Added pg_cron to Alpine Linux

[gjrtimmer]

I've added pg_cron to the Alpine Linux distribution; this because alpine is heavily used within docker environments, so pg_cron can be used within a docker container which runs postgresql on Alpine.

Currently it's only available for the latest 'edge' branch under testing. https://pkgs.alpinelinux.org/packages?name=pg_cron&branch=&repo=&arch=&maintainer=

Architectures:

• aarch64
• armhf
• x86
• x86_64

Question: Currently the latest version is a release candidate, is there any information when the final 1.0.0 will be released ?

[marcocitus]

Awesome!

Currently the latest version is a release candidate, is there any information when the final 1.0.0 will be released ?

Should be in the next 2 weeks.

[gjrtimmer]

@marcocitus great to know the final will be released soon. I suggest to keep this issue open until then. Can you send a message or update this issue so I will get a notification. So I can update the alpine package?

Thanks in advance. Gert

[gjrtimmer]

@marcocitus are you still on schedule for the 1.0.0 final release ?

[letientai299]

Bump. Coming here looking for an easy solution for install pg_cron on alpine or ubuntu.

I've tried apk add --update pg_cron but it's didn't work. Any update on this, please?

[marcocitus]

Coming here looking for an easy solution for install pg_cron on alpine or ubuntu.

Ubuntu packages are available from: https://wiki.postgresql.org/wiki/Apt Alpine packages are available from: https://pkgs.alpinelinux.org/packages?name=pg_cron&branch=&repo=&arch=&maintainer=

Current version is 1.0.2

[danigosa]

You can build it directly with this script (tested on alpine 3.6 and 3.7), concretely with the official postgres-alpine image postgres:10.1-alpine:

PG_CRON_VERSION=1.0.2
apk add --no-cache --virtual .build-deps build-base ca-certificates openssl tar \
    && wget -O /pg_cron.tgz https://github.com/citusdata/pg_cron/archive/v$PG_CRON_VERSION.tar.gz \
    && tar xvzf /pg_cron.tgz && cd pg_cron-$PG_CRON_VERSION \
    && sed -i.bak -e 's/-Werror//g' Makefile \
    && sed -i.bak -e 's/-Wno-implicit-fallthrough//g' Makefile \
    && make && make install \
    && cd .. && rm -rf pg_cron.tgz && rm -rf pg_cron-*

[letientai299]

That's what I'm doing right now for our postgres docker image.

@marcocitus, @GJRTimmer pg_cron package ver 1.0.2-r0 is only available on edge branch, which is suposingly not stable enough for production usage. Please consider add it to v3.7 or v3.6 if you consider the package is production ready.

[photz]

I'm using the following Dockerfile to add pg_cron to the Postgres image based on Ubuntu:

FROM postgres:9.6

# Follow the instructions on https://wiki.postgresql.org/wiki/Apt
# to install pg_cron
RUN sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
RUN apt-get update
RUN apt-get install -y wget ca-certificates
RUN wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
RUN apt-get update
RUN apt-get install -y postgresql-9.6-cron

CMD ["-c", "cron.database_name=app", "-c", "shared_preload_libraries=pg_cron"]

It works but being a relatively inexperienced Docker user, I haven't yet managed to make database_name configurable through an environment variable. Maybe someone here knows how to improve on this.

[dereisele]

If you're wondering how the Alpine page is called: postgresql-pg_cron in community/edge: https://pkgs.alpinelinux.org/packages?name=postgresql-pg_cron

Install: apk add postgresql-pg_cron --repository=http://dl-cdn.alpinelinux.org/alpine/edge/community

[mlegenhausen]

For pg_cron 1.3.0 you can use this slightly modified version from @danigosa

FROM postgres:13-alpine

ENV PG_CRON_VERSION 1.3.0

RUN apk add --no-cache --virtual .build-deps build-base ca-certificates clang-dev llvm10 openssl tar \
    && wget -O /pg_cron.tgz https://github.com/citusdata/pg_cron/archive/v$PG_CRON_VERSION.tar.gz \
    && tar xvzf /pg_cron.tgz && cd pg_cron-$PG_CRON_VERSION \
    && sed -i.bak -e 's/-Werror//g' Makefile \
    && sed -i.bak -e 's/-Wno-implicit-fallthrough//g' Makefile \
    && make && make install \
    && cd .. && rm -rf pg_cron.tgz && rm -rf pg_cron-* \
    && apk del .build-deps

CMD ["-c", "shared_preload_libraries=pg_cron", "-c", "cron.database_name=postgres"]

[wrossmann]

If you're pushing these images into a registry or would otherwise like to save ~160MB [all those build deps you installed] on your image size, use a multistage build and only copy the pg_cron.so into the final image. Eg:

FROM postgres:XX-alpine as build
ENV ...
RUN ...

