Skip to content

Commit

Permalink
switching from reflow to semantic line breaks
Browse files Browse the repository at this point in the history
  • Loading branch information
@corymhall
corymhall committed Dec 23, 2024
1 parent 25fd230 commit 8b506a0
Show file tree
Hide file tree
Showing 2 changed files with 28 additions and 51 deletions.
76 changes: 27 additions & 49 deletions content/docs/iac/adopting-pulumi/migrating-to-pulumi/from-cdk.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -52,8 +52,7 @@ All we need to do is run `pulumi up` and the Pulumi runtime will know how to que

Let's say you want to migrate from AWS CDK to Pulumi and that simply co-existing side-by-side as shown above isn't sufficient. In this case you can convert your AWS CDK application to a Pulumi CDK application using the [Pulumi CDK Adapter](https://github.com/pulumi/pulumi-cdk).

Using the below example as a starting point, we will convert this CDK
application to use Pulumi CDK.
Using the below example as a starting point, we will convert this CDK application to use Pulumi CDK.

```ts
import * as cdk from 'aws-cdk-lib/core';
Expand Down Expand Up @@ -88,8 +87,7 @@ npm install @pulumi/aws @pulumi/aws-native @pulumi/docker-build @pulumi/pulumi

### Convert the CDK Stack and App

Replace the CDK `Stack` and `App` classes with Pulumi CDK `Stack` and `App`
classes.
Replace the CDK `Stack` and `App` classes with Pulumi CDK `Stack` and `App` classes.

```ts
import * as pulumicdk from '@pulumi/cdk';
Expand All @@ -111,32 +109,26 @@ const app = new pulumicdk.App('app', (scope: pulumicdk.App) => {

### Deploy the Pulumi Stack

Now that you have converted your AWS CDK application to a Pulumi CDK application
you can use the Pulumi CLI to create a Pulumi Stack and deploy.
Now that you have converted your AWS CDK application to a Pulumi CDK application you can use the Pulumi CLI to create a Pulumi Stack and deploy.

```console
$ pulumi up
```

## Converting Multi-Stack CDK Applications

If your CDK application contains multiple CDK Stacks they may fall into a couple
of scenarios.
If your CDK application contains multiple CDK Stacks they may fall into a couple of scenarios.

1. You have multiple CDK Stacks that all deploy to the same environment (AWS account/region).
2. You have multiple CDK Stacks that deploy to multiple environments

### Converting Same Environment Stacks

If all of your CDK Stacks deploy to the same environment you can combine them
all into a single Pulumi CDK Stack. Pulumi CDK Stacks do not have the same
resource limits that CloudFormation Stacks have. You can also control
termination protection at the resource level in Pulumi instead of at the
CloudFormation Stack level in CDK.
If all of your CDK Stacks deploy to the same environment you can combine them all into a single Pulumi CDK Stack.
Pulumi CDK Stacks do not have the same resource limits that CloudFormation Stacks have.
You can also control termination protection at the resource level in Pulumi instead of at the CloudFormation Stack level in CDK.

Consider a common scenario of creating your stateful resources (e.g. an RDS
database) in one stack and your non-stateful resources (e.g. a Lambda Function)
in a separate Stack.
Consider a common scenario of creating your stateful resources (e.g. an RDS database) in one stack and your non-stateful resources (e.g. a Lambda Function) in a separate Stack.

```ts
import * as cdk from 'aws-cdk-lib/core';
Expand Down Expand Up @@ -177,8 +169,7 @@ new AppStack(app, 'app-stack', {
});
```

To convert this to a Pulumi CDK app, you would combine the two stacks into a single
stack and then use `transforms` to set `protect: true` on the `DbCluster`.
To convert this to a Pulumi CDK app, you would combine the two stacks into a single stack and then use `transforms` to set `protect: true` on the `DbCluster`.

```ts
import * as pulumi from '@pulumi/pulumi';
Expand Down Expand Up @@ -219,9 +210,8 @@ const app = new pulumicdk.App('app', (scope: pulumicdk.App) => {

### Converting Stacks with Different Environments

If your application has stacks in different environments you can convert it to
Pulumi CDK as long as there are no dependencies between the stacks. You would
convert each individual CDK Stack to a Pulumi CDK Stack.
If your application has stacks in different environments you can convert it to Pulumi CDK as long as there are no dependencies between the stacks.
You would convert each individual CDK Stack to a Pulumi CDK Stack.

For example, this:

Expand Down Expand Up @@ -302,10 +292,9 @@ const app = new pulumicdk.App('app', (scope: pulumicdk.App) => {

## Converting CDK Stages

An AWS CDK [Stage](https://docs.aws.amazon.com/cdk/v2/guide/stages.html) represents a group of one or more AWS CDK Stacks that are configured
to deploy together to a particular environment. For example, taking the example
from above where we deploy a `StatefulStack` and an `AppStack`, we would use
stages to deploy these to different environments.
An AWS CDK [Stage](https://docs.aws.amazon.com/cdk/v2/guide/stages.html) represents a group of one or more AWS CDK Stacks that are configured to deploy together to a particular environment.
For example, taking the example from above where we deploy a `StatefulStack` and an `AppStack`,
we would use stages to deploy these to different environments.

