docs(build): 修正上下文存储与构建镜像拉取的过时描述

docs/troubleshooting.md

@@ -470,11 +470,12 @@ installer).
 ### 8e. Build Pods never start: executor images and air-gapped installs
 
 The build Job runs Kaniko and Trivy from external registries by default
-(`gcr.io/kaniko-project/executor:latest`, `aquasec/trivy:latest`). On a box whose
-build namespace cannot reach those registries (the egress policy allows only
-DNS, the internal registry and `--package-cidr` mirrors — and an air-gapped box
-has no route at all), the Pods sit in `ImagePullBackOff`/`ErrImagePull` and the
-build stays `building` until its deadline. Point the overrides at images **in
+(`gcr.io/kaniko-project/executor:latest`, `aquasec/trivy:latest`). The kubelet
+pulls those images over the node's own network, so the build namespace's egress
+policy does not apply to the pull; what blocks it is a node without a route to
+those registries (an air-gapped box, a firewall, a rate-limited Docker Hub).
+The Pods then sit in `ImagePullBackOff`/`ErrImagePull` and the build stays
+`building` until its deadline. Point the overrides at images **in
 the internal registry** — the one pull source that survives an image GC (a bare
 node-containerd import does not: kubelet's image GC collects unused images under
 disk pressure, and an air-gapped box then has nothing to restore them from) —

internal/config/config.go

@@ -149,14 +149,12 @@ type RegistryConfig struct {
 	BuildNamespace string `toml:"build_namespace"`
 	// KanikoImage / TrivyImage / BuildCPULimit / BuildMemLimit override the
 	// build subsystem's compiled-in defaults (gcr.io/kaniko-project/executor and
-	// aquasec/trivy, 2 CPU / 4Gi per build container). The defaults assume the
-	// build namespace can reach those registries; on an air-gapped or mirrored
-	// install there IS no such reach (the build egress policy allows only DNS,
-	// the internal registry and explicit package mirrors), so the operator must
-	// point these at whatever their box can actually pull — typically images
-	// mirrored into the in-cluster registry (docs/troubleshooting.md §8e); a
-	// bare node-containerd import does not survive an image GC, there is no pull
-	// source for it. Empty keeps the default.
+	// aquasec/trivy, 2 CPU / 4Gi per build container). The kubelet pulls the
+	// executor images over the node's network, so the defaults need a node that
+	// can reach those registries; an air-gapped or mirrored install points these
+	// at images mirrored into the in-cluster registry (docs/troubleshooting.md
+	// §8e). A bare node-containerd import does not survive an image GC, there is
+	// no pull source for it. Empty keeps the default.
 	KanikoImage   string `toml:"kaniko_image"`
 	TrivyImage    string `toml:"trivy_image"`
 	BuildCPULimit string `toml:"build_cpu_limit"`

internal/submit/blobstore.go

@@ -32,16 +32,13 @@ var idRE = regexp.MustCompile(`^[a-z0-9][a-z0-9-]{0,127}$`)
 // Manager.Blobs nil so the upload endpoint returns 503 rather than pretending to
 // accept a file it cannot persist.
 //
-// Base MUST equal the Manager's ContextStore so the blob lands exactly where
-// deriveContextRef points Kaniko's --context; cmd/felis wires both from the one
+// Base MUST equal the Manager's ContextStore; cmd/felis wires both from the one
 // config field (registry.user_uploads_context).
 //
-// INTEGRATION-ONLY seam (out of scope of the upload transport): persisting the
-// blob is end-to-end only once the same uploads PVC is mounted into the Kaniko
-// build Pod and Kaniko is told to read a local context (build/jobspec.go passes
-// the ref straight into --context). The transport here makes the file durable at
-// the derived location; wiring that path into the sandboxed build Job is a
-// separate deployment integration, exactly like the restore executor's PVC mount.
+// The build Pod never mounts this PVC. With Manager.ContextBaseURL set (every
+// installed API) the derived context ref is the internal face's
+// /api/v1/internal/submissions/{id}/context route, which streams the blob out
+// of this store to the build Job's `felis fetch-context` step.
 type LocalContextStore struct {
 	// Base is the directory (uploads PVC mount) submission contexts are written
 	// under. Each submission gets its own {Base}/{id}/ subdirectory.