add kubectl-node-shell

tools/kubectl-node_shell

@@ -0,0 +1,158 @@
+#!/usr/bin/env sh
+# from: https://github.com/kvaps/kubectl-node-shell
+
+set -e
+
+kubectl=kubectl
+version=1.5.5
+generator=""
+node=""
+nodefaultctx=0
+nodefaultns=0
+cmd='[ "nsenter", "--target", "1", "--mount", "--uts", "--ipc", "--net", "--pid", "--"'
+if [ -t 0 ]; then
+  tty=true
+else
+  tty=false
+fi
+while [ $# -gt 0 ]; do
+  key="$1"
+
+  case $key in
+  -v | --version)
+    echo "kubectl-node-shell $version"
+    exit 0
+    ;;
+  --context)
+    nodefaultctx=1
+    kubectl="$kubectl --context $2"
+    shift
+    shift
+    ;;
+  --kubecontext=*)
+    nodefaultctx=1
+    kubectl="$kubectl --context=${key##*=}"
+    shift
+    ;;
+  --kubeconfig)
+    kubectl="$kubectl --kubeconfig $2"
+    shift
+    shift
+    ;;
+  --kubeconfig=*)
+    kubectl="$kubectl --kubeconfig=${key##*=}"
+    shift
+    ;;
+  -n | --namespace)
+    nodefaultns=1
+    kubectl="$kubectl --namespace $2"
+    shift
+    shift
+    ;;
+  --namespace=*)
+    nodefaultns=1
+    kubectl="$kubectl --namespace=${key##*=}"
+    shift
+    ;;
+  --)
+    shift
+    break
+    ;;
+  *)
+    if [ -z "$node" ]; then
+      node="${1#node/}"
+      shift
+    else
+      echo "exactly one node required"
+      exit 1
+    fi
+    ;;
+  esac
+done
+
+# Set the default context and namespace to avoid situations where the user switch them during the build process
+[ "$nodefaultctx" = 1 ] || kubectl="$kubectl --context=$(${kubectl} config current-context)"
+[ "$nodefaultns" = 1 ] || kubectl="$kubectl --namespace=$(${kubectl} config view --minify --output 'jsonpath={.contexts..namespace}')"
+
+if [ $# -gt 0 ]; then
+  while [ $# -gt 0 ]; do
+    cmd="$cmd, \"$(echo "$1" | \
+      awk '{gsub(/["\\]/,"\\\\&");gsub(/\x1b/,"\\u001b");printf "%s",last;last=$0"\\n"} END{print $0}' \
+    )\""
+    shift
+  done
+  cmd="$cmd ]"
+else
+  cmd="$cmd, \"bash\", \"-l\" ]"
+fi
+
+if [ -z "$node" ]; then
+  echo "Please specify node name"
+  exit 1
+fi
+
+image="${KUBECTL_NODE_SHELL_IMAGE:-docker.io/library/alpine}"
+pod="nsenter-$(env LC_ALL=C tr -dc a-z0-9 </dev/urandom | head -c 6)"
+
+# Check the node
+$kubectl get node "$node" >/dev/null || exit 1
+
+container_cpu="${KUBECTL_NODE_SHELL_POD_CPU:-100m}"
+container_memory="${KUBECTL_NODE_SHELL_POD_MEMORY:-256Mi}"
+labels="${KUBECTL_NODE_SHELL_LABELS}"
+
+overrides="$(
+  cat <<EOT
+{
+  "spec": {
+    "nodeName": "$node",
+    "hostPID": true,
+    "hostNetwork": true,
+    "containers": [
+      {
+        "securityContext": {
+          "privileged": true
+        },
+        "image": "$image",
+        "name": "nsenter",
+        "stdin": true,
+        "stdinOnce": true,
+        "tty": $tty,
+        "command": $cmd,
+        "resources": {
+          "limits": {
+            "cpu": "${container_cpu}",
+            "memory": "${container_memory}"
+          },
+          "requests": {
+            "cpu": "${container_cpu}",
+            "memory": "${container_memory}"
+          }
+        }
+      }
+    ],
+    "tolerations": [
+      {
+        "key": "CriticalAddonsOnly",
+        "operator": "Exists"
+      },
+      {
+        "effect": "NoExecute",
+        "operator": "Exists"
+      }
+    ]
+  }
+}
+EOT
+)"
+
+# Support Kubectl <1.18
+m=$(kubectl version --client -o yaml | awk -F'[ :"]+' '$2 == "minor" {print $3+0}')
+if [ "$m" -lt 18 ]; then
+  generator="--generator=run-pod/v1"
+fi
+
+trap "EC=\$?; $kubectl delete pod --wait=false $pod >&2 || true; exit \$EC" EXIT INT TERM
+
+echo "spawning \"$pod\" on \"$node\"" >&2
+$kubectl run --image "$image" --restart=Never --overrides="$overrides" --labels="$labels" $([ "$tty" = true ] && echo -t) -i "$pod" $generator