helm-op: Purge release if install fails

[stefanprodan]

If a chart is broken, Tiller will reserve the name and mark the release as failed. If at a later time the chart is fixed, helm-op can't install it anymore because the release name is in use. Purging the release after each failed install allows helm-op to keep retrying the installation.

Fix #1343

[geoah]

1. pushing broken chart for the first time

ts=2018-09-06T09:18:30.370705709Z caller=release.go:175 component=release error="Chart release failed: vault-controller: &status.statusError{Code:2, Message:\"release vault-controller failed: ClusterRole.rbac.authorization.k8s.io \\\"vault-controller\\\" is invalid: rules[0].apiGroups: Required value: resource rules must supply at least one api group\", Details:[]*any.Any(nil)}"
...
ts=2018-09-06T09:18:30.371122924Z caller=release.go:176 component=release info="Deleting failed release: [vault-controller]"

helm list
-- shows nothing

2. pushing working chart

ts=2018-09-06T09:26:33.550388616Z caller=release.go:135 component=release info="releaseName= vault-controller, action=CREATE, install options: {DryRun:false ReuseName:false}"

helm list
NAME                REVISION    UPDATED                     STATUS      CHART                     APP VERSION    NAMESPACE
vault-controller    1           Thu Sep  6 10:26:33 2018    DEPLOYED    vault-controller-0.1.1                   default

3. pushing broken chart

s=2018-09-06T09:30:12.575997977Z caller=release.go:135 component=release info="releaseName= vault-controller-temp, action=CREATE, install options: {DryRun:true ReuseName:false}"
ts=2018-09-06T09:30:12.580566756Z caller=release.go:135 component=release info="releaseName= datadog-agent-temp, action=CREATE, install options: {DryRun:true ReuseName:false}"
ts=2018-09-06T09:30:12.664316665Z caller=chartsync.go:415 component=chartsync error="Release vault-controller: Chart has diverged due to manual Chart release"
ts=2018-09-06T09:30:12.664440373Z caller=release.go:135 component=release info="releaseName= vault-controller, action=UPDATE, install options: {DryRun:false ReuseName:false}"
...
ts=2018-09-06T09:30:12.836069908Z caller=release.go:206 component=release error="Chart upgrade release failed: vault-controller: &status.statusError{Code:2, Message:\"ClusterRole.rbac.authorization.k8s.io \\\"vault-controller\\\" is invalid: rules[0].apiGroups: Required value: resource rules must supply at least one api group\", Details:[]*any.Any(nil)}"
ts=2018-09-06T09:30:12.836183597Z caller=chartsync.go:268 component=chartsync warning="Failed to upgrade chart" namespace=default name=vault-controller error="rpc error: code = Unknown desc = ClusterRole.rbac.authorization.k8s.io \"vault-controller\" is invalid: rules[0].apiGroups: Required value: resource rules must supply at least one api group"
ts=2018-09-06T09:30:12.836242905Z caller=operator.go:218 component=operator info="Successfully synced 'default/vault-controller'"
ts=2018-09-06T09:30:12.83627529Z caller=operator.go:173 component=operator debug="Processing next work queue job ..."
I0906 09:30:12.837467       5 event.go:221] Event(v1.ObjectReference{Kind:"FluxHelmRelease", Namespace:"default", Name:"vault-controller", UID:"3738d1ce-b1ad-11e8-9bc8-02b1ab54db8a", APIVersion:"helm.integrations.flux.weave.works/v1alpha2", ResourceVersion:"2023509", FieldPath:""}): type: 'Normal' reason: 'ChartSynced' Chart managed by FluxHelmRelease processed successfully

helm list
NAME                REVISION    UPDATED                     STATUS      CHART                     APP VERSION    NAMESPACE
vault-controller    2           Thu Sep  6 10:30:12 2018    FAILED      vault-controller-0.1.1                   default

4. pushing working chart

ts=2018-09-06T09:33:18.485710475Z caller=operator.go:218 component=operator info="Successfully synced 'default/vault-controller'"
ts=2018-09-06T09:33:18.485833611Z caller=operator.go:173 component=operator debug="Processing next work queue job ..."
I0906 09:33:18.486578       5 event.go:221] Event(v1.ObjectReference{Kind:"FluxHelmRelease", Namespace:"default", Name:"vault-controller", UID:"3738d1ce-b1ad-11e8-9bc8-02b1ab54db8a", APIVersion:"helm.integrations.flux.weave.works/v1alpha2", ResourceVersion:"2025102", FieldPath:""}): type: 'Normal' reason: 'ChartSynced' Chart managed by FluxHelmRelease processed successfully

helm list
NAME                REVISION    UPDATED                     STATUS      CHART                     APP VERSION    NAMESPACE
vault-controller    1           Thu Sep  6 10:33:17 2018    DEPLOYED    vault-controller-0.1.1