> ## Documentation Index > Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt > Use this file to discover all available pages before exploring further. # Step 3 Using Inputs in Reusable Workflow > Learn to pass variables from a caller workflow into a reusable workflow using workflow_call inputs to avoid empty environment variables. In this lesson, you’ll learn how to pass variables from a caller workflow into a reusable workflow using `workflow_call` inputs. By declaring inputs explicitly, you avoid the common pitfall where environment variables defined at the caller level don’t automatically propagate. Reusable workflows require GitHub Actions `workflow_call`. See the [GitHub Actions Reusing Workflows](https://docs.github.com/actions/using-workflows/reusing-workflows) guide for details. ## The Problem: Empty Environment Variables When you define environment variables in the caller workflow, they aren’t forwarded to the reusable workflow. For example, this secret creation command ran with an empty `MONGO_URI`: ```bash theme={null} kubectl -n development create secret generic mongo-db-creds \ --from-literal=MONGO_URI='' \ --from-literal=MONGO_USERNAME=superuser \ --from-literal=MONGO_PASSWORD='***' \ --save-config \ --dry-run=client \ -o yaml | kubectl apply -f - ``` Because `MONGO_URI` was never passed, the URI value remained blank: ![The image shows a GitHub Docs page about GitHub Actions, specifically focusing on the limitations of reusable workflows. It includes a navigation menu on the left and detailed text about workflow limitations on the right.](https://kodekloud.com/kk-media/image/upload/v1752876734/notes-assets/images/GitHub-Actions-Step-3-Using-Inputs-in-Reusable-Workflow/github-actions-reusable-workflows-limitations.jpg) To fix this, we define inputs in the reusable workflow and explicitly pass values from the caller. ## Define an Input in the Reusable Workflow Edit your reusable workflow (e.g. `.github/workflows/reuse-deployment.yml`) and add an `inputs` section under `workflow_call`. Here we declare a required string input `mongodb-uri`: ```yaml theme={null} name: Deployment - Reusable Workflow on: workflow_call: inputs: mongodb-uri: required: true type: string secrets: k8s-kubeconfig: required: true mongodb-password: required: true jobs: reuse-deploy: environment: name: development url: https://${{ steps.set-ingress-host-address.outputs.APP_INGRESS_HOST }} outputs: APP_INGRESS_URL: ${{ steps.set-ingress-host-address.outputs.APP_INGRESS_HOST }} runs-on: ubuntu-latest steps: - name: Checkout Repo uses: actions/checkout@v4 - name: Install kubectl CLI uses: azure/setup-kubectl@v3 with: version: '1.26.0' - name: Create MongoDB Secret run: | kubectl -n ${{ vars.NAMESPACE }} create secret generic mongo-db-creds \ --from-literal=MONGO_URI=${{ inputs.mongodb-uri }} \ --from-literal=MONGO_USERNAME=${{ vars.MONGO_USERNAME }} \ --from-literal=MONGO_PASSWORD=${{ secrets.mongodb-password }} \ --save-config \ --dry-run=client -o yaml | kubectl apply -f - ``` Notice how we replaced the hard-coded `MONGO_URI` with `${{ inputs.mongodb-uri }}`. ## Store the URI as a Repository Variable In your repository settings under **Settings › Actions › Variables**, create a variable named `mongo_uri`: ![The image shows a GitHub repository settings page focused on "Actions secrets and variables," displaying environment variables for different namespaces and replicas.](https://kodekloud.com/kk-media/image/upload/v1752876735/notes-assets/images/GitHub-Actions-Step-3-Using-Inputs-in-Reusable-Workflow/github-repo-actions-secrets-variables.jpg) * **Name**: `mongo_uri` * **Value**: `mongodb+srv://supercluster.d8jjj.mongodb.net/superData` Repository variables are not encrypted. Use **Secrets** for sensitive values like passwords. ## Call the Reusable Workflow with Inputs In your caller workflow (e.g. `.github/workflows/solar-system.yml`), remove the old `env:` block for MongoDB and invoke the reusable workflow using a `with` block: ```yaml theme={null} name: Solar System Workflow on: workflow_dispatch: push: branches: - main - 'feature/*' jobs: # ... other jobs ... dev-deploy: needs: docker if: contains(github.ref, 'feature/') uses: ./.github/workflows/reuse-deployment.yml with: mongodb-uri: ${{ vars.mongo_uri }} secrets: k8s-kubeconfig: ${{ secrets.KUBECONFIG }} mongodb-password: ${{ secrets.MONGO_PASSWORD }} prod-deploy: needs: docker if: github.ref == 'refs/heads/main' uses: ./.github/workflows/reuse-deployment.yml with: mongodb-uri: ${{ vars.mongo_uri }} secrets: k8s-kubeconfig: ${{ secrets.KUBECONFIG }} mongodb-password: ${{ secrets.MONGO_PASSWORD }} ``` This ensures both development and production deployments receive the correct `mongodb-uri`. ## Adding Dynamic Inputs To make your reusable workflow more flexible, you can declare additional inputs—such as `kubectl-version`, `k8s-manifest-dir`, and `environment`. Update `workflow_call` like so: ```yaml theme={null} on: workflow_call: inputs: mongodb-uri: required: true type: string kubectl-version: description: Provide the required kubectl version default: v1.26.0 required: false type: string k8s-manifest-dir: description: Directory containing Kubernetes manifest files default: kubernetes/ required: true type: string environment: description: Deployment environment (e.g., dev, prod) default: dev required: true type: string secrets: k8s-kubeconfig: required: true mongodb-password: required: true ``` Table: Reusable Workflow Inputs | Input Name | Description | Default | Required | | ---------------- | ---------------------------------------- | ----------- | -------- | | mongodb-uri | MongoDB connection URI | — | true | | kubectl-version | Version of `kubectl` to install | v1.26.0 | false | | k8s-manifest-dir | Path to Kubernetes manifest directory | kubernetes/ | true | | environment | Deployment environment (e.g., dev, prod) | dev | true | Reference these inputs in your job steps: ```yaml theme={null} jobs: reuse-deploy: environment: ${{ inputs.environment }} runs-on: ubuntu-latest steps: - name: Install kubectl CLI uses: azure/setup-kubectl@v3 with: version: ${{ inputs.kubectl-version }} - name: Replace tokens in manifests uses: cschleiden/replace-tokens@v1 with: tokenPrefix: '_' tokenSuffix: '_' files: '${{ inputs.k8s-manifest-dir }}/*.yaml' - name: Create MongoDB Secret run: | kubectl -n ${{ vars.NAMESPACE }} create secret generic mongo-db-creds \ --from-literal=MONGO_URI=${{ inputs.mongodb-uri }} \ --from-literal=MONGO_USERNAME=${{ vars.MONGO_USERNAME }} \ --from-literal=MONGO_PASSWORD=${{ secrets.mongodb-password }} \ --save-config \ --dry-run=client -o yaml | kubectl apply -f - - name: Deploy to ${{ inputs.environment }} run: | kubectl apply -f ${{ inputs.k8s-manifest-dir }} ``` And in the caller workflow, pass all required inputs: ```yaml theme={null} dev-deploy: uses: ./.github/workflows/reuse-deployment.yml with: mongodb-uri: ${{ vars.mongo_uri }} environment: dev kubectl-version: v1.26.0 k8s-manifest-dir: kubernetes/development/ secrets: k8s-kubeconfig: ${{ secrets.KUBECONFIG }} mongodb-password: ${{ secrets.MONGO_PASSWORD }} prod-deploy: uses: ./.github/workflows/reuse-deployment.yml with: mongodb-uri: ${{ vars.mongo_uri }} environment: production kubectl-version: v1.26.0 k8s-manifest-dir: kubernetes/production/ secrets: k8s-kubeconfig: ${{ secrets.KUBECONFIG }} mongodb-password: ${{ secrets.MONGO_PASSWORD }} ``` Keep input names consistent between caller and reusable workflows to minimize errors. ## Verification in Workflow Run When the workflow executes, you’ll see the passed inputs in the reusable job’s **Inputs** section: ![The image shows a GitHub Actions workflow interface with a series of jobs and their statuses, including unit testing, code coverage, and deployment steps. The workflow is in a "Waiting" status, with some jobs completed and others in progress.](https://kodekloud.com/kk-media/image/upload/v1752876736/notes-assets/images/GitHub-Actions-Step-3-Using-Inputs-in-Reusable-Workflow/github-actions-workflow-jobs-status.jpg) * **`mongodb-uri`**, **`kubectl-version`**, **`k8s-manifest-dir`**, and **`environment`** are listed under **Inputs**. * The MongoDB secret is created with the correct URI. * Manifests are applied from the specified directory. * The deployment environment dynamically matches your input. *** Next, we’ll explore how to propagate outputs from the reusable workflow back into the caller workflow for advanced chaining and reporting. ## References * [GitHub Actions Reusing Workflows](https://docs.github.com/actions/using-workflows/reusing-workflows) * [GitHub Actions Variables](https://docs.github.com/actions/learn-github-actions/variables) * [Azure/setup-kubectl Action](https://github.com/Azure/setup-kubectl) * [cschleiden/replace-tokens Action](https://github.com/cschleiden/replace-tokens)