The architectural necessity of interacting with infrastructure that exists independently of a specific Infrastructure as Code (IaC) lifecycle is a common challenge in modern cloud engineering. Pulumi addresses this requirement through the implementation of the get functionality, a specialized mechanism designed to look up and reference existing resources that are not currently managed by the Pulumi state engine. This capability allows developers to maintain a hybrid environment where some resources are provisioned via the Pulumi CLI and others are managed via manual console entries, legacy scripts, or separate organizational teams, without sacrificing the ability to programmatically reference those external assets.
The integration of external resources is not a matter of bringing them under full management, but rather a method of consumption. By utilizing get, a developer can extract specific attributes—such as a Virtual Private Cloud (VPC) ID, a security group ARN, or a subnet identifier—and inject those values into new resources being deployed. This prevents the need for hard-coding physical IDs within the source code, which is a critical security and maintainability failure in professional DevOps pipelines.
The Mechanics of Get Functions
Pulumi provides three distinct architectural avenues to implement the look-up of existing resources. Each method serves the same primary purpose: accessing a resource not managed by the current Pulumi stack.
The static get method is a class-level implementation available on all resource classes. This approach allows for a clean, object-oriented syntax when retrieving resource data.
The Get function serves as a package-level alternative. For instance, using ec2.GetSecurityGroup allows a developer to call the function directly from the provider package. This is often preferred in functional programming styles or when the developer wants to avoid instantiating a class just to retrieve a value.
The get stanza provides a declarative way to perform the look-up. This is integrated into the resource type definitions, ensuring that the resource lookup is handled as part of the overall resource graph definition.
The impact of these three methods is the democratization of resource access. Whether a developer prefers a class-based, function-based, or stanza-based approach, the end result is a seamless connection between managed and unmanaged infrastructure. This flexibility ensures that Pulumi fits into any existing coding standard without forcing a specific paradigm on the user.
Functional Distinction Between Get and Import
A critical point of technical confusion for many practitioners is the difference between the get functionality and the pulumi import CLI command. While both involve existing resources, their operational impact on the state file and the cloud environment is fundamentally different.
The pulumi import command is used to bring an existing resource under the full management of Pulumi. When a resource is imported, Pulumi takes ownership of its lifecycle. This means that any subsequent pulumi up command will compare the current state of the resource in the cloud against the desired state defined in the code. If a discrepancy is found, Pulumi will attempt to update the resource to match the code. Furthermore, if the resource is removed from the code, Pulumi will delete the actual physical resource in the cloud.
Conversely, the get function is used solely to allow the attributes of an existing resource to be used within a Pulumi program. It is a read-only operation. A resource read with the get function will never be updated or deleted by Pulumi during an update, regardless of whether the code is modified or deleted.
The contextual impact of this distinction is massive for risk management. Using get allows a developer to reference a production database or a critical network gateway without the risk of accidentally deleting it through a code change. It provides a "safe" way to interact with high-stakes infrastructure that must remain untouched by the automated deployment pipeline.
Input Parameters for Resource Lookup
To successfully execute a get operation, Pulumi requires two specific pieces of information. These values ensure that the engine can uniquely identify the target asset across the vast landscape of a cloud provider.
- The logical name Pulumi will use to refer to the resource. This is an internal identifier used within the Pulumi program to track the resource reference.
- The physical ID that the resource has in the target cloud. This is the actual unique identifier (e.g., an AWS ARN or a GCP Project ID) assigned by the cloud provider.
The relationship between these two values is foundational. The physical ID tells Pulumi exactly which asset to look for in the cloud, while the logical name allows other resources in the Pulumi program to reference that asset using a human-readable variable.
Practical Application and Consumption
The primary use case for the get function is to consume properties from a resource that was provisioned elsewhere. In a real-world enterprise scenario, this often manifests as a "Hub and Spoke" network architecture.
A central networking team might provision a transit gateway or a shared VPC. The application team, using Pulumi, does not have the authority or the need to manage that shared infrastructure. However, to deploy their serverless functions or containers, they need the ID of that shared VPC. By utilizing the get function, the application team can programmatically fetch the VPC ID and associate their new resources with it.
This creates a dense web of interdependence where the application is decoupled from the management of the core infrastructure but remains logically connected. This ensures that if the networking team changes a property of the VPC, the application team can retrieve the updated property in the next deployment without needing to manually update their code.
Pulumi Ecosystem and Deployment Workflow
Understanding how to use get functions is part of a larger deployment lifecycle. Pulumi enables the build and deployment of infrastructure for any architecture and on any cloud using general-purpose programming languages.
The deployment process typically follows a structured sequence:
- Installation: The CLI must be installed on the local machine.
- Project Creation: A project is initialized using templates.
- Deployment: The infrastructure is pushed to the cloud.
- Interaction: The deployed resources are utilized.
To initiate this process, the Pulumi CLI can be installed via various methods depending on the operating system.
