Reorganize documentation for new website (#213)

This PR should be merged after the new website is deployed.

- [x] Rename files
- [x] Add front matter section to all `.md` files in the book (necessary for Zola)
- [x] Change all internal links to use Zola's linking system that checks broken links
- [x] Some updates to documentation contents and organization

Co-authored-by: Alex Auvolat <alex@adnab.me>
Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/213
Co-authored-by: Alex <alex@adnab.me>
Co-committed-by: Alex <alex@adnab.me>

1 files changed, 0 insertions, 105 deletions

diff --git a/doc/book/src/working_documents/migration_04.md b/doc/book/src/working_documents/migration_04.md
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-# Migrating from 0.3 to 0.4
-
-**Migrating from 0.3 to 0.4 is unsupported. This document is only intended to
-document the process internally for the Deuxfleurs cluster where we have to do
-it. Do not try it yourself, you will lose your data and we will not help you.**
-
-**Migrating from 0.2 to 0.4 will break everything for sure. Never try it.**
-
-The internal data format of Garage hasn't changed much between 0.3 and 0.4.
-The Sled database is still the same, and the data directory as well.
-
-The following has changed, all in the meta directory:
-
-- `node_id` in 0.3 contains the identifier of the current node. In 0.4, this
-  file does nothing and should be deleted. It is replaced by `node_key` (the
-  secret key) and `node_key.pub` (the associated public key). A node's
-  identifier on the ring is its public key.
-
-- `peer_info` in 0.3 contains the list of peers saved automatically by Garage.
-  The format has changed and it is now stored in `peer_list` (`peer_info`
-  should be deleted).
-
-When migrating, all node identifiers will change. This also means that the
-affectation of data partitions on the ring will change, and lots of data will
-have to be rebalanced.
-
-- If your cluster has only 3 nodes, all nodes store everything, therefore nothing has to be rebalanced.
-
-- If your cluster has only 4 nodes, for any partition there will always be at
-  least 2 nodes that stored data before that still store it after. Therefore
-  the migration should in theory be transparent and Garage should continue to
-  work during the rebalance.
-
-- If your cluster has 5 or more nodes, data will disappear during the
-  migration. Do not migrate (fortunately we don't have this scenario at
-  Deuxfleurs), or if you do, make Garage unavailable until things stabilize
-  (disable web and api access).
-
-
-The migration steps are as follows:
-
-1. Prepare a new configuration file for 0.4. For each node, point to the same
-   meta and data directories as Garage 0.3. Basically, the things that change
-   are the following:
-
-  - No more `rpc_tls` section
-  - You have to generate a shared `rpc_secret` and put it in all config files
-  - `bootstrap_peers` has a different syntax as it has to contain node keys.
-    Leave it empty and use `garage node-id` and `garage node connect` instead (new features of 0.4)
-  - put the publicly accessible RPC address of your node in `rpc_public_addr` if possible (its optional but recommended)
-  - If you are using Consul, change the `consul_service_name` to NOT be the name advertised by Nomad.
-    Now Garage is responsible for advertising its own service itself.
-
-2. Disable api and web access for some time (Garage does not support disabling
-   these endpoints but you can change the port number or stop your reverse
-   proxy for instance).
-
-3. Do `garage repair -a --yes tables` and `garage repair -a --yes blocks`,
-   check the logs and check that all data seems to be synced correctly between
-   nodes.
-
-4. Save somewhere the output of `garage status`. We will need this to remember
-   how to reconfigure nodes in 0.4.
-
-5. Turn off Garage 0.3
-
-6. Backup metadata folders if you can (i.e. if you have space to do it
-   somewhere). Backuping data folders could also be usefull but that's much
-   harder to do. If your filesystem supports snapshots, this could be a good
-   time to use them.
-
-7. Turn on Garage 0.4
-
-8. At this point, running `garage status` should indicate that all nodes of the
-   previous cluster are "unavailable". The nodes have new identifiers that
-   should appear in healthy nodes once they can talk to one another (use
-   `garage node connect` if necessary`). They should have NO ROLE ASSIGNED at
-   the moment.
-
-9. Prepare a script with several `garage node configure` commands that replace
-   each of the v0.3 node ID with the corresponding v0.4 node ID, with the same
-   zone/tag/capacity. For example if your node `drosera` had identifier `c24e`
-   before and now has identifier `789a`, and it was configured with capacity
-   `2` in zone `dc1`, put the following command in your script:
-
-```bash
-garage node configure 789a -z dc1 -c 2 -t drosera --replace c24e
-```
-
-10. Run your reconfiguration script. Check that the new output of `garage
-	status` contains the correct node IDs with the correct values for capacity
-	and zone. Old nodes should no longer be mentioned.
-
-11. If your cluster has 4 nodes or less, and you are feeling adventurous, you
-	can reenable Web and API access now. Things will probably work.
-
-12. Garage might already be resyncing stuff. Issue a `garage repair -a --yes
-	tables` and `garage repair -a --yes blocks` to force it to do so.
-
-13. Wait for resyncing activity to stop in the logs. Do steps 12 and 13 two or
-	three times, until you see that when you issue the repair commands, nothing
-	gets resynced any longer.
-
-14. Your upgraded cluster should be in a working state. Re-enable API and Web
-	access and check that everything went well.