Learning postgres using podman
I thought of learning postgres. Instead of installing in the host machine how difficult it would be to spin up the container. Let’s find out.
Installing podman
- I installed the podman that is available in ubuntu repo
sudo apt install podman- Note: you won’t get the latest podman
Let’s check podman
- Let’s pull the postgres container
podman pull postgres- Nothing happened, so i tried
podman search postgreswhich gave me the following error
ERRO[0000] User-selected graph driver "vfs" overwritten by graph driver "overlay" from database - delete libpod local files to resolve - After some googling and github issue surfing i found
fuse-overlayfsis missing in my system, which caused the above error
sudo apt install fuse-overlayfs- Only install this if you face error, by default it should be installed along with podman.
- source: https://unix.stackexchange.com/questions/701784/podman-no-longer-searches-dockerhub-error-short-name-did-not-resolve-to-an
Pod initialize
- we will spin the container inside the pod, later if we want we can migrate it to kubernetes :p.
- Creating the pod
podman pod create --name postgres-pod -p 9876:80- Install postgres in the pod
podman run --pod=postgres-pod \
-v ~/Documents/Postgres:/var/lib/postgresql/data \
-e POSTGRES_PASSWORD=goldayan \
-e POSTGRES_USER=goldayan \
--name db \
-d postgres- I got the following error
short-name "postgres" did not resolve to an alias and no unqualified-search registries are defined in "/etc/containers/registries.conf" - I found the answer for this issue in the following stackoverflow answer, https://unix.stackexchange.com/questions/701784/podman-no-longer-searches-dockerhub-error-short-name-did-not-resolve-to-an
NOTE: RISK OF USING UNQUALIFIED IMAGE NAMESWe recommend always using fully qualified image names including the registry server (full dns name), namespace, image name, and tag (e.g., registry.redhat.io/ubi8/ubi:latest). Pulling by digest (i.e., quay.io/repository/name@digest) further eliminates the ambiguity of tags- Run the following command, let’s replace postgres with docker.io/postgres.
- Telling it to fetch the image from docker.io registery.
podman run --pod=postgres-pod \
-v ~/Documents/Postgres:/var/lib/postgresql/data \
-e POSTGRES_PASSWORD=goldayan \
-e POSTGRES_USER=goldayan \
--name db \
-d docker.io/postgres- pgadmin web version
podman run --pod=postgres-pod \
-e 'PGADMIN_DEFAULT_EMAIL=me@goldayan.in' \
-e 'PGADMIN_DEFAULT_PASSWORD=goldayan' \
--name pgadmin \ # name the container
-d docker.io/dpage/pgadmin4 # the image we are pulling- Login to pgadmin using the following url
localhost:9876 - Enter the creds, same as what you given for PGADMIN_DEFAULT_EMAIL and PGADMIN_DEFAULT_PASSWORD when running pgadmin container
- After SignIn, Press add new server
- Give any name for the server and for the connection type
localhostfor server and5432as port number. - Maintenance database will be postgres by default.
- Username and password will be what you specified in the POSTGRES_USER and POSTGRES_PASSWORD when running postgres container.
- Press save.
Pod commands
- Status of the pod
podman pod stats postgres-pod- Pause and unpause the pod
podman pod pause postgres-pod
podman pod unpause postgres-pod- Start and stop the pod
podman pod start postgres-pod
podman pod stop postgres-pod- Last but not least, generate kubeconfig from the pod
podman generate kube postgres-pod >> postgres-pod-conf.ymlLog into postgres container
- we will log into the postgres container and use the psql command
podman exec -it db bash- psql command to connect to the db
psql -U goldayan- we use goldayan because that is the username we used previously during creating postgres container.
When importing csv file in pgadmin
- Before I upload the csv file i removed the header
- Select the upload csv file then press import, voila… imported.
Reset the podman [WARN]
- To delete all the images, containers, pods and cache
podman system reset- Just delete containers
sudo rm -rf ~/.local/share/containers/