Multiple environments
Dev, staging, prod aligned from the same modules.
What is Infrastructure as Code (IaC)?
Infrastructure as Code (IaC) means describing servers, networks, databases, and cloud policies in versioned files, then applying them with tools (Terraform, Pulumi, CloudFormation, Bicep). Instead of clicking in a console, you review, test, and reproduce infrastructure like application code—with Git history, peer review, and CI pipelines.
In one sentence
IaC manages the cloud with versioned code instead of console clicks.
Key points
- Desired state is declared; the tool computes and applies the diff.
- Reproducibility: staging and prod actually look alike.
- Git review + CI reduce human error and drift.
- Secrets and state backends must be secured (remote state, locking).
Term at a glance
- Infrastructure as Code
- IaC · Infra as Code · Infrastructure en tant que code
- English term
- Infrastructure as Code
- Domain
- Cloud & DevOps
- Category
- Infrastructure
- Level
- Intermediate
What does “Infrastructure as Code” mean exactly?
Provisioning used to be manual. IaC formalizes VPCs, subnets, balancers, buckets, and IAM into reusable modules.
Declarative tools (Terraform, CloudFormation) describe the end state; imperative scripts describe steps. Declarative dominates for cloud.
For an SME, IaC often starts with networking and a managed database, then expands to ephemeral preview environments.
How do you implement IaC?
- 01
Inventory what exists
List critical resources and dependencies before encoding everything.
- 02
Pick tool and state
Terraform/OpenTofu, Pulumi, or cloud-native; encrypted locked remote state.
- 03
Modularize
Modules by domain (network, data, app) and per-environment variables.
- 04
Plan/apply pipeline
Plan on PR, apply on merge with guards and policies.
Concrete IaC example
A manufacturing SME in Longueuil codes its Azure VPC, App Service, and Postgres in Bicep. A PR shows the plan: +1 staging slot. After merge, the pipeline applies without touching prod. A new demo environment stands up in twenty minutes instead of two days of clicking.
What is IaC for?
Disaster recovery
Rebuild infra in another region from the repo.
Compliance
Policies and tags applied uniformly.
Team onboarding
A terraform apply documents architecture better than a stale wiki.
Pros and cons of IaC
- Reproducibility and Git audit trail
- Fewer manual mistakes
- Faster provisioning
- Collaboration via code review
- Tooling learning curve
- Mismanaged state is risky
- Legacy refactor can be delicate
- Abstraction can hide cloud cost
IaC vs manual console provisioning?
| Infrastructure as Code | Manual clicks in the cloud console | |
|---|---|---|
| Traceability | Versioned commits and plans | Limited console history |
| Reproducibility | Same code → same infra | Clicks hard to replay |
| Review | PR + plan before apply | Often no structured review |
| Speed at scale | Reusable modules | Slow and fragile for N environments |
Why IaC matters for a Quebec SME
Lean teams cannot depend on one admin who “knows the clicks.” IaC turns infrastructure into a documented asset, speeds audits, and cuts operational risk—critical when uptime hits revenue.
FAQ
Is Terraform required?
No. Terraform/OpenTofu is popular; CloudFormation, Bicep, or Pulumi fit depending on cloud and team.
Does IaC replace runbooks?
It complements them: code provisions; runbooks cover incidents and human procedures.
What about state?
Remote backend (S3+DynamoDB, Azure Storage, Terraform Cloud) with encryption and locking.
Can we import existing resources?
Yes—most tools support progressive import of already-created resources.
Related terms
Sources and references
Want to version your cloud infra without rewriting everything at once? We can scope a progressive IaC foundation.
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