feat: step functions example

snippets/pulumi/aws/step function to create clones of an rds instance.ts

@@ -0,0 +1,219 @@
+import * as pulumi from "@pulumi/pulumi";
+import * as aws from "@pulumi/aws";
+
+const iamRole: pulumi.Output<aws.iam.GetRoleResult> = aws.iam.getRoleOutput({
+    name: 'SomeServiceRole',
+});
+
+// -----------------
+
+/**
+ * Base type for Step Function states.
+ *
+ * States are elements in a state machine.\
+ * A state is referred to by its name, which can be any string, but which must be unique within the scope of the entire
+ * state machine.
+ *
+ * States take input from their own invocation or a previous state.\
+ * States can filter their input and manipulate the output that is sent to the next state.
+ *
+ * Refer <https://docs.aws.amazon.com/step-functions/latest/dg/workflow-states.html>.
+ */
+type StateMachineBaseState = {
+    Type: string;
+    Comment?: string;
+    Next?: string;
+    End?: boolean;
+};
+
+/**
+ * Choice state.\
+ * Enables conditional branching.
+ */
+interface StateMachineChoiceState extends StateMachineBaseState {
+    Type: "Choice";
+    Choices: Record<string, any>[];
+    Default: string;
+};
+
+/**
+ * Branch type for Parallel states.\
+ * Itself a smaller state machine.
+ */
+type StateMachineParallelBranch = {
+    StartAt: string;
+    States: Record<string, StateMachineStepState>;
+}
+/**
+ * Parallel state.\
+ * Runs other step states in parallel.
+ */
+interface StateMachineParallelState extends StateMachineBaseState {
+    Type: "Parallel";
+    Branches: StateMachineParallelBranch[];
+};
+
+/**
+ * Task state.\
+ * Runs a service integration or Lambda function.
+ */
+interface StateMachineTaskState extends StateMachineBaseState {
+    Type: "Task";
+    Resource: string;
+    Arguments?: Record<string, any>;
+    Output?: Record<string, any>;
+};
+
+/**
+ * Wait state.\
+ * Pauses execution for a fixed duration or until a specified time or date.
+ */
+interface StateMachineWaitState extends StateMachineBaseState {
+    Type: "Wait";
+    Seconds?: number;
+    Timestamp?: string;
+};
+
+/**
+ * Union type for Step Function states.
+ */
+type StateMachineStepState =
+    | StateMachineChoiceState
+    | StateMachineParallelState
+    | StateMachineTaskState
+    | StateMachineWaitState;
+
+/**
+ * Generic State Machine definition.
+ */
+interface StateMachineDefinition {
+    Comment?: string;
+    QueryLanguage?: string;
+    StartAt: string;
+    States: Record<string, StateMachineStepState>;
+};
+
+// -----------------
+
+const changeClonedDbInstancePassword: StateMachineTaskState = {
+    Type: "Task",
+    Resource: "arn:aws:states:::aws-sdk:rds:modifyDBInstance",
+    Arguments: {
+        DbInstanceIdentifier: "{% $states.input.ClonedDBInstance.DbInstanceIdentifier %}",
+        MasterUserPassword: "some-Secur3-Password",
+        ApplyImmediately: true,
+    },
+    End: true,
+};
+
+const checkClonedDbInstanceIsAvailable: StateMachineChoiceState = {
+    Type: "Choice",
+    Choices: [
+        {
+            Condition: "{% $states.input.ClonedDBInstance.DBInstanceStatus in ['available'] %}",
+            Next: "ChangeClonedDBInstancePassword",
+        },
+    ],
+    Default: "WaitForClonedDBInstanceNextCheck",
+};
+
+const createClonedDbInstance: StateMachineTaskState = {
+    Type: "Task",
+    Resource: "arn:aws:states:::aws-sdk:rds:restoreDBInstanceToPointInTime",
