> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/continuous-integration/3.0/use-harness-ci/migrate-to-harness-ci/migrating-from-gitlab.md). # Migrate from GitLab CI to Harness CI Harness CI and GitLab CI both allow you to create workflows that automatically build, test, publish, release, and deploy code. This guide describes the important differences between Harness CI and GitLab CI so that you can migrate your existing GitLab CI workflows to Harness CI. ### What makes Harness CI unique? Harness CI provides proprietary technologies, like Cache Intelligence and Test Intelligence, which make Harness CI [four times faster](https://harness.io/blog/fastest-ci-tool) than other leading CI tools. * Harness [Test Intelligence (TI)](/continuous-integration/3.0/use-harness-ci/use-harness-ci/run-tests/ti-overview.md) is a proprietary technology that accelerates test cycles by running only the tests necessary to confirm the quality of the code changes that triggered a build. Visualizations show which code changes caused which tests to be selected, and TI can help you identify gaps in your test plan. TI also detects negative trends and provides actionable insights to improve quality. With TI, it's possible to reduce build cycle times by up to 90% without compromising application quality. * Harness [Cache Intelligence](/continuous-integration/3.0/use-harness-ci/use-harness-ci/caching-ci-data/cache-intelligence.md) is a proprietary technology that reduces pipeline execution time by automatically caching well-known directories for languages like Java and Node.js. In addition, you can [use plugins](/continuous-integration/3.0/use-harness-ci/use-harness-ci/use-drone-plugins/explore-ci-plugins.md) to include GitHub Actions, Bitrise Workflow Steps, Jira updates, and more in your Harness CI pipelines. Harness CI is part of The [Harness Platform](/harness-ai/new-to-harness-platform/overview.md), which is a self-service CI/CD platform that enables end-to-end software delivery. The Harness Platform includes features, functionality, and additional modules to help you build, test, deploy, and verify software. For example: * [Secrets management](/harness-ai/use-harness-platform/secrets/secrets-management.md) through the [Harness secrets manager](/harness-ai/use-harness-platform/secrets/secrets-management/harness-secret-manager-overview.md) or an [external secrets manager](/harness-ai/troubleshooting-and-resources/tutorials/add-secrets-manager.md). * Role-Based Access Control (RBAC) helps you control user and group access to Harness resources according to users' roles. Using RBAC increases security and improves efficiency. * Harness Policy as Code is a centralized policy management and rules service that leverages the Open Policy Agent (OPA) to meet compliance requirements across software delivery and enforce governance policies. * The Harness Enterprise Ready Self-Managed Edition is an end-to-end solution for continuous, self-managed delivery. You can install and update Harness Self-Managed Enterprise Edition using online or offline (air-gapped) methods. ### Comparison: Workflow architecture Both Harness CI and GitLab CI use workflows to organize builds. In Harness CI, these workflows are called pipelines. In both products, workflows are made up of one or more stages, which represent major segments of the workflow. Each stage include one or more jobs or steps, which in turn contain individual commands. The following truncated examples provide a simple comparison of stage and step structure in GitLab CI and Harness CI. {% tabs %} {% tab title="GitLab CI" %} ```yaml step1: stage: stage1 image: openjdk:17.0-jdk only: - /^dev-.*$/ except: - branches script: - echo "this runs on openjdk" ``` {% endtab %} {% tab title="Harness" %} ```yaml - stage: name: Stage1 ... steps: - step: type: Run name: step1 identifier: step1 spec: connectorRef: my-docker-hub-connector image: openjdk:17.0-jdk shell: Bash command: echo "this runs on openjdk" ``` {% endtab %} {% endtabs %} For more information about Harness terminology, features, and pipeline components, go to the [CI key concepts](/continuous-integration/3.0/new-to-harness-ci/key-concepts.md). #### Jobs and steps Jobs in GitLab CI are similar to steps in Harness CI. In both products, jobs/steps contain commands. Some commands are declared explicitly, whereas others run inherently based on the step type or configuration. An important difference is that GitLab CI jobs run in parallel by default, whereas in Harness CI steps run sequentially. However, you can enable [parallelism and other looping strategies](#comparison-matrix-and-parallelism) in Harness CI. {% hint style="info" %} **ROOT AND NON-ROOT USERS** Steps run as the root user, generally. For example, with Harness Cloud build infrastructure, steps run directly on the host and, therefore, run as the root user. For services running on containers (which are steps where you specify a **Container Registry** and **Image** to use to execute the step's commands), you can use the **Run as User** setting to specify a user to use for that container. With Kubernetes cluster build infrastructure, you can use the **Run as User** setting to specify a user to use for individual steps, or you can [set a default user for all steps](/continuous-integration/3.0/use-harness-ci/use-harness-ci/set-up-build-infrastructure/k8s-build-infrastructure/set-up-a-kubernetes-cluster-build-infrastructure.md#run-as-non-root-or-a-specific-user) and then override the default user as needed for individual steps. {% endhint %} #### Scripts in workflows Both Harness CI and GitLab CI support running scripts or shell commands in jobs/steps. In GitLab CI, you use the `script` key to declare a script step. In Harness CI scripts are supplied in the `command` key, and can be supplied for any step type that supports `command`. #### Writing workflows Both Harness CI and GitLab CI workflows are written in YAML. Whereas GitLab workflow configurations are always stored in the `.gitlab-ci.yml` file in your code repo's root directory, Harness provides you a choice of inline pipeline storage or [importing pipelines from Git](/harness-ai/use-harness-platform/git-experience/import-a-pipeline.md). Harness also provides both visual and code-based pipeline editors. * The Harness YAML editor includes schema validation and auto-complete recommendations to simplify and expedite pipeline configuration. * The Harness visual editor provides a guided experience that enables anyone to easily build, debug, and run pipelines. * You can switch back and forth between editors.
