tell me how can I store PostgreSQL database data in an Azure Storage account. The PostgreSQL deploy to Azure Container Instance. When I restart the Azure Container instance all data disappears.
Dockerfile
FROM timescale/timescaledb:latest-pg12
ENV POSTGRES_USER=admin
POSTGRES_DB=dev-timescaledb
POSTGRES_PASSWORD=password
PGDATA=/var/lib/postgresql/data/pgdata
CMD ["postgres", "-c", "max_connections=500"]
Command for creating a Container Instance and mounting a Storage Account
az container create --resource-group test-env --name test-env --image
test-env.azurecr.io/timescale:latest --registry-username test-env
--registry-password "registry-password" --dns-name-label test-env --ports 5432 --cpu 2 --memory 5 --azure-file-volume-account-name testenv --azure-file-volume-account-key
'account-key'
--azure-file-volume-share-name 'postgres-data' --azure-file-volume-mount-path '/var/lib/postgresql/data'
but i got an error
data directory “/var/lib/postgresql/data/pgdata” has wrong ownership
The server must be started by the user that owns the data directory.
It caused by an existing issue that you cannot change the ownership of the mount point when you mount the Azure File Share to the Container Instance. And it cannot be solved currently. You can find the same issue in SO. I recommend you use the AKS with the disk volume and it will solve the problem for Postgres on persisting data.
Related
I am trying to deploy PostgresDatabase on azure container instance.
To deploy on docker using bind mount(since Azure container Instance only support bind mount) i am using the below command, and it is deployed on docker.
docker run -d -p 5434:5432 --name some-postgres -e POSTGRES_PASSWORD=mysecretpassword -e PGDATA=/var/lib/postgresql/data/pgdata -v /home/ubuntu/volum:/var/lib/postgresql/data postgres
If i do something similar for deploying on Azure container Instance
az container create \
--resource-group $ACI_PERS_RESOURCE_GROUP \
--name postgreariesdb25-1 \
--location eastus \
--image postgres \
--dns-name-label $ACI_DNS_LABEL \
--environment-variables POSTGRES_PASSWORD=mysecretpassword PGDATA=/var/lib/postgresql/data/pgdata \
--ports 5432 \
--azure-file-volume-account-name $ACI_PERS_STORAGE_ACCOUNT_NAME \
--azure-file-volume-account-key $STORAGE_KEY \
--azure-file-volume-share-name $ACI_PERS_SHARE_NAME \
--azure-file-volume-mount-path /var/lib/postgresql/data
I am getting the below message inside logs of Azure Container
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.
The database cluster will be initialized with locale "en_US.utf8".
The default database encoding has accordingly been set to "UTF8".
The default text search configuration will be set to "english".
Data page checksums are disabled.
fixing permissions on existing directory /var/lib/postgresql/data/pgdata ... ok
creating subdirectories ... ok
selecting dynamic shared memory implementation ... posix
selecting default max_connections ... 20
selecting default shared_buffers ... 400kB
selecting default time zone ... Etc/UTC
creating configuration files ... ok
2020-11-24 05:23:39.218 UTC [85] FATAL: data directory "/var/lib/postgresql/data/pgdata" has wrong ownership
2020-11-24 05:23:39.218 UTC [85] HINT: The server must be started by the user that owns the data directory.
child process exited with exit code 1
initdb: removing contents of data directory "/var/lib/postgresql/data/pgdata"
running bootstrap script ...
Volume Mount is required to have data in case of container restart.
This is a known error for mounting Azure File Share to Azure Container Instance. Currently, it does not support to change the ownership of the mount point. If you do not want to use other services, then you need to create a script to move the data to the mount point and the mount point should be a new folder that does not exist in the image. For you, the mount point /var/lib/postgresql/data exists in the image and contains the files that Postgresql depends on, then this point cannot be the mount point.
I'm using this Dockerfile to deploy it on openshift. - https://github.com/sclorg/postgresql-container/tree/master/9.5
It works fine, until I enabled ssl=on and injected the server.crt and server.key file into the postgres pod via volume mount option.
Secret is created like
$ oc secret new postgres-secrets \
server.key=postgres/server.key \
server.crt=postgres/server.crt \
root-ca.crt=ca-cert
The volume is created as bellow and attached to the given BuidlConfig of postgres.
