From 5bc985b2a66f618a688482b886c3400753a2f906 Mon Sep 17 00:00:00 2001
From: Maximilian Kratz <account@maxkratz.com>
Date: Wed, 29 Mar 2023 06:49:22 +0200
Subject: [PATCH] Documents the S3 migration process

---
 inventory/hosts.example    |  1 +
 s3-migration/.gitignore    |  4 +++
 s3-migration/MIGRATION.md  | 50 ++++++++++++++++++++++++++++++++++++++
 s3-migration/migrate-s3.sh |  2 +-
 4 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 s3-migration/.gitignore
 create mode 100644 s3-migration/MIGRATION.md

diff --git a/inventory/hosts.example b/inventory/hosts.example
index 5d835c7..a1f69df 100644
--- a/inventory/hosts.example
+++ b/inventory/hosts.example
@@ -1,2 +1,3 @@
 staging ansible_host=staging.forgejo.dev ansible_user=maxkratz ansible_port="{{ sshd_port }}"
 production ansible_host=forgejo.dev ansible_user=maxkratz ansible_port="{{ sshd_port }}"
+s3-mig ansible_host=s3-mig.forgejo.dev ansible_user=maxkratz ansible_port="{{ sshd_port }}"
diff --git a/s3-migration/.gitignore b/s3-migration/.gitignore
new file mode 100644
index 0000000..49da8f2
--- /dev/null
+++ b/s3-migration/.gitignore
@@ -0,0 +1,4 @@
+*.json
+*.zip
+*.zip*
+*.txt
diff --git a/s3-migration/MIGRATION.md b/s3-migration/MIGRATION.md
new file mode 100644
index 0000000..49dd077
--- /dev/null
+++ b/s3-migration/MIGRATION.md
@@ -0,0 +1,50 @@
+# Minio S3 Migration
+
+In order to migrate the Minio S3 data + metadata, one has to spin up a temporary (newer) Minio S3 instance.
+
+Steps (in theory):
+- Create new VM
+- Deploy temporary Minio S3 instance
+- Migrate metadata + bucket data from old instance to temporary instance
+- Shutdown the old instance
+    - Also clear its data/config mounts
+- Re-deploy a new instance with the new backend version to replace the old instance
+- Migrate metadata + bucket data from temporary instance to the new instance
+
+
+## Commands/Steps to run
+
+- `$ terraform apply -var-file="secrets.tfvars" -target hcloud_server.s3-migration`
+- Adjust the DNS settings of these zones:
+    - `s3-mig.forgejo.dev`
+    - `s3.s3-mig.forgejo.dev`
+    - `console.s3.s3-mig.forgejo.dev`
+- `$ ansible-playbook s3-mig.yaml -l s3-mig`
+- Verify that the temporary instance is available at https://consolse.s3.s3-mig.forgejo.dev
+- [Install `mc`](https://min.io/docs/minio/linux/reference/minio-mc.html) on your local machine if not already done
+- Set the environment variables:
+    - `$ export ACCESS_KEY=123`
+    - `$ export SECRET_KEY=456`
+    - `$ export SOURCE=https://s3.forgejo.dev`
+    - `$ export TARGET=https://s3.s3-mig.forgejo.dev`
+- `$ cd s3-migration && chmod +x migration.sh && ./migration.sh`
+    - Wait until the mirror process has finished
+- Stop the old instance: `$ cd /srv/docker-compose/minio && docker-compose down`
+- Delete or rename the old data folders: `$ cd /srv/docker-compose/minio && mv minio-config minio-config_old && mv minio-data minio-data_old`
+- Re-deploy Minio S3 with the new backend: `$ ansible-playbook s3.yaml -l production`
+- Set the environment variables but replace `SOURCE` with `TARGET` and vice versa:
+    - `$ export ACCESS_KEY=123`
+    - `$ export SECRET_KEY=456`
+    - `$ export SOURCE=https://s3.s3-mig.forgejo.dev`
+    - `$ export TARGET=https://s3.forgejo.dev`
+- `$ cd s3-migration && chmod +x migration.sh && ./migration.sh`
+    - Wait until the mirror process has finished
+- Verify that all data has successfully been migrated to the new instance
+- Stop the temporary instance and destroy the VM: `$ terraform destroy -var-file="secrets.tfvars" -target hcloud_server.s3-migration`
+
+
+## References
+
+- https://min.io/docs/minio/linux/operations/install-deploy-manage/migrate-fs-gateway.html
+- https://min.io/docs/minio/linux/operations/install-deploy-manage/deploy-minio-single-node-single-drive.html#minio-snsd
+- https://min.io/docs/minio/linux/reference/minio-mc.html
diff --git a/s3-migration/migrate-s3.sh b/s3-migration/migrate-s3.sh
index d2dd351..370ab5d 100755
--- a/s3-migration/migrate-s3.sh
+++ b/s3-migration/migrate-s3.sh
@@ -30,5 +30,5 @@ mc admin service restart s3trg
 mc admin cluster bucket export s3src
 mc admin cluster bucket import s3trg cluster-metadata.zip
 
-# mirroring
+# mirroring existing bucket -> migration server/bucket
 mc mirror -preserve --watch s3src/gitea s3trg/gitea