SpEL Tricks

Spinnaker uses the Spring Expression Language (SpEL) for pipeline expressions, so you can do a lot of interesting things with Spinnaker expressions.

Here are a couple of the more interesting examples that we’ve come across (this page will grow):

Basic Math

Take the number of instances for a deployment and multiply by a non-integer value:
Note: “Get Deployment” is the name of the “Find Artifacts from Resource (Manifest)” stage that looks at a Kubernetes deployment object.

${ (0.8 * #stage("Get Deployment")["outputs"]["manifest"]["spec"]["replicas"]).intValue() }

Helper Properties

Create a parameter environment with 3 options:

environment parameter
Access the value of the variable via a helper property, in this case, parameter. For example:

The environment is: ${ parameters.environment }

Some Helper Properties are already defined, for example:

The execution id is automatically set: ${execution['id']}

Helper Functions

Read and print a JSON, for example:

${#readJson('{"development": "dev", "staging": "stage", "production":"prod"}').toString()}

You can also access a value in the JSON with the environment parameter from the Helper Properties Section:

${#readJson('{"development": "dev", "staging": "stage", "production":"prod"}')[parameters.environment]}

Ternary Operator

<some-condition> ? <value-if-true> : <value-if-false>

Simple example:

${ true ? "True text" : "False text" }

Example (in the text of a Manual Judgement stage), where Get Service is a “Find Artifacts From Resource (Manifest)” that looks at a Kubernetes service object:

The loadBalancer ingress is ${ #stage("Get Service")["outputs"]["manifest"]["status"]["loadBalancer"].containsKey("ingress") ? "ready" : "not ready" }.

Whitelisted Java Classes

Some Java classes are available for use in SpEL expressions (see Spinnaker Reference Docs)
For example, generating the current date in MM-dd-yyyy format:

${new java.text.SimpleDateFormat("MM-dd-yyyy").format(new java.util.Date())}

Sometimes you may want to call a static method. For example, to generate a UUID:

 ${T(java.util.UUID).randomUUID() }


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