feat(langsmith): add extraManifests values key

[karantyagi-reltio]

Summary

Adds two top-level lists to the langsmith chart so users can ship arbitrary Kubernetes resources alongside the chart without forking it:

• extraManifests — plain resources, normal lifecycle.
• preInstallManifests — prerequisite resources rendered as pre-install / pre-upgrade Helm hooks, applied before the rest of the chart. Useful for resources the chart consumes during install/upgrade, such as an ExternalSecret (External Secrets Operator) whose materialized Kubernetes Secret is referenced by config.existingSecretName or the per-datastore *.external.existingSecretName values.

Each entry in either list may be a YAML object or a multi-line YAML string; both are rendered through tpl so template expressions like {{ .Release.Name }} work.

Useful for ConfigMaps, Secrets, NetworkPolicies, ServiceMonitors, ExternalSecrets, or anything else the chart doesn't natively support.

Usage

extraManifests (plain resources)

extraManifests:
  - apiVersion: v1
    kind: ConfigMap
    metadata:
      name: my-extra
    data:
      key: value
  - |
    apiVersion: v1
    kind: Secret
    metadata:
      name: {{ .Release.Name }}-token
    stringData:
      token: changeme

preInstallManifests (pre-requisite hooks)

preInstallManifests:
  - apiVersion: external-secrets.io/v1beta1
    kind: ExternalSecret
    metadata:
      name: langsmith-app
    spec:
      refreshInterval: 1h
      secretStoreRef:
        name: vault-backend
        kind: ClusterSecretStore
      target:
        name: langsmith-app-secret      # matches config.existingSecretName
        creationPolicy: Orphan          # so the materialized Secret survives upgrades
      data:
        - secretKey: langsmith_license_key
          remoteRef:
            key: secret/langsmith/app
            property: langsmith_license_key

The chart then consumes the materialized Secret via the existing knobs:

config:
  disableSecretCreation: true
  existingSecretName: langsmith-app-secret

Implementation

• templates/extra-manifests.yaml — iterates .Values.extraManifests, runs each entry through tpl (object entries via toYaml first).
• templates/pre-install-manifests.yaml — iterates .Values.preInstallManifests, runs each entry through tpl, then injects the following annotations (user-provided values on the same keys win):
  • helm.sh/hook: pre-install,pre-upgrade
  • helm.sh/hook-weight: "-5"
  • helm.sh/hook-delete-policy: before-hook-creation
• values.yaml — adds extraManifests: [] and preInstallManifests: [] with doc comments and examples covering both forms.

Defaults are [] for both, so behavior is unchanged for existing users.

Caveats

• Hook resources (preInstallManifests) are not tracked as part of the Helm release and are recreated on every upgrade. For ExternalSecret entries, prefer target.creationPolicy: Orphan (or target.deletionPolicy: Retain on newer ESO versions) so the materialized Secret survives upgrades and pods consuming it don't restart.
• Each preInstallManifests entry must be a single resource (no --- separators inside one string); extraManifests continues to pass strings through as-is and supports multi-doc strings.

[joaquin-borggio-lc]

For adding arbitrary manifests, I would recommend using helm composition.

something where you have this kind of structure:

my-langsmith/
  Chart.yaml
  values.yaml
  templates/
    my-configmap.yaml

this is your chart.yaml:

# Chart.yaml
apiVersion: v2
name: my-langsmith
version: 0.1.0
dependencies:
  - name: langsmith
    version: "0.x.x"
    repository: "https://langchain-ai.github.io/helm"

this anything you want in the templates folder. example:

# templates/my-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Release.Name }}-custom-config
  namespace: {{ .Release.Namespace }}
data:
  APP_ENV: production
  SOME_FLAG: "true"

and your values file would look like this:

# values.yaml
langsmith:
  config:
    existingSecretName: langsmith-app-secret
  # any other langsmith values nested here

That's the general idea with the helm composition that allows you to combine different manifests or helm charts.

[karantyagi-reltio]

Thanks joaquin-borggio-lc — composition is the right tool for arbitrary side-car manifests, and I'm convinced it covers the extraManifests half of this PR.

The reason I'd still like to land the preInstallManifests half is install/upgrade ordering, which composition genuinely doesn't solve:

In a parent/child chart setup, both layers render into a single release manifest list, and Helm sorts by kind, not by chart. So a parent-chart ExternalSecret is not guaranteed to be applied (and reconciled by ESO into the target Secret) before the langsmith Deployments that consume it. On a clean install you get a window where the pods reference a not-yet-materialized Secret and crash-loop until ESO catches up; on upgrade you get a brief flap whenever the ES spec changes.

The standard fix is helm.sh/hook: pre-install,pre-upgrade with a negative weight, which is what preInstallManifests injects. You can do this by hand in a wrapper chart by annotating every entry, but:

• it's easy to forget on one resource and silently get pod restarts,
• the annotation set (hook, hook-weight, hook-delete-policy) and its caveats (e.g. creationPolicy: Orphan so the materialized Secret survives upgrades) are non-obvious,
• ESO + LangSmith is a common enough combination that having a blessed path in the chart saves every adopter the same debug cycle.

[karantyagi-reltio]

joaquin-borggio-lc Any update here ?

CC: Saad Farooq (@saad-supports-langchain)