Timezones in Alpine Docker Containers
June 14, 2021
In the evening I noticed the container I was running to create my tumblelog Plurrrr ran in timezone GMT, not GMT + 2:00. Excerpt from the generated JSON feed:
...
"date_published": "2021-06-14T23:59:59+00:00",
"id": "https://plurrrr.com/archive/2021/06/14.html",
...
Adding the tzdata package to the installation step in the Docker image:
# syntax=docker/dockerfile:1
FROM alpine:latest AS base
WORKDIR /app
FROM base AS builder
RUN apk add --no-cache --virtual .build-deps \
make wget gcc musl-dev perl-dev \
perl-app-cpanminus \
&& apk add perl cmark-dev tzdata \
&& cpanm URI JSON::XS YAML::XS Path::Tiny CommonMark Try::Tiny \
&& apk del .build-deps
FROM base AS run
COPY --from=builder /usr/bin/perl /usr/bin
COPY --from=builder /usr/lib/ /usr/lib/
COPY --from=builder /usr/share /usr/share
COPY --from=builder /usr/local /usr/local
COPY tumblelog.pl .
WORKDIR /data
ENTRYPOINT ["perl", "/app/tumblelog.pl"]
And adding an environment variable to the docker run command solved this issue. In my case I used -e TZ="Europe/Amsterdam". Example of how I run
the Perl version of tumblelog:
docker run --rm --volume "`pwd`:/data" --user `id -u`:`id -g` \
-e TZ="Europe/Amsterdam" \
tumblelog/perl --template-filename plurrrr.html \
--author 'John Bokma' \
--description "John Bokma's tumblelog" \
--blog-url https://plurrrr.com/ \
--date-format '%a %d %b %Y' \
--tags \
--name 'Plurrrr' \
--output-dir htdocs \
--css soothe.css \
--quiet \
plurrrr.md