zeroFruit

// SoftwareUpgradeProposal is a gov Content type for initiating a software
// upgrade.
message SoftwareUpgradeProposal {
  string title       = 1;
  string description = 2;
  Plan   plan        = 3 [(gogoproto.nullable) = false];
}

// Plan specifies information about a planned upgrade and when it should occur.
message Plan {

zeroFruit

// EndBlocker called every block, process inflation, update validator set.
func EndBlocker(ctx sdk.Context, keeper keeper.Keeper) {
    keeper.IterateActiveProposalsQueue(ctx, ctx.BlockHeader().Time, func(proposal types.Proposal) bool {
        passes, burnDeposits, tallyResults := keeper.Tally(ctx, proposal)
        ...
      
        if passes {
            handler := keeper.Router().GetRoute(proposal.ProposalRoute())
            cacheCtx, writeCache := ctx.CacheContext()
            err := handler(cacheCtx, proposal.GetContent())

zeroFruit

func NewSimApp(...) *SimApp {
    ...
    // register the proposal types
    govRouter := govtypes.NewRouter()
    govRouter.AddRoute(govtypes.RouterKey, govtypes.ProposalHandler).
        AddRoute(upgradetypes.RouterKey, upgrade.NewSoftwareUpgradeProposalHandler(app.UpgradeKeeper))
 
    govKeeper := govkeeper.NewKeeper(
        appCodec, keys[govtypes.StoreKey], app.GetSubspace(govtypes.ModuleName), app.AccountKeeper, app.BankKeeper,
        &stakingKeeper, govRouter,

zeroFruit

// UpgradeHandler specifies the type of function that is called when an upgrade
// is applied.
//
// `fromVM` is a VersionMap of moduleName to fromVersion (unit64), where
// fromVersion denotes the version from which we should migrate the module, the
// target version being the module's latest version in the return VersionMap,
// let's call it `toVM`.
//
// `fromVM` is retrieved from x/upgrade's store, whereas `toVM` is chosen
// arbitrarily by the app developer (and persisted to x/upgrade's store right

zeroFruit

// VersionMap is a map of moduleName -> version
type VersionMap map[string]uint64

zeroFruit

func (am AppModule) BeginBlock(ctx sdk.Context, req abci.RequestBeginBlock) {
    BeginBlocker(am.keeper, ctx, req)
}

func BeginBlocker(k keeper.Keeper, ctx sdk.Context, _ abci.RequestBeginBlock) {
    plan, found := k.GetUpgradePlan(ctx)
    ...
    if !found {
        return
    }

zeroFruit

. # application project root
├── app
│   ├── upgrades
│   │   ├── v2
│   │   │   ├── constants.go 
│   │   │   └── upgrades.go
│   │   └── ...
│   ├── app.go
│   └── upgrades.go
└── ...

zeroFruit

package v2 // constants.go

const (
    UpgradeName = "v2.0.0"
    ...
)

zeroFruit

package v2 // upgrades.go

func CreateUpgradeHandler(
    mm *module.Manager,
    configurator module.Configurator,
    ...
) upgradetypes.UpgradeHandler {
    return func(ctx sdk.Context, plan upgradetypes.Plan, vm module.VersionMap) (module.VersionMap, error) {
        ...
        

zeroFruit

package app // upgrades.go

func (app *App) setupUpgradeHandlers(
    configurator module.Configurator,
    ...
) {
    app.UpgradeKeeper.SetUpgradeHandler(
        v2.UpgradeName,
        v2.CreateUpgradeHandler(app.mm, configurator, ...),
    )