Default registry username to Gitea actor

.gitea/workflows/build-ci-image.yml

@@ -11,6 +11,8 @@ on:
 env:
   REGISTRY_HOST: git.neosisyphus.com
   REGISTRY_IMAGE: git.neosisyphus.com/evol3d/evol-testbed
+  # Optional. If this secret is not set, the workflow uses GITHUB_ACTOR.
+  REGISTRY_USERNAME: ${{ secrets.REGISTRY_USERNAME }}
 
 jobs:
   image:
@@ -21,8 +23,18 @@ jobs:
 
       - name: Log in to container registry
         run: |
+          set -eu
+          username="${REGISTRY_USERNAME:-${GITHUB_ACTOR:-}}"
+          if [ -z "$username" ]; then
+            echo "REGISTRY_USERNAME secret is empty and GITHUB_ACTOR is not set" >&2
+            exit 1
+          fi
+          if [ -z "${{ secrets.REGISTRY_PASSWORD }}" ]; then
+            echo "REGISTRY_PASSWORD secret is empty. Set it to a Gitea access token with package write permission." >&2
+            exit 1
+          fi
           echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login "$REGISTRY_HOST" \
-            -u "${{ secrets.REGISTRY_USERNAME }}" \
+            -u "$username" \
             --password-stdin
 
       - name: Build CI image

ci/README.md

@@ -35,15 +35,22 @@ REGISTRY_IMAGE=git.neosisyphus.com/evol3d/evol-testbed
 CI_IMAGE=git.neosisyphus.com/evol3d/evol-testbed
 ```
 
-Add these **Actions secrets**:
+Add this **Actions secret**:
 
 ```text
-REGISTRY_USERNAME=your-gitea-username
 REGISTRY_PASSWORD=your-gitea-token-or-password
 ```
 
 The token/password needs permission to publish packages/container images.
 
+Optional: add this secret if your registry username is different from the Gitea Actions actor:
+
+```text
+REGISTRY_USERNAME=your-gitea-username
+```
+
+If `REGISTRY_USERNAME` is not set, the workflow uses `$GITHUB_ACTOR`.
+
 ## Build manually
 
 ```bash

ci/USE_CI_IMAGE.md

@@ -169,24 +169,28 @@ In your repository:
 1. Go to **Settings**.
 2. Go to **Actions**.
 3. Go to **Secrets**.
-4. Add:
+4. Add this required secret:
 
 ```text
-REGISTRY_USERNAME
 REGISTRY_PASSWORD
 ```
 
 Example:
 
 ```text
-REGISTRY_USERNAME=myusername
 REGISTRY_PASSWORD=<your-gitea-access-token>
 ```
 
-Use your Gitea username for `REGISTRY_USERNAME`.
-
 Use the token from step 3 for `REGISTRY_PASSWORD`.
 
+Optional: add this secret if your registry username is different from the Gitea Actions actor:
+
+```text
+REGISTRY_USERNAME=myusername
+```
+
+If `REGISTRY_USERNAME` is not set, the workflow uses `$GITHUB_ACTOR`.
+
 ---
 
 ## 6. Check the image build workflow
@@ -592,13 +596,10 @@ This avoids surprise breakage when `clang22` or `latest` changes.
 ```text
 1. Commit ci/Dockerfile and workflows.
 2. Create Gitea token with package/container write access.
-3. Add Actions variables:
+3. Registry/image values are already hardcoded in the workflow.
-   - REGISTRY_HOST
-   - REGISTRY_IMAGE
-   - CI_IMAGE
 4. Add Actions secrets:
-   - REGISTRY_USERNAME
    - REGISTRY_PASSWORD
+   - REGISTRY_USERNAME only if needed
 5. Make sure the runner can run docker build.
 6. Run build-ci-image workflow.
 7. Confirm image appears in Gitea Packages.