{"id":49335,"date":"2025-05-16T15:43:02","date_gmt":"2025-05-16T15:43:02","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=49335"},"modified":"2025-07-12T05:54:57","modified_gmt":"2025-07-12T05:54:57","slug":"openshift-buildconfig-tutorial","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/openshift-buildconfig-tutorial\/","title":{"rendered":"OpenShift BuildConfig Tutorial"},"content":{"rendered":"\n

\u2705 What is OpenShift BuildConfig<\/strong>?<\/h3>\n\n\n\n

BuildConfig<\/code><\/strong> in OpenShift is a Kubernetes-native custom resource provided by OpenShift that defines how to build a container image from source code<\/strong>. It automates the end-to-end image build process \u2014 from fetching source code to producing and storing container images \u2014 using build strategies<\/strong> like Source-to-Image (S2I), Docker, or custom workflows.<\/p>\n\n\n\n

\n\n\n\n

\ud83d\udcd8 BuildConfig Definition<\/strong><\/h2>\n\n\n\n
\n

A BuildConfig<\/code> is a declarative configuration object in OpenShift that defines the strategy, source, triggers, and output for building container images automatically or on-demand.<\/strong><\/p>\n<\/blockquote>\n\n\n\n

It\u2019s like a recipe<\/strong> for converting application source code into a deployable container image.<\/p>\n\n\n\n

\n\n\n\n

\u2b50 Key Features of BuildConfig<\/h2>\n\n\n\n
Feature<\/th>Description<\/th><\/tr><\/thead>
\ud83c\udfaf Multiple Build Strategies<\/strong><\/td>Supports S2I<\/strong>, Dockerfile<\/strong>, and Custom<\/strong> strategies.<\/td><\/tr>
\ud83d\udd17 Git Integration<\/strong><\/td>Pulls source code directly from public\/private Git repositories.<\/td><\/tr>
\ud83d\udd01 Automatic Triggers<\/strong><\/td>Rebuilds can be triggered by Git changes<\/strong>, image changes<\/strong>, or config changes<\/strong>.<\/td><\/tr>
\ud83d\udee0 Custom Build Environment<\/strong><\/td>Supports environment variables, secrets, and configmaps during builds.<\/td><\/tr>
\ud83c\udff7\ufe0f ImageStream Integration<\/strong><\/td>Built images can be pushed to internal ImageStreams<\/strong> or external registries.<\/td><\/tr>
\ud83d\udc65 Webhooks<\/strong><\/td>Allows GitHub\/GitLab to trigger builds via webhooks.<\/td><\/tr>
\ud83d\udd0d Build Logs & History<\/strong><\/td>Easily view build logs, status, and retry failed builds.<\/td><\/tr>
\ud83d\udd10 Secure Build Contexts<\/strong><\/td>Supports source credentials, secrets, and isolated build pods.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n

\ud83d\udd27 Example Use Cases<\/h2>\n\n\n\n
Scenario<\/th>How BuildConfig Helps<\/th><\/tr><\/thead>
CI\/CD automation<\/td>Auto-rebuild on Git push or base image update<\/td><\/tr>
DevOps in hybrid cloud<\/td>Works with internal and external image registries<\/td><\/tr>
Compliance & traceability<\/td>Full build history and image tracking<\/td><\/tr>
S2I app deployment (Node.js, Python, etc.)<\/td>Uses language-specific builder images<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n

\ud83d\udce6 BuildConfig vs Dockerfile vs Pipelines<\/h2>\n\n\n\n
Tool\/Concept<\/th>Role<\/th><\/tr><\/thead>
BuildConfig<\/strong><\/td>Defines how to build<\/strong> an image from source<\/td><\/tr>
Dockerfile<\/strong><\/td>Manual build instructions (used in Docker strategy)<\/td><\/tr>
Pipelines<\/strong><\/td>Orchestrates multiple stages\/jobs<\/strong> (Tekton-based)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n

