* Parse and process helm version using github.com/Masterminds/semver/v3.
* Add --force-update only when Helm version >= 3.3.2, < 3.3.4.
See: https://github.com/helm/helm/pull/8777.
* Add test cases.
In #1172, we accidentally changed the meaning of prepare hook that is intended to be called BEFORE the pathExists check. It broke the scenario where one used a prepare hook for generating the local chart dynamically. This fixes Helmfile not to fetch local chart generated by prepare hook.
In addition to that, this patch results in the following fixes:
- Fix an issue that `helmfile template` without `--skip-deps` fails while trying to run `helm dep build` on `helm fetch`ed chart, when the remote chart has outdated dependencies in the Chart.lock file. It should be up to the chart maintainer to update Chart.lock and the user should not be blocked due to that. So, after this patch `helm dep build` is run only on the local chart, not on fetched remote chart.
- Skip fetching chart on `helmfile template` when using Helm v3. `helm template` in helm v3 does support rendering remote charts so we do not need to fetch beforehand.
Fixes#1328
May relate to #1341
Runs `helm version` in helmexec.New, and exposes a method on Interface to allow other packages to use the detected version. Preserves compatibility with previous HELMFILE_HELM3 mechanism.
Resolves#923
At the moment, if you have a helmfile.yaml like so:
```
releases:
- name: metrics-server
namespace: kube-system
chart: stable/metrics-server
```
If you try to run `helmfile deps`, you will get a 0 exit code and no log
output at whatsoever, signaling that there weren't any problems, but no
lock file will get created.
For example:
```
root@316073d4a104:/# helmfile deps
root@316073d4a104:/#
```
This behavior doesn't appear to be documented and is unintuitive to the
user.
This change adds a warning output for this same use case:
```
root@316073d4a104:/# helmfile deps
There are no repositories defined in your helmfile.yaml.
This means helmfile cannot update your dependencies or create a lock file.
See https://github.com/roboll/helmfile/issues/878 for more information.
root@316073d4a104:/#
```
Fixes#878
Rein van 't Veer
Wi1dcard
KUOKA Yusuke
刘相轩
Andrew Drake
Aaron Batilo