docs: add ADR 058 Auto-Generated CLI (#11877)

* docs: add ADR 058 Auto-Generated CLI

* Update docs/architecture/adr-058-auto-generated-cli.md

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>

* updates based on code review

* Update docs/architecture/adr-058-auto-generated-cli.md

Co-authored-by: Ryan Christoffersen <12519942+ryanchristo@users.noreply.github.com>

* updates based on code review

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
Co-authored-by: Ryan Christoffersen <12519942+ryanchristo@users.noreply.github.com>
Co-authored-by: Marko <marbar3778@yahoo.com>

docs/architecture/README.md

@@ -57,6 +57,7 @@ When writing ADRs, follow the same best practices for writing RFCs. When writing
 * [ADR 030: Message Authorization Module](./adr-030-authz-module.md)
 * [ADR 031: Protobuf Msg Services](./adr-031-msg-service.md)
 * [ADR 055: ORM](./adr-055-orm.md)
+* [ADR 058: Auto-Generated CLI](./adr-058-auto-generated-cli.md)
 
 ### Proposed
 

docs/architecture/adr-058-auto-generated-cli.md

@@ -0,0 +1,95 @@
+# ADR 058: Auto-Generated CLI
+
+## Changelog
+
+* 2022-05-04: Initial Draft
+
+## Status
+
+ACCEPTED Partially Implemented
+
+## Abstract
+
+In order to make it easier for developers to write Cosmos SDK modules, we provide infrastructure which automatically
+generates CLI commands based on protobuf definitions.
+
+## Context
+
+Current Cosmos SDK modules generally implement a CLI command for every transaction and every query supported by the
+module. These are handwritten for each command and essentially amount to providing some CLI flags or positional
+arguments for specific fields in protobuf messages.
+
+In order to make sure CLI commands are correctly implemented as well as to make sure that the application works
+in end-to-end scenarios, we do integration tests using CLI commands. While these tests are valuable on some-level,
+they can be hard to write and maintain, and run slowly. [Some teams have contemplated](https://github.com/regen-network/regen-ledger/issues/1041)
+moving away from CLI-style integration tests (which are really end-to-end tests) towards narrower integration tests
+which exercise `MsgClient` and `QueryClient` directly. This might involve replacing the current end-to-end CLI
+tests with unit tests as there still needs to be some way to test these CLI commands for full quality assurance.
+
+## Decision
+
+To make module development simpler, we provide infrastructure - in the new [`client/v2`](https://github.com/cosmos/cosmos-sdk/tree/main/client/v2)
+go module - for automatically generating CLI commands based on protobuf definitions to either replace or complement
+handwritten CLI commands. This will mean that when developing a module, it will be possible to skip both writing and
+testing CLI commands as that can all be taken care of by the framework.
+
+The basic design for automatically generating CLI commands is to:
+
+* create one CLI command for each `rpc` method in a protobuf `Query` or `Msg` service
+* create a CLI flag for each field in the `rpc` request type
+* for `query` commands call gRPC and print the response as protobuf JSON or YAML (via the `-o`/`--output` flag)
+* for `tx` commands, create a transaction and apply common transaction flags
+
+In order to make the auto-generated CLI as easy to use (or easier) than handwritten CLI, we need to do custom handling
+of specific protobuf field types so that the input format is easy for humans:
+* `Coin`, `Coins`, `DecCoin`, and `DecCoins` should be input using the existing format (i.e. `1000uatom`)
+* it should be possible to specify an address using either the bech32 address string or a named key in the keyring
+* `Timestamp` and `Duration` should accept strings like `2001-01-01T00:00:00Z` and `1h3m` respectively
+* pagination should be handled with flags like `--page-limit`, `--page-offset`, etc.
+* it should be possible to customize any other protobuf type either via its message name or a `cosmos_proto.scalar` annotation
+
+At a basic level it should be possible to generate a command for a single `rpc` method as well as all the commands for
+a whole protobuf `service` definition. It should be possible to mix and match auto-generated and handwritten commands.
+
+## Consequences
+
+### Backwards Compatibility
+
+Existing modules can mix and match auto-generated and handwritten CLI commands so it is up to them as to whether they
+make breaking changes by replacing handwritten commands with slightly different auto-generated ones.
+
+For now the SDK will maintain the existing set of CLI commands for backwards compatibility but new commands will use
+this functionality.
+
+### Positive
+
+* module developers will not need to write CLI commands
+* module developers will not need to test CLI commands
+* [lens](https://github.com/strangelove-ventures/lens) may benefit from this
+
+### Negative
+
+### Neutral
+
+## Further Discussions
+
+We would like to be able to customize:
+* short and long usage strings for commands
+* aliases for flags (ex. `-a` for `--amount`)
+* which fields are positional parameters rather than flags
+
+It is an [open discussion](https://github.com/cosmos/cosmos-sdk/pull/11725#issuecomment-1108676129)
+as to whether these customizations options should line in:
+* the .proto files themselves,
+* separate config files (ex. YAML), or
+* directly in code
+
+Providing the options in .proto files would allow a dynamic client to automatically generate
+CLI commands on the fly. However, that may pollute the .proto files themselves with information that is only relevant
+for a small subset of users.
+
+## References
+
+* https://github.com/regen-network/regen-ledger/issues/1041
+* https://github.com/cosmos/cosmos-sdk/tree/main/client/v2
+* https://github.com/cosmos/cosmos-sdk/pull/11725#issuecomment-1108676129