linkerd-proxy-init

Infra

Updated 4 days ago

Linkerd Proxy-Init Overview

Secure your stack with a hardened Linkerd Proxy-Init image freshly-built by Minimus. Minimus images always include the most up-to-date package version for all packages and dependencies contained in the image.

Linkerd is an ultralight, security-first service mesh for Kubernetes. Linkerd Proxy-Init is an init container that runs before the linkerd-proxy sidecar starts on every meshed workload, configuring iptables rules to transparently redirect inbound and outbound traffic through the proxy so Pods can join the data plane without any application changes.

Try It Out

We will use a Helm chart to deploy the Linkerd control plane with the Linkerd Proxy-Init image.

Prerequisites

A running Kubernetes cluster (v1.21 or higher is recommended)
Helm v3.8 or higher for OCI support (Installation instructions)
kubectl installed and configured
OpenSSL installed

Step 1: Start Cluster

If you have a cluster to work with, skip this step. Otherwise, start a Minikube cluster. Deployment instructions

Step 2: Add Repository to your Local Client and Create a Namespace

Add the official Helm chart repository to your local Helm client.

helm repo add linkerd https://helm.linkerd.io/edge
helm repo update

Create a namespace:

kubectl create ns linkerd-test-ns

Step 3: Create Certificates with OpenSSL

Create SSL certificates for this deployment:

certs_dir=/tmp
namespace='linkerd-test-ns'

Prepare ECDSA certificates (or put your certificates to $certs_dir directory:

# Root CA: ECDSA P-256
openssl ecparam -name prime256v1 -genkey -noout -out "$certs_dir/ca.key"
openssl req -new -x509 -days 365 \
  -subj "/CN=root.linkerd.cluster.local" \
  -key "$certs_dir/ca.key" \
  -out "$certs_dir/ca.crt"

# Issuer: ECDSA P-256
openssl ecparam -name prime256v1 -genkey -noout -out "$certs_dir/issuer.key"
openssl req -new -key "$certs_dir/issuer.key" \
  -subj "/CN=identity.linkerd.cluster.local" \
  -out "$certs_dir/issuer.csr"

cat > "$certs_dir/issuer.ext" <<EOF
basicConstraints=CA:TRUE
keyUsage=keyCertSign,cRLSign
subjectKeyIdentifier=hash
authorityKeyIdentifier=keyid,issuer
EOF

openssl x509 -req -days 365 \
  -in "$certs_dir/issuer.csr" \
  -CA "$certs_dir/ca.crt" \
  -CAkey "$certs_dir/ca.key" \
  -CAcreateserial \
  -out "$certs_dir/issuer.crt" \
  -extfile "$certs_dir/issuer.ext"

Step 4: Create CRDs with Helm

helm install linkerd-crds linkerd/linkerd-crds  \
  --namespace $namespace \
  --set namespace=$namespace \
  --set installNamespace=false

Step 5: Install Linkerd Control Plane

helm install linkerd-control-plane linkerd/linkerd-control-plane \
  --namespace $namespace \
  --set namespace=$namespace \
  --set installNamespace=false \
  --set-file identityTrustAnchorsPEM="$certs_dir/ca.crt" \
  --set-file identity.issuer.tls.crtPEM="$certs_dir/issuer.crt" \
  --set-file identity.issuer.tls.keyPEM="$certs_dir/issuer.key" \
  --set proxyInit.image.name=reg.mini.dev/linkerd-proxy-init \
  --set proxyInit.image.version=latest

Check that all Pods are up and running:

kubectl -n linkerd-test-ns get po

Step 6: Verify the Proxy-Init Image

Confirm the destination component's init container is running the Minimus image:

kubectl -n linkerd-test-ns get deploy linkerd-destination -o jsonpath='{.spec.template.spec.initContainers[*].image}'

Technical Considerations

The Linkerd Proxy-Init image provided by Minimus is a slim, security-hardened alternative to the public image from Docker Hub. The images are largely interchangeable, with a few differences as noted below.

Linkerd Proxy-Init built by Minimus:

Runs as non-root by default for a security-first approach that protects against privilege escalation attacks.
Drill down on the version specification tab to see the default user, listening ports, entrypoint, volumes, environment variables, etc.

The Payoff

A hardened, minimal image that will remain more secure for the long run and accrue vulnerabilities at a slower rate.

See the risk reduction dashboard for a detailed CVE comparison over the past 30 days.
Review the compliance report to see the default hardening and security configurations for the image.

Terms & Info

Trademark

This catalog is published by Minimus. All product names, logos, and marks, other than those belonging to Minimus, shown are owned by their respective rights holders and appear here only to identify the open source software each image contains. Minimus claims no ownership of those marks and implies no affiliation with, endorsement by, certification by, or sponsorship by any rights holder.

Disclaimer

Images are provided "as-is" without warranty of any kind. "Hardened" refers to the security configuration applied at the time of build and does not constitute a guarantee of ongoing security or absence of vulnerabilities. The free tier is provided without support, SLA, or guaranteed patching timelines. Security updates may be applied to paid subscriptions before or instead of free tier images. By pulling or using any image you agree to our Terms of Use.