docs: v2 upgrading instructions

UPGRADING.md

@@ -1,3 +1,273 @@
-# Upgrade AtomOne
+# Upgrading AtomOne
 
-This guide provides instructions for upgrading to specific versions of AtomOne.
+This guide provides instructions for upgrading AtomOne from v1.x to v2.x.
+
+This document describes the steps for validators and full node operators, to
+upgrade successfully for the AtomOne v2 release.
+
+For more details on the release, please see the [release notes][v2].
+
+## Release Binary
+
+Please use the correct release binary: `v2.0.0`.
+
+## Instructions
+
+- [Upgrading AtomOne](#upgrading-atomeone)
+  - [Release Binary](#release-binary)
+  - [Instructions](#instructions)
+  - [On-chain governance proposal attains consensus](#on-chain-governance-proposal-attains-consensus)
+  - [Upgrade date](#upgrade-date)
+  - [Preparing for the upgrade](#preparing-for-the-upgrade)
+    - [System requirements](#system-requirements)
+    - [Backups](#backups)
+    - [Testing](#testing)
+    - [Current runtime](#current-runtime)
+    - [Target runtime](#target-runtime)
+  - [Upgrade steps](#upgrade-steps)
+    - [`minimum-gas-prices` change](#minimum-gas-prices-change)
+    - [Method I: Manual Upgrade](#method-i-manual-upgrade)
+    - [Method II: Upgrade using Cosmovisor](#method-ii-upgrade-using-cosmovisor)
+      - [Manually preparing the binary](#manually-preparing-the-binary)
+        - [Preparation](#preparation)
+      - [Auto-Downloading the AtomOne binary](#auto-downloading-the-gaia-binary)
+  - [Expected upgrade result](#expected-upgrade-result)
+  - [Upgrade duration](#upgrade-duration)
+  - [Rollback plan](#rollback-plan)
+  - [Communications](#communications)
+  - [Risks](#risks)
+
+## On-chain governance proposal attains consensus
+
+Once a software upgrade governance proposal is submitted to the Cosmos Hub,
+both a reference to this proposal and an `UPGRADE_HEIGHT` are added to the
+[release notes][v2].
+If and when this proposal reaches consensus, the upgrade height will be used to
+halt the "old" chain binaries. You can check the proposal on one of the block
+explorers or using the `atomoned` CLI tool.
+Neither core developers nor core funding entities control the governance.
+
+## Upgrade date
+
+The date/time of the upgrade is subject to change as blocks are not generated
+at a constant interval. You can stay up-to-date by checking the estimated
+estimated time until the block is produced one of the block explorers (e.g.
+https://www.mintscan.io/atomone/blocks/`UPGRADE_HEIGHT`).
+
+## Preparing for the upgrade
+
+### System requirements
+
+### Backups
+
+Prior to the upgrade, validators are encouraged to take a full data snapshot.
+Snapshotting depends heavily on infrastructure, but generally this can be done
+by backing up the `.atomone` directory.
+If you use Cosmovisor to upgrade, by default, Cosmovisor will backup your data
+upon upgrade. See below [upgrade using cosmovisor](#method-ii-upgrade-using-cosmovisor)
+section.
+
+It is critically important for validator operators to back-up the
+`.atomone/data/priv_validator_state.json` file after stopping the atomoned
+process. This file is updated every block as your validator participates in
+consensus rounds. It is a critical file needed to prevent double-signing, in
+case the upgrade fails and the previous chain needs to be restarted.
+
+### Testing
+
+XXX UPDATE
+For those validator and full node operators that are interested in ensuring
+preparedness for the impending upgrade, you can run a [v15 Local Testnet](https://github.com/cosmos/testnets/tree/master/local) or join in our [Cosmos Hub Public Testnet](https://github.com/cosmos/testnets/tree/master/public).
+
+### Current runtime
+
+The AtomOne mainnet network, `atomone-1`, is currently running [AtomOne
+v1.0.0][v1]. We anticipate that operators who are running on v1.0.0, will be
+able to upgrade successfully. Validators are expected to ensure that their
+systems are up to date and capable of performing the upgrade. This includes
+running the correct binary and if building from source, building with the
+appropriate `go` version.
+
+### Target runtime
+
+The AtomOne mainnet network, `atomone-1`, will run **[AtomOne v2.0.0][v2].
+Operators _**MUST**_ use this version post-upgrade to remain connected to the
+network. The new version requires `go v1.21` to build successfully.
+
+## Upgrade steps
+
+There are 2 major ways to upgrade a node:
+
+- Manual upgrade
+- Upgrade using [Cosmovisor](https://pkg.go.dev/cosmossdk.io/tools/cosmovisor)
+    - Either by manually preparing the new binary
+    - Or by using the auto-download functionality (this is not yet recommended)
+
+If you prefer to use Cosmovisor to upgrade, some preparation work is needed
+before upgrade.
+
+### `minimum-gas-prices` change
+
+**AtomOne v2.0.0** introduces `photon` as the only fee token, so it requires a
+modification of the validator configuration, namely the `minimum-gas-prices`
+which must contain the `uphoton` denom in addition to the `uatone` denom (so
+both denom). This setting is located in the `$ATOMONE_HOME/config/app.toml`
+file.
+
+For example, considering this existing setting:
+```toml
+minimum-gas-prices = "0.001uatone"
+```
+Before upgrading, the setting should be changed to:
+```toml
+minimum-gas-prices = "0.001uatone,0.001uphoton"
