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.
