Merge pull request #2609 from miminar/blobrepositorycachettl-option

Registry config update

install_config/install/docker_registry.adoc

@@ -844,6 +844,7 @@ middleware:
         pullthrough: true
         enforcequota: false
         projectcachettl: 1m
+        blobrepositorycachettl: 10m
   storage:
     - name: openshift
 ----
@@ -1024,6 +1025,7 @@ middleware:
         pullthrough: true <3>
         enforcequota: false <4>
         projectcachettl: 1m <5>
+        blobrepositorycachettl: 10m <6>
   storage:
     - name: openshift <1>
 ----
@@ -1037,6 +1039,11 @@ schema v2] during a push to the registry. See xref:middleware-repository-accepts
 value, the less time will it take for the limit changes to propagate to the
 registry. However, the registry will query limits from the server more
 frequently and, as a consequence, pushes will be slower.
+<6> An expiration timeout for remembered associations between blob and
+repository. The higher the value, the higher probability of fast lookup and
+more efficient registry operation. On the other hand, memory usage will raise
+as well as a risk of serving image layer to user, who is no longer authorized
+to access it.
 ====
 
 The link:https://docs.docker.com/registry/configuration/#cloudfront[*CloudFront*
@@ -1057,10 +1064,25 @@ middleware:
         acceptschema2: false <1>
         enforcequota: false <2>
         projectcachettl: 1m <3>
-----
-<1> A configuration option that can be overridden by the boolean environment variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ACCEPTSCHEMA2*`, which allows for the ability to accept manifest schema v2 on manifest put requests.
-<2> A configuration option that can be overridden by the boolean environment variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ENFORCEQUOTA*`, which allows the ability to turn quota enforcement on or off. By default, quota enforcement is off. It overrides {product-title} middleware configuration option. Recognized values are *true* and *false*.
-<3> A configuration option that can be overridden by the environment variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_PROJECTCACHETTL*`, specifying an eviction timeout for project quota objects. It takes a valid time duration string (for example, *2m*). If empty, you get the default timeout. If zero (*0m*), caching is disabled.
+        blobrepositorycachettl: 10m <4>
+----
+<1> A configuration option that can be overridden by the boolean environment
+variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ACCEPTSCHEMA2*`, which
+allows for the ability to accept manifest schema v2 on manifest put requests.
+<2> A configuration option that can be overridden by the boolean environment
+variable `*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ENFORCEQUOTA*`, which
+allows the ability to turn quota enforcement on or off. By default, quota
+enforcement is off. It overrides {product-title} middleware configuration
+option. Recognized values are *true* and *false*.
+<3> A configuration option that can be overridden by the environment variable
+`*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_PROJECTCACHETTL*`, specifying an
+eviction timeout for project quota objects. It takes a valid time duration
+string (for example, *2m*). If empty, you get the default timeout. If zero
+(*0m*), caching is disabled.
+<4> A configuration option that can be overriden by the environment variable
+`*REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_BLOBREPOSITORYCACHETTL*`, specifying
+an eviction timeout for associations between blob and containing repository.
+The format of the value is the same as in `projectcachettl` case.
 ====
 
 [[middleware-repository-pullthrough]]