helm-charts/rss-bridge/templates/_helpers.tpl

{{/*
Render the body of a container "resources:" block from a values dict of the form

  resources:
    limitFactor: 3          # optional, default 3
    requests: { cpu, memory, ephemeral-storage / ephemeralStorage, ... }
    limits:   { ... }       # optional, every entry optional

Rules (variant B, see issue #19):
  - requests are rendered as given (camelCase "ephemeralStorage" is normalized
    to the Kubernetes key "ephemeral-storage").
  - an explicitly set limit always wins.
  - a missing memory / ephemeral-storage limit is computed as
    limitFactor x the corresponding request.
  - a missing cpu limit is NOT set at all (the kubelet then treats CPU as
    unlimited; CPU is compressible, so this cannot kill the workload).

NOTE: this helper is duplicated into every chart's templates/_helpers.tpl with
the chart's name as define prefix, because sharing it would mean a library
chart, and a dependency is admissible but expensive (README, guideline 14) -
this chart takes none. template-chart holds the reference implementation.
*/}}
{{- define "rss-bridge.resources" -}}
{{- $resources := . | default dict -}}
{{- $factor := 3.0 -}}
{{- if not (kindIs "invalid" $resources.limitFactor) -}}
{{- $factor = float64 $resources.limitFactor -}}
{{- end -}}
{{- $requests := dict -}}
{{- range $key, $value := ($resources.requests | default dict) -}}
{{- if not (kindIs "invalid" $value) -}}
{{- $_ := set $requests (include "rss-bridge.resourceKey" $key) $value -}}
{{- end -}}
{{- end -}}
{{- $limits := dict -}}
{{- range $key, $value := ($resources.limits | default dict) -}}
{{- if not (kindIs "invalid" $value) -}}
{{- $_ := set $limits (include "rss-bridge.resourceKey" $key) $value -}}
{{- end -}}
{{- end -}}
{{- range $key, $request := $requests -}}
{{- if and (ne $key "cpu") (not (hasKey $limits $key)) -}}
{{- $_ := set $limits $key (include "rss-bridge.multiplyQuantity" (dict "quantity" $request "factor" $factor)) -}}
{{- end -}}
{{- end -}}
{{- $out := dict -}}
{{- with $requests }}{{- $_ := set $out "requests" . }}{{- end -}}
{{- with $limits }}{{- $_ := set $out "limits" . }}{{- end -}}
{{- toYaml $out -}}
{{- end -}}

{{/*
Normalize a resource name from values to its Kubernetes key.
*/}}
{{- define "rss-bridge.resourceKey" -}}
{{- if eq . "ephemeralStorage" -}}ephemeral-storage{{- else -}}{{ . }}{{- end -}}
{{- end -}}

{{/*
Multiply a Kubernetes quantity by a factor, keeping its suffix.
Input: dict "quantity" <string|number> "factor" <float64>.
Handles plain numbers ("2", "0.5", 1073741824), decimal ("1.5Gi"), binary
("512Mi", "1Gi", "10Ki") and milli/SI suffixes ("100m", "500M"). Integer
results are printed without a decimal point.
*/}}
{{- define "rss-bridge.multiplyQuantity" -}}
{{- $quantity := include "rss-bridge.formatNumber" .quantity -}}
{{- $number := regexFind "^[0-9]+(\\.[0-9]+)?" $quantity -}}
{{- if not $number -}}
{{- fail (printf "cannot parse resource quantity %q" $quantity) -}}
{{- end -}}
{{- $suffix := trimPrefix $number $quantity -}}
{{- if not (regexMatch "^(m|k|M|G|T|P|E|Ki|Mi|Gi|Ti|Pi|Ei)?$" $suffix) -}}
{{- fail (printf "unsupported resource quantity suffix %q in %q" $suffix $quantity) -}}
{{- end -}}
{{- $product := mulf (float64 $number) .factor -}}
{{- if eq $product (floor $product) -}}
{{- printf "%d%s" (int64 $product) $suffix -}}
{{- else -}}
{{- printf "%s%s" (include "rss-bridge.formatNumber" $product) $suffix -}}
{{- end -}}
{{- end -}}

{{/*
Render a number as a plain decimal string, never in exponential notation.

