openstack-helm/helm-toolkit/templates/utils/_merge.tpl
Sean Eagan a9e74b84fd Add deep merge utility to helm-toolkit
Adds "helm-toolkit.utils.merge" which is a replacement for the
upstream sprig "merge" function which didn't quite do what we
wanted, specifically it didn't merge slices, it just overrode
one with the other.

Change-Id: I6402ffe043c75eb3a63797ef1be5b56f35b0adc4
2018-02-14 08:48:26 -06:00

101 lines
3.8 KiB
Smarty

{{/*
Copyright 2018 The Openstack-Helm Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/}}
{{/*
Takes a tuple of values and merges into the first (target) one each subsequent
(source) one in order. If all values to merge are maps, then the tuple can be
passed as is and the target will be the result, otherwise pass a map with a
"values" key containing the tuple of values to merge, and the merge result will
be assigned to the "result" key of the passed map.
When merging maps, for each key in the source, if the target does not define
that key, the source value is assigned. If both define the key, then the key
values are merged using this algorithm (recursively) and the result is assigned
to the target key. Slices are merged by appending them and removing any
duplicates. Any other values are merged by simply keeping the source, and
throwing away the target.
*/}}
{{- define "helm-toolkit.utils.merge" -}}
{{- $local := dict -}}
{{- if kindIs "map" $ -}}
{{- $_ := set $local "values" $.values -}}
{{- else -}}
{{- $_ := set $local "values" $ -}}
{{- end -}}
{{- $target := first $local.values -}}
{{- range $item := rest $local.values -}}
{{- $call := dict "target" $target "source" . -}}
{{- $_ := include "helm-toolkit.utils._merge" $call -}}
{{- $_ := set $local "result" $call.result -}}
{{- end -}}
{{- if kindIs "map" $ -}}
{{- $_ := set $ "result" $local.result -}}
{{- end -}}
{{- end -}}
{{- define "helm-toolkit.utils._merge" -}}
{{- $local := dict -}}
{{- $_ := set $ "result" $.source -}}
{{/*
TODO: Should we `fail` when trying to merge a collection (map or slice) with
either a different kind of collection or a scalar?
*/}}
{{- if and (kindIs "map" $.target) (kindIs "map" $.source) -}}
{{- range $key, $sourceValue := $.source -}}
{{- if not (hasKey $.target $key) -}}
{{- $_ := set $local "newTargetValue" $sourceValue -}}
{{- if kindIs "map" $sourceValue -}}
{{- $copy := dict -}}
{{- $call := dict "target" $copy "source" $sourceValue -}}
{{- $_ := include "helm-toolkit.utils._merge.shallow" $call -}}
{{- $_ := set $local "newTargetValue" $copy -}}
{{- end -}}
{{- else -}}
{{- $targetValue := index $.target $key -}}
{{- $call := dict "target" $targetValue "source" $sourceValue -}}
{{- $_ := include "helm-toolkit.utils._merge" $call -}}
{{- $_ := set $local "newTargetValue" $call.result -}}
{{- end -}}
{{- $_ := set $.target $key $local.newTargetValue -}}
{{- end -}}
{{- $_ := set $ "result" $.target -}}
{{- else if and (kindIs "slice" $.target) (kindIs "slice" $.source) -}}
{{- $call := dict "target" $.target "source" $.source -}}
{{- $_ := include "helm-toolkit.utils._merge.append_slice" $call -}}
{{- $_ := set $ "result" (uniq $call.result) -}}
{{- end -}}
{{- end -}}
{{- define "helm-toolkit.utils._merge.shallow" -}}
{{- range $key, $value := $.source -}}
{{- $_ := set $.target $key $value -}}
{{- end -}}
{{- end -}}
{{- define "helm-toolkit.utils._merge.append_slice" -}}
{{- $local := dict -}}
{{- $_ := set $local "result" $.target -}}
{{- range $value := $.source -}}
{{- $_ := set $local "result" (append $local.result $value) -}}
{{- end -}}
{{- $_ := set $ "result" $local.result -}}
{{- end -}}