Complete workflow comparison Here are YAML examples of complete workflows in GitLab CI and Harness CI. image: docker:latestvariables: pipelinevar1: someval POSTGRES\_USER: postgres POSTGRES\_PASSWORD: "$POSTGRES\_PASS" POSTGRES\_DB: postgresservices:- docker:postgres:10.8stages:- stage1- stage2- matrixstagebefore\_script:- docker login $REGISTRY -u $REGISTRY\_USER -p $REGISTRY\_USER\_PASSWORDstep1: stage: stage1 image: openjdk:17.0-jdk only: - /^dev-.\*$/ except: - branches script: - echo "this runs on openjdk"step1: stage: stage2 image: node:13.0.0 only: - /^prod-.\*$/ except: - branches script:echo "project level var:" "$PROJ\_VAR"echo "pipeline var:" "$PIPELINE\_VAR"echo "secret example :" "$DB\_PASSWORD" step1: stage: matrixstage only: - /^prod-.\*$/ except: - branches script:echo "Testing matrix" parallel: matrix: - PLATFORM: \[windows, mac, linux]pipeline: name: gitlab test identifier: gitlab\_test projectIdentifier: gitlab\_test orgIdentifier: default tags: {} stages: - stage: name: Stage1 identifier: stage1 type: CI spec: cloneCodebase: true execution: steps: - step: type: Background name: Background\_1 identifier: Background\_1 spec: connectorRef: YOUR\_IMAGE\_REGISTRY\_CONNECTOR image: postgres:10.8 envVariables: POSTGRES\_USER: postgres POSTGRES\_PASSWORD: <+secrets.getValue("DbPasswordSecret")> POSTGRES\_DB: postgres - step: type: Run name: step1 identifier: step1 spec: connectorRef: myDockerHubConnector image: openjdk:17.0-jdk shell: Bash command: echo "this runs on openjdk" platform: os: Linux arch: Amd64 runtime: type: Cloud spec: {} - stage: name: Stage2 identifier: Stage2 type: CI spec: cloneCodebase: true execution: steps: - step: type: Run name: step1 identifier: step1 spec: connectorRef: myDockerHubConnector image: node:13.0.0 shell: Bash command: |- echo "pipeline var:" <+pipeline.variables.pipelinevar1> echo "project level var:" <+variable.proj\_var> echo "secret example :" <+secrets.getValue("DbPasswordSecret")> platform: os: Linux arch: Amd64 runtime: type: Cloud spec: {} variables: \[] - stage: name: matrix stage identifier: Stage4 type: CI spec: cloneCodebase: true execution: steps: - step: type: Run name: step1 identifier: step1 spec: shell: Bash command: echo "Testing on <+matrix.testparam>" failureStrategies: \[] platform: os: Linux arch: Amd64 runtime: type: Cloud spec: {} strategy: matrix: testparam: - node - python - ubuntu maxConcurrency: 3 properties: ci: codebase: connectorRef: account.myscm repoName: test build: <+input> variables: - name: pipelinevar1 type: String description: "" value: someval
### Comparison: Specify a Docker image In GitLab CI, images are defined at the job level, and you can specify global images that are used by jobs that don't have an image specified, for example: ```yaml step1: stage: stage1 image: openjdk:17.0-jdk ``` In Harness CI, you specify *connectors* and images for each step, if necessary. Depending on the step type, the commands you are running, and your build infrastructure, you may not need to specify an image. For example, if a binary is already available on your build farm, you may not need to pull an image for that binary. For example, the following step includes a `connectorRef` referencing a Docker connector. [Docker connectors](/harness-ai/use-harness-platform/connectors/cloud-providers/ref-cloud-providers/docker-registry-connector-settings-reference.md) are platform-agnostic and can be used to connect to any Docker container registry. ```yaml - step: type: Run name: step1 identifier: step1 spec: connectorRef: my-docker-hub-connector image: openjdk:17.0-jdk shell: Bash command: echo "this runs on openjdk" ``` {% hint style="info" %} **WHAT ARE CONNECTORS?