pg-migrator

Small CLI tool to run PostgreSQL migrations/dumps between two databases. Entrypoint: main.main. Core logic lives in Migrator.Migrate and the dump/restore implementation is in Migrator.DumpDatabase. Relevant files: main.go, Dockerfile, go.mod, pg-migrator, kubernetes/job.yaml, kubernetes/configmap.yaml, kubernetes/secret.yaml.

Prerequisites

• Go (to build locally) or Docker (to run container)
• kubectl + access to a cluster (for Kubernetes)
• If running the built binary locally, ensure pg_dump and pg_restore are available in PATH (the official Docker image includes them).

Quick CLI (local) build and run

1. Build the binary:

go build -o pg-migrator main.go

2. Run the CLI. Required flags are shown in the binary (see main.main). Example:

./pg-migrator \
  -src-host=SRC_HOST -src-port=5432 -src-user=SRC_USER -src-password=SRC_PASSWORD \
  -dst-host=DST_HOST -dst-port=5432 -dst-user=DST_USER -dst-password=DST_PASSWORD \
  -dump-dir=/tmp/pg_migration

Flags available (defined in main.go):

• -src-host, -src-port, -src-user, -src-password
• -dst-host, -dst-port, -dst-user, -dst-password
• -dump-dir

Note: the binary uses external commands (pg_dump / pg_restore) via exec (see Migrator.DumpDatabase), so they must be present when running locally.

Build Docker image The repository includes a multi-stage Dockerfile that builds a static Go binary and uses the official Postgres image (so pg_dump/pg_restore are available).

Build:

docker build -t registry.your.domain/pg-migrator/pg-migrator:latest .

Dockerfile: Dockerfile

Run container locally (example):

docker run --rm \
  -e SRC_HOST=... -e SRC_PORT=5432 -e SRC_USER=... -e SRC_PASSWORD=... \
  -e DST_HOST=... -e DST_PORT=5432 -e DST_USER=... -e DST_PASSWORD=... \
  registry.your.domain/pg-migrator/pg-migrator:latest \
  -dump-dir=/tmp/pg_migration

Push to registry:

docker push registry.your.domain/pg-migrator/pg-migrator:latest

Kubernetes usage Manifests are provided under kubernetes/. See:

• kubernetes/configmap.yaml
• kubernetes/secret.yaml
• kubernetes/job.yaml

The Job mounts an emptyDir at /tmp/pg_migration and passes flags from environment variables. To deploy:

1. Edit kubernetes/configmap.yaml and kubernetes/secret.yaml for your environment (or create equivalents).
2. Update the image tag in kubernetes/job.yaml if you built a custom image.
3. Apply manifests:

kubectl apply -f kubernetes/configmap.yaml
kubectl apply -f kubernetes/secret.yaml
kubectl apply -f kubernetes/job.yaml

4. Watch job and fetch logs:

kubectl get jobs -n default
kubectl logs job/pg-migration-job -n default

Important details from the manifests

• The Job disables retries: backoffLimit: 0 and uses ttlSecondsAfterFinished: 86400 to clean up after 24 hours (see kubernetes/job.yaml).
• The Job sets env vars from the ConfigMap and Secret (see kubernetes/job.yaml, kubernetes/configmap.yaml, kubernetes/secret.yaml).
• Dumps are written to an emptyDir with a 10Gi size limit (see kubernetes/job.yaml).

Troubleshooting

• If running locally and you see pg_dump/pg_restore errors, install the Postgres client tools or run the provided Docker image which includes them.
• If the Job cannot pull the image, verify the image name and registry credentials.
• Logs from the binary include success/failure messages from Migrator.MigrateDatabases (see Migrator.MigrateDatabases).

References

• Entrypoint: main.main — main.go
• Dump logic: Migrator.DumpDatabase — main.go
• Migration orchestration: Migrator.Migrate / Migrator.MigrateDatabases — main.go
• Dockerfile: Dockerfile
• Go module: go.mod
• Kubernetes manifests: kubernetes/job.yaml, kubernetes/configmap.yaml, kubernetes/secret.yaml
• Prebuilt binary in repo: pg-migrator