Merge branch 'main' into next

5 files changed, 317 insertions, 20 deletions

diff --git a/doc/book/reference-manual/admin-api.md b/doc/book/reference-manual/admin-api.md
index 0b7e2e16..363bc886 100644
--- a/doc/book/reference-manual/admin-api.md
+++ b/doc/book/reference-manual/admin-api.md
@@ -1,6 +1,6 @@
 +++
 title = "Administration API"
-weight = 60
+weight = 40
 +++
 
 The Garage administration API is accessible through a dedicated server whose
diff --git a/doc/book/reference-manual/configuration.md b/doc/book/reference-manual/configuration.md
index 2d9c3f0c..38062bab 100644
--- a/doc/book/reference-manual/configuration.md
+++ b/doc/book/reference-manual/configuration.md
@@ -3,6 +3,8 @@ title = "Configuration file format"
 weight = 20
 +++
 
+## Full example
+
 Here is an example `garage.toml` configuration file that illustrates all of the possible options:
 
 ```toml
@@ -96,7 +98,7 @@ Performance characteristics of the different DB engines are as follows:
 
 - Sled: the default database engine, which tends to produce
   large data files and also has performance issues, especially when the metadata folder
-  is on a traditionnal HDD and not on SSD.
+  is on a traditional HDD and not on SSD.
 - LMDB: the recommended alternative on 64-bit systems,
   much more space-efficiant and slightly faster. Note that the data format of LMDB is not portable
   between architectures, so for instance the Garage database of an x86-64
@@ -259,13 +261,17 @@ Compression is done synchronously, setting a value too high will add latency to
 This value can be different between nodes, compression is done by the node which receive the
 API call.
 
-### `rpc_secret`
+### `rpc_secret`, `rpc_secret_file` or `GARAGE_RPC_SECRET` (env)
+
+Garage uses a secret key, called an RPC secret, that is shared between all
+nodes of the cluster in order to identify these nodes and allow them to
+communicate together. The RPC secret is a 32-byte hex-encoded random string,
+which can be generated with a command such as `openssl rand -hex 32`.
 
-Garage uses a secret key that is shared between all nodes of the cluster
-in order to identify these nodes and allow them to communicate together.
-This key should be specified here in the form of a 32-byte hex-encoded
-random string. Such a string can be generated with a command
-such as `openssl rand -hex 32`.
+The RPC secret should be specified in the `rpc_secret` configuration variable.
+Since Garage `v0.8.2`, the RPC secret can also be stored in a file whose path is
+given in the configuration variable `rpc_secret_file`, or specified as an
+environment variable `GARAGE_RPC_SECRET`.
 
 ### `rpc_bind_addr`
 
@@ -407,24 +413,30 @@ If specified, Garage will bind an HTTP server to this port and address, on
 which it will listen to requests for administration features.
 See [administration API reference](@/documentation/reference-manual/admin-api.md) to learn more about these features.
 
-### `metrics_token` (since version 0.7.2)
+### `metrics_token`, `metrics_token_file` or `GARAGE_METRICS_TOKEN` (env)
 
-The token for accessing the Metrics endpoint. If this token is not set in
-the config file, the Metrics endpoint can be accessed without access
-control.
+The token for accessing the Metrics endpoint. If this token is not set, the
+Metrics endpoint can be accessed without access control.
 
 You can use any random string for this value. We recommend generating a random token with `openssl rand -hex 32`.
 
-### `admin_token` (since version 0.7.2)
+`metrics_token` was introduced in Garage `v0.7.2`.
+`metrics_token_file` and the `GARAGE_METRICS_TOKEN` environment variable are supported since Garage `v0.8.2`.
+
+
+### `admin_token`, `admin_token_file` or `GARAGE_ADMIN_TOKEN` (env)
 
 The token for accessing all of the other administration endpoints.  If this
-token is not set in the config file, access to these endpoints is disabled
-entirely.
+token is not set, access to these endpoints is disabled entirely.
 
 You can use any random string for this value. We recommend generating a random token with `openssl rand -hex 32`.
 
+`admin_token` was introduced in Garage `v0.7.2`.
+`admin_token_file` and the `GARAGE_ADMIN_TOKEN` environment variable are supported since Garage `v0.8.2`.
+
+
 ### `trace_sink`
 
-Optionnally, the address of an Opentelemetry collector.  If specified,
-Garage will send traces in the Opentelemetry format to this endpoint. These
+Optionally, the address of an OpenTelemetry collector.  If specified,
+Garage will send traces in the OpenTelemetry format to this endpoint. These
 trace allow to inspect Garage's operation when it handles S3 API requests.
diff --git a/doc/book/reference-manual/k2v.md b/doc/book/reference-manual/k2v.md
index 207d056a..ed069b27 100644
--- a/doc/book/reference-manual/k2v.md
+++ b/doc/book/reference-manual/k2v.md
@@ -1,6 +1,6 @@
 +++
 title = "K2V"
-weight = 70
+weight = 100
 +++
 
 Starting with version 0.7.2, Garage introduces an optionnal feature, K2V,
@@ -16,7 +16,7 @@ the `k2v` feature flag enabled can be obtained from our download page under
 with `-k2v` (example: `v0.7.2-k2v`).
