Use specific versions of images

.gitlab/ci/hydra/Dockerfile

@@ -3,7 +3,7 @@
 
 # This Dockerfile is only used for testing CI/CD testing and is not used in
 # production.
-FROM oryd/hydra:latest
+FROM oryd/hydra:v1.10.7-alpine
 
 # Set DSN in Dockerfile, as services variables in CI/CD testing as shared
 # between services and the DSN is different for different services.

.gitlab/ci/kratos/Dockerfile

@@ -3,7 +3,7 @@
 
 # This Dockerfile is only used for testing CI/CD testing and is not used in
 # production.
-FROM oryd/kratos:latest
+FROM oryd/kratos:v0.8.0-alpha.3
 
 # Set DSN in Dockerfile, as services variables in CI/CD testing as shared
 # between services and the DSN is different for different services.

.gitlab/ci/postgres/Dockerfile

@@ -4,7 +4,7 @@
 # This Dockerfile is only used for testing CI/CD testing and is not used in
 # production.
 
-FROM postgres:latest
+FROM postgres:bullseye
 
 # Copy our setup SQL to the image to create databases at setup/first run
 COPY setup.sql /docker-entrypoint-initdb.d/setup.sql