A minimalistic Postgresql 9.4.1.0 image
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This is a minimal postgres 9.4.1.0 server image. The server is built from source, with make world (thus containing the standard extensions).
A container built from this image depends on communitycloud/postgres-data:9.4 image with data. To run the server:
docker create --name pgdata -v /var communitycloud/postgres-data :
docker run --rm -it --volumes-from pgdata -u 1000 -p 5432:5432 communitycloud/postgres -D /var/pgsql/data
Note the : at the end of the docker create command is the minimal command; since the container only exists to seed the data volume and contains no binaries, this is the simplest command that docker will allow when creating a container.
Optionally, one can modify the configuration files after creating the container, but before starting the server. Mount the data container's volume from a stock distribution that contains an editor, and then edit the config files in /var/pgsql/data:
docker run --rm -it --volumes-from pgdata debian:jessie /bin/bash
# vim /var/pgsql/data/pg_hba.conf
...
This image was built by hand on the scractch base to incorporate only the postgres binary and the libraries it depends on.
The build process is like this:
docker run --rm \
--name pg-builder \
--hostname pg-builder \
-v /var/run/docker.sock:/var/run/docker.sock \
-it communitycloud/docker-builder
communitycloud/docker-builder is a bare-bones Debian jessie official image with a statically compiled docker 1.4.1 binary copied into it.
To get the latest Postgres stuff, we'll need to add postgres sources first to apt, as described on the postgres wiki:
echo "deb http://apt.postgresql.org/pub/repos/apt/ jessie-pgdg main" > /etc/apt/sources.list.d/pgdg.list \
&& apt-get update && DEBIAN_FRONTEND=noninteractive \
&& apt-get install -y wget ca-certificates sudo \
&& wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add - \
&& apt-get update \
&& apt-get install -y build-essential tree strace libreadline-dev libncurses5-dev \
libpcre3-dev libssl-dev perl libpq-dev libossp-uuid-dev locales
Now that we have all prerequisites, building Postgres is fairly straightforward. We'll use /opt as the root:
wget https://ftp.postgresql.org/pub/source/v9.4.1/postgresql-9.4.1.tar.bz2 \
&& bunzip2 postgresql-9.4.1.tar.bz2 \
&& tar -xf postgresql-9.4.1.tar \
&& rm postgresql-9.4.1.tar \
&& cd postgresql-* \
&& ./configure \
--prefix=/opt/pgsql \
--with-openssl \
--with-ossp-uuid \
&& make world \
&& make install-world \
&& cd .. \
&& rm -rf postgresql-* \
&& ldconfig
Remove unnecessary stuff:
rm -r /opt/pgsql/include/ /opt/pgsql/lib/pgxs /opt/pgsql/share/{doc,man}
cd / \
&& tar cf pgsql.tar \
/opt/pgsql/bin/postgres \
/opt/pgsql/lib/ \
/opt/pgsql/share/
In addition, we'll need all libraries that the postgres binary and the extensions link to:
ldd /opt/pgsql/bin/postgres /opt/pgsql/lib/*.so \
| grep -v '^/' \
| awk 'BEGIN{ORS=" "}$1~/^\//{print $1}$3~/^\//{print $3}' \
| sed 's/ /\n/g; s/_at\n/_at /g' \
| sort | uniq \
| tar rhf pgsql.tar -T -
This command figures out which libraries the binary depends on and collects them into a tar file. The h flag in tar dereferences all symlinks and imports the target files instead.
It turns out that Postgres also needs this file when running in a container:
tar rhf /pgsql.tar /lib/x86_64-linux-gnu/libnss_files.so.2
While we are at it, let's help our container find the libraries faster, and a few more files it wants, as we gleaned from the strace output:
tar rf /pgsql.tar /etc/ld.so.cache /etc/host.conf /etc/gai.conf \
/etc/nsswitch.conf /etc/protocols
Next, we need the postgres user in /etc.
mkdir -p /tmp/etc; cd tmp \
&& echo 'postgres:x:1000:1000::/home/postgres:/bin/sh' > etc/passwd \
&& echo 'postgres:x:1000:' > etc/group \
&& echo 'postgres:!:16452:0:99999:7:::' > etc/shadow \
&& echo 'postgres:!::' > etc/gshadow \
&& tar rf /pgsql.tar etc/
Since we mounted the docker client and a socket to the docker server, we can build the runtime image directly from the builder:
rm -rf /images/pgsql \
&& mkdir -p /images/pgsql && cp /pgsql.tar /images/pgsql \
&& cd /images/pgsql \
&& cat > Dockerfile <<EOF
FROM scratch
ADD pgsql.tar /
EXPOSE 5432
ENV PGDATA=/var/pgsql/data
ENTRYPOINT ["/opt/pgsql/bin/postgres"]
EOF
docker build -t pgsql .
The container must run as uid 1000, which will translate into the postgres user inside the container.
docker run --rm -u 1000 pgsql --version
=> postgres (PostgreSQL) 9.4.1
|-- etc
|-- lib
| `-- x86_64-linux-gnu
|-- lib64
|-- opt
| `-- pgsql
| |-- bin
| |-- lib
| | `-- pkgconfig
| `-- share
| |-- extension
| |-- timezone
| | |-- Africa
| | |-- America
| | | |-- Argentina
| | | |-- Indiana
| | | |-- Kentucky
| | | `-- North_Dakota
| | |-- Antarctica
| | |-- Arctic
| | |-- Asia
| | |-- Atlantic
| | |-- Australia
| | |-- Brazil
| | |-- Canada
| | |-- Chile
| | |-- Etc
| | |-- Europe
| | |-- Indian
| | |-- Mexico
| | |-- Pacific
| | `-- US
| |-- timezonesets
| `-- tsearch_data
`-- usr
`-- lib
`-- x86_64-linux-gnu
Content type
Image
Digest
sha256:c5bc9fa6f…
Size
8.3 MB
Last updated
over 10 years ago
docker pull communitycloud/postgres