For macOS and Linux users, the installation script is the most direct method:
curl -fsSL https://get.pulumi.com/ | sh
macOS users can also leverage the Homebrew package manager:
brew install pulumi/tap/pulumi
Subsequent updates are handled through Homebrew:
brew upgrade pulumi
For Windows users, multiple paths exist. The native Windows 11 winget tool provides a streamlined installation:
winget install pulumi
Updating via winget is similarly simple:
winget upgrade pulumi
Alternatively, Windows users can use a PowerShell command to execute the installation script:
@"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; iex ((New-Object System.Net.WebClient).DownloadString('https://get.pulumi.com/install.ps1'))" && SET "PATH=%PATH%;%USERPROFILE%\.pulumi\bin"
The binary installation for Windows x64 is also available, which automatically adds Pulumi to the system path for machine-wide availability.
Project Initialization and Cloud Deployment
Once the CLI is installed, the transition to active infrastructure management begins with the pulumi new command. This command is the entry point for creating projects. If run without arguments, it prompts the user to choose from available projects.
For example, to create an AWS Serverless Lambda project utilizing TypeScript, the following sequence is used:
mkdir pulumi-demo && cd pulumi-demo
pulumi new serverless-aws-typescript
This process creates a boilerplate project that includes the necessary language runtime and cloud configurations. This is where the get functions described earlier would be implemented within the TypeScript code to reference existing AWS resources.
To deploy the infrastructure, the user executes:
pulumi up
This command performs a critical operation: it computes the minimal diff between the current cloud state and the desired state defined in the code. If a get function is used to reference an external resource, that resource is read into the program, but it is not modified. The pulumi up command then provisions only the new or changed resources that depend on those read values.
Infrastructure as Code (IaC) Capabilities
Pulumi's core value proposition is the ability to embed IaC anywhere using the Automation API. Because it is open source under the Apache 2.0 license, it supports a vast array of languages and clouds.
The platform's versatility is reflected in its support for major cloud providers, which are often categorized in example repositories using a specific naming convention: <cloud>-<language>.
| Cloud Provider | Short Code | Description |
|---|---|---|
| Amazon Web Services | aws | Comprehensive support for AWS services |
| Microsoft Azure | azure | Integration with Azure cloud resources |
| Google Cloud Platform | gcp | Management of GCP infrastructure |
| Kubernetes | kubernetes | Orchestration of K8s clusters and pods |
This structured approach allows users to transition between clouds while maintaining the same CLI and deployment workflow. For example, a developer can use a sparse checkout to retrieve specific examples, such as the aws-go-fargate example, to see how to implement containerized workloads in Go on AWS.
State Management and Backend Configuration
A fundamental aspect of Pulumi is how it handles the state of the infrastructure. State is the mapping between the logical names in the code and the physical IDs in the cloud.
By default, Pulumi uses Pulumi Cloud, a hosted state-management backend. This service is free for individuals and requires no credit card, making it the recommended starting point for beginners. The primary action to authenticate with this service is:
pulumi login
For organizations requiring total control over their data, Pulumi supports self-managed state backends. These include:
- S3 (Amazon Simple Storage Service)
- Azure Blob Storage
- GCS (Google Cloud Storage)
- Local file system
The choice of backend affects how the get function operates. Regardless of the backend, the get function always reaches out to the cloud provider's API to fetch the most current attributes of the unmanaged resource, ensuring that the data used in the program is accurate and not stale.
Community and Developer Resources
The ecosystem surrounding Pulumi is designed to facilitate collaborative problem-solving and continuous learning. Developers have access to several high-impact resources to master the use of get functions and other IaC concepts.
- GitHub Discussions: A forum for asking technical questions and sharing architectural builds.
- Slack Community: An online space for real-time interaction with thousands of developers.
- Local Pulumi User Groups (PUGs): In-person or virtual workshops and meetups.
- PulumiTV (YouTube): A source for workshops, demos, and AI/ML essentials.
- Pulumi Registry: A centralized repository for searching packages and supported resources.
- Pulumi Blog: A hub for technical announcements and insightful articles.
For those looking to advance their skills, Pulumi provides specialized examples, such as testing with Policies using Policy-as-Code in TypeScript or performing integration testing in Go using a deploy-check-destroy pattern.
Analysis of Resource Lifecycle Integration
The implementation of the get function represents a shift in how IaC tools handle the reality of "brownfield" environments. In a perfect "greenfield" scenario, every single resource is defined in code and managed by a single tool. In reality, infrastructure is almost always a mixture of managed and unmanaged assets.
The get function solves the "dependency deadlock" that often occurs when a resource needs to be created based on the output of another resource that is not under the same management tool. By allowing a read-only look-up, Pulumi enables a non-destructive integration path.
From a DevOps perspective, this allows for a tiered governance model. A core infrastructure team can maintain the "source of truth" for the network (unmanaged by the application's Pulumi stack), while the application team can maintain the "source of truth" for the compute layer. The get function acts as the bridge between these two spheres of influence.
The technical impact of this design is the reduction of "state pollution." By using get instead of import, the state file remains lean, containing only the resources that the specific project is responsible for. This reduces the complexity of the state file and minimizes the risk of accidental deletions during an update cycle.
Furthermore, the integration of get functions into the broader Pulumi workflow—from pulumi new to pulumi up—demonstrates a mature understanding of the developer experience. By providing this capability as a first-class citizen in the resource classes, Pulumi eliminates the need for cumbersome "look-up" scripts or manual variable injection, effectively treating the cloud provider's API as a dynamic database of infrastructure properties.