* Do fail on a possible typo in `needs` entries
Helmfile kindly fails with a friendly error when you made a typo in a `needs` entry, i.e. a `needs` entry included a reference to a release that is not defined in the helmfile config.
Example Output:
```
in ./helmfile.needs.yaml: release(s) "app" depend(s) on an undefined release "infrastructure/cert-manager2". Perhaps you made a typo in `needs` or forgot defining a release named "cert-manager2" with appropriate `namespace` and `kubeContext`?
```
This prevents issues like #1959
* Fix regression in helmfile-diff (This may break when you had two or more duplicated releases that are intended to be de-duplicated before DAG calculation using selectors
* Fix regression when you used selector to deduplicate releases before DAG calculation
* Comments
* Fix regressions in helmfile-apply and helmfile-sync
* Fix regression in duplicate release detection
#1772 broke `--selector` with `needs` in many ways.
The two biggest problems I've encountered were:
- duplicate releases even if you've provided a proper `selector` to deduplicate
- sync/deletion ordering broken when you have `needs`
For the first issue, we had to update `getSelectedReleases` function to also calculate the "selected releases and releases needed by the selected releases", and use that to calculate the DAG. That should have been done in #1772.
The latter started happening after I've fixed the first issue. The source of the issue was that `needs` turned out to be ambiguous in a few cases.
Previously, `needs: ["foo/bar"]` had two meanings. One for "needs release bar in kubecontext foo", another for "needs release bar in namespace foo".
Moreover, `needs: ["foo/bar/baz"]` had three meanings.
- `needs release baz in tiller namespace foo and namespace baz`
- `needs release baz in namespace bar in kubecontext foo`
- `needs release baz in tiller namespace bar in kubecontext foo`.
Especially, the first meaning doesn't make sense at all. Helm 2 solely use tillerNamespace for namespacing the release and Helm 3 uses namespace for that.
This fix sorts all the bugs and issues I've found so far around that, by changing the meanings of the above two examples as follows:
- `foo/bar` means `namespace=foo,name=bar` for Helm 3 and `tillerNamespace=foo,name=bar` for Helm 2
- `needs release bar in kubecontext foo` is now `foo//bar`. Notice the extra `/` between `foo` and `bar`.
- `foo/bar/baz` means `kubecontext=foo,namespace=bar,name=baz` for Helm 3 and `kubecontext=foo,tillerNamespace=bar,name=baz` in Helm 2
Fixes#1818
Yusuke Kuoka
katsew