Why this exists (issue #157): the null-safe fallback helpers pass values
through fromYaml, which parses every number as float64. Go's "%v" switches
float64 to exponential notation from about 1e6 upwards, so a bare byte count
like 1048576 became "1.048576e+06" - not a valid Kubernetes quantity, and the
render aborted. Strings ("512Mi") are passed through untouched.
*/}}
{{- define "rss-bridge.formatNumber" -}}
{{- if kindIs "float64" . -}}
{{- regexReplaceAll "\\.?0+$" (printf "%.10f" .) "" -}}
{{- else -}}
{{- printf "%v" . -}}
{{- end -}}
{{- end -}}

{{/*
Render the replica count for a Deployment/StatefulSet.

Input: dict
  "scaleDown"  the chart-global .Values.scaleDown flag (may be nil)
  "replicas"   the workload's replicas value (may be nil)

Rules (issue #25):
  - scaleDown: true takes precedence and always yields 0.
  - otherwise an explicitly set replicas value is used as given, including an
    explicit 0 - Helm's "default" would swallow 0, hence the explicit
    kindIs "invalid" nil check.
  - a missing replicas value defaults to 1.
*/}}
{{- define "rss-bridge.replicas" -}}
{{- if .scaleDown -}}
0
{{- else if not (kindIs "invalid" .replicas) -}}
{{- .replicas -}}
{{- else -}}
1
{{- end -}}
{{- end -}}

{{/*
Merge a user-supplied values sub-tree onto a dict of chart defaults so that a
null / empty override falls back to the defaults instead of erasing them.

Input: dict "defaults" <dict> "given" <dict|nil> "path" <string, optional
values path used in error messages>. Output: YAML of the merged dict (consume
it with fromYaml).

Why this exists (issues #61 and #99): Helm merges values maps recursively, but
an override key written without children - e.g. a leftover

  securityContext:

after deleting its last remaining sub-key - is YAML null. Where the chart
defines a default, Helm treats that null as a deletion of the default; the
template then renders "securityContext: null": no readOnlyRootFilesystem, no
dropped capabilities, no allowPrivilegeEscalation: false. The workload starts
and reports healthy while being unhardened, so nothing points at the mistake.
The same shape erases a probe (it disappears) or the resources block (no
requests, no computed limits). This helper defines the opposite semantics: an
empty block means "chart defaults apply".

Rules:
  - a nil "given" is treated as an empty dict (all defaults apply).
  - a key whose override value is null keeps the default (nulls never delete).
  - a key present in both as a map is merged recursively, so a partially
    filled block only overrides the keys it actually sets.
  - a scalar override for a key the defaults define as a map is rejected with
    a message naming the values path, instead of failing later with a template
    field error.
  - any other set value wins as given, including an explicit false or 0 -
    Helm's "default" and sprig's "mergeOverwrite" would both swallow those
    zero values, hence the explicit kindIs "invalid" nil check.
  - keys only present in the override are passed through unchanged.
*/}}
{{- define "rss-bridge.defaultedDict" -}}
{{- $defaults := .defaults | default dict -}}
{{- $given := .given -}}
{{- $path := .path | default "value" -}}
{{- if kindIs "invalid" $given -}}
{{- $given = dict -}}
{{- end -}}
{{- if not (kindIs "map" $given) -}}
{{- fail (printf "%s must be a mapping or null, got %s (%v)" $path (kindOf $given) $given) -}}
{{- end -}}
{{- $out := deepCopy $defaults -}}
{{- range $key, $value := $given -}}
{{- if not (kindIs "invalid" $value) -}}
{{- $default := index $defaults $key -}}
{{- if and (kindIs "map" $value) (kindIs "map" $default) -}}
{{- $_ := set $out $key (fromYaml (include "rss-bridge.defaultedDict" (dict "defaults" $default "given" $value "path" (printf "%s.%s" $path $key)))) -}}
{{- else if kindIs "map" $default -}}
{{- fail (printf "%s.%s must be a mapping or null, got %s (%v)" $path $key (kindOf $value) $value) -}}
{{- else -}}
{{- $_ := set $out $key $value -}}
{{- end -}}
{{- end -}}
{{- end -}}
{{- toYaml $out -}}
{{- end -}}

{{/*
Pick one sub-block out of a values block that may itself be null.