```ts
import * as cdk from 'aws-cdk-lib/core';
Expand Down Expand Up @@ -359,7 +348,7 @@ class MyStage extends cdk.Stage {
constructor(scope: Construct, id: string, props: MyStageProps) {
super(scope, id, props);
const stateful = new StatefulStack(app, 'stateful-stack', {
instanceType: props.instanceSize,
instanceType: props.instanceType,
});
new AppStack(app, 'app-stack', {
cluster: stateful.cluster,
Expand All @@ -377,14 +366,12 @@ new MyStage(app, 'prod', {
});
```

The AWS CDK Stages can be converted to [Pulumi Stacks](https://www.pulumi.com/docs/iac/concepts/stacks/). Similar to CDK
Stages, Pulumi Stacks can be used to deploy groups of resources to different environments.
The AWS CDK Stages can be converted to [Pulumi Stacks](https://www.pulumi.com/docs/iac/concepts/stacks/).
Similar to CDK Stages, Pulumi Stacks can be used to deploy groups of resources to different environments.

In AWS CDK applications differences in configuration between environments are
typically configured through input parameters on the Stage. In the above
example, the `DatabaseCluster` uses a different `InstanceType` between the `dev` and `prod` environments.
When we convert this application to Pulumi, we will move this configuration from
the Stage input properties to [Stack Configuration](https://www.pulumi.com/docs/iac/concepts/config/)
In AWS CDK applications differences in configuration between environments are typically configured through input parameters on the Stage.
In the above example, the `DatabaseCluster` uses a different `InstanceType` between the `dev` and `prod` environments.
When we convert this application to Pulumi, we will move this configuration from the Stage input properties to [Stack Configuration](https://www.pulumi.com/docs/iac/concepts/config/)

When we convert the AWS CDK application we will:

Expand Down Expand Up @@ -441,16 +428,14 @@ const app = new pulumicdk.App('app', (scope: pulumicdk.App) => {
});
```

Once we have converted the code, we create the `dev` Pulumi Stack and set the
`instanceType` config property.
Once we have converted the code, we create the `dev` Pulumi Stack and set the `instanceType` config property.

```console
$ pulumi stack init dev
$ pulumi config set instanceType r6g.medium
```

Then we create the `prod` Pulumi Stack and set the `instanceType` config
property.
Then we create the `prod` Pulumi Stack and set the `instanceType` config property.

```console
$ pulumi stack init prod
Expand All @@ -459,13 +444,9 @@ $ pulumi config set instanceType r6g.xlarge

## Importing CDK Resources

All the prior examples in this guide discuss standing up a new Pulumi CDK Stack
and creating new AWS resources. If you want to instead have Pulumi import the
state of your existing resources you can try the experimental [Pulumi CDK Import
Tool](https://github.com/pulumi/pulumi-tool-cdk-importer). This tool allows you
to specify a CDK stack to import and then the resources in that stack will be
imported into your Pulumi Stack so that Pulumi can take over management of those
resources.
All the prior examples in this guide discuss standing up a new Pulumi CDK Stack and creating new AWS resources.
If you want to instead have Pulumi import the state of your existing resources you can try the experimental [Pulumi CDK Import Tool](https://github.com/pulumi/pulumi-tool-cdk-importer).
This tool allows you to specify a CDK stack to import and then the resources in that stack will be imported into your Pulumi Stack so that Pulumi can take over management of those resources.

**1. Install the tool**

Expand All @@ -481,11 +462,8 @@ $ pulumi plugin run cdk-importer -- -stack $StackName

**3. Run `pulumi preview` to ensure there are no diffs**

If there are any issues with importing, the tool can be run again to try the
import again without it affecting previously imported resources.
If there are any issues with importing, the tool can be run again to try the import again without it affecting previously imported resources.

## More Info

For more info on using Pulumi CDK check out the [Pulumi CDK
Guide](https://www.pulumi.com/docs/iac/clouds/aws/guides/cdk/) or the [Pulumi
CDK GitHub Repository](https://github.com/pulumi/pulumi-cdk) for more info.
For more info on using Pulumi CDK check out the [Pulumi CDK Guide](https://www.pulumi.com/docs/iac/clouds/aws/guides/cdk/) or the [Pulumi CDK GitHub Repository](https://github.com/pulumi/pulumi-cdk) for more info.
3 changes: 1 addition & 2 deletions content/docs/iac/clouds/aws/guides/cdk.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -796,5 +796,4 @@ create the following staging resources.

## Migrating from AWS CDK

For a detailed guide on migrating from AWS CDK applications to Pulumi check out
the [Migration Guide](https://www.pulumi.com/docs/iac/adopting-pulumi/migrating-to-pulumi/from-cdk/).
For a detailed guide on migrating from AWS CDK applications to Pulumi check out the [Migration Guide](https://www.pulumi.com/docs/iac/adopting-pulumi/migrating-to-pulumi/from-cdk/).

0 comments on commit 8b506a0

Please sign in to comment.