Can you use property subsitution in liquibase changelog? - postgresql

Question

I am using github actions to run my liquibase deployments. I have variables that I want to substitute into my liquibase script during deployment the liquibase article here states that this should be possible. I have a changelog.json that simply includes the sql files like so:
"databaseChangeLog": [
{
"include":{"file": "path-to-sql/my_file.sql"}
}
]
now in my_file.sql I have:
--changeset author:1
create user my-user with password ${MY_ENV};
However, I receive the error:
Unexpected error running Liquibase: Migration failed for changeset my_file.sql:
Reason: liquibase.exception.DatabaseException: ERROR: syntax error at or near "$"...
Any one come across this specific error with variable substitution? Is this just a syntax error? Thanks.

Answer 1

You can use the -d parameter,
-D<property.name>=<property.value> Pass a name/value pair for substitution of ${} blocks in the changelogs.
For example:
--liquibase formatted sql
--changeset your.name:1 labels:example-label context:example-context
--comment: example comment
create table ${daTableName} (
id int primary key auto_increment not null,
name varchar(50) not null,
address1 varchar(50),
address2 varchar(50),
city varchar(30)
)
--rollback DROP TABLE ${daTableName};
And the command:
liquibase update -DdaTableName=MySofExampleTable
Did work for me
Note that this approach will log your variables in Github actions, and in your case the value represents a password so be carful with that, or you add this value to your liquibase.properties file, for example
parameter.daTableName=SomeTable
then you just run your liquibase commands without passing the -d parameter.
From Github actions side, you would fetch the secret, and ammend it to your properties file, for example:
jobs:
foo:
runs-on: ubuntu-latest
steps:
- run: echo "liquibase.MY_ENV=${{ secrets.MY_SECRET }}" >> liquibase.properties
Or as a plan-B for some use-cases, you can use envsubst to replace your environment variables, for example:
jobs:
foo:
runs-on: ubuntu-latest
steps:
- run: echo "create user my-user with password \${MY_ENV};" > my-migration.template.sql
- run: envsubst < my-migration.template.sql > my-migration.sql
env:
MY_ENV: bob
- run: cat my-migration.sql
Result:
So you basically create actions (or scripts) that replace your environment variables, if you have multiple files you may do something like:
for f in $(find ./lqb-src -regex '.*\.sql'); do envsubst < $f > "./lqb-out/$(basename $f)"; done