Helm Chart

This Terraform module installs a Helm chart on a K8s cluster. It is useful for overcoming the limitations of the main Helm release resource when you want to spin up a cluster and use it as a provider for k8s resources within the same Terraform plan.

Usage
Variables
Links

Usage

Here are a few different examples for how to use this module:

Cert-Manager

module "cert-manager" {
  source     = "git@github.com:dansible/terraform-null-helm-chart.git?ref=v0.0.2"

  # This is assumed to be the output of the GKE module but can be any Kubeconfig
  kubeconfig  = "${module.k8s.kubeconfig}"

  # This is used to manage install/uninstall process
  enabled    = true

  # This is assumed to be the output of the Helm install module but can be any TF resource
  depends_on = "${module.helm.dependency}"

  name          = "certmanager"
  chart_name    = "stable/cert-manager"
  chart_version = "0.5.2"
  namespace     = "kube-system"
  values            = "${file("values.yaml")}"

  helm-extra-args   = "--set resources.requests.cpu=10m --set resources.requests.memory=32Mi --set resources.limits.cpu=50m --set resources.limits.memory=128Mi"

  pre-install-cmds  = ""
  post-install-cmds = ""
  pre-destroy-cmds  = ""

  # Delete any remaining CRDs created by the cert-manager chart
  post-destroy-cmds = "kubectl delete customresourcedefinitions.apiextensions.k8s.io certificates.certmanager.k8s.io clusterissuers.certmanager.k8s.io issuers.certmanager.k8s.io"
}

Vault

module "vault" {
  source        = "git@github.com:dansible/terraform-null-helm-chart.git?ref=v0.0.2"
  kubeconfig     = "${module.k8s.kubeconfig}"
  enabled       = true
  depends_on    = ["${module.helm.dependency}"]
  name          = "vault"
  chart_name    = "."
  chart_version = "0.0.1"
  namespace     = "default"

  helm-extra-args  = "--set consul.affinity=\"\""
  pre-install-cmds  = <<EOF
if [ ! -d vault-helm ] ; then git clone https://github.com/helm/charts.git ; fi
cd charts/incubator/vault/
EOF
  pre-destroy-cmds  = ""
  post-destroy-cmds = ""
}

Fluent-Bit

module "fluentbit" {
  source            = "git@github.com:dansible/terraform-null-helm-chart.git?ref=v0.0.2"
  kubeconfig         = "${module.k8s.kubeconfig}"
  enabled           = true
  depends_on        = ["${module.helm.dependency}"]
  name              = "fluentbit"
  chart_name        = "lms-helm-charts/fluent-bit"
  chart_version     = "0.10.0"
  namespace         = "infra"
  pre-install-cmds  = "${file("${path.module}/fluent-bit.sh")}"
  values            = "${data.vault_generic_secret.fluentbit-values.data_json}"
}

Contents of fluent-bit.sh:

set -o errexit
set -o pipefail
set -o nounset

if ! helm plugin list | grep s3 > /dev/null; then
  helm plugin install https://github.com/hypnoglow/helm-s3.git
fi

if helm repo list | grep private-helm-charts > /dev/null; then
  helm repo update
else
  helm repo add lms-helm-charts s3://private-helm-charts/
fi

set +o errexit
set +o pipefail
set +o nounset

Variables

For more info, please see the variables file.

Variable	Description	Default
`kubeconfig`	Kubeconfig for cluster in which Helm will be installed.	`(Required)`
`enabled`	Whether to enable this module. Set to `false` to properly uninstall the chart.	`true`
`name`	The name to assign to the chart & temporary resources.	`certmanager`
`chart_name`	The name of the chart to install.	`stable/cert-manager`
`chart_version`	Version of Tiller component. Must match the Helm cli on the machine executing Terraform.	`0.5.2`
`namespace`	The namespace to install the chart to.	`default`
`helm-extra-args`	Extra arguments to pass to helm command.	`""`
`values`	Content of Helm values file rendered as a string.	`""`
`pre-install-cmds`	Custom commands to run before installing the chart.	`""`
`post-install-cmds`	Custom commands to run after installing the chart.	`""`
`pre-destroy-cmds`	Custom commands to run before destroying the chart.	`""`
`post-destroy-cmds`	Custom commands to run after destroying the chart.	`""`

Dependency Variables

This module exposes two variables to work around the limitations of module dependencies in Terraform.

Name	Type	Description
`depends_on`	`list variable`	Dummy variable to enable module dependencies.
`dependency`	`list output`	Dummy output to enable module dependencies.

Using these two, you can emulate the functionality of depends_on by chaining one module's dependency output to another's depends_on input.