+```
+
+### Method I: Manual Upgrade
+
+Make sure **AtomOne v1.0.0** is installed by either downloading a [compatible
+binary][v1], or building from source. Check the required version to build this
+binary in the `Makefile`.
+
+Run AtomOne v1.0.0 till upgrade height, the node will panic:
+
+```shell
+ERR UPGRADE "v2" NEEDED at height: <UPGRADE_HEIGHT>: upgrade to v2 and applying upgrade "v2" at height:<UPGRADE_HEIGHT>
+```
+
+Stop the node, and switch the binary to **AtomOne v2.0.0** and re-start by `atomone start`.
+
+It may take several minutes to a few hours until validators with a total sum
+voting power > 2/3 to complete their node upgrades. After that, the chain can
+continue to produce blocks.
+
+### Method II: Upgrade using Cosmovisor
+
+#### Manually preparing the binary
+
+##### Preparation
+
+- Install the latest version of Cosmovisor (`1.5.0`):
+
+```shell
+go install cosmossdk.io/tools/cosmovisor/cmd/cosmovisor@latest
+cosmovisor version
+# cosmovisor version: v1.5.0
+```
+
+- Create a `cosmovisor` folder inside `$ATOMONE_HOME` and move AtomOne `v1.0.0`
+into `$ATOMONE_HOME/cosmovisor/genesis/bin`:
+
+```shell
+mkdir -p $ATOMONE_HOME/cosmovisor/genesis/bin
+cp $(which atomoned) $ATOMONE_HOME/cosmovisor/genesis/bin
+```
+
+- Build AtomOne `v2.0.0`, and move atomoned `v2.0.0` to
+  `$ATOMONE_HOME/cosmovisor/upgrades/v2/bin`
+
+```shell
+mkdir -p  $ATOMONE_HOME/cosmovisor/upgrades/v2/bin
+cp $(which atomoned) $ATOMONE_HOME/cosmovisor/upgrades/v2/bin
+```
+
+At this moment, you should have the following structure:
+
+```shell
+.
+├── current -> genesis or upgrades/<name>
+├── genesis
+│   └── bin
+│       └── atomoned  # old: v1.0.0
+└── upgrades
+    └── v2
+        └── bin
+            └── atomoned  # new: v2.0.0
+```
+
+- Export the environmental variables:
+
+```shell
+export DAEMON_NAME=atomoned
+# please change to your own gaia home dir
+# please note `DAEMON_HOME` has to be absolute path
+export DAEMON_HOME=$ATOMONE_HOME
+export DAEMON_RESTART_AFTER_UPGRADE=true
+```
+
+- Start the node:
+
+```shell
+cosmovisor run start --x-crisis-skip-assert-invariants --home $DAEMON_HOME
+```
+
+XXX NOTE: keep that sentence ??
+Skipping the invariant checks is strongly encouraged since it decreases the
+upgrade time significantly and since there are some other improvements coming
+to the crisis module in the next release of the Cosmos SDK.
+
+#### Auto-Downloading the AtomOne binary
+
+**This method is not recommended!**
+
+## Expected upgrade result
+
+When the upgrade block height is reached, AtomOne will panic and stop:
+
+This may take a few minutes to a few hours.
+After upgrade, the chain will continue to produce blocks when validators with a
+total sum voting power > 2/3 complete their node upgrades.
+
+## Upgrade duration
+
+The upgrade may take a few minutes to several hours to complete because
+atomone-1 participants operate globally with differing operating hours and it
+may take some time for operators to upgrade their binaries and connect to the
+network.
+
+## Rollback plan
+
+During the network upgrade, core Cosmos teams will be keeping an ever vigilant
+eye and communicating with operators on the status of their upgrades. During
+this time, the core teams will listen to operator needs to determine if the
+upgrade is experiencing unintended challenges. In the event of unexpected
+challenges, the core teams, after conferring with operators and attaining
+social consensus, may choose to declare that the upgrade will be skipped.
+
+Steps to skip this upgrade proposal are simply to resume the `atomone-1`
+network with the (downgraded) v1.0.0 binary using the following command:
+
+```shell
+atomoned start --unsafe-skip-upgrade <UPGRADE_HEIGHT>
+```
+
+Note: There is no particular need to restore a state snapshot prior to the
+upgrade height, unless specifically directed by core Cosmos teams.
+
+Important: A social consensus decision to skip the upgrade will be based solely
+on technical merits, thereby respecting and maintaining the decentralized
+governance process of the upgrade proposal's successful YES vote.
+
+## Communications
+
+Operators are encouraged to join the `#validate-private` channel
+of the AtomOne (unofficial) Discord. This channel is the primary communication
+tool for operators to ask questions, report upgrade status, report technical
+issues, and to build social consensus should the need arise. This channel is
+restricted to known operators and requires verification beforehand. Requests to
+join the `#validator-private` channel can be sent to the `#support` channel.
+
+## Risks
+
+As a validator performing the upgrade procedure on your consensus nodes carries
+a heightened risk of double-signing and being slashed. The most important piece
+of this procedure is verifying your software version and genesis file hash
+before starting your validator and signing.
+
+The riskiest thing a validator can do is discover that they made a mistake and
+repeat the upgrade procedure again during the network startup. If you discover
+a mistake in the process, the best thing to do is wait for the network to start
+before correcting it.
+
+[v1]: https://github.com/atomone-hub/atomone/releases/tag/v1.0.0
+[v2]: https://github.com/atomone-hub/atomone/releases/tag/v2.0.0