Update Docker build to use python3

[jdeglopper]

Based on the changes by @nqkdev in #117, but including needed changes to launch elastalert under Python 3 while still using Python 2 for node-gyp.

[caleb15]

Jira needs to be updated to work with the new elastalert by the way - see Yelp/elastalert#2437

jira>=2.0.0 should fix the problem.

[Folyd]

Why this PR still didn't get merged?

[alvarolmedo]

+1

[alvarolmedo]

This dockerfile installs python3.7, this version is not supported by elastalert yet.

[hottwister]

I use this dockerfile and it's installs python3.6

[alvarolmedo]

Well, I found the problem, and I can confirm that python3.7 is installed. the problem is the second Form in the multi-stage Dockerfile and the python installation in this stage (lines 27 and 32):

FROM node:alpine
(....)
RUN apk add --update --no-cache curl tzdata python2 python3 make libmagic

If you build a docker image with this sentences and run a container with the image generated, the version of python can be checked:

$ cat Dockerfile 
FROM node:alpine
RUN apk add --update --no-cache curl tzdata python2 python3

$ docker build -t test_python_version:latest .
Sending build context to Docker daemon  2.048kB
Step 1/2 : FROM node:alpine
 ---> 5f8b3338a759
Step 2/2 : RUN apk add --update --no-cache curl tzdata python2 python3
 ---> Running in 6ed63b22c022
fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/community/x86_64/APKINDEX.tar.gz
(....)
Removing intermediate container 6ed63b22c022
 ---> 22d58201ed43
Successfully built 22d58201ed43
Successfully tagged test_python_version:latest

$ docker run --rm -ti --entrypoint /bin/sh test_python_version:latest
/ # python3 --version
Python 3.7.5
/ # exit

[hottwister]

And this is my python versions from running container builded with this DockerFile

# docker exec -u root -it elastalert sh
/opt/elastalert-server # python --version
Python 2.7.16
/opt/elastalert-server # python3 --version
Python 3.6.8

[alvarolmedo]

When you build the image used by these container?
Alpine could update this package in some moment between your build and my first build one month ago...
Or, maybe, node:alpine image is in the host when the build is done (the FROM sentence doesn't forces the docker pull action), in this way, I've forced the docker pull of node:alpine and now the python3 version is right respect the info in alpine website[1]:

$ docker build -t test_python_version:latest .
Sending build context to Docker daemon  2.048kB
Step 1/2 : FROM node:alpine
 ---> 364fb8e7f28a
Step 2/2 : RUN apk add --update --no-cache python3
 ---> Running in 9d86ff9da0ea
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz
(...)
(11/11) Installing python3 (3.8.1-r0)
Executing busybox-1.31.1-r8.trigger
OK: 73 MiB in 27 packages
Removing intermediate container 9d86ff9da0ea
 ---> eedaffec0d97
Successfully built eedaffec0d97
Successfully tagged test_python_version:latest

$ docker run --rm -ti --entrypoint /bin/sh test_python_version:latest
/ # python3 --version
Python 3.8.1

[1] https://pkgs.alpinelinux.org/package/edge/main/x86/python3

[Karql]

@alvarolmedo thx for pointing to python version issue.

I've managed with this by:

RUN echo 'http://dl-cdn.alpinelinux.org/alpine/v3.6/main' >> /etc/apk/repositories
RUN apk add --update --no-cache curl tzdata python2 'python3<3.6.9' make libmagic

Karql/elastalert2-server@b2790b2

[alvarolmedo]

Great solution @Karql .

I changed the second base image:

FROM nikolaik/python-nodejs:python3.6-nodejs13-alpine

And a pair of changes more....
The target path changed:

COPY --from=py-ea /usr/local/lib/python3.6/site-packages /usr/local/lib/python3.6/site-packages

And I need to create node user correctly:

RUN addgroup -g 1000 node && \
    adduser -u 1000 -G node -s /bin/sh -D node && \

I don't create a PR with my fix, because I consider it a temporary solution.
So I will change my Dockerfile to your solution.