 
 The specification of the K2V API can be found
-[here](https://git.deuxfleurs.fr/Deuxfleurs/garage/src/branch/k2v/doc/drafts/k2v-spec.md).
+[here](https://git.deuxfleurs.fr/Deuxfleurs/garage/src/branch/main/doc/drafts/k2v-spec.md).
 This document also includes a high-level overview of K2V's design.
 
 The K2V API uses AWSv4 signatures for authentification, same as the S3 API.
diff --git a/doc/book/reference-manual/monitoring.md b/doc/book/reference-manual/monitoring.md
new file mode 100644
index 00000000..97c533d3
--- /dev/null
+++ b/doc/book/reference-manual/monitoring.md
@@ -0,0 +1,285 @@
+
++++
+title = "Monitoring"
+weight = 60
++++
+
+
+For information on setting up monitoring, see our [dedicated page](@/documentation/cookbook/monitoring.md) in the Cookbook section.
+
+## List of exported metrics
+
+### Garage system metrics
+
+#### `garage_build_info` (counter)
+
+Exposes the Garage version number running on a node.
+
+```
+garage_build_info{version="1.0"} 1
+```
+
+#### `garage_replication_factor` (counter)
+
+Exposes the Garage replication factor configured on the node
+
+```
+garage_replication_factor 3
+```
+
+### Metrics of the API endpoints
+
+#### `api_admin_request_counter` (counter)
+
+Counts the number of requests to a given endpoint of the administration API. Example:
+
+```
+api_admin_request_counter{api_endpoint="Metrics"} 127041
+```
+
+#### `api_admin_request_duration` (histogram)
+
+Evaluates the duration of API calls to the various administration API endpoint. Example:
+
+```
+api_admin_request_duration_bucket{api_endpoint="Metrics",le="0.5"} 127041
+api_admin_request_duration_sum{api_endpoint="Metrics"} 605.250344830999
+api_admin_request_duration_count{api_endpoint="Metrics"} 127041
+```
+
+#### `api_s3_request_counter` (counter)
+
+Counts the number of requests to a given endpoint of the S3 API. Example:
+
+```
+api_s3_request_counter{api_endpoint="CreateMultipartUpload"} 1
+```
+
+#### `api_s3_error_counter` (counter)
+
+Counts the number of requests to a given endpoint of the S3 API that returned an error. Example:
+
+```
+api_s3_error_counter{api_endpoint="GetObject",status_code="404"} 39
+```
+
+#### `api_s3_request_duration` (histogram)
+
+Evaluates the duration of API calls to the various S3 API endpoints. Example:
+
+```
+api_s3_request_duration_bucket{api_endpoint="CreateMultipartUpload",le="0.5"} 1
+api_s3_request_duration_sum{api_endpoint="CreateMultipartUpload"} 0.046340762
+api_s3_request_duration_count{api_endpoint="CreateMultipartUpload"} 1
+```
+
+#### `api_k2v_request_counter` (counter), `api_k2v_error_counter` (counter), `api_k2v_error_duration` (histogram)
+
+Same as for S3, for the K2V API.
+
+
+### Metrics of the Web endpoint
+
+
+#### `web_request_counter` (counter)
+
+Number of requests to the web endpoint
+
+```
+web_request_counter{method="GET"} 80
+```
+
+#### `web_request_duration` (histogram)
+
+Duration of requests to the web endpoint
+
+```
+web_request_duration_bucket{method="GET",le="0.5"} 80
+web_request_duration_sum{method="GET"} 1.0528433229999998
+web_request_duration_count{method="GET"} 80
+```
+
+#### `web_error_counter` (counter)
+
+Number of requests to the web endpoint resulting in errors
+
+```
+web_error_counter{method="GET",status_code="404 Not Found"} 64
+```
+
+
+### Metrics of the data block manager
+
+#### `block_bytes_read`, `block_bytes_written` (counter)
+
+Number of bytes read/written to/from disk in the data storage directory.
+
+```
+block_bytes_read 120586322022
+block_bytes_written 3386618077
+```
+
+#### `block_compression_level` (counter)
+
+Exposes the block compression level configured for the Garage node.
+
+```
+block_compression_level 3
+```
+
+#### `block_read_duration`, `block_write_duration` (histograms)
+
+Evaluates the duration of the reading/writing of individual data blocks in the data storage directory.
+
+```
+block_read_duration_bucket{le="0.5"} 169229
+block_read_duration_sum 2761.6902550310056
+block_read_duration_count 169240
+block_write_duration_bucket{le="0.5"} 3559
+block_write_duration_sum 195.59170078500006
+block_write_duration_count 3571
+```
+
+#### `block_delete_counter` (counter)
+
+Counts the number of data blocks that have been deleted from storage.
+
+```
+block_delete_counter 122
+```
+
+#### `block_resync_counter` (counter), `block_resync_duration` (histogram)
+
+Counts the number of resync operations the node has executed, and evaluates their duration.