\ud83d\ude80 BuildConfig Lifecycle<\/h2>\n\n\n\n
    \n
  1. Developer pushes code to Git<\/li>\n\n\n\n
  2. OpenShift triggers a build (via webhook or manually)<\/li>\n\n\n\n
  3. Code is fetched and built using specified strategy<\/li>\n\n\n\n
  4. Final image is stored (ImageStream or registry)<\/li>\n\n\n\n
  5. App is deployed or updated automatically<\/li>\n<\/ol>\n\n\n\n
    \n\n\n\n

    \u2705 Works on OpenShift 4.13+ (including Azure Red Hat OpenShift)<\/p>\n\n\n\n

    \n\n\n\n

    \ud83c\udfaf Goal<\/h2>\n\n\n\n

    Build a Node.js application using:<\/p>\n\n\n\n

      \n
    • \u2705 Git source<\/li>\n\n\n\n
    • \u2705 External Red Hat base image (ubi8\/nodejs-16<\/code>)<\/li>\n\n\n\n
    • \u2705 OpenShift S2I strategy (using DockerImage)<\/li>\n\n\n\n
    • \u2705 No need for preloaded ImageStreams<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n

      \ud83e\uddf1 Prerequisites<\/h2>\n\n\n\n
      Requirement<\/th>Details<\/th><\/tr><\/thead>
      OpenShift cluster<\/td>Access to 4.13+ (Azure, local, etc.)<\/td><\/tr>
      Project created<\/td>Use oc new-project<\/code> or create via Web UI<\/td><\/tr>
      GitHub repo with app code<\/td>e.g., sclorg\/nodejs-ex<\/code><\/a><\/td><\/tr>
      OpenShift CLI (optional)<\/td>oc<\/code> logged in<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
      \n\n\n\n

      \ud83e\uddfe Option 1: YAML Method (CLI or Web Console YAML Editor)<\/strong><\/h2>\n\n\n\n

