feat: Add max metadata length as a group keeper parameter (#11034)

## Description

Closes: #10972 

Add MaxMetadataLength as a group keeper parameter.

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

simapp/app.go

@@ -294,7 +294,12 @@ func NewSimApp(
 
 	app.AuthzKeeper = authzkeeper.NewKeeper(keys[authzkeeper.StoreKey], appCodec, app.msgSvcRouter, app.AccountKeeper)
 
-	app.GroupKeeper = groupkeeper.NewKeeper(keys[group.StoreKey], appCodec, app.msgSvcRouter, app.AccountKeeper)
+	groupConfig := groupkeeper.DefaultConfig()
+	/*
+		Example of setting group params:
+		groupConfig.MaxMetadataLen = 1000
+	*/
+	app.GroupKeeper = groupkeeper.NewKeeper(keys[group.StoreKey], appCodec, app.msgSvcRouter, app.AccountKeeper, groupConfig)
 
 	// register the proposal types
 	govRouter := govv1beta1.NewRouter()

x/group/keeper/config.go

@@ -0,0 +1,14 @@
+package keeper
+
+// Config is a config struct used for intialising the group module to avoid using globals.
+type Config struct {
+	// MaxMetadataLen defines the max length of the metadata bytes field for various entities within the group module. Defaults to 255 if not explicitly set.
+	MaxMetadataLen uint64
+}
+
+// DefaultConfig returns the default config for group.
+func DefaultConfig() Config {
+	return Config{
+		MaxMetadataLen: 255,
+	}
+}

x/group/keeper/keeper.go

@@ -73,9 +73,11 @@ type Keeper struct {
 	voteByVoterIndex    orm.Index
 
 	router *authmiddleware.MsgServiceRouter
+
+	config Config
 }
 
-func NewKeeper(storeKey storetypes.StoreKey, cdc codec.Codec, router *authmiddleware.MsgServiceRouter, accKeeper group.AccountKeeper) Keeper {
+func NewKeeper(storeKey storetypes.StoreKey, cdc codec.Codec, router *authmiddleware.MsgServiceRouter, accKeeper group.AccountKeeper, config Config) Keeper {
 	k := Keeper{
 		key:       storeKey,
 		router:    router,
@@ -204,6 +206,11 @@ func NewKeeper(storeKey storetypes.StoreKey, cdc codec.Codec, router *authmiddle
 	}
 	k.voteTable = *voteTable
 
+	if config.MaxMetadataLen == 0 {
+		config.MaxMetadataLen = DefaultConfig().MaxMetadataLen
+	}
+	k.config = config
+
 	return k
 
 }
@@ -213,6 +220,9 @@ func (k Keeper) Logger(ctx sdk.Context) log.Logger {
 	return ctx.Logger().With("module", fmt.Sprintf("x/%s", group.ModuleName))
 }
 
+// MaxMetadataLength returns the max length of the metadata bytes field for various entities within the group module.
+func (k Keeper) MaxMetadataLength() uint64 { return k.config.MaxMetadataLen }
+
 // GetGroupSequence returns the current value of the group table sequence
 func (k Keeper) GetGroupSequence(ctx sdk.Context) uint64 {
 	return k.groupTable.Sequence().CurVal(ctx.KVStore(k.key))

x/group/keeper/msg_server.go

@@ -34,14 +34,14 @@ func (k Keeper) CreateGroup(goCtx context.Context, req *group.MsgCreateGroup) (*
 		return nil, err
 	}
 
-	if err := assertMetadataLength(metadata, "group metadata"); err != nil {
+	if err := k.assertMetadataLength(metadata, "group metadata"); err != nil {
 		return nil, err
 	}
 
 	totalWeight := math.NewDecFromInt64(0)
 	for i := range members.Members {
 		m := members.Members[i]
-		if err := assertMetadataLength(m.Metadata, "member metadata"); err != nil {
+		if err := k.assertMetadataLength(m.Metadata, "member metadata"); err != nil {
 			return nil, err
 		}
 
@@ -105,7 +105,7 @@ func (k Keeper) UpdateGroupMembers(goCtx context.Context, req *group.MsgUpdateGr
 			return err
 		}
 		for i := range req.MemberUpdates {
-			if err := assertMetadataLength(req.MemberUpdates[i].Metadata, "group member metadata"); err != nil {
+			if err := k.assertMetadataLength(req.MemberUpdates[i].Metadata, "group member metadata"); err != nil {
 				return err
 			}
 			groupMember := group.GroupMember{GroupId: req.GroupId,
@@ -221,7 +221,7 @@ func (k Keeper) UpdateGroupMetadata(goCtx context.Context, req *group.MsgUpdateG
 		return k.groupTable.Update(ctx.KVStore(k.key), g.GroupId, g)
 	}
 
-	if err := assertMetadataLength(req.Metadata, "group metadata"); err != nil {
+	if err := k.assertMetadataLength(req.Metadata, "group metadata"); err != nil {
 		return nil, err
 	}
 
@@ -243,7 +243,7 @@ func (k Keeper) CreateGroupPolicy(goCtx context.Context, req *group.MsgCreateGro
 	groupID := req.GetGroupID()
 	metadata := req.GetMetadata()
 
-	if err := assertMetadataLength(metadata, "group policy metadata"); err != nil {
+	if err := k.assertMetadataLength(metadata, "group policy metadata"); err != nil {
 		return nil, err
 	}
 
@@ -359,7 +359,7 @@ func (k Keeper) UpdateGroupPolicyMetadata(goCtx context.Context, req *group.MsgU
 		return k.groupPolicyTable.Update(ctx.KVStore(k.key), groupPolicy)
 	}
 
