Add auto install of custom modules, functions in docker [Working sample]

svenjanssen · 7 January 2021 00:21

Description

Script to automatically install custom modules, custom modules with unsafe permissions and whitelisted modules for functions according to set env variables.

Behavior

The first of the directory specified in N8N_CUSTOM_EXTENSIONS gets created and will be the install directory for custom modules (Delimiter ;)
example -e N8N_CUSTOM_EXTENSIONS="/home/jim/n8n/custom-nodes;/data/n8n/nodes

Custom modules are installed according to $CUSTOM_MODULES (Delimiter ;)
example -e CUSTOM_MODULES="n8n-nodes-suitecrm;n8n-nodes-dnc-activecampaign-legacy

Custom modules with unsafe-perms are installed according to $CUSTOM_MODULES_UNSAFEPERM (Delimiter ;)
example -e CUSTOM_MODULES_UNSAFEPERM="n8n-nodes-dnc-suitecrm

Custom modules for functions according to NODE_FUNCTION_ALLOW_EXTERNAL (such as date-fns) will be installed to /usr/local/lib “alongside of n8n” (Delimiter ,)
example -e NODE_FUNCTION_ALLOW_EXTERNAL="date-fns,date-fns-tz,feiertagejs

Dockerfile (apk add + bash)

github.com

sutidor/n8n/blob/master/docker/images/n8n/Dockerfile

FROM node:12.19-alpine

ARG N8N_VERSION

RUN if [ -z "$N8N_VERSION" ] ; then echo "The N8N_VERSION argument is missing!" ; exit 1; fi

# Update everything and install needed dependencies
RUN apk add --update graphicsmagick tzdata git tini su-exec bash

# # Set a custom user to not have n8n run as root
USER root

# Install n8n and the also temporary all the packages
# it needs to build it correctly.
RUN apk --update add --virtual build-dependencies python build-base ca-certificates && \
	npm_config_user=root npm install -g full-icu [email protected]${N8N_VERSION} && \
	apk del build-dependencies

# Install fonts
RUN apk --no-cache add --virtual fonts msttcorefonts-installer fontconfig && \

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Modified entrypoint (execute install-custom-modules.sh)

github.com

sutidor/n8n/blob/master/docker/images/n8n/docker-entrypoint.sh

#!/bin/sh

if [ -d /root/.n8n ] ; then
  chmod o+rx /root
  chown -R node /root/.n8n
  ln -s /root/.n8n /home/node/
fi

chown -R node /home/node

bash -c "/install-custom-modules.sh"

if [ "$#" -gt 0 ]; then
  # Got started with arguments
  exec su-exec node "[email protected]"
else
  # Got started without arguments
  exec su-exec node n8n
fi

Actual script (install-custom-modules.sh)

github.com

sutidor/n8n/blob/master/docker/images/n8n/install-custom-modules.sh

apk --virtual build-dependencies add python make g++ bash
CUSTOM_MODULE_DIR="/home/node/.n8n/custom"
CUSTOM_FUNCTION_DIR="/usr/local/lib"

if [ ! -z "$N8N_CUSTOM_EXTENSIONS" ]
then
    LIST=(${N8N_CUSTOM_EXTENSIONS//;/ })
    if [[ ! -d "${LIST[0]}" ]]
    then
        echo "custom extension: ${LIST[0]}"
        mkdir "${LIST[0]}"
    fi
    CUSTOM_MODULE_DIR="${LIST[0]}"
else
    if [[ ! -d "$CUSTOM_MODULE_DIR" ]]
    then
        mkdir "$CUSTOM_MODULE_DIR"
    fi
fi

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I had to insert script execution in the docker-entrypoint.sh, because the folder /home/node/.n8n/custom needs to be created first.

I assume the concept is more valuable than my actual implementation right now, and a core dev should be able to figure out a more elegant way to implement it in live n8n. But if you wish, I can do a PR.