Remove all non-seed Head Ambassador members from the Program (polkado…

…t-fellows#422)

The original OpenGov for the Ambassador Program stated
[21](https://polkadot.polkassembly.io/referenda/487) maximal Head
Ambassadors. The limit of 21 has now been put in place, but there area
already more than 21 in there. This Merge Requests removes everyone that
was not among the first 21.

quote:
>The program should only allow up to 21 Head Ambassadors. Once the
number is reached, adding a new HA shall require replacing an existing
HA or making a proposal to all token holders on the Ambassador Admin
track to alter the program.

Change:
Add a migration that executes with the next runtime upgrade and removes
everyone from the Ambassador program that is not part of the first 21
elected Head Ambassadors:

```pre
- 14Gn7SEmCgMX7Ukuppnw5TRjA7pao2HFpuJo39frB42tYLEh
- 1LboBQLsa1iTpGzZvXcSd5VF7jfUYf6MzPNoRy2HT9D9FNk
- 12xRcHjvStkUYgzTh9vyqinN3tUpddgcPnSUcLXZ3ty44Mq1
- 16SQKanFTrN18k9UE8EFbtyeSGNFPjRBg8caVhGoUNL8cdh6
- 1HPKZzzd9nyr2DdvtPxytNMZm3Ld5nh3BBY4Ecgg9JxgL7G
- 13Ec62Cvw9jmPxA23EidSwASPs9X2Vohqv9RCogCfDvXC4c8
- 14N5cTFuzJf6irrQkKNAjiADKsCxgk48LUKx2fA77YRruzMW
- 1hFmn2CuqXqxHgKDqqs2xRBpsPkiRXzJfcLbfDgsW7qgmpA
- 15rYBV5YwGmhzee5PWqrnQtb2HhwWP2rK2f4cLMhFfcNdPZL
- 14x5RbyJxD6KvNyncbJQuJJJ3zHinXg57YKwhJ7q9T9aJq4n
- 1ZSPR3zNg5Po3obkhXTPR95DepNBzBZ3CyomHXGHK9Uvx6w
- 1yCg8NSCgjS4K5KDK5DZGhxUCxmgVyhyG6vBPn5wqUmLuYo
- 14VDkd5mWY9SajUUnEg2LgMgVrbY412H7xn7Y7EXjhnGkiBF
- 1CRmVRcQymMpot855oKDq76kF19jJezMMkGcrvHh1ozEqXa
- 15cZn8K1DaE7qiBWK6mGFJMKYKjFrALTVwe5urpD9PzKSsPY
- 146ZZqm2cMHLf3ju7oc8M9JnPaAktuADAKThagKnXqzjPJbZ
- 14DJADQdE3bUQMFsjsejwCLiG1tiMDsFhCCiXavyBTKHu6kr
- 1HGnvAkk9nbfZ58CzUJhjcrLdEDMkr5qNkqqYkyD5BF5v6Y
- 155G4q3yS7gW933PrdxrY4ersg2YhqWUnGC8GUd7NWiZwuKj
- 16XYgDGN6MxvdmjhRsHLT1oqQVDwGdEPVQqC42pRXiZrE8su
- 15fHj7Q7SYxqMgZ38UpjXS8cxdq77rczTP3JgY9JVi5piMPN
```

## Implications

- Also removes all non-HA members
- Could end up with less than 21 HAs if seed HAs are being removed in
the meantime

---------

Signed-off-by: Oliver Tale-Yazdi <[email protected]>
Co-authored-by: joe petrowski <[email protected]>
Co-authored-by: fellowship-merge-bot[bot] <151052383+fellowship-merge-bot[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -50,6 +50,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Added
 
 - Fast promotion tracks for the Fellowship ranks I-III ([polkadot-fellows/runtimes#356](https://github.com/polkadot-fellows/runtimes/pull/356)).
+- Migration to remove all but the 21 first elected Head Ambassador members from the Program ([polkadot-fellows/runtimes#422](https://github.com/polkadot-fellows/runtimes/pull/422)).
 