Input: dict "block" <dict|nil> "key" <string> "path" <string>.
Returns YAML of dict "value" <the sub-block, may be nil>, after rejecting a
non-mapping block with a message that names the values path. Needed because
".Values.rssBridge.securityContext" can itself be erased, and indexing into nil
inside a template is not an error but silently yields nothing.
*/}}
{{- define "rss-bridge.subBlock" -}}
{{- $block := .block -}}
{{- if kindIs "invalid" $block -}}
{{- $block = dict -}}
{{- end -}}
{{- if not (kindIs "map" $block) -}}
{{- fail (printf "%s must be a mapping or null, got %s (%v)" .path (kindOf $block) $block) -}}
{{- end -}}
{{- toYaml (dict "value" (index $block .key)) -}}
{{- end -}}

{{/*
The effective security contexts, probes and resources (issue #99).

The defaults below MUST stay in sync with the corresponding blocks in
values.yaml, which stays the documented, user-facing place for them; this copy
is only the fallback for the case where an override has erased the block.

Two chart-specific facts a rebuilt default must not lose:

  - uid/gid 33 (www-data) is not a stylistic choice. The image ships /app and
    everything in it owned by www-data, and both nginx and php-fpm are
    configured for that user. A "cleaner" high uid would leave the app unable
    to read its own bridge sources.
  - the ip_unprivileged_port_start sysctl is what lets a non-root nginx bind
    port 80, and this chart has no choice about that port - see the comment on
    it in values.yaml. Dropping it from a rebuilt default does not fail at
    render time; it fails on the first node whose default differs.
  - the probes address the port BY NAME (rss-bridge-port) and use the app's
    own health action. A default that drops the query string would probe the
    1.5 MB front page instead of a 49-byte JSON response, and a default that
    drops the port name would not resolve at all.
*/}}
{{- define "rss-bridge.podSecurityContext" -}}
{{- $given := (fromYaml (include "rss-bridge.subBlock" (dict "block" . "key" "pod" "path" "rssBridge.securityContext"))).value -}}
{{- $defaults := dict
      "runAsNonRoot" true
      "runAsUser" 33
      "runAsGroup" 33
      "fsGroup" 33
      "fsGroupChangePolicy" "Always"
      "seccompProfile" (dict "type" "RuntimeDefault")
      "sysctls" (list (dict "name" "net.ipv4.ip_unprivileged_port_start" "value" "0")) -}}
{{- include "rss-bridge.defaultedDict" (dict "defaults" $defaults "given" $given "path" "rssBridge.securityContext.pod") -}}
{{- end -}}

{{- define "rss-bridge.containerSecurityContext" -}}
{{- $given := (fromYaml (include "rss-bridge.subBlock" (dict "block" . "key" "container" "path" "rssBridge.securityContext"))).value -}}
{{- $defaults := dict
      "allowPrivilegeEscalation" false
      "readOnlyRootFilesystem" true
      "runAsNonRoot" true
      "capabilities" (dict "drop" (list "ALL")) -}}
{{- include "rss-bridge.defaultedDict" (dict "defaults" $defaults "given" $given "path" "rssBridge.securityContext.container") -}}
{{- end -}}

{{/*
The probe target, shared by all three probes.

"/?action=health" is RSS-Bridge's own health action: it renders a fixed JSON
document and touches neither the file cache nor any remote site, so no outage
of a scraped website and no unwritable cache directory can restart the pod
(guideline 3). The front page "/" would be a bad choice for the opposite
reason - it enumerates every bridge and answers with ~1.5 MB.
*/}}
{{- define "rss-bridge.probeHttpGet" -}}
{{- dict "path" "/?action=health" "port" "rss-bridge-port" | toYaml -}}
{{- end -}}

{{- define "rss-bridge.livenessProbe" -}}
{{- $defaults := dict
      "httpGet" (fromYaml (include "rss-bridge.probeHttpGet" .))
      "periodSeconds" 10
      "timeoutSeconds" 5
      "failureThreshold" 3 -}}
{{- include "rss-bridge.defaultedDict" (dict "defaults" $defaults "given" . "path" "rssBridge.livenessProbe") -}}
{{- end -}}

