \
  --value "secret123" \
  --secret true \
  --project MyProject

Link to Azure Key Vault:

• Variable group → Link secrets from Azure Key Vault → select secrets
• Requires service connection with Key Vault access
• Secrets auto-refresh on pipeline run

4. Environments & Approvals

# Create environment
az pipelines environment create \
  --name "production" \
  --project MyProject

Add approval check via UI: Environment → Approvals and checks → Add → Approvals

• Set approvers, timeout (default 30 days), instructions
• Allow pipeline to self-approve: disable for prod

Environment resources: VMs and Kubernetes clusters can be registered as resources for deployment target tracking.

Key Concepts

• Agent pool — collection of agents that can run pipeline jobs
• Service connection — authenticated connection to external service (Azure, Docker, GitHub)
• Variable group — shared variables across multiple pipelines (vs pipeline-specific variables)
• Secure file — binary files (certificates, provisioning profiles) stored encrypted
• Environment — logical target (dev/staging/prod) with history, approvals, and resource tracking
• Scale set agents — auto-scaling agent pool backed by Azure VMSS

Checklist

• Self-hosted agents using service account (not personal user)?
• Service connections using service principal (not personal PAT)?
• Service principal has minimum required permissions only?
• Secrets in Key Vault-linked variable group (not hardcoded in pipeline)?
• Production environment has approval gates?
• Agent capabilities documented (for pool selection in pipeline YAML)?

Key Outputs

• Agent pools registered and agents online
• Service connections created with least-privilege service principals
• Variable groups with Key Vault linking for secrets
• Environments with approvals for production

Output Format

• 🔴 Critical — service connection using personal PAT (breaks on offboarding), no approval on production environment, secrets hardcoded in pipeline YAML
• 🟡 Warning — all pipelines using single service connection (no isolation), no environment resource tracking, variable groups without Key Vault
• 🟢 Suggestion — use scale set agents for variable workloads, link variable groups to Key Vault, add Exclusive Lock check for sequential deployments

Anti-Patterns

• Service connections using personal user credentials (offboarding breaks pipelines)
• Granting service principal Owner role (least-privilege: Contributor on specific RG)
• Secrets in pipeline variables instead of Key Vault-linked variable groups
• No approval gates on production deployments
• Running pipeline agents as root/admin (security risk)

Integration

• ado-security-policies — control who can create/modify service connections and pipeline resources
• ado-api-cli — automate service connection creation and variable group management
• azure-devops-pipelines — YAML authoring that consumes the infrastructure set up here