opentelemetry-operator VS cert-manager

We used Lightstep’s Prometheus Kubernetes OpenTelemetry Collector to get these Metrics into Lightstep. This Helm chart is inspired by kube-prometheus-stack, but with one crucial difference -- no Prometheus! We’re able to use recent enhancements to the OpenTelemetry Operator for Kubernetes such as support for Service Monitors in order to scrape Prometheus metrics from pods, system components, and more.

# Pre-req: kubernetes cluster with cert-manager enabled # Deployment based $ kubectl apply -f https://github.com/open-telemetry/opentelemetry-operator/releases/latest/download/opentelemetry-operator.yaml namespace/opentelemetry-operator-system created customresourcedefinition.apiextensions.k8s.io/instrumentations.opentelemetry.io created customresourcedefinition.apiextensions.k8s.io/opentelemetrycollectors.opentelemetry.io created serviceaccount/opentelemetry-operator-controller-manager created role.rbac.authorization.k8s.io/opentelemetry-operator-leader-election-role created clusterrole.rbac.authorization.k8s.io/opentelemetry-operator-manager-role created clusterrole.rbac.authorization.k8s.io/opentelemetry-operator-metrics-reader created clusterrole.rbac.authorization.k8s.io/opentelemetry-operator-proxy-role created rolebinding.rbac.authorization.k8s.io/opentelemetry-operator-leader-election-rolebinding created clusterrolebinding.rbac.authorization.k8s.io/opentelemetry-operator-manager-rolebinding created clusterrolebinding.rbac.authorization.k8s.io/opentelemetry-operator-proxy-rolebinding created service/opentelemetry-operator-controller-manager-metrics-service created service/opentelemetry-operator-webhook-service created deployment.apps/opentelemetry-operator-controller-manager created certificate.cert-manager.io/opentelemetry-operator-serving-cert created issuer.cert-manager.io/opentelemetry-operator-selfsigned-issuer created mutatingwebhookconfiguration.admissionregistration.k8s.io/opentelemetry-operator-mutating-webhook-configuration created validatingwebhookconfiguration.admissionregistration.k8s.io/opentelemetry-operator-validating-webhook-configuration created $ kubectl get crds | grep opentel instrumentations.opentelemetry.io 2022-11-14T06:14:32Z opentelemetrycollectors.opentelemetry.io 2022-11-14T06:14:32Z $ kubectl get deployments.apps -n opentelemetry-operator-system NAME READY UP-TO-DATE AVAILABLE AGE opentelemetry-operator-controller-manager 1/1 1 1 56s # Create a collector like below $ kubectl apply -f - <

# cert-manager kubectl apply -f https://github.com/jetstack/cert-manager/releases/latest/download/cert-manager.yaml # open telemetry operator kubectl apply -f https://github.com/open-telemetry/opentelemetry-operator/releases/latest/download/opentelemetry-operator.yaml

cert-manager

The second one is a combination of tools: External DNS, cert-manager, and NGINX ingress. Using these as a stack, you can quickly deploy an application, making it available through a DNS with a TLS without much effort via simple annotations. When I first discovered External DNS, I was amazed at its quality.

On top of its core components, SpinKube depends on cert-manager. cert-Manager is responsible for provisioning and managing TLS certificates that are used by the admission webhook system of the Spin Operator. Let’s install cert-manager and KWasm using the commands shown here:

terraform { required_providers { kubectl = { source = "gavinbunney/kubectl" version = "1.14.0" } } } # The reference to the current project or a AWS project data "google_client_config" "provider" {} # The reference to the current cluster or EKS data "google_container_cluster" "my_cluster" { name = var.cluster_name location = var.cluster_location } # We configure the kubectl provider to use those values for authenticating provider "kubectl" { host = data.google_container_cluster.my_cluster.endpoint token = data.google_client_config.provider.access_token cluster_ca_certificate = base64decode(data.google_container_cluster.my_cluster.master_auth[0].cluster_ca_certificate) } #Download the multiple manifests file. data "http" "cert_manager_crds" { url = "https://github.com/cert-manager/cert-manager/releases/download/v${var.cert_manager_version}/cert-manager.crds.yaml" } data "kubectl_file_documents" "cert_manager_crds" { content = data.http.cert_manager_crds.response_body lifecycle { precondition { condition = 200 == data.http.cert_manager_crds.status_code error_message = "Status code invalid" } } } # We use the for_each or else this kubectl_manifest will only import the first manifest in the file. resource "kubectl_manifest" "cert_manager_crds" { for_each = data.kubectl_file_documents.cert_manager_crds.manifests yaml_body = each.value }

SSL certificates thanks to Cloudflare and cert-manager

kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/${CERT_MANAGER_VERSION}/cert-manager.crds.yaml

put the Sub-CA inside hashicorp vault to be used for automatic signing of services like https://cert-manager.io/ inside our k8s clusters.

install-cert-manager: desc: Install cert-manager deps: - init-cluster cmds: - kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/{{.CERT_MANAGER_VERSION}}/cert-manager.yaml - echo "Waiting for cert-manager to be ready" && sleep 25 status: - kubectl -n cert-manager get pods | grep Running | wc -l | grep -q 3

I've been pretty frustrated with how private CAs are supported. Your private root CA can be maliciously used to MITM every domain on the Internet, even though you intend to use it for only a couple domain names. Most people forget to set Name Constraints when they create these and many helper tools lack support [1][2]. Worse, browser support for Name Constraints has been slow [3] and support isn't well tracked [4]. Public CAs give you certificate transparency and you can subscribe to events to detect mis-issuance. Some hosted private CAs like AWS's offer logs [5], but DIY setups don't.

Even still, there are a lot of folks happily using private CAs, they aren't the target audience for this initial release.

[1] https://github.com/FiloSottile/mkcert/issues/302

[2] https://github.com/cert-manager/cert-manager/issues/3655

[3] https://alexsci.com/blog/name-non-constraint/

[4] https://github.com/Netflix/bettertls/issues/19

[5] https://docs.aws.amazon.com/privateca/latest/userguide/secur...

the Cert Manager