dockeralpine-linuxnode-canvas

node canvas on alpine within docker

I'm trying to install node canvas (https://github.com/Automattic/node-canvas) on Alpine within docker.

These are (parts of) my Dockerfile:

# Use node/alpine image for final build
FROM keymetrics/pm2:latest-alpine as app

# install dependencies for canvas
RUN apk --no-cache --virtual .build-deps add \
        python \
        make \
        g++ \
        gcc \
    && apk --no-cache --virtual .canvas-build-deps add \
        build-base \
        cairo-dev \
        jpeg-dev \
        pango-dev \
        giflib-dev \
        pixman-dev \
        pangomm-dev \
        libjpeg-turbo-dev \
        freetype-dev \
    && apk --no-cache add \
        pixman \
        cairo \
        pango \
        giflib
RUN apk add --update  --repository http://dl-3.alpinelinux.org/alpine/edge/testing libmount ttf-dejavu ttf-droid ttf-freefont ttf-liberation ttf-ubuntu-font-family fontconfig

# Install dependencies
RUN npm install --prod
RUN npm rebuild canvas --build-from-source

When I try to boot my docker container the following error appears:

Error: Error relocating /var/www/app/node_modules/canvas/build/Release/canvas.node: FcConfigGetCurrent: symbol not found
    at Object.Module._extensions..node (internal/modules/cjs/loader.js:775:18)
    at Module.load (internal/modules/cjs/loader.js:626:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:566:12)
    at Function.Module._load (internal/modules/cjs/loader.js:558:3)
    at Module.require (internal/modules/cjs/loader.js:663:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (/var/www/app/node_modules/canvas/lib/bindings.js:3:18)
    at Module._compile (internal/modules/cjs/loader.js:734:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:745:10)
    at Module.load (internal/modules/cjs/loader.js:626:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:566:12)
    at Function.Module._load (internal/modules/cjs/loader.js:558:3)
    at Module.require (internal/modules/cjs/loader.js:663:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (/var/www/app/node_modules/canvas/lib/canvas.js:9:18)
    at Module._compile (internal/modules/cjs/loader.js:734:30)

I'm guessing that it has something to do with the fact that Alpine uses musl instead of glibc but I thought that rebuilding canvas from source npm rebuild canvas --build-from-source would be enough.

I've already tried most suggestions from https://github.com/Automattic/node-canvas/issues but none is working for me.

Any suggestions ?

Solution

  • OK, here's an answer--a way to install node-canvas v2.5 under the official node:10.16.0-alpine Docker image. As you probably know, the error you posted, "Error relocating...canvas.node" indicates your build failed. This is because canvas uses glibc but alpine uses musl. Canvas needs to link to glibc, so you need to add it to your image. Sasha Gerrand offers alpine-pkg-glibc as one way to do it. Using his installation instructions, here's how it looks in a docker file:

        #  geo_core layer
    #  build on a node image, in turn built on alpine linux, Docker's official linux pulled from hub.docker.com
    FROM node:10.16.0-alpine

    #  add libraries; sudo so non-root user added downstream can get sudo
    RUN apk add --no-cache \
        sudo \
        curl \
        build-base \
        g++ \
        libpng \
        libpng-dev \
        jpeg-dev \
        pango-dev \
        cairo-dev \
        giflib-dev \
        python \
        ;

    #  add glibc and install canvas
    RUN apk --no-cache add ca-certificates wget  && \
        wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub && \
        wget https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.29-r0/glibc-2.29-r0.apk && \
        apk add glibc-2.29-r0.apk && \
        npm install canvas@2.5.0
        ;