typhoon/bare-metal/container-linux/kubernetes/ssh.tf

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Introduce cluster creation without local writes to asset_dir * Allow generated assets (TLS materials, manifests) to be securely distributed to controller node(s) via file provisioner (i.e. ssh-agent) as an assets bundle file, rather than relying on assets being locally rendered to disk in an asset_dir and then securely distributed * Change `asset_dir` from required to optional. Left unset, asset_dir defaults to "" and no assets will be written to files on the machine that runs terraform apply * Enhancement: Managed cluster assets are kept only in Terraform state, which supports different backends (GCS, S3, etcd, etc) and optional encryption. terraform apply accesses state, runs in-memory, and distributes sensitive materials to controllers without making use of local disk (simplifies use in CI systems) * Enhancement: Improve asset unpack and layout process to position etcd certificates and control plane certificates more cleanly, without unneeded secret materials Details: * Terraform file provisioner support for distributing directories of contents (with unknown structure) has been limited to reading from a local directory, meaning local writes to asset_dir were required. https://github.com/poseidon/typhoon/issues/585 discusses the problem and newer or upcoming Terraform features that might help. * Observation: Terraform provisioner support for single files works well, but iteration isn't viable. We're also constrained to Terraform language features on the apply side (no extra plugins, no shelling out) and CoreOS / Fedora tools on the receive side. * Take a map representation of the contents that would have been splayed out in asset_dir and pack/encode them into a single file format devised for easy unpacking. Use an awk one-liner on the receive side to unpack. In pratice, this has worked well and its rather nice that a single assets file is transferred by file provisioner (all or none) Rel: https://github.com/poseidon/terraform-render-bootstrap/pull/162
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locals {
# format assets for distribution
assets_bundle = [
# header with the unpack location
for key, value in module.bootstrap.assets_dist:
format("##### %s\n%s", key, value)
]
}
# Secure copy assets to controllers. Activates kubelet.service
resource "null_resource" "copy-controller-secrets" {
count = length(var.controllers)
# Without depends_on, remote-exec could start and wait for machines before
# matchbox groups are written, causing a deadlock.
depends_on = [
matchbox_group.install,
matchbox_group.controller,
matchbox_group.worker,
module.bootstrap,
]
connection {
type = "ssh"
host = var.controllers.*.domain[count.index]
user = "core"
timeout = "60m"
}
provisioner "file" {
content = module.bootstrap.kubeconfig-kubelet
destination = "$HOME/kubeconfig"
}
provisioner "file" {
Introduce cluster creation without local writes to asset_dir * Allow generated assets (TLS materials, manifests) to be securely distributed to controller node(s) via file provisioner (i.e. ssh-agent) as an assets bundle file, rather than relying on assets being locally rendered to disk in an asset_dir and then securely distributed * Change `asset_dir` from required to optional. Left unset, asset_dir defaults to "" and no assets will be written to files on the machine that runs terraform apply * Enhancement: Managed cluster assets are kept only in Terraform state, which supports different backends (GCS, S3, etcd, etc) and optional encryption. terraform apply accesses state, runs in-memory, and distributes sensitive materials to controllers without making use of local disk (simplifies use in CI systems) * Enhancement: Improve asset unpack and layout process to position etcd certificates and control plane certificates more cleanly, without unneeded secret materials Details: * Terraform file provisioner support for distributing directories of contents (with unknown structure) has been limited to reading from a local directory, meaning local writes to asset_dir were required. https://github.com/poseidon/typhoon/issues/585 discusses the problem and newer or upcoming Terraform features that might help. * Observation: Terraform provisioner support for single files works well, but iteration isn't viable. We're also constrained to Terraform language features on the apply side (no extra plugins, no shelling out) and CoreOS / Fedora tools on the receive side. * Take a map representation of the contents that would have been splayed out in asset_dir and pack/encode them into a single file format devised for easy unpacking. Use an awk one-liner on the receive side to unpack. In pratice, this has worked well and its rather nice that a single assets file is transferred by file provisioner (all or none) Rel: https://github.com/poseidon/terraform-render-bootstrap/pull/162
2019-12-05 07:10:55 +01:00
content = join("\n", local.assets_bundle)
destination = "$HOME/assets"
}
provisioner "remote-exec" {
inline = [
"sudo mv $HOME/kubeconfig /etc/kubernetes/kubeconfig",
Introduce cluster creation without local writes to asset_dir * Allow generated assets (TLS materials, manifests) to be securely distributed to controller node(s) via file provisioner (i.e. ssh-agent) as an assets bundle file, rather than relying on assets being locally rendered to disk in an asset_dir and then securely distributed * Change `asset_dir` from required to optional. Left unset, asset_dir defaults to "" and no assets will be written to files on the machine that runs terraform apply * Enhancement: Managed cluster assets are kept only in Terraform state, which supports different backends (GCS, S3, etcd, etc) and optional encryption. terraform apply accesses state, runs in-memory, and distributes sensitive materials to controllers without making use of local disk (simplifies use in CI systems) * Enhancement: Improve asset unpack and layout process to position etcd certificates and control plane certificates more cleanly, without unneeded secret materials Details: * Terraform file provisioner support for distributing directories of contents (with unknown structure) has been limited to reading from a local directory, meaning local writes to asset_dir were required. https://github.com/poseidon/typhoon/issues/585 discusses the problem and newer or upcoming Terraform features that might help. * Observation: Terraform provisioner support for single files works well, but iteration isn't viable. We're also constrained to Terraform language features on the apply side (no extra plugins, no shelling out) and CoreOS / Fedora tools on the receive side. * Take a map representation of the contents that would have been splayed out in asset_dir and pack/encode them into a single file format devised for easy unpacking. Use an awk one-liner on the receive side to unpack. In pratice, this has worked well and its rather nice that a single assets file is transferred by file provisioner (all or none) Rel: https://github.com/poseidon/terraform-render-bootstrap/pull/162
2019-12-05 07:10:55 +01:00
"sudo /opt/bootstrap/layout",
]
}
}
# Secure copy kubeconfig to all workers. Activates kubelet.service
resource "null_resource" "copy-worker-secrets" {
count = length(var.workers)
# Without depends_on, remote-exec could start and wait for machines before
# matchbox groups are written, causing a deadlock.
depends_on = [
matchbox_group.install,
matchbox_group.controller,
matchbox_group.worker,
]
connection {
type = "ssh"
host = var.workers.*.domain[count.index]
user = "core"
timeout = "60m"
}
provisioner "file" {
content = module.bootstrap.kubeconfig-kubelet
destination = "$HOME/kubeconfig"
}
provisioner "remote-exec" {
inline = [
"sudo mv $HOME/kubeconfig /etc/kubernetes/kubeconfig",
]
}
}
# Connect to a controller to perform one-time cluster bootstrap.
resource "null_resource" "bootstrap" {
# Without depends_on, this remote-exec may start before the kubeconfig copy.
# Terraform only does one task at a time, so it would try to bootstrap
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# while no Kubelets are running.
depends_on = [
null_resource.copy-controller-secrets,
null_resource.copy-worker-secrets,
]
connection {
type = "ssh"
host = var.controllers[0].domain
user = "core"
timeout = "15m"
}
provisioner "remote-exec" {
inline = [
"sudo systemctl start bootstrap",
]
}
}