-	if err := assertMetadataLength(metadata, "group policy metadata"); err != nil {
+	if err := k.assertMetadataLength(metadata, "group policy metadata"); err != nil {
 		return nil, err
 	}
 
@@ -381,7 +381,7 @@ func (k Keeper) CreateProposal(goCtx context.Context, req *group.MsgCreatePropos
 	proposers := req.Proposers
 	msgs := req.GetMsgs()
 
-	if err := assertMetadataLength(metadata, "metadata"); err != nil {
+	if err := k.assertMetadataLength(metadata, "metadata"); err != nil {
 		return nil, err
 	}
 
@@ -491,7 +491,7 @@ func (k Keeper) Vote(goCtx context.Context, req *group.MsgVote) (*group.MsgVoteR
 	choice := req.Choice
 	metadata := req.Metadata
 
-	if err := assertMetadataLength(metadata, "metadata"); err != nil {
+	if err := k.assertMetadataLength(metadata, "metadata"); err != nil {
 		return nil, err
 	}
 
@@ -773,10 +773,10 @@ func (k Keeper) doAuthenticated(ctx sdk.Context, req authNGroupReq, action actio
 }
 
 // assertMetadataLength returns an error if given metadata length
-// is greater than a fixed maxMetadataLength.
-func assertMetadataLength(metadata []byte, description string) error {
-	if len(metadata) > group.MaxMetadataLength {
-		return sdkerrors.Wrap(errors.ErrMaxLimit, description)
+// is greater than a pre-defined maxMetadataLen.
+func (k Keeper) assertMetadataLength(metadata []byte, description string) error {
+	if metadata != nil && uint64(len(metadata)) > k.config.MaxMetadataLen {
+		return sdkerrors.Wrapf(errors.ErrMaxLimit, description)
 	}
 	return nil
 }

x/group/spec/03_messages.md

@@ -8,9 +8,12 @@ order: 3
 
 A new group can be created with the `MsgCreateGroup`, which has an admin address, a list of members and some optional metadata bytes.
 
+The metadata has a maximum length that is chosen by the app developer, and
+passed into the group keeper as a config.
+
 +++ https://github.com/cosmos/cosmos-sdk/blob/6f58963e7f6ce820e9b33f02f06f7b96f6d2e347/proto/cosmos/group/v1beta1/tx.proto#L54-L65
 
-It's expecting to fail if metadata length is greater than some `MaxMetadataLength`.
+It's expecting to fail if metadata length is greater than `MaxMetadataLen` config.
 
 ## Msg/UpdateGroupMembers
 
@@ -37,7 +40,7 @@ The `UpdateGroupMetadata` can be used to update a group metadata.
 +++ https://github.com/cosmos/cosmos-sdk/blob/6f58963e7f6ce820e9b33f02f06f7b96f6d2e347/proto/cosmos/group/v1beta1/tx.proto#L107-L118
 
 It's expecting to fail if:
-- new metadata length is greater than some `MaxMetadataLength`.
+- new metadata length is greater than `MaxMetadataLen` config.
 - the signer is not the admin of the group.
 
 ## Msg/CreateGroupPolicy
@@ -46,7 +49,7 @@ A new group policy can be created with the `MsgCreateGroupPolicy`, which has an
 
 +++ https://github.com/cosmos/cosmos-sdk/blob/6f58963e7f6ce820e9b33f02f06f7b96f6d2e347/proto/cosmos/group/v1beta1/tx.proto#L121-L142
 
-It's expecting to fail if metadata length is greater than some `MaxMetadataLength`.
+It's expecting to fail if metadata length is greater than `MaxMetadataLen` config.
 
 ## Msg/UpdateGroupPolicyAdmin
 
@@ -71,7 +74,7 @@ The `UpdateGroupPolicyMetadata` can be used to update a group policy metadata.
 +++ https://github.com/cosmos/cosmos-sdk/blob/6f58963e7f6ce820e9b33f02f06f7b96f6d2e347/proto/cosmos/group/v1beta1/tx.proto#L184-L195
 
 It's expecting to fail if:
-- new metadata length is greater than some `MaxMetadataLength`.
+- new metadata length is greater than `MaxMetadataLen` config.
 - the signer is not the admin of the group.
 
 ## Msg/CreateProposal
@@ -81,7 +84,7 @@ An optional `Exec` value can be provided to try to execute the proposal immediat
 
 +++ https://github.com/cosmos/cosmos-sdk/blob/6f58963e7f6ce820e9b33f02f06f7b96f6d2e347/proto/cosmos/group/v1beta1/tx.proto#L218-L239
 
-It's expecting to fail if metadata length is greater than some `MaxMetadataLength`.
+It's expecting to fail if metadata length is greater than `MaxMetadataLen` config.
 
 ## Msg/Vote
 
@@ -90,7 +93,7 @@ An optional `Exec` value can be provided to try to execute the proposal immediat
 
 +++ https://github.com/cosmos/cosmos-sdk/blob/6f58963e7f6ce820e9b33f02f06f7b96f6d2e347/proto/cosmos/group/v1beta1/tx.proto#L248-L265
 
-It's expecting to fail if metadata length is greater than some `MaxMetadataLength`.
+It's expecting to fail if metadata length is greater than `MaxMetadataLen` config.
 
 ## Msg/Exec
 

x/group/types.go

@@ -16,11 +16,6 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/group/internal/orm"
 )
 
-// MaxMetadataLength defines the max length of the metadata bytes field
-// for various entities within the group module
-// TODO: This could be used as params once x/params is upgraded to use protobuf
-const MaxMetadataLength = 255
-
 type DecisionPolicyResult struct {
 	Allow bool
 	Final bool