Migrate from Jenkins

Jenkins estates grow organically: freestyle jobs configured in the UI, scripted and declarative pipelines in Groovy, shared libraries, and dozens of plugins. Slipway is declarative YAML with a deployment model on top. Plan to simplify while you migrate, not transliterate.

Concept map

Jenkins	Slipway
Controller	Control plane (server, scheduler, worker)
Agent / node / label	Runner in a pool; runs_on labels
Cloud agents (Kubernetes plugin pod templates)	kubernetes executor: a pod per job
Freestyle job	A pipeline with one job
Jenkinsfile (declarative)	.slipway/*.yaml
pipeline { agent ... }	runs_on, container
stages { stage(...) }	stages: with jobs:
parallel { ... }	Several jobs in a stage, or a matrix
steps { sh '...' }	steps: - run: ...
when { branch 'main' }	if: git.branch == "main"
environment { X = '...' }	env:
credentials('id')	${{ secrets.NAME }} in env
post { always / failure }	Steps or jobs with if: always() / if: failure()
options { timeout, retry }	timeout, retry
triggers { cron, pollSCM }	on: schedule; SCM webhooks replace polling
parameters { string ... }	on.manual.inputs
stash / unstash	artifacts between jobs
archiveArtifacts	artifacts:
junit	Test reports are parsed from JUnit files automatically
Shared library	template: / extends: / registry steps
Multibranch pipeline	Automatic: pipelines run per branch and PR
Input step	Approval on an environment
Promoted builds / deploy jobs	Release, lifecycle, deployment
Folders and credentials domains	Projects and secret scopes
Role Strategy plugin	RBAC roles and bindings
Blue Ocean	The Slipway UI

Plugins

Jenkins plugin purpose	In Slipway
Git, GitHub, GitLab, Bitbucket	SCM integrations
Docker, Kubernetes	Container executors; registry integrations
Credentials, Vault	Secrets with external references
Slack, email notifications	Notification integrations
JIRA	Jira integration
SonarQube, security scanners	Scanner steps and ingestion
Pipeline utility steps	Shell and CEL functions

Worked conversion

Jenkinsfile:

pipeline {
  agent { label 'linux && docker' }
  options { timeout(time: 30, unit: 'MINUTES') }
  environment { REGISTRY = 'ghcr.io/acme' }
  stages {
    stage('Test') { steps { sh 'make test' } }
    stage('Build') {
      when { branch 'main' }
      steps {
        withCredentials([string(credentialsId: 'registry-token', variable: 'TOKEN')]) {
          sh 'echo $TOKEN | docker login ghcr.io -u ci --password-stdin && make image push'
        }
      }
    }
    stage('Deploy') {
      when { branch 'main' }
      steps { input 'Deploy to production?'; sh './deploy.sh production' }
    }
  }
  post { failure { slackSend channel: '#ci', message: "Build failed: ${env.BUILD_URL}" } }
}

Slipway:

version: 1
name: api
on:
  push: { branches: [main] }
  pull_request:
defaults: { runs_on: [linux, docker], timeout: 30m }
env: { REGISTRY: ghcr.io/acme }
jobs:
  - name: test
    steps:
      - uses: slipway/checkout@v1
      - run: make test
  - name: build
    needs: [test]
    if: git.branch == "main"
    outputs: { version: "${{ steps.v.outputs.version }}" }
    steps:
      - uses: slipway/checkout@v1
      - run: echo "$TOKEN" | docker login ghcr.io -u ci --password-stdin && make image push
        env: { TOKEN: "${{ secrets.REGISTRY_TOKEN }}" }
      - id: v
        run: echo "version=$(git describe --tags --always)" >> "$SLIPWAY_OUTPUT"
      - uses: slipway/release-create@v1
  - name: deploy
    needs: [build]
    if: git.branch == "main"
    environment: { name: production, service: api }   # approval is a protection rule, not a pipeline step
    steps:
      - uses: slipway/deploy@v1
        with: { release: "${{ needs.build.outputs.version }}", strategy: rolling }

Notifications move out of the pipeline: create a Slack subscription for run.finished (filtered to failures) instead of a post block in every Jenkinsfile.

Steps

1. Inventory jobs by value. Many Jenkins jobs are stale. Migrate the ones that ran in the last quarter.
2. Install runners where your Jenkins agents live (same network, same tooling). Reuse labels as runner labels.
3. Move secrets out of Jenkins credentials into your secret manager and reference them, or federate with OIDC.
4. Convert the build first, then model environments and deployments properly with approvals and strategies, replacing input steps and deploy scripts.
5. Replace polling with webhooks. Connect the SCM integration; delete pollSCM.
6. Retire the controller once nothing depends on it.

Gotchas

• Groovy logic (loops, functions, dynamic stages) has no direct equivalent. Move it into scripts the steps call, or express it with matrix and if.
• Jenkins workspaces persist on agents; Slipway job workspaces are fresh per job. Use cache: and artifacts: explicitly.
• Shared global state (environment variables set in the UI, credentials domains) must become explicit project or org variables and secrets.