#369 Use SHA for Docker tags if no branch detected

On GH pull requests the `git branch --show-current` does not return the
branch name. In this case we use the SHA tag (only) for Docker tagging.

Author: ascheman

htmlSanityCheck-cli/build.gradle

@@ -34,10 +34,20 @@ shadowJar {
 
 def dockerTags(Project project) {
     String currentBranch = "${'git branch --show-current'.execute().text.trim()}"
-    def result = [
-            java.time.LocalDateTime.now().format(java.time.format.DateTimeFormatter.ofPattern('yyyyMMddHHmmss')) as String,
-            "${currentBranch.replaceAll('/', '-')}" as String,
-            ]
+    // Determine a safe tag: prefer branch name, fallback to Git SHA (from env or git)
+    String githubSha = System.getenv('GITHUB_SHA') ?: "${'git rev-parse --short=12 HEAD'.execute().text.trim()}"
+    String branchOrShaTag = currentBranch ? currentBranch.replaceAll('/', '-') : (githubSha ? "sha-${githubSha}" : null)
+
+    def result = [] as List<String>
+    // Always include a timestamp tag for traceability
+    result += java.time.LocalDateTime.now().format(java.time.format.DateTimeFormatter.ofPattern('yyyyMMddHHmmss')) as String
+    // Include branch or SHA-derived tag if available
+    if (branchOrShaTag) {
+        result += branchOrShaTag as String
+    } else {
+        logger.quiet("No branch name or Git SHA could be determined; only timestamp tag will be used")
+    }
+
     if (currentBranch == 'main') {
         // On the main branch we should have the latest major prepended with 'v' for GH actions
         result += ['v' + project.version.substring(0, 1), 'latest']
@@ -49,7 +59,8 @@ def dockerTags(Project project) {
         result += additionalTags.split(',').collect { it.trim() }
     }
 
-    return result
+    // Avoid duplicate tags (e.g., if additionalTags repeats a SHA)
+    return result.findAll { it && it.trim() }.unique()
 }
 
 docker {
@@ -62,7 +73,9 @@ docker {
 }
 
 tasks.register('dockerBuildLocal', com.fussionlabs.gradle.docker.tasks.DockerBuildx) {
-    def tag = "${'git branch --show-current'.execute().text.trim().replaceAll('/', '-')}"
+    def branch = "${'git branch --show-current'.execute().text.trim()}"
+    def sha = System.getenv('GITHUB_SHA') ?: "${'git rev-parse --short=12 HEAD'.execute().text.trim()}"
+    def tag = branch ? branch.replaceAll('/', '-') : (sha ?: 'timestamp-only')
     logger.quiet("Using tag '${tag}' for dockerBuildLocal")
     loadImage = true
     pushImage = false

integration-test/build.gradle

@@ -227,6 +227,7 @@ tasks.register("integrationTestDocker") {
         String reportsDir = buildReportsDirectory.absolutePath
 
         String params = "--rm -v \"${docsDir}:${docsDir}\" -v \"${reportsDir}\":/reports -w \"${docsDir}\" ${image} -r /reports --exclude https://www\\.baeldung\\.com/.* --fail-on-errors"
+        logger.quiet("Executing Docker run with '${params}'")
         def result = exec {
             if (System.getProperty("os.name") ==~ /Windows.*/) {
                 // Use cmd to run docker on Windows