$ oc volume dc/postgres \
--add --type=secret \
--secret-name=postgres-secrets \
--default-mode=0600 \
-m /var/lib/pgdata/data/secrets/secrets/
Problem is the mounted files of secret.crt and secret.key files is owned by root user, but postgres expect it should be owned by the postgres user. Because of that the postgres server won't come up and says this error.
waiting for server to start....FATAL: could not load server
certificate file "/var/lib/pgdata/data/secrets/secrets/server.crt":
Permission denied stopped waiting pg_ctl: could not start server
How we can insert a volume and update the uid:guid of the files in it ?
It looks like this is not trivial, as it requires to set Volume Security Context so all the containers in the pod are run as a certain user https://docs.openshift.com/enterprise/3.1/install_config/persistent_storage/pod_security_context.html
In the Kubernetes projects, this is something that is still under discussion https://github.com/kubernetes/kubernetes/issues/2630, but seems that you may have to use Security Contexts and PodSecurityPolicies in order to make it work.
I think the easiest option (without using the above) would be to use a container entrypoint that, before actually executing PostgreSQL, it chowns the files to the proper user (postgres in this case).
I'm a bit new to Docker.
I have two containers running using docker-compose.
One is the API and the other is the actual application.
I want to add a new DB container using the Postgres official image.
It's a bit hard to find a simple tutorial on how to create the container and populate it with a predefined sql file (of schemas and data).
When I start with "CMD /etc/init.d/postgresql start" in the Dockerfile I get an error saying: "No PostgreSQL clusters exist; see "man pg_createcluster" ... (warning)."
Since it takes me too much time to get things going I was wondering if it might be better to get an Ubuntu image and install Postgres on my own since there is only one source on how to use the image - docker hub, and I don't seem to understand it that well.
Any ideas or simple steps on how to compose and 'configure' this image?
If you want populate your database with some file, A simply way to do this is:
How to extend this image
If you would like to do additional initialization in an image derived
from this one, add one or more *.sql, *.sql.gz, or *.sh scripts under
/docker-entrypoint-initdb.d (creating the directory if necessary).
After the entrypoint calls initdb to create the default postgres user
and database, it will run any *.sql files and source any *.sh scripts
found in that directory to do further initialization before starting
the service.
Dockerfile
FROM postgres:alpine
COPY init.sql /docker-entrypoint-initdb.d/init.sql
docker-compose.yml
version: '3'
services:
app:
//your app definition
postgres:
build: .
Pull the postgres image
docker pull postges:14.2
Create the service with the below command
docker service create --name postgres --network my_overlay --env "POSTGRES_PASSWORD=password" --publish 5432:5432 postgres:14.2
Try to connect using userName as postgres and password as password to the default postgres db.
jdbc:postgresql://127.0.0.1:5432/postgres // JDBC connection
I have a data only postgresql container
docker create -v /var/lib/postgresql/data --name bevdata mdillon/postgis /bin/true
I have a running Postgis container
docker run --name bevaddress -e POSTGRES_USER=bevsu -e POSTGRES_DB=bevaddress -P -d --volumes-from bevdata mdillon/postgis
I have made a backup of that database into the bavaddress container into directory /var/lib/postgresql/backup
I think this means that the backup data is in container bevaddress (the running process) and NOT the data only container bevdata which I think is good.
Now if I docker pull mdillon/postgis to a new version, how can I attach the folder /var/lib/postgresql/backup of container bevaddress so that a new instance and version of mdillon/postgis can access that folder to restore the database?
To the best of my knowledge, you cannot. The file system in your running container only exists for the duration of the run. Without mounting a volume, you have no way to allow a second container access to the backup.
For future backups, you could create a second volume only container that mounts /var/lib/postgresql/backup.
I'm using the stock official Postgres image from Docker Hub. docker pull postgres. I wanted to map the data directory in the Postgres container to my OS X host. So, I tried this.
docker run --rm -p 5432:5432 -e POSTGRES_PASSWORD=mypass -v `pwd`/data:/var/lib/postgresql/data postgres
This resulted in the Postgres container failing to launch correctly.
fixing permissions on existing directory /var/lib/postgresql/data ... ok
creating subdirectories ... initdb: could not create directory "/var/lib/postgresql/data/global": Permission denied
initdb: removing contents of data directory "/var/lib/postgresql/data"
The goal I'm trying to achieve is to have my database data stored on the host machine, so that I can start a postgres container and have it read (or load) the database from a previous instance. Am I on the right track or is this a stupid way to achieve database persistence?
According to official documentation you should use boot2docker to resolve the issue. However, without it, you won't be able to mount container.