Use conditional inputs to request compute resources and wait for approval

Turn ad hoc resource requests into a governed, auditable workflow. This blueprint shows how to combine Kestra conditional inputs, a Slack approval notification, and a human-in-the-loop pause so that access permissions, SaaS applications, development tools, and cloud VMs are only provisioned after a reviewer signs off. The form adapts to what the requester picks, the approver gets a one-click Slack link, and every decision is captured in the execution history for compliance and IT service management.

How it works

1. The requester selects a resource_type (Access permissions, SaaS application, Development tool, or Cloud VM). Using the dependsOn property with a condition, only the relevant follow-up inputs appear: access_permissions, saas_applications, development_tools, or the cloud_provider, cloud_vms, and region chain. Option lists are loaded dynamically from the KV store via {{ kv(...) }} expressions.
2. The send_approval_request task (io.kestra.plugin.slack.notifications.SlackIncomingWebhook) posts an approval message to Slack containing a Resume link back to the execution.
3. The wait_for_approval task (io.kestra.plugin.core.flow.Pause) halts the execution with onResume fields approved (BOOL) and comment (STRING), waiting for a human decision.
4. Once resumed, the approve task (io.kestra.plugin.core.http.Request) POSTs the collected {{ inputs }} to a downstream provisioning endpoint.
5. The log task (io.kestra.plugin.core.log.Log) records the approval comment and the response body for traceability.

What you get

• A self-service intake form that changes based on the request type.
• Slack-based approvals with a direct resume link, no extra UI.
• A built-in audit trail of who requested what and how it was decided.
• A clean handoff to any provisioning API via an HTTP request.

Who it's for

• Platform and IT teams running access or infrastructure request queues.
• DevOps engineers automating cloud VM and tooling provisioning.
• Ops and compliance owners who need approvals on the record.

Why orchestrate this with Kestra

Slack and KV lists alone cannot pause a process, wait for a human, and resume exactly where it left off. Kestra adds event-driven and API-triggered execution, a durable Pause with typed onResume inputs, retries on the Slack and HTTP calls, full execution lineage, and everything defined declaratively in YAML. The dynamic dependsOn inputs build a smart form that no chat tool or static webhook can replicate.

Prerequisites

• A running Kestra instance.
• A Slack incoming webhook URL.
• KV pairs that populate the dynamic dropdowns (see Quick start).

Secrets

This blueprint uses a mock webhook URL inline for demonstration. In production, replace the url on send_approval_request with your real Slack incoming webhook, ideally stored as a secret and referenced with {{ secret('SLACK_WEBHOOK_URL') }}.

Quick start

1. Add the required KV pairs (access_permissions, saas_applications, development_tools, cloud_vms, cloud_regions) used by the input expressions:

   id: add_kv_pairs
   namespace: company.team
   
   tasks:
     - id: access_permissions
       type: io.kestra.plugin.core.kv.Set
       key: "{{ task.id }}"
       kvType: JSON
       value: |
         ["Admin", "Developer", "Editor", "Launcher", "Viewer"]
   
     - id: saas_applications
       type: io.kestra.plugin.core.kv.Set
       key: "{{ task.id }}"
       kvType: JSON
       value: |
         ["Slack", "Notion", "HubSpot", "GitHub", "Jira"]
   
     - id: development_tools
       type: io.kestra.plugin.core.kv.Set
       key: "{{ task.id }}"
       kvType: JSON
       value: |
         ["Cursor", "IntelliJ IDEA", "PyCharm Professional", "Datagrip"]
   
     - id: cloud_vms
       type: io.kestra.plugin.core.kv.Set
       key: "{{ task.id }}"
       kvType: JSON
       value: |
         {
           "AWS": ["t2.micro", "t2.small", "t2.medium", "t2.large"],
           "GCP": ["f1-micro", "g1-small", "n1-standard-1", "n1-standard-2"],
           "Azure": ["Standard_B1s", "Standard_B1ms", "Standard_B2s", "Standard_B2ms"]
         }
   
     - id: cloud_regions
       type: io.kestra.plugin.core.kv.Set
       key: "{{ task.id }}"
       kvType: JSON
       value: |
         {
           "AWS": ["us-east-1", "us-west-1", "us-west-2", "eu-west-1"],
           "GCP": ["us-central1", "us-east1", "us-west1", "europe-west1"],
           "Azure": ["eastus", "westus", "centralus", "northcentralus"]
         }
   

2. Point send_approval_request at your Slack webhook (or its secret).

3. Run the flow, pick a resource_type, and submit the dynamic form.

4. Open the Slack message, click Resume, set approved and comment, and watch the flow finish.

How to extend

• Swap the mock approve URL for your real provisioning API (Terraform Cloud, AWS, GCP, or an ITSM system).
• Branch on approved with an If task to skip provisioning when rejected.
• Add labels or a notification on completion to close the loop with the requester.
• Replace the manual Pause with an approval gate tied to your identity provider.

Links

• Plugin docs: https://kestra.io/plugins/plugin-notifications
• Orchestrate Slack with Kestra: https://kestra.io/orchestration/slack