      \u2705 Step-by-Step (Using YAML)<\/h3>\n\n\n\n
        \n
      1. Create\/Open a project<\/strong> oc new-project nodejs-s2i-demo<\/code><\/li>\n\n\n\n
      2. Apply this working BuildConfig<\/code> YAML<\/strong>:<\/li>\n<\/ol>\n\n\n
        apiVersion: build.openshift.io\/v1\nkind<\/span>: BuildConfig\nmetadata<\/span>:\n  name: nodejs-sample-build\n  labels<\/span>:\n    app: nodejs-sample\nspec<\/span>:\n  source:\n    type: Git\n    git<\/span>:\n      uri: https:\/\/github.com\/sclorg\/nodejs-ex.git<\/span>\n      ref: main\n    contextDir<\/span>: .\n  strategy:\n    type: Source\n    sourceStrategy<\/span>:\n      from<\/span>:\n        kind: DockerImage\n        name<\/span>: registry.access.redhat.com\/ubi8\/nodejs-16<\/span>\n      forcePull<\/span>: true<\/span>\n  output<\/span>:\n    to:\n      kind: ImageStreamTag\n      name<\/span>: nodejs-sample:latest\n  triggers<\/span>:\n    - type: ConfigChange\n    - type: ImageChange\n  runPolicy<\/span>: Serial\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
          \n
        1. Start the build manually<\/strong>: oc start-build nodejs-sample-build --follow<\/code><\/li>\n\n\n\n
        2. Deploy the built image<\/strong>: oc new-app nodejs-sample oc expose svc\/nodejs-sample<\/code><\/li>\n\n\n\n
        3. Access the app<\/strong>: oc get route<\/code><\/li>\n<\/ol>\n\n\n\n
          \n\n\n\n
          \ud83d\uddb1\ufe0f Option 2: Using the OpenShift Developer Console UI<\/strong><\/h2>\n\n\n\n
          \n
          Based on your screenshots \u2014 modern and guided flow<\/p>\n<\/blockquote>\n\n\n\n
          \u2705 Step-by-Step (Using Developer Web Console)<\/h3>\n\n\n\n
            \n
          1. Go to Developer \u2192 +Add \u2192 From Git<\/strong><\/li>\n\n\n\n
          2. Fill Git Repository info:<\/strong>\n
              \n
            • Git Repo URL: https:\/\/github.com\/sclorg\/nodejs-ex.git<\/code><\/li>\n\n\n\n
            • Git Reference: main<\/code> (or leave blank)<\/li>\n\n\n\n
            • Context Dir: .<\/code><\/li>\n<\/ul>\n<\/li>\n\n\n\n
            • Builder Image Selection (Build from)<\/strong>:\n
                \n
              • Select \u201cDocker Image\u201d<\/strong> from the build option dropdown<\/li>\n\n\n\n
              • Input Docker Image: registry.access.redhat.com\/ubi8\/nodejs-16<\/code><\/li>\n<\/ul>\n<\/li>\n\n\n\n
              • Deployment Settings<\/strong>:\n
                  \n
                • App Name: nodejs-sample<\/code><\/li>\n\n\n\n
                • Resources: Deployment (leave default)<\/li>\n\n\n\n
                • Create Route: \u2705 (enabled)<\/li>\n<\/ul>\n<\/li>\n\n\n\n
                • Click “Create”<\/strong><\/li>\n<\/ol>\n\n\n\n
                  OpenShift will:<\/p>\n\n\n\n
                    \n
                  • Create BuildConfig<\/code>, ImageStream<\/code>, Deployment<\/code>, and Route<\/code><\/li>\n\n\n\n
                  • Trigger an initial build<\/li>\n\n\n\n
                  • Watch progress from Builds<\/strong> or Topology<\/strong><\/li>\n<\/ul>\n\n\n\n
                    \n\n\n\n
                    \ud83e\uddea How to Monitor<\/h2>\n\n\n\n
                      \n
                    • Build logs<\/strong>:
                      Developer \u2192 Builds \u2192 nodejs-sample-build<\/code> \u2192 View Logs<\/li>\n\n\n\n
                    • Application route<\/strong>:
                      Developer \u2192 Topology \u2192 Click route link<\/li>\n\n\n\n
                    • BuildConfig YAML<\/strong>:
                      Admin \u2192 Builds \u2192 nodejs-sample-build<\/code> \u2192 YAML<\/li>\n<\/ul>\n\n\n\n
                      \n\n\n\n
                      \ud83d\udd01 Updating Code<\/h2>\n\n\n\n
                      Just push code to GitHub and trigger a build manually:<\/p>\n\n\n
                      oc start-build nodejs-sample-build\n<\/code><\/span><\/pre>\n\n\n
                      Or setup GitHub webhook using:<\/p>\n\n\n
                      oc describe bc nodejs-sample-build\n<\/code><\/span><\/pre>\n\n\n
                      \n\n\n\n
                      \u2705 Summary<\/h2>\n\n\n\n
                      Step<\/th>UI Path<\/th>YAML Equivalent<\/th><\/tr><\/thead>
                      Git source<\/td>From Git<\/td>source.git.uri<\/code><\/td><\/tr>
                      Docker image<\/td>Select \u201cDocker Image\u201d<\/td>strategy.sourceStrategy.from.kind: DockerImage<\/code><\/td><\/tr>
                      Deployment<\/td>Auto-created via +Add<\/td>Use oc new-app<\/code> after build manually<\/td><\/tr>
                      Route<\/td>Enabled in UI<\/td>oc expose svc\/nodejs-sample<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
                      \n\n\n\n
                      <\/p>\n","protected":false},"excerpt":{"rendered":"
                      \u2705 What is OpenShift BuildConfig? BuildConfig in OpenShift is a Kubernetes-native custom resource provided by OpenShift that defines how to build a container image from source code. It automates the… <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_joinchat":[],"footnotes":""},"categories":[5153],"tags":[],"class_list":["post-49335","post","type-post","status-publish","format-standard","hentry","category-openshift"],"_links":{"self":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/49335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/comments?post=49335"}],"version-history":[{"count":1,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/49335\/revisions"}],"predecessor-version":[{"id":49336,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/49335\/revisions\/49336"}],"wp:attachment":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media?parent=49335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/categories?post=49335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/tags?post=49335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}