First version of admin API (#298)

**Spec:**

- [x] Start writing
- [x] Specify all layout endpoints
- [x] Specify all endpoints for operations on keys
- [x] Specify all endpoints for operations on key/bucket permissions
- [x] Specify all endpoints for operations on buckets
- [x] Specify all endpoints for operations on bucket aliases

View rendered spec at <https://git.deuxfleurs.fr/Deuxfleurs/garage/src/branch/admin-api/doc/drafts/admin-api.md>

**Code:**

- [x] Refactor code for admin api to use common api code that was created for K2V

**General endpoints:**

- [x] Metrics
- [x] GetClusterStatus
- [x] ConnectClusterNodes
- [x] GetClusterLayout
- [x] UpdateClusterLayout
- [x] ApplyClusterLayout
- [x] RevertClusterLayout

**Key-related endpoints:**

- [x] ListKeys
- [x] CreateKey
- [x] ImportKey
- [x] GetKeyInfo
- [x] UpdateKey
- [x] DeleteKey

**Bucket-related endpoints:**

- [x] ListBuckets
- [x] CreateBucket
- [x] GetBucketInfo
- [x] DeleteBucket
- [x] PutBucketWebsite
- [x] DeleteBucketWebsite

**Operations on key/bucket permissions:**

- [x] BucketAllowKey
- [x] BucketDenyKey

**Operations on bucket aliases:**

- [x] GlobalAliasBucket
- [x] GlobalUnaliasBucket
- [x] LocalAliasBucket
- [x] LocalUnaliasBucket

**And also:**

- [x] Separate error type for the admin API (this PR includes a quite big refactoring of error handling)
- [x] Add management of website access
- [ ] Check that nothing is missing wrt what can be done using the CLI
- [ ] Improve formatting of the spec
- [x] Make sure everyone is cool with the API design

Fix #231
Fix #295

Co-authored-by: Alex Auvolat <alex@adnab.me>
Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/298
Co-authored-by: Alex <alex@adnab.me>
Co-committed-by: Alex <alex@adnab.me>

1 files changed, 4 insertions, 43 deletions

diff --git a/src/garage/cli/layout.rs b/src/garage/cli/layout.rs
index 0247c32b..db0af57c 100644
--- a/src/garage/cli/layout.rs
+++ b/src/garage/cli/layout.rs
@@ -1,5 +1,4 @@
 use garage_util::crdt::Crdt;
-use garage_util::data::*;
 use garage_util::error::*;
 use garage_util::formater::format_table;
 
@@ -212,31 +211,9 @@ pub async fn cmd_apply_layout(
 	rpc_host: NodeID,
 	apply_opt: ApplyLayoutOpt,
 ) -> Result<(), Error> {
-	let mut layout = fetch_layout(rpc_cli, rpc_host).await?;
-
-	match apply_opt.version {
-		None => {
-			println!("Please pass the --version flag to ensure that you are writing the correct version of the cluster layout.");
-			println!("To know the correct value of the --version flag, invoke `garage layout show` and review the proposed changes.");
-			return Err(Error::Message("--version flag is missing".into()));
-		}
-		Some(v) => {
-			if v != layout.version + 1 {
-				return Err(Error::Message("Invalid value of --version flag".into()));
-			}
-		}
-	}
-
-	layout.roles.merge(&layout.staging);
-
-	if !layout.calculate_partition_assignation() {
-		return Err(Error::Message("Could not calculate new assignation of partitions to nodes. This can happen if there are less nodes than the desired number of copies of your data (see the replication_mode configuration parameter).".into()));
-	}
+	let layout = fetch_layout(rpc_cli, rpc_host).await?;
 
-	layout.staging.clear();
-	layout.staging_hash = blake2sum(&rmp_to_vec_all_named(&layout.staging).unwrap()[..]);
-
-	layout.version += 1;
+	let layout = layout.apply_staged_changes(apply_opt.version)?;
 
 	send_layout(rpc_cli, rpc_host, layout).await?;
 
@@ -251,25 +228,9 @@ pub async fn cmd_revert_layout(
 	rpc_host: NodeID,
 	revert_opt: RevertLayoutOpt,
 ) -> Result<(), Error> {
-	let mut layout = fetch_layout(rpc_cli, rpc_host).await?;
-
-	match revert_opt.version {
-		None => {
-			println!("Please pass the --version flag to ensure that you are writing the correct version of the cluster layout.");
-			println!("To know the correct value of the --version flag, invoke `garage layout show` and review the proposed changes.");
-			return Err(Error::Message("--version flag is missing".into()));
-		}
-		Some(v) => {
-			if v != layout.version + 1 {
-				return Err(Error::Message("Invalid value of --version flag".into()));
-			}
-		}
-	}
-
-	layout.staging.clear();
-	layout.staging_hash = blake2sum(&rmp_to_vec_all_named(&layout.staging).unwrap()[..]);
+	let layout = fetch_layout(rpc_cli, rpc_host).await?;
 
-	layout.version += 1;
+	let layout = layout.revert_staged_changes(revert_opt.version)?;
 
 	send_layout(rpc_cli, rpc_host, layout).await?;