+    Arguments: {
+        SourceDBInstanceIdentifier: "{% $states.input.ExistingDBInstanceInfo.DbInstanceIdentifier %}",
+        UseLatestRestorableTime: true,
+        TargetDBInstanceIdentifier: "{% $join([$states.input.ExistingDBInstanceInfo.DbInstanceIdentifier, 'clone'], '-') %}",
+        Engine: "postgres",
+        MultiAZ: false,
+        AvailabilityZone: "eu-west-1a",
+        DbSubnetGroupName: "default",
+        PubliclyAccessible: false,
+        VpcSecurityGroupIds: [],
+        DbParameterGroupName: "{% $states.input.ExistingDBInstanceInfo.DbParameterGroups[0].DbParameterGroupName %}",
+        OptionGroupName: "{% $states.input.ExistingDBInstanceInfo.OptionGroupMemberships[0].OptionGroupName %}",
+        StorageType: "gp3",
+        DedicatedLogVolume: false,
+        DbInstanceClass: "db.t4g.medium",
+        DeletionProtection: false,
+        AutoMinorVersionUpgrade: false,
+    },
+    Output: {
+        ClonedDBInstance: "{% $states.result.DbInstance %}",
+    },
+    Next: "GetClonedDBInstanceState",
+};
+
+const getClonedDbInstanceState: StateMachineTaskState = {
+    Type: "Task",
+    Resource: "arn:aws:states:::aws-sdk:rds:describeDBInstances",
+    Arguments: {
+        DbInstanceIdentifier: "{% $states.input.ClonedDBInstance.DbInstanceIdentifier %}",
+    },
+    Output: {
+        ClonedDBInstance: "{% $states.result.DbInstances[0] %}",
+    },
+    Next: "CheckClonedDBInstanceIsAvailable",
+};
+
+const getExistingDbInstanceInfo: StateMachineTaskState = {
+    Type: "Task",
+    Resource: "arn:aws:states:::aws-sdk:rds:describeDBInstances",
+    Arguments: {
+        DbInstanceIdentifier: "some-existing-rds-instance",
+    },
+    Output: {
+        ExistingDBInstanceInfo: "{% $states.result.DbInstances[0] %}",
+    },
+    Next: "ParallelZone",
+};
+
+const waitForClonedDbInstanceNextCheck: StateMachineWaitState = {
+    Type: "Wait",
+    Seconds: 60,
+    Next: "GetClonedDBInstanceState",
+};
+
+const parallelZone: StateMachineParallelState = {
+    Type: "Parallel",
+    Branches: [
+        {
+            StartAt: "CreateClonedDBInstance",
+            States: {
+                CreateClonedDBInstance: createClonedDbInstance,
+                GetClonedDBInstanceState: getClonedDbInstanceState,
+                CheckClonedDBInstanceIsAvailable: checkClonedDbInstanceIsAvailable,
+                WaitForClonedDBInstanceNextCheck: waitForClonedDbInstanceNextCheck,
+                ChangeClonedDBInstancePassword: changeClonedDbInstancePassword,
+            },
+        },
+        // FIXME: another branch here
+    ],
+    End: true,
+};
+
+const stateMachineDefinition: StateMachineDefinition = {
+    QueryLanguage: "JSONata",
+    States: {
+        GetExistingDBInstanceInfo: getExistingDbInstanceInfo,
+        ParallelZone: parallelZone,
+    },
+    StartAt: "GetExistingDBInstanceInfo",
+};
+// pulumi.jsonStringify(stateMachineDefinition).apply(s => console.log(s))
+
+const dbCloner_stateMachine: aws.sfn.StateMachine = new aws.sfn.StateMachine(
+    'dbCloner',
+    {
+        name: 'DBCloner',
+        roleArn: iamRole.arn,
+        loggingConfiguration: {
+            level: "OFF",
+        },
+        encryptionConfiguration: {
+            type: "AWS_OWNED_KEY",
+        },
+        publish: false,
+        definition: pulumi.jsonStringify(stateMachineDefinition),
+    },
+);