The error handling of the ACL code relies on the presence of certain
magic error messages. Since the error values are sent via RPC between
older and newer consul agents we cannot just replace the magic values
with typed errors and switch to type checks since this would break
compatibility with older clients.
Therefore, this patch moves all magic ACL error messages into the acl
package and provides default error values and helper functions which
determine the type of error.
* Updates Raft library to get new snapshot/restore API.
* Basic backup and restore working, but need some cleanup.
* Breaks out a snapshot module and adds a SHA256 integrity check.
* Adds snapshot ACL and fills in some missing comments.
* Require a consistent read for snapshots.
* Make sure snapshot works if ACLs aren't enabled.
* Adds a bit of package documentation.
* Returns an empty response from restore to avoid EOF errors.
* Adds API client support for snapshots.
* Makes internal file names match on-disk file snapshots.
* Adds DC and token coverage for snapshot API test.
* Adds missing documentation.
* Adds a unit test for the snapshot client endpoint.
* Moves the connection pool out of the client for easier testing.
* Fixes an incidental issue in the prepared query unit test.
I realized I had two servers in bootstrap mode so this wasn't a good setup.
* Adds a half close to the TCP stream and fixes panic on error.
* Adds client and endpoint tests for snapshots.
* Moves the pool back into the snapshot RPC client.
* Adds a TLS test and fixes half-closes for TLS connections.
* Tweaks some comments.
* Adds a low-level snapshot test.
This is independent of Consul so we can pull this out into a library
later if we want to.
* Cleans up snapshot and archive and completes archive tests.
* Sends a clear error for snapshot operations in dev mode.
Snapshots require the Raft snapshots to be readable, which isn't supported
in dev mode. Send a clear error instead of a deep-down Raft one.
* Adds docs for the snapshot endpoint.
* Adds a stale mode and index feedback for snapshot saves.
This gives folks a way to extract data even if the cluster has no
leader.
* Changes the internal format of a snapshot from zip to tgz.
* Pulls in Raft fix to cancel inflight before a restore.
* Pulls in new Raft restore interface.
* Adds metadata to snapshot saves and a verify function.
* Adds basic save and restore snapshot CLI commands.
* Gets rid of tarball extensions and adds restore message.
* Fixes an incidental bad link in the KV docs.
* Adds documentation for the snapshot CLI commands.
* Scuttle any request body when a snapshot is saved.
* Fixes archive unit test error message check.
* Allows for nil output writers in snapshot RPC handlers.
* Renames hash list Decode to DecodeAndVerify.
* Closes the client connection for snapshot ops.
* Lowers timeout for restore ops.
* Updates Raft vendor to get new Restore signature and integrates with Consul.
* Bounces the leader's internal state when we do a restore.
Prior to this change, prepared queries had the following behavior for
ACLs, which will need to change to support templates:
1. A management token, or a token with read access to the service being
queried needed to be provided in order to create a prepared query.
2. The token used to create the prepared query was stored with the query
in the state store and used to execute the query.
3. A management token, or the token used to create the query needed to be
supplied to perform and CRUD operations on an existing prepared query.
This was pretty subtle and complicated behavior, and won't work for
templates since the service name is computed at execution time. To solve
this, we introduce a new "prepared-query" ACL type, where the prefix
applies to the query name for static prepared query types and to the
prefix for template prepared query types.
With this change, the new behavior is:
1. A management token, or a token with "prepared-query" write access to
the query name or (soon) the given template prefix is required to do
any CRUD operations on a prepared query, or to list prepared queries
(the list is filtered by this ACL).
2. You will no longer need a management token to list prepared queries,
but you will only be able to see prepared queries that you have access
to (you get an empty list instead of permission denied).
3. When listing or getting a query, because it was easy to capture
management tokens given the past behavior, this will always blank out
the "Token" field (replacing the contents as <hidden>) for all tokens
unless a management token is supplied. Going forward, we should
discourage people from binding tokens for execution unless strictly
necessary.
4. No token will be captured by default when a prepared query is created.
If the user wishes to supply an execution token then can pass it in via
the "Token" field in the prepared query definition. Otherwise, this
field will default to empty.
5. At execution time, we will use the captured token if it exists with the
prepared query definition, otherwise we will use the token that's passed
in with the request, just like we do for other RPCs (or you can use the
agent's configured token for DNS).
6. Prepared queries with no name (accessible only by ID) will not require
ACLs to create or modify (execution time will depend on the service ACL
configuration). Our argument here is that these are designed to be
ephemeral and the IDs are as good as an ACL. Management tokens will be
able to list all of these.
These changes enable templates, but also enable delegation of authority to
manage the prepared query namespace.
