Nested Patterns Examples

---

Nested Conditionals

Use if/else inside another if/else block for multi-dimensional decisions. OrchStep limits nesting to 2 levels to keep workflows readable.

Code

# Example: Nested Conditionals
# Use if/else inside another if/else block for multi-dimensional decisions.
# Here we check environment first, then feature flag status.
#
# Outer condition: is this production or development?
# Inner condition: is the feature flag enabled?
#
# Note: OrchStep limits nesting to 2 levels to keep workflows readable.
# For deeper branching, consider switch/case or separate tasks.
#
# Try: orchstep run
# Try: orchstep run --var environment=production --var feature_flag=enabled
# Try: orchstep run --var environment=development --var feature_flag=disabled

name: nested-conditionals
desc: "Multi-level conditional decisions for deployment gating"

defaults:
environment: "production"
feature_flag: "enabled"

tasks:
main:
desc: "Gate deployment based on environment and feature flag"
steps:
  - name: check_environment
    if: '{{ eq vars.environment "production" }}'
    then:
      - name: check_feature_prod
        if: '{{ eq vars.feature_flag "enabled" }}'
        then:
          - name: deploy_with_feature
            func: shell
            do: echo "PRODUCTION -- deploying with new feature enabled"
        else:
          - name: deploy_without_feature
            func: shell
            do: echo "PRODUCTION -- deploying without new feature (flag disabled)"
    else:
      - name: check_feature_dev
        if: '{{ eq vars.feature_flag "enabled" }}'
        then:
          - name: dev_with_feature
            func: shell
            do: echo "DEVELOPMENT -- testing new feature locally"
        else:
          - name: dev_without_feature
            func: shell
            do: echo "DEVELOPMENT -- running baseline (no feature flag)"

  - name: summary
    func: shell
    do: |
      echo "=== Deployment Gate ==="
      echo "Environment:  {{ vars.environment }}"
      echo "Feature Flag: {{ vars.feature_flag }}"

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---

Switch Inside Loop

Process a list of items where each item needs different handling based on its type. Combines loop iteration with switch/case routing.

Code

# Example: Switch Inside Loop
# Process a list of items where each item needs different handling
# based on its type. Combines loop iteration with switch/case routing.
#
# Scenario: an event processing pipeline receives mixed event types.
# Each event is routed to the appropriate handler.
#
# Try: orchstep run

name: switch-in-loop
desc: "Route mixed event types using switch/case inside a loop"

defaults:
events: ["deploy", "alert", "metric", "log"]

tasks:
main:
desc: "Process a stream of mixed events"
steps:
  - name: process_events
    loop: '{{ vars.events }}'
    then:
      - name: route_event
        switch:
          value: '{{ loop.item }}'
          cases:
            - when: deploy
              then:
                - name: handle_deploy
                  func: shell
                  do: echo "Deploy event -- triggering release pipeline"

            - when: alert
              then:
                - name: handle_alert
                  func: shell
                  do: echo "Alert event -- notifying on-call team"

            - when: metric
              then:
                - name: handle_metric
                  func: shell
                  do: echo "Metric event -- forwarding to monitoring dashboard"

          default:
            - name: handle_other
              func: shell
              do: echo "Unknown event type '{{ loop.item }}' -- logging for review"

  - name: done
    func: shell
    do: echo "Processed {{ vars.events | len }} events"

---

Deep elif Chains

Use elif chains for multi-branch routing without deep nesting. Better than nested if/else when checking one variable against many values.

Code

# Example: Deep elif Chains
# Use elif chains for multi-branch routing without deep nesting.
# Better than nested if/else when checking one variable against many values.
#
# Scenario: route incident alerts based on severity level.
# Each severity maps to a different response action.
#
# Try: orchstep run
# Try: orchstep run --var severity=critical
# Try: orchstep run --var severity=high
# Try: orchstep run --var severity=low

name: deep-elif-chains
desc: "Multi-branch routing with elif for incident severity"

defaults:
severity: "medium"

tasks:
main:
desc: "Route an incident based on its severity"
steps:
  - name: route_severity
    if: '{{ eq vars.severity "critical" }}'
    task: page_oncall
    elif:
      - if: '{{ eq vars.severity "high" }}'
        task: create_ticket
      - if: '{{ eq vars.severity "medium" }}'
        task: log_warning
    else: ignore_noise

  - name: done
    func: shell
    do: |
      echo "=== Incident Routed ==="
      echo "Severity: {{ vars.severity }}"

page_oncall:
desc: "Critical -- wake up the on-call engineer"
steps:
  - name: page
    func: shell
    do: echo "CRITICAL -- paging on-call engineer via PagerDuty"

create_ticket:
desc: "High -- create a tracking ticket"
steps:
  - name: ticket
    func: shell
    do: echo "HIGH -- creating Jira ticket for investigation"

log_warning:
desc: "Medium -- log a warning for review"
steps:
  - name: warn
    func: shell
    do: echo "MEDIUM -- logging warning to monitoring system"

ignore_noise:
desc: "Low -- no action needed"
steps:
  - name: skip
    func: shell
    do: echo "LOW -- ignoring noise, no action required"