** Harness integrates with many different types of repositories and providers. A connection from Harness to other platforms is called a [connector](/harness-ai/use-harness-platform/connectors.md). Connectors can connect to source control providers, cloud providers, container registries, and more. {% endhint %} ### Comparison: Define a multi-stage pipeline Both GitLab CI and Harness CI execute workflow stages in a specific order based on the YAML configuration. {% tabs %} {% tab title="GitLab CI" %} ``` stages: - test - build - deploy ``` {% endtab %} {% tab title="Harness" %} ```yaml stages: - stage: name: Test ... - stage: name: Build ... - stage: name: Upload ... ``` {% endtab %} {% endtabs %} The following examples compare GitLab CI and Harness CI workflows with multiple stages.
YAML examples: Multi-stage pipelines image: golang:lateststages: - test - buildformat: stage: test script: - go fmt $(go list ./... | grep -v /vendor/) - go vet $(go list ./... | grep -v /vendor/) - go test -race $(go list ./... | grep -v /vendor/)compile: stage: build script: - mkdir -p mybinaries - go build -o mybinaries ./... artifacts: paths: - mybinaries stages: - stage: name: test identifier: test description: "" type: CI spec: cloneCodebase: true platform: os: Linux arch: Amd64 runtime: type: Cloud spec: {} execution: steps: - step: type: Run name: test-step identifier: teststep spec: shell: Sh command: | go fmt $(go list ./... | grep -v /vendor/) go vet $(go list ./... | grep -v /vendor/) go test -race $(go list ./... | grep -v /vendor/) - stage: name: build identifier: build type: CI spec: cloneCodebase: true platform: os: Linux arch: Amd64 runtime: type: Cloud spec: {} execution: steps: - step: type: Run name: build-step identifier: buildstep spec: shell: Sh command: | mkdir -p mybinaries go build -o mybinaries ./... sharedPaths: - mybinaries
### Comparison: Environment variables In GitLab CI, you can use environment variables to control the behavior of jobs and pipelines, store values you want to reuse, or avoid hard-coding values in your `.gitlab-ci.yml` file. You can use predefined environment variables, define custom variables in the `.gitlab-ci.yml` file, or define variables at the project, group, or instance levels. This range of variable definition is also possible in Harness CI. In addition to built-in variables, you can define variables within individual pipelines, stages, and steps as well as at the project, organization, and account levels. {% tabs %} {% tab title="GitLab CI" %} This GitLab example demonstrates use of a pre-defined variable as well as a custom variable definition. ```yaml test_variable: stage: test script: - echo "$CI_JOB_STAGE" #Uses pre-defined variable # Custom variable definition in .gitlab-ci.yml file variables: SA_PASSWORD: $SA_PASSWORD ``` {% endtab %} {% tab title="Harness" %} To reference project, organization, and account variables, you use variable expressions formatted as: `<+variable.[scope].[variable_id]>`. Here are the syntax formats for variables declared at different levels: * Account-level variable reference: `<+variable.account.[var_id]>` * Organization-level variable reference: `<+variable.org.[var_id]>` * Project-level variable reference: `<+variable.[var_id]>` In this example, a step references a project-level environment variable called `ENV_VAR`. ```yaml - step: type: Run name: test-variable identifier: test_variable spec: command: echo "environment variable: " <+variable.env_var> ``` Within a single pipeline, you can define variables at the step, stage, and pipeline levels. For example, this step includes environment variable definitions. ```yaml - step: type: Background name: Background_1 identifier: Background_1 spec: connectorRef: YOUR_IMAGE_REGISTRY_CONNECTOR image: postgres:10.8 envVariables: POSTGRES_USER: postgres POSTGRES_PASSWORD: <+secrets.getValue("DbPasswordSecret")> POSTGRES_DB: postgres ``` To learn more about defining and fetching variables go to: * [Use Harness expressions](/harness-ai/use-harness-platform/variables-and-expressions/harness-variables.md) * [Define variables](/harness-ai/use-harness-platform/variables-and-expressions/add-a-variable.md) {% endtab %} {% endtabs %} ### Comparison: Matrix and parallelism GitLab CI jobs run in parallel by default, whereas