From 54e206cde09af4898a8836d6a49e74d5088d3ab0 Mon Sep 17 00:00:00 2001
From: Kevyn Bruyere <kevynb@users.noreply.github.com>
Date: Wed, 22 Jul 2020 11:38:17 +0200
Subject: [PATCH] Add BP about bootstraping using node instead of npm

---
 README.md                               |  7 +--
 sections/docker/bootstrap-using-node.md | 62 +++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 3 deletions(-)
 create mode 100644 sections/docker/bootstrap-using-node.md

diff --git a/README.md b/README.md
index cdc071fc..ffc47c45 100644
--- a/README.md
+++ b/README.md
@@ -1094,11 +1094,12 @@ Bear in mind that with the introduction of the new V8 engine alongside the new E
 
 ## ![✔] 8.2. Bootstrap the code using 'node' command, avoid 'npm run' scripts
 
-**TL;DR:**
+**TL;DR:** use `CMD ['node','server.js']` to start your app. This prevents problems with child-process, signal handling and avoid creating unnecessary processes.
 
-**Otherwise:**
 
-🔗 [**Read More: Clean npm cache**](/sections/docker/file.md)
+**Otherwise:** You'll have hard shutdowns, possibly losing current requests and/or data
+
+[**Read More: Bootstrap container using node command, avoid npm start**](/sections/docker/bootstrap-using-node.md)
 
 <br /><br /><br />
 
diff --git a/sections/docker/bootstrap-using-node.md b/sections/docker/bootstrap-using-node.md
new file mode 100644
index 00000000..e636471d
--- /dev/null
+++ b/sections/docker/bootstrap-using-node.md
@@ -0,0 +1,62 @@
+# Bootstrap container using node command instead of npm
+
+## One paragraph explainer
+
+We are used to see code examples where folks start their app using `CMD 'npm start'`. This is a bad practice. The `npm` binary will not forward signals to your app which prevents graceful shutdown (see #716). If you are using Child-processes they won’t be cleaned up correctly in case of unexpected shutdown, leaving zombie processes on your host. `npm start` also results in having an extra process for no benefit. To start you app use `CMD ['node','server.js']`.
+
+### Code example
+
+```dockerfile
+
+FROM node:12-slim AS build
+WORKDIR /usr/src/app
+COPY package.json package-lock.json ./
+RUN npm ci --production && npm clean cache --force
+
+CMD ['node', 'server.js']
+```
+
+### Antipatterns
+
+Using npm start
+```dockerfile
+
+FROM node:12-slim AS build
+WORKDIR /usr/src/app
+COPY package.json package-lock.json ./
+RUN npm ci --production && npm clean cache --force
+
+# don’t do that!
+CMD “npm start”
+```
+
+Using node in a single string will start a bash/ash shell process to execute your command. That is almost the same as using `npm`
+
+```dockerfile
+
+FROM node:12-slim AS build
+WORKDIR /usr/src/app
+COPY package.json package-lock.json ./
+RUN npm ci --production && npm clean cache --force
+
+# don’t do that, it will start bash
+CMD "node server.js"
+```
+
+Starting with npm, here’s the process tree:
+```
+$ ps falx
+  UID   PID  PPID   COMMAND
+    0     1     0   npm
+    0    16     1   sh -c node server.js
+    0    17    16    \_ node server.js
+```
+There is no advantage to those two extra process.
+
+Sources:
+
+
+https://maximorlov.com/process-signals-inside-docker-containers/
+
+
+https://github.com/nodejs/docker-node/blob/master/docs/BestPractices.md#handling-kernel-signals