implemented 05-artifact-store.md: filesystem artifact store with legacy-compatible naming, atomic persist from concurrent builds, retention pruning, and artifacts.rootDir config

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/main/kotlin/de/hoennig/gittally/build/ArtifactKeys.kt

@@ -1,5 +1,6 @@
 package de.hoennig.gittally.build
 
+import java.nio.file.Path
 import java.security.MessageDigest
 import java.time.Instant
 
@@ -16,6 +17,9 @@ object ArtifactKeys {
         startedAt: Instant,
     ): String = "${branchKey(branch)}-${sanitize(startedAt.toString())}-${sha256Prefix("$branch\t$startedAt")}"
 
+    /** Legacy `repository_key`: the sanitized absolute repository path. */
+    fun repoKey(repoDir: Path): String = sanitize(repoDir.toAbsolutePath().normalize().toString())
+
     private fun sanitize(value: String): String = value.replace(Regex("[^A-Za-z0-9._-]"), "_")
 
     private fun sha256Prefix(value: String): String =

src/main/kotlin/de/hoennig/gittally/build/ArtifactStore.kt

@@ -1,29 +1,31 @@
 package de.hoennig.gittally.build
 
-import org.slf4j.LoggerFactory
-import org.springframework.stereotype.Component
 import java.nio.file.Path
 
 /**
- * Takes over the staging directory of a finished build.
- * The real store (naming, retention, serving) arrives in step 05.
+ * Persists the artifacts of finished builds (logs plus configured report directories)
+ * and prunes them together with the result retention.
+ * Implemented by `de.hoennig.gittally.artifacts.FileArtifactStore`.
  */
 interface ArtifactStore {
+    /**
+     * Takes over the staging directory of the finished [build] (log files) plus the
+     * configured `artifactDirs` from [workspace] and stores them under the build's
+     * artifact key. [workspace] is null when the build crashed before its workspace
+     * was prepared; only the logs are stored then.
+     */
     fun persist(
         build: BuildResult,
         stagingDir: Path,
+        workspace: Path?,
     )
-}
 
-/** Placeholder until step 05: logs and leaves the staging directory untouched. */
-@Component
-class NoOpArtifactStore : ArtifactStore {
-    private val log = LoggerFactory.getLogger(NoOpArtifactStore::class.java)
+    /**
+     * Deletes all stored artifact directories whose keys are not in [keptResults];
+     * call after repository retention pruning. Returns the removed artifact keys.
+     */
+    fun prune(keptResults: Collection<BuildResult>): List<String>
 
-    override fun persist(
-        build: BuildResult,
-        stagingDir: Path,
-    ) {
-        log.info("artifact store not implemented yet; leaving build output of {} in {}", build.artifactKey, stagingDir)
-    }
+    /** The stored artifact directory for [artifactKey], or null if none exists. */
+    fun artifactDir(artifactKey: String): Path?
 }

src/main/kotlin/de/hoennig/gittally/build/BuildExecutor.kt

@@ -111,6 +111,7 @@ class BuildExecutor(
     private fun execute(build: ActiveBuild) {
         var slot: Semaphore? = null
         var finalStatus = BuildStatus.FAILED
+        var workspace: Path? = null
         try {
             slot = slotsFor(build.workingDir)
             slot.acquire()
@@ -120,13 +121,14 @@ class BuildExecutor(
             }
             build.running = true
             transition(build, BuildStatus.RUNNING, duration = null)
-            val workspace =
+            val preparedWorkspace =
                 workspaces.prepare(
                     branch = build.runningBuild.branch,
                     commit = build.runningBuild.commit,
                     repoDir = build.workingDir,
                 )
-            val exitCode = runBuildCommands(build, workspace)
+            workspace = preparedWorkspace
+            val exitCode = runBuildCommands(build, preparedWorkspace)
             finalStatus =
                 when {
                     build.cancelled.get() -> BuildStatus.CANCELLED
@@ -141,7 +143,7 @@ class BuildExecutor(
             val duration = Duration.between(build.runningBuild.startedAt, Instant.now())
             val result = transition(build, finalStatus, duration)
             try {
-                artifactStore.persist(result, build.runningBuild.stagingDir)
+                artifactStore.persist(result, build.runningBuild.stagingDir, workspace)
             } catch (e: Exception) {
                 log.warn("could not persist artifacts of {}: {}", result.artifactKey, e.message)
             }