FROM postgres:XX-alpine as release
COPY --from=build /usr/local/lib/postgresql/pg_cron.so /usr/local/lib/postgresql/pg_cron.so

[hanefi]

If you're pushing these images into a registry or would otherwise like to save ~160MB [all those build deps you installed] on your image size, use a multistage build and only copy the pg_cron.so into the final image.

Having the .so is not enough. The following files are also needed:

• .control file to show the default version and package name
• .sql files for schema migrations on extension updates

[habibcefal0]

For pg_cron 1.3.0 you can use this slightly modified version from @danigosa

FROM postgres:13-alpine

ENV PG_CRON_VERSION 1.3.0

RUN apk add --no-cache --virtual .build-deps build-base ca-certificates clang-dev llvm10 openssl tar \
    && wget -O /pg_cron.tgz https://github.com/citusdata/pg_cron/archive/v$PG_CRON_VERSION.tar.gz \
    && tar xvzf /pg_cron.tgz && cd pg_cron-$PG_CRON_VERSION \
    && sed -i.bak -e 's/-Werror//g' Makefile \
    && sed -i.bak -e 's/-Wno-implicit-fallthrough//g' Makefile \
    && make && make install \
    && cd .. && rm -rf pg_cron.tgz && rm -rf pg_cron-* \
    && apk del .build-deps

CMD ["-c", "shared_preload_libraries=pg_cron", "-c", "cron.database_name=postgres"]

Hi.. does it work for 'postgres:12-alpine'. I used PG_CRON_VERSION=1.2.0 but the postgesql.conf file didn't change.

[inikolaev]

Does this package work or am I missing some extra steps to set it up? Here's my Dockerfile:

FROM public.ecr.aws/docker/library/postgres:13-alpine

RUN apk add postgresql-pg_cron

CMD ["-c", "shared_preload_libraries=pg_cron", "-c", "cron.database_name=postgres", "-c", "log_statement=all"]

But when container is started I'm getting the following error:

PostgreSQL Database directory appears to contain a database; Skipping initialization

2022-12-19 10:17:20.827 UTC [97] FATAL:  could not access file "pg_cron": No such file or directory
2022-12-19 10:17:20.827 UTC [97] LOG:  database system is shut down

The pg_cron.so is installed /usr/lib/postgresql14/pg_cron.so:

-rwxr-xr-x    1 root     root         71792 Nov 12  2021 pg_cron.so
-rwxr-xr-x    1 root     root         22192 Aug 15 00:19 pgoutput.so
-rwxr-xr-x    1 root     root        198400 Aug 15 00:19 plpgsql.so

pg_cron.control is present at /usr/share/postgresql14/extension/pg_cron.control along with .sql files:

comment = 'Job scheduler for PostgreSQL'
default_version = '1.4'
module_pathname = '$libdir/pg_cron'
relocatable = false

[CyberDem0n]

FROM public.ecr.aws/docker/library/postgres:13-alpine The pg_cron.so is installed /usr/lib/postgresql14/pg_cron.so:

For me it looks like the pg_cron package is built for Postgres 14, and you can't use it with 13.

[inikolaev]

That explains why I managed to make it work with PostgreSQL 15, though I still had to make some adjustments:

RUN apk add --no-cache postgresql-pg_cron sudo \
    && cp /usr/lib/postgresql15/pg_cron.so /usr/local/lib/postgresql/ \
    && cp /usr/share/postgresql/extension/* /usr/local/share/postgresql/extension

[inikolaev]

So I guess I should either try another PostgreSQL base image or build pg_cron from source.

[sepsol]

@gjrtimmer Seems like the package is no longer available? https://pkgs.alpinelinux.org/packages?name=pg_cron&branch=edge&repo=&arch=&maintainer=