Docker Desktop预填充PostGIS+OSM正常，Azure Pipeline构建后数据库为空

本地构建正常场景 #

在Windows笔记本手动执行以下Docker构建命令后，生成的PostGIS镜像可正常预填充OSM数据，Docker Desktop启动容器后数据库数据存在：

docker build -f Dockerfile --no-cache --tag my-postgis:16-3.4 \
    --build-arg DOWNLOAD_URLS="https://download.geofabrik.de/europe/germany/berlin-latest.osm.pbf https://download.geofabrik.de/europe/germany/hamburg-latest.osm.pbf" \
    --build-arg OSM_PASSWORD=osm_password \
    --build-arg POSTGIS_TAG=16-3.4 .

Azure Pipeline构建异常场景 #

通过Azure Pipeline执行以下构建脚本，将镜像推送到ACR后，拉取镜像在Kubernetes中启动时，数据库文件夹为空：

- task: AzureCLI@2
  displayName: Build and push PostGIS image
  inputs:
    azureSubscription: $(ArmConnection)
    scriptType: bash
    scriptLocation: inlineScript
    inlineScript: |
      image_tag='$(ContainerRegistry)/postgis-${{ parameters.OsmRegion }}:${{ parameters.PostGisTag }}'
      # delete old images to avoid the error "no space left on device"
      docker system prune --all --force
      docker build --file $(Build.SourcesDirectory)/src/Services/PostGIS/Dockerfile --no-cache --tag $image_tag --build-arg POSTGIS_TAG=${{parameters.PostGisTag}} --build-arg OSM_PASSWORD=$(OsmPassword) --build-arg DOWNLOAD_URLS="$(DownloadUrls)" $(Build.SourcesDirectory)/src/
      # building the Docker image takes longer time, so be sure to acr login just before pushing the image
      az acr login -n $(ContainerRegistry)
      docker push $image_tag

背景说明 #

已知在docker build阶段启停服务并非推荐做法，但因生产环境使用28GB的europe-latest.osm.pbf，若在/docker-entrypoint-initdb.d中执行脚本会导致Pod启动耗时数小时，故采用当前构建时预填充数据的方案。相关Dockerfile参考postgis/docker-postgis模板编写，内容如下：

ARG POSTGIS_TAG
FROM postgis/postgis:$POSTGIS_TAG
EXPOSE 5432

# Install ps, top, netstat, curl, wget, osmium, osm2pgsql
RUN apt-get update && \
    apt-get upgrade -y && \
    apt install -y procps net-tools curl wget osmium-tool osm2pgsql

WORKDIR /data
RUN chown -R postgres:postgres /data
USER postgres

# Download one or multiple OSM files
ARG DOWNLOAD_URLS
RUN wget $DOWNLOAD_URLS
# Print summaries of the downloaded OSM files
RUN for f in *.osm.pbf; do osmium fileinfo -e "$f"; done
# Merge one or multiple files into a new file map.osm.pbf
RUN osmium merge *.osm.pbf -o map.osm.pbf
# Remove all files except the map.osm.pbf
RUN find . -type f -name '*.osm.pbf' | grep -v 'map.osm.pbf' | xargs rm -f

ARG OSM_PASSWORD
ENV PGPASSWORD=$OSM_PASSWORD
ENV PGUSER=osm_user
ENV PGDATABASE=osm_database
ENV PGDATA=/var/lib/postgresql/data

# create PostgreSQL instance in the $PGDATA folder
# configure PostgreSQL as recommended by osm2pgsql doc
# start PostgreSQL and create database and user
# load data from the map.osm.pbf file into the database
# remove the map.osm.pbf file and stop PostgreSQL
# configure password based access for osm_user
RUN set -eux && \
    pg_ctl init && \
    echo "shared_buffers = 1GB"                >> $PGDATA/postgresql.conf && \
    echo "work_mem = 50MB"                     >> $PGDATA/postgresql.conf && \
    echo "maintenance_work_mem = 10GB"         >> $PGDATA/postgresql.conf && \
    echo "autovacuum_work_mem = 2GB"           >> $PGDATA/postgresql.conf && \
    echo "wal_level = minimal"                 >> $PGDATA/postgresql.conf && \
    echo "checkpoint_timeout = 60min"          >> $PGDATA/postgresql.conf && \
    echo "max_wal_size = 10GB"                 >> $PGDATA/postgresql.conf && \
    echo "checkpoint_completion_target = 0.9"  >> $PGDATA/postgresql.conf && \
    echo "max_wal_senders = 0"                 >> $PGDATA/postgresql.conf && \
    echo "random_page_cost = 1.0"              >> $PGDATA/postgresql.conf && \
    echo "password_encryption = scram-sha-256" >> $PGDATA/postgresql.conf && \
    pg_ctl start && \
    createuser --username=postgres $PGUSER && \
    createdb --username=postgres --encoding=UTF8 --owner=$PGUSER $PGDATABASE && \
    psql --username=postgres $PGDATABASE --command="ALTER USER $PGUSER WITH PASSWORD '$PGPASSWORD';" && \
    psql --username=postgres $PGDATABASE --command='CREATE EXTENSION IF NOT EXISTS postgis;' && \
    psql --username=postgres $PGDATABASE --command='CREATE EXTENSION IF NOT EXISTS hstore;' && \
    osm2pgsql --username=$PGUSER --database=$PGDATABASE --create --cache=60000 --hstore --latlong /data/map.osm.pbf && \
    rm -f /data/map.osm.pbf && \
    pg_ctl stop && \
    echo '# TYPE DATABASE USER ADDRESS METHOD'                > $PGDATA/pg_hba.conf && \
    echo "local all postgres peer"                           >> $PGDATA/pg_hba.conf && \
    echo "local $PGDATABASE $PGUSER           scram-sha-256" >> $PGDATA/pg_hba.conf && \
    echo "host  $PGDATABASE $PGUSER 0.0.0.0/0 scram-sha-256" >> $PGDATA/pg_hba.conf

该问题已同步至docker-postgis的GitHub讨论区。

内容的提问来源于stack exchange，提问作者Alexander Farber