k8s-path-check.sh

File: ex_blog/k8s-path-check.sh

#!/bin/bash
# k8s-path-check.sh
# Checks expected K8s paths exist AND cross-references against what processes actually read

GREEN='\033[0;32m'
RED='\033[0;31m'
YELLOW='\033[1;33m'
GREY='\033[0;90m'
NC='\033[0m'

ok()   { echo -e "${GREEN}[OK]${NC}    $1"; }
fail() { echo -e "${RED}[MISS]${NC}  $1"; }
info() { echo -e "${YELLOW}[INFO]${NC}  $1"; }
sep()  { echo -e "${GREY}───────────────────────────────────────────${NC}"; }

echo ""
echo "K8s Path Checker"
sep

# ── 1. STATIC PATHS — do they exist? ──────────────────────────────────────────
echo ""
info "Static path existence"
sep

PATHS=(
  "/etc/kubernetes/manifests"
  "/etc/kubernetes/pki"
  "/etc/kubernetes/admin.conf"
  "/etc/kubernetes/kubelet.conf"
  "/etc/kubernetes/scheduler.conf"
  "/etc/kubernetes/controller-manager.conf"
  "/var/lib/kubelet/config.yaml"
  "/var/lib/etcd"
  "/etc/cni/net.d"
  "/opt/cni/bin"
  "/run/containerd/containerd.sock"
  "/var/lib/containerd"
  "/var/log/pods"
  "$HOME/.kube/config"
)

for path in "${PATHS[@]}"; do
  if [ -e "$path" ]; then
    ok "$path"
  else
    fail "$path"
  fi
done

# ── 2. CROSS-CHECK: what is kubelet actually reading? ─────────────────────────
echo ""
info "Kubelet process — actual flags"
sep

KUBELET_CMD=$(ps aux | grep '[k]ubelet' | awk '{for(i=11;i<=NF;i++) printf $i" "; print ""}')

if [ -z "$KUBELET_CMD" ]; then
  fail "kubelet process not found"
else
  # extract key flags
  CONFIG=$(echo "$KUBELET_CMD"    | grep -oP '(?<=--config=)\S+')
  KUBECONFIG=$(echo "$KUBELET_CMD" | grep -oP '(?<=--kubeconfig=)\S+')
  RUNTIME=$(echo "$KUBELET_CMD"   | grep -oP '(?<=--container-runtime-endpoint=)\S+')

  [ -n "$CONFIG" ]     && ok    "kubelet --config=$CONFIG" \
                        && [ -f "$CONFIG" ] \
                        && echo -e "        ${GREY}↳ file exists${NC}" \
                        || echo -e "        ${RED}↳ FILE MISSING${NC}"

  [ -n "$KUBECONFIG" ] && ok    "kubelet --kubeconfig=$KUBECONFIG" \
                        && [ -f "$KUBECONFIG" ] \
                        && echo -e "        ${GREY}↳ file exists${NC}" \
                        || echo -e "        ${RED}↳ FILE MISSING${NC}"

  [ -n "$RUNTIME" ]    && ok    "kubelet --container-runtime-endpoint=$RUNTIME"
fi

# ── 3. CROSS-CHECK: kube-apiserver manifest flags ────────────────────────────
echo ""
info "kube-apiserver manifest — cert paths"
sep

APISERVER_MANIFEST="/etc/kubernetes/manifests/kube-apiserver.yaml"

if [ -f "$APISERVER_MANIFEST" ]; then
  grep -E '\-\-(tls-cert|tls-private|client-ca|etcd-ca|etcd-cert|etcd-key|kubelet-client-cert|kubelet-client-key)' \
    "$APISERVER_MANIFEST" | while read -r line; do
      path=$(echo "$line" | grep -oP '(?<==)/\S+')
      flag=$(echo "$line" | grep -oP '\-\-\S+(?==)')
      if [ -n "$path" ]; then
        if [ -f "$path" ]; then
          ok "$flag=$path"
        else
          fail "$flag=$path  ← FILE MISSING"
        fi
      fi
    done
else
  fail "$APISERVER_MANIFEST not found"
fi

# ── 4. CROSS-CHECK: etcd manifest data-dir ───────────────────────────────────
echo ""
info "etcd manifest — data dir"
sep

ETCD_MANIFEST="/etc/kubernetes/manifests/etcd.yaml"

if [ -f "$ETCD_MANIFEST" ]; then
  ETCD_DATA=$(grep -oP '(?<=--data-dir=)\S+' "$ETCD_MANIFEST")
  if [ -n "$ETCD_DATA" ]; then
    if [ -d "$ETCD_DATA" ]; then
      ok "etcd --data-dir=$ETCD_DATA"
    else
      fail "etcd --data-dir=$ETCD_DATA  ← DIR MISSING"
    fi
  fi
else
  fail "$ETCD_MANIFEST not found"
fi

# ── 5. CROSS-CHECK: containerd socket ────────────────────────────────────────
echo ""
info "containerd — socket"
sep

CONTAINERD_CMD=$(ps aux | grep '[c]ontainerd' | grep -v shim | awk '{for(i=11;i<=NF;i++) printf $i" "; print ""}')

if [ -z "$CONTAINERD_CMD" ]; then
  fail "containerd process not found"
else
  SOCK=$(echo "$CONTAINERD_CMD" | grep -oP '(?<=--address=)\S+')
  if [ -n "$SOCK" ]; then
    [ -S "$SOCK" ] && ok "containerd --address=$SOCK" || fail "containerd --address=$SOCK  ← SOCKET MISSING"
  else
    # default socket
    [ -S "/run/containerd/containerd.sock" ] \
      && ok "containerd socket at default /run/containerd/containerd.sock" \
      || fail "containerd socket not found"
  fi
fi

# ── 6. kubeconfig server address ─────────────────────────────────────────────
echo ""
info "~/.kube/config — server address"
sep

KUBECONFIG_FILE="$HOME/.kube/config"
if [ -f "$KUBECONFIG_FILE" ]; then
  SERVER=$(grep 'server:' "$KUBECONFIG_FILE" | awk '{print $2}')
  info "server: $SERVER"
  # extract port
  PORT=$(echo "$SERVER" | grep -oP '(?<=:)\d+$')
  if [ "$PORT" -ge 1 ] && [ "$PORT" -le 65535 ] 2>/dev/null; then
    ok "port $PORT is valid"
  else
    fail "port '$PORT' looks wrong — typo?"
  fi
else
  fail "$KUBECONFIG_FILE not found"
fi

echo ""
sep
echo "done"
echo ""