+
+```
+block_resync_counter 308897
+block_resync_duration_bucket{le="0.5"} 308892
+block_resync_duration_sum 139.64204196100016
+block_resync_duration_count 308897
+```
+
+#### `block_resync_queue_length` (gauge)
+
+The number of block hashes currently queued for a resync.
+This is normal to be nonzero for long periods of time.
+
+```
+block_resync_queue_length 0
+```
+
+#### `block_resync_errored_blocks` (gauge)
+
+The number of block hashes that we were unable to resync last time we tried.
+**THIS SHOULD BE ZERO, OR FALL BACK TO ZERO RAPIDLY, IN A HEALTHY CLUSTER.**
+Persistent nonzero values indicate that some data is likely to be lost.
+
+```
+block_resync_errored_blocks 0
+```
+
+
+### Metrics related to RPCs (remote procedure calls) between nodes
+
+#### `rpc_netapp_request_counter` (counter)
+
+Number of RPC requests emitted
+
+```
+rpc_request_counter{from="<this node>",rpc_endpoint="garage_block/manager.rs/Rpc",to="<remote node>"} 176
+```
+
+#### `rpc_netapp_error_counter` (counter)
+
+Number of communication errors (errors in the Netapp library, generally due to disconnected nodes)
+
+```
+rpc_netapp_error_counter{from="<this node>",rpc_endpoint="garage_block/manager.rs/Rpc",to="<remote node>"} 354
+```
+
+#### `rpc_timeout_counter` (counter)
+
+Number of RPC timeouts, should be close to zero in a healthy cluster.
+
+```
+rpc_timeout_counter{from="<this node>",rpc_endpoint="garage_rpc/membership.rs/SystemRpc",to="<remote node>"} 1
+```
+
+#### `rpc_duration` (histogram)
+
+The duration of internal RPC calls between Garage nodes.
+
+```
+rpc_duration_bucket{from="<this node>",rpc_endpoint="garage_block/manager.rs/Rpc",to="<remote node>",le="0.5"} 166
+rpc_duration_sum{from="<this node>",rpc_endpoint="garage_block/manager.rs/Rpc",to="<remote node>"} 35.172253716
+rpc_duration_count{from="<this node>",rpc_endpoint="garage_block/manager.rs/Rpc",to="<remote node>"} 174
+```
+
+
+### Metrics of the metadata table manager
+
+#### `table_gc_todo_queue_length` (gauge)
+
+Table garbage collector TODO queue length
+
+```
+table_gc_todo_queue_length{table_name="block_ref"} 0
+```
+
+#### `table_get_request_counter` (counter), `table_get_request_duration` (histogram)
+
+Number of get/get_range requests internally made on each table, and their duration.
+
+```
+table_get_request_counter{table_name="bucket_alias"} 315
+table_get_request_duration_bucket{table_name="bucket_alias",le="0.5"} 315
+table_get_request_duration_sum{table_name="bucket_alias"} 0.048509778000000024
+table_get_request_duration_count{table_name="bucket_alias"} 315
+```
+
+
+#### `table_put_request_counter` (counter), `table_put_request_duration` (histogram)
+
+Number of insert/insert_many requests internally made on this table, and their duration
+
+```
+table_put_request_counter{table_name="block_ref"} 677
+table_put_request_duration_bucket{table_name="block_ref",le="0.5"} 677
+table_put_request_duration_sum{table_name="block_ref"} 61.617528636
+table_put_request_duration_count{table_name="block_ref"} 677
+```
+
+#### `table_internal_delete_counter` (counter)
+
+Number of value deletions in the tree (due to GC or repartitioning)
+
+```
+table_internal_delete_counter{table_name="block_ref"} 2296
+```
+
+#### `table_internal_update_counter` (counter)
+
+Number of value updates where the value actually changes (includes creation of new key and update of existing key)
+
+```
+table_internal_update_counter{table_name="block_ref"} 5996
+```
+
+#### `table_merkle_updater_todo_queue_length` (gauge)
+
+Merkle tree updater TODO queue length (should fall to zero rapidly)
+
+```
+table_merkle_updater_todo_queue_length{table_name="block_ref"} 0
+```
+
+#### `table_sync_items_received`, `table_sync_items_sent` (counters)
+
+Number of data items sent to/recieved from other nodes during resync procedures
+
+```
+table_sync_items_received{from="<remote node>",table_name="bucket_v2"} 3
+table_sync_items_sent{table_name="block_ref",to="<remote node>"} 2
+```
+
+
diff --git a/doc/book/reference-manual/s3-compatibility.md b/doc/book/reference-manual/s3-compatibility.md
index dd3492a0..15b29bd1 100644
--- a/doc/book/reference-manual/s3-compatibility.md
+++ b/doc/book/reference-manual/s3-compatibility.md
@@ -1,6 +1,6 @@
 +++
 title = "S3 Compatibility status"
-weight = 40
+weight = 70
 +++
 
 ## DISCLAIMER