Make's "define" feature (macros) is subtle and it took me a long time to
convince myself this all works. In particular, we (prior to this commit)
are terribly inconsistent about the use of `$` vs `$$`. We mostly get
away with it because the "variables" are more like "constants", but the
inconsistency trips up some things. For example, using `$(shell)`
inside a macro will run at macro expansion time rather than when the
resulting make code is executed.
For a contrived, but concrete example, derived from our Makefile:
```
define MACRO
ifeq ($(DBG),1)
$(warning dbg is $(DBG))
endif
endef # macro
TGTS=a b c
$(foreach pfx, $(TGTS), $(eval $(MACRO)))
default:
@echo $@
```
yields:
```
$ make
Makefile:8: dbg is
Makefile:8: dbg is
Makefile:8: dbg is
default
$ make DBG=1
Makefile:8: dbg is 1
Makefile:8: dbg is 1
Makefile:8: dbg is 1
default
```
This is because `$(warning)` is evaluated as the macro is expanded.
Replace that with `$(shell)` and you can see how you might end up
running a bunch of things you didn't need to run. The fix is:
```
define MACRO
ifeq ($(DBG),1)
$$(warning dbg is $$(DBG))
endif
endef # macro
TGTS=a b c
$(foreach pfx, $(TGTS), $(eval $(MACRO)))
default:
@echo $@
```
which yields:
```
$ make
default
$ make DBG=1
Makefile:8: dbg is 1
Makefile:8: dbg is 1
Makefile:8: dbg is 1
default
```
We COULD have only changed `$(warning)` to `$$(warning)` and left
`$(DBG)` alone, because that's a cheap expansion. I chose NOT to do
that here because it requires brainpower to think about this all, and it
seems easier to set a simple rule: inside a `define`/`endef` block, you
always use `$$` unless you KNOW that you NEED expansion-time evaluation
(as in the `$(prefix)` in this commit, which is effectively an argument
to the macros).
* kube-proxy cluder-cidr arg accepts comma-separated list
It is possible in dual-stack clusters to provide kube-proxy with
a comma-separated list with an IPv4 and IPv6 CIDR for pods.
update: signoff
update2: update email profile
Signed-off-by: Tyler Lloyd <Tyler.Lloyd@microsoft.com>
Signed-off-by: Tyler Lloyd <tylerlloyd928@gmail.com>
* Updating cluster-cidr comment description
Signed-off-by: Tyler Lloyd <tyler.lloyd@microsoft.com>
ResourceVersion values are opaque and math should not be done on them.
The intent of this test was to watch from a resourceVersion before the
moment where the objects were created, and we can find such a version by
listing from the API server before the tests begin.
Signed-off-by: Steve Kuznetsov <skuznets@redhat.com>
This test wishes to observe a watch event. In order to do this in the
past, the test chose a well-known `Service` object, fetched it, and did
arithmetic on the returned `resourceVersion` in order to start a watch
that was guaranteed to see an event. It is not valid to parse the
`resourceVersion` as an integer or to do arithmetic on it, so in order
to make the test conformant to an appropriate use of the API it now:
- creates a namespace
- fetches the current `resourceVersion`
- creates an object
- watches from the previous `resourceVersion` that was read
This ensures that an event is seen by the watch, but uses the publically
supported API.
`ConfigMap`s are used instead of `Service`s as they do not require a
valid `spec` for creation and make the test terser.
Signed-off-by: Steve Kuznetsov <skuznets@redhat.com>
For the YAML examples, make the indentation consistent
by starting with a space and following with a TAB.
Also adjust the indentation of some fields to place them under
the right YAML field parent - e.g. ignorePreflightErrors
is under nodeRegistration.
Previously, callers of `Exists()` would not know why the cGroup was or
was not existing. In one call-site in particular, the `kubelet` would
entirely fail to start if the cGroup validation did not succeed. In
these cases we MUST explain what went wrong and pass that information
clearly to the caller. Previously, some but not all of the reasons for
invalidation were logged at a low log-level instead. This led to poor
UX.
The original method was retained on the interface so as to make this
diff small.
Signed-off-by: Steve Kuznetsov <skuznets@redhat.com>