in Harness CI steps and stages run sequentially unless you enable parallelism. For example, this Harness CI YAML example shows a pipeline with two stages that run in parallel, as indicated by `- parallel`, and two stages that run sequentially after the two parallel stages. ```yaml stages: - parallel: - stage: name: Stage1 ... - stage: name: Stage2 ... - stage: name: Stage3 ... - stage: name: Stage4 ... ``` In addition to parallelism, you can use Harness CI's [looping strategies](/harness-ai/use-harness-platform/pipelines/looping-strategies/looping-strategies-matrix-repeat-and-parallelism.md) to make your pipelines more dynamic and versatile. These strategies allow your pipelines to execute the same set of tasks multiple times for several different configurations without requiring you to intentionally create unique steps or stages for each iteration. This is achieved by mentioning user-defined tags and referencing them in the pipeline using the following expression syntax: `<+matrix.usertag>` As in GitLab CI, you also can combine parallelism and matrix strategies in Harness CI, as shown in the following examples. {% tabs %} {% tab title="GitLab CI" %} ```yaml test: stage: test script: run-test $PLATFORM parallel: matrix: - PLATFORM: [windows, mac, linux] ``` {% endtab %} {% tab title="Harness" %} The following example describes a stage in a Harness CI pipeline that includes one step with matrix and parallelism strategies. The looping strategies are defined in `strategy` at the stage level. One matrix strategy, called `testparam`, is defined in `matrix` and parallelism is defined by `maxConcurrency: 3`. The script in the `Run` step calls the inputs from the matrix strategy by using the expression `+matrix.testparam>`. ```yaml stages: - stage: name: Stage1 identifier: Stage1 type: CI spec: cloneCodebase: true execution: steps: - step: type: Run name: step1 identifier: step1 spec: connectorRef: dockerconectorref image: dockerimage:tag shell: Bash command: echo "Testing on <+matrix.testparam>" strategy: matrix: testparam: - node - python - ubuntu maxConcurrency: 3 ``` {% endtab %} {% endtabs %} ### Comparison: Triggers Webhooks are a convenient way to trigger CI builds on demand by sending an HTTP post request to specialized URLs. This is particularly useful for event-based triggering, in which a webhook can be called whenever a specified event occurs. In GitLab CI, pipelines can be triggered only through API. Harness CI supports webhook, artifact, manifest and schedule triggers. The two most commonly used triggers are webhook triggers based on Git events and scheduled triggers based on `cron` expressions. To learn more about creating a trigger, go to [Triggers](/harness-ai/use-harness-platform/triggers.md). {% tabs %} {% tab title="GitLab CI" %} ```yaml trigger_pipeline: stage: deploy script: - 'curl --fail --request POST --form token=$MY_TRIGGER_TOKEN --form ref=main "https://gitlab.example.com/api/v4/projects/123456/trigger/pipeline"' rules: - if: $CI_COMMIT_TAG environment: production ``` {% endtab %} {% tab title="Harness" %} ```yaml trigger: name: make build identifier: make_build enabled: true orgIdentifier: default projectIdentifier: DhrubaCI pipelineIdentifier: Demo3 source: type: Scheduled spec: type: Cron spec: expression: 45 13 13 09 2 inputYaml: | pipeline: identifier: Demo3 properties: ci: codebase: build: type: branch spec: branch: main ``` {% endtab %} {% endtabs %} ### See also Review the following information before proceeding with migration: * [Harness CI pipeline creation overview](/continuous-integration/3.0/use-harness-ci/use-harness-ci/prep-ci-pipeline-components.md) * [Caching in Harness CI](/continuous-integration/3.0/use-harness-ci/use-harness-ci/caching-ci-data.md) * [Split tests in Run steps](/continuous-integration/3.0/use-harness-ci/use-harness-ci/run-tests/speed-up-ci-test-pipelines-using-parallelism.md) * [Harness Platform documentation](https://app.gitbook.com/s/3F2TpHXhur2QtQnORSM9/README)