Why Won't My AWS CDK Code Build in AWS Code Pipelines? - aws-cdk

Question

Problem: In the AWS Code Pipeline Build Stage, I am receiving the error Phase context status code: COMMAND_EXECUTION_ERROR Message: Error while executing command: npm ci. Reason: exit status 254
Desired Outcome: To deploy new changes to the Code Commit Repository, and for the Cloud Formation Stacks to deploy successfully, just like cdk deploy --all.
I have followed this AWS tutorial. Everything deploys successfully.
The Code Pipeline Stack:
export class CodePipelineStack extends Stack {
private readonly codePipeline: CodePipeline;
private readonly codeRepository : Repository;
constructor(scope: Construct, id: string, props: StackProps, context: CDKContext){
super(scope, id, props);
this.codeRepository = new Repository(this, "Repo-CDK", { repositoryName: "Repo-CDK", description: "Building A Repo using CDK Methodology" });
this.codePipeline = new CodePipeline(this, "pipeline", {
pipelineName: "pipeline",
selfMutation: true,
synth: new ShellStep('DeploymentStep', {
input: CodePipelineSource.codeCommit(this.codeRepository, environment),
commands: ['npm ci', 'npm run build', 'npx cdk synth'],
})
});
}
}
I also have app.synth(); at the bottom of the function that builds the stacks.

Answer 1

The reason that npm ci does not work is that CodeBuild uses an old version of npm.
Updating npm before running npm ci fixed the issue:
const pipeline = new pipelines.CodePipeline(this, 'Pipeline', {
synth: new pipelines.ShellStep('Synth', {
...
// Update npm before running commands
installCommands: ['npm i -g npm#latest'],
commands: [
'npm ci',
'npm run build',
'npx cdk synth',
],
}),
});