Loading a Data Container allows you to run your Data Container (database) with the data saved at a moment in time.
In this tutorial we will create a Data Image, then create a Data Container from that image. We will then make some changes to the Data Container and save those changes. After this we will load the previous revision and inspect the Data Container.
As a prerequisite you should've followed the instructions to install spawnctl
Create a file
development.yamlwith your Data Image specifications.sourceType: emptyname: devengine: postgresqlversion: 11.0
In this case we want to create a PostgreSQL Data Image that is completely empty and is named
Run the following command to create a Data Image.$ spawnctl create data-image -f ./development.yamlData image 'dev' created!
You can verify your Data Image by running the following command.$ spawnctl get data-imagesNAME IMAGE ID ENGINE STATUS MESSAGE CREATEDdev 10001 PostgreSQL 2 Created 2 minutes ago
Create a Data Container from the newly created Data Image.$ spawnctl create data-container --image devData container 'dev-rambbomj' created!-> Host=instances.spawn.cc;Port=53223;User ID=<some_user_id>;Password=<some_password>;
You can verify your Data Container was properly created by running the following command.
Notice the created Data Container has revision
rev.0.$ spawnctl get data-containersNAME CONTAINER ID REVISION STATUS MESSAGE ENGINE CREATEDdev-rambbomj 10001 rev.0 2 Running PostgreSQL 1 minute ago
You should now be able to connect to your database and execute queries.
In this example we connect to the PostgreSQL Data Container (database) using psql.$ psql -h instances.spawn.cc -p 53223 -U <some_user_id>Password for user <some_user_id>:psql (10.5, server 11.0 (Debian 11.0-1.pgdg90+2))SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)Type "help" for help.<some_user_id>=# CREATE TABLE customers(id INT);CREATE TABLE<some_user_id>=# \dtList of relationsSchema | Name | Type | Owner--------+-----------+-------+------------------public | customers | table | <some_user_id>(1 row)
We can now perform a save operation on this Data Container.$ spawnctl save data-container devSaving container....Data container 'dev-rambbomj' saved!New revision is 'rev.1'
You can now load the Data Container at revision
rev.0.$ spawnctl load data-container dev-rambbomj --revision=rev.0Data container 'dev-rambbomj' loaded!New revision is 'rev.0-ciys.0'
Notice that your existing Data Container now has revision
You can now connect to this Data Container (database) and verify its content.$ psql -h instances.spawn.cc -p 53223 -U <some_user_id>psql (10.5, server 11.0 (Debian 11.0-1.pgdg90+2))SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)Type "help" for help.<some_user_id>=# \dtDid not find any relations.
Notice that there are no relations even though our Data Container at revision
rev.1had one table