Add helper function to generate subjects

Signed-off-by: Timofei Larkin <lllamnyp@gmail.com>

packages/apps/tenant/charts/cozy-lib

@@ -0,0 +1 @@
+../../../library/cozy-lib

packages/library/cozy-lib/templates/_rbac.tpl

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+{{- define "cozy-lib.rbac.accessLevelMap" }}
+view: 0
+use: 1
+admin: 2
+super-admin: 3
+{{- end }}
+
+{{- define "cozy-lib.rbac.accessLevelToInt" }}
+{{-   $accessMap := include "cozy-lib.rbac.accessLevelMap" "" | fromYaml }}
+{{-   $accessLevel := dig . -1 $accessMap | int }}
+{{-   if eq $accessLevel -1 }}
+{{-     printf "encountered access level of %s, allowed values are %s" . ($accessMap | keys) | fail }}
+{{-   end }}
+{{-   $accessLevel }}
+{{- end }}
+
+{{- define "cozy-lib.rbac.accessLevelsAtOrAbove" }}
+{{-   $minLevelInt := include "cozy-lib.rbac.accessLevelToInt" . | int }}
+{{-   range $k, $v := (include "cozy-lib.rbac.accessLevelMap" "" | fromYaml) }}
+{{-     if ge (int $v) $minLevelInt }}
+- {{ $k }}
+{{-     end }}
+{{-   end }}
+{{- end }}
+
+{{- define "cozy-lib.rbac.allParentTenantsAndThis" }}
+{{-   if not (hasPrefix "tenant-" .) }}
+{{-     printf "'%s' is not a valid tenant identifier" . | fail }}
+{{-   end }}
+{{-   $parts := append (splitList "-" .) "" }}
+{{-   $tenants := list }}
+{{-   range untilStep 2 (len $parts) 1 }}
+{{-     $tenants = append $tenants (slice $parts 0 . | join "-") }}
+{{-   end }}
+{{-   range $tenants }}
+- {{ . }}
+{{-   end }}
+{{- end }}
+
+{{- define "cozy-lib.rbac.groupSubject" -}}
+- kind: Group
+  name: {{ . }}
+  apiGroup: rbac.authorization.k8s.io
+{{- end }}
+
+{{- /* 
+  A helper function to get a list of groups that should have access, given a
+  minimal access level and the tenant. Invoked as:
+  {{ include "cozy-lib.rbac.subjectsForTenantAndAccessLevel" (list "use" $) }}
+  For an example input of (list "use" $) and a .Release.Namespace of
+  tenant-abc-def it will return:
+  ---
+  - kind: Group
+    name: tenant-abc-admin
+    apiGroup: rbac.authorization.k8s.io
+  - kind: Group
+    name: tenant-abc-def-admin
+    apiGroup: rbac.authorization.k8s.io
+  - kind: Group
+    name: tenant-abc-super-admin
+    apiGroup: rbac.authorization.k8s.io
+  - kind: Group
+    name: tenant-abc-def-super-admin
+    apiGroup: rbac.authorization.k8s.io
+  - kind: Group
+    name: tenant-abc-use
+    apiGroup: rbac.authorization.k8s.io
+  - kind: Group
+    name: tenant-abc-def-use
+    apiGroup: rbac.authorization.k8s.io
+
+  in other words, all roles including use and higher and for tenant-abc-def, as
+  well as all parent, grandparent, etc. tenants.
+*/}}
+{{- define "cozy-lib.rbac.subjectsForTenantAndAccessLevel" }}
+{{-   include "cozy-lib.checkInput" . }}
+{{-   $level := index . 0 }}
+{{-   $global := index . 1 }}
+{{-   $levels := include "cozy-lib.rbac.accessLevelsAtOrAbove" $level | fromYamlArray }}
+{{-   $tenants := include "cozy-lib.rbac.allParentTenantsAndThis" $global.Release.Namespace | fromYamlArray }}
+{{-   range $l := $levels }}
+{{-     range $t := $tenants }}
+{{-       include "cozy-lib.rbac.groupSubject" (printf "%s-%s" $t $l) }}{{ printf "\n" }}
+{{-     end }}
+{{-   end}}
+{{- end }}