{{- define "rss-bridge.readinessProbe" -}}
{{- $defaults := dict
      "httpGet" (fromYaml (include "rss-bridge.probeHttpGet" .))
      "periodSeconds" 10
      "timeoutSeconds" 5
      "failureThreshold" 3 -}}
{{- include "rss-bridge.defaultedDict" (dict "defaults" $defaults "given" . "path" "rssBridge.readinessProbe") -}}
{{- end -}}

{{- define "rss-bridge.startupProbe" -}}
{{- $defaults := dict
      "httpGet" (fromYaml (include "rss-bridge.probeHttpGet" .))
      "periodSeconds" 5
      "timeoutSeconds" 5
      "failureThreshold" 30 -}}
{{- include "rss-bridge.defaultedDict" (dict "defaults" $defaults "given" . "path" "rssBridge.startupProbe") -}}
{{- end -}}

{{/*
The effective resources block, fed into the resources helper above so that an
erased "resources:" still yields the chart's requests and computed limits
instead of a container without any resource accounting.

The explicit limits are part of the default on purpose - see the measurements
in values.yaml. Reproducing only the requests here would let limitFactor
compute a 384Mi memory limit, which is below the measured concurrent peak.
*/}}
{{- define "rss-bridge.effectiveResources" -}}
{{- $defaults := dict
      "limitFactor" 3
      "requests" (dict "cpu" 0.1 "memory" "128Mi" "ephemeral-storage" "64Mi")
      "limits" (dict "memory" "512Mi" "ephemeral-storage" "2Gi") -}}
{{- $merged := fromYaml (include "rss-bridge.defaultedDict" (dict "defaults" $defaults "given" . "path" "rssBridge.resources")) -}}
{{- include "rss-bridge.resources" $merged -}}
{{- end -}}

{{/*
Group the configured ingress hosts by their TLS secret name.

Returns YAML of dict "order" <list of secret names, in first-appearance order>
and "groups" <secret name -> list of hosts>. Hosts that share a secret name end
up in one tls entry (one certificate with several SANs); hosts with distinct
names keep one certificate each, which is what the existing installation needs
(see the TLS comment in values.yaml).

First-appearance order rather than sorted order, so the rendered tls list can
be compared line by line against the manifest the chart replaces.

INGRESS MODE ONLY - THIS HELPER IS INERT IN GATEWAY MODE (Gitea #114)

Its entire purpose is to group hosts by TLS secret name, and in Gateway mode
there is no TLS in this chart to group: the certificate sits on the Gateway's
listener and belongs to the platform. Both of its callers - the Ingress
template and the Ingress branch of NOTES.txt - live behind ingress.enabled,
which Gateway mode forces to false, so it is simply never invoked there.

Named rather than left to be noticed, because it is the most intricate part of
this chart's Ingress and its absence from the Gateway path is a SIMPLIFICATION,
not an omission. The corollary is that ingress.hosts[].tlsSecretName has no
meaning in Gateway mode, which is why httpRoute.hostnames is a plain list of
strings instead of a reuse of ingress.hosts - see the header of
rss-bridge.httproute.yaml.
*/}}
{{- define "rss-bridge.tlsGroups" -}}
{{- $root := .root -}}
{{- $default := printf "tls-%s-%s-ingress" $root.Release.Name $root.Chart.Name -}}
{{- $groups := dict -}}
{{- $order := list -}}
{{- range $entry := .hosts -}}
{{- $host := required "Every ingress.hosts entry needs a host (ingress.hosts[].host)" $entry.host -}}
{{- $secret := $entry.tlsSecretName | default $default -}}
{{- if not (hasKey $groups $secret) -}}
{{- $_ := set $groups $secret (list) -}}
{{- $order = append $order $secret -}}
{{- end -}}
{{- $_ := set $groups $secret (append (index $groups $secret) $host) -}}
{{- end -}}
{{- toYaml (dict "order" $order "groups" $groups) -}}
{{- end -}}