 ### Changed
 

system-parachains/collectives/collectives-polkadot/src/ambassador/migrations.rs

@@ -0,0 +1,104 @@
+// Copyright (C) 2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Migrations for the Ambassador Program.
+
+use super::*;
+use crate::AccountId;
+#[cfg(feature = "try-runtime")]
+use frame_support::ensure;
+use frame_support::traits::{Defensive, OnRuntimeUpgrade, UnfilteredDispatchable};
+use frame_system::RawOrigin;
+use pallet_ranked_collective::WeightInfo;
+use sp_core::crypto::Ss58Codec;
+
+/// The first 21 Head Ambassadors that have been inducted.
+///
+/// Query `AmbassadorCollective::members` at block 4,326,024 (hash
+/// `0x7ca86d410526e9e3cefa210bfb71b3abc52396e658d5c63f553c8a6ee5845289`).
+fn first_21() -> [AccountId; 21] {
+	[
+		AccountId::from_ss58check("14Gn7SEmCgMX7Ukuppnw5TRjA7pao2HFpuJo39frB42tYLEh").unwrap(),
+		AccountId::from_ss58check("1LboBQLsa1iTpGzZvXcSd5VF7jfUYf6MzPNoRy2HT9D9FNk").unwrap(),
+		AccountId::from_ss58check("12xRcHjvStkUYgzTh9vyqinN3tUpddgcPnSUcLXZ3ty44Mq1").unwrap(),
+		AccountId::from_ss58check("16SQKanFTrN18k9UE8EFbtyeSGNFPjRBg8caVhGoUNL8cdh6").unwrap(),
+		AccountId::from_ss58check("1HPKZzzd9nyr2DdvtPxytNMZm3Ld5nh3BBY4Ecgg9JxgL7G").unwrap(),
+		AccountId::from_ss58check("13Ec62Cvw9jmPxA23EidSwASPs9X2Vohqv9RCogCfDvXC4c8").unwrap(),
+		AccountId::from_ss58check("14N5cTFuzJf6irrQkKNAjiADKsCxgk48LUKx2fA77YRruzMW").unwrap(),
+		AccountId::from_ss58check("1hFmn2CuqXqxHgKDqqs2xRBpsPkiRXzJfcLbfDgsW7qgmpA").unwrap(),
+		AccountId::from_ss58check("15rYBV5YwGmhzee5PWqrnQtb2HhwWP2rK2f4cLMhFfcNdPZL").unwrap(),
+		AccountId::from_ss58check("14x5RbyJxD6KvNyncbJQuJJJ3zHinXg57YKwhJ7q9T9aJq4n").unwrap(),
+		AccountId::from_ss58check("1ZSPR3zNg5Po3obkhXTPR95DepNBzBZ3CyomHXGHK9Uvx6w").unwrap(),
+		AccountId::from_ss58check("1yCg8NSCgjS4K5KDK5DZGhxUCxmgVyhyG6vBPn5wqUmLuYo").unwrap(),
+		AccountId::from_ss58check("14VDkd5mWY9SajUUnEg2LgMgVrbY412H7xn7Y7EXjhnGkiBF").unwrap(),
+		AccountId::from_ss58check("1CRmVRcQymMpot855oKDq76kF19jJezMMkGcrvHh1ozEqXa").unwrap(),
+		AccountId::from_ss58check("15cZn8K1DaE7qiBWK6mGFJMKYKjFrALTVwe5urpD9PzKSsPY").unwrap(),
+		AccountId::from_ss58check("146ZZqm2cMHLf3ju7oc8M9JnPaAktuADAKThagKnXqzjPJbZ").unwrap(),
+		AccountId::from_ss58check("14DJADQdE3bUQMFsjsejwCLiG1tiMDsFhCCiXavyBTKHu6kr").unwrap(),
+		AccountId::from_ss58check("1HGnvAkk9nbfZ58CzUJhjcrLdEDMkr5qNkqqYkyD5BF5v6Y").unwrap(),
+		AccountId::from_ss58check("155G4q3yS7gW933PrdxrY4ersg2YhqWUnGC8GUd7NWiZwuKj").unwrap(),
+		AccountId::from_ss58check("16XYgDGN6MxvdmjhRsHLT1oqQVDwGdEPVQqC42pRXiZrE8su").unwrap(),
+		AccountId::from_ss58check("15fHj7Q7SYxqMgZ38UpjXS8cxdq77rczTP3JgY9JVi5piMPN").unwrap(),
+	]
+}
+
+/// Removes everyone from the Ambassador collective besides the first 21 HAs that were registered.
+pub struct TruncateHeadAmbassadors;
+
+impl OnRuntimeUpgrade for TruncateHeadAmbassadors {
+	fn on_runtime_upgrade() -> Weight {
+		let mut to_be_removed =
+			pallet_ranked_collective::Members::<Runtime, AmbassadorCollectiveInstance>::iter_keys()
+				.collect::<Vec<_>>();
+
+		// first 21 should not be removed
+		let first_21 = first_21();
+		to_be_removed.retain(|acc| !first_21.contains(acc));
+
+		log::info!("Removing {} member(s) from the Ambassador Collective.", to_be_removed.len());
+
+		for acc in &to_be_removed {
+			log::info!("Removing member {}", acc.to_ss58check());
+
+			// The pallet has no nice trait that we could call, so need to use the extrinsic...
+			let origin: RuntimeOrigin = RawOrigin::Root.into();
+
+			let call = pallet_ranked_collective::Call::<Runtime, AmbassadorCollectiveInstance>::remove_member { who: acc.clone().into(), min_rank: 3 };
+			let _ = call.dispatch_bypass_filter(origin).defensive();
+		}
+
+		crate::weights::pallet_ranked_collective_ambassador_collective::WeightInfo::<Runtime>::remove_member(3).saturating_mul(to_be_removed.len() as u64)
+	}
+
+	#[cfg(feature = "try-runtime")]
+	fn post_upgrade(_: Vec<u8>) -> Result<(), sp_runtime::TryRuntimeError> {
+		let num =
+			pallet_ranked_collective::Members::<Runtime, AmbassadorCollectiveInstance>::iter_keys()
+				.count();
+		ensure!(num <= 21, "There must be not more than 21 Head Ambassadors.");
+
+		let seed = first_21();
+		for ambassador in
+			pallet_ranked_collective::Members::<Runtime, AmbassadorCollectiveInstance>::iter_keys()
+		{
+			ensure!(
+				seed.contains(&ambassador),
+				"Ambassador is not in the seed and should have been removed."
+			);
+		}
+
+		Ok(())
+	}
+}

system-parachains/collectives/collectives-polkadot/src/ambassador/mod.rs

@@ -28,6 +28,7 @@
 //! imported or inducted into [AmbassadorCore](pallet_core_fellowship)).
 //! - Ambassador Program Sub-Treasury (via [AmbassadorTreasury](pallet_treasury)).
 
+pub mod migrations;
 pub mod origins;
 mod tracks;
 

system-parachains/collectives/collectives-polkadot/src/lib.rs

@@ -756,6 +756,7 @@ type Migrations = (
 	cumulus_pallet_xcmp_queue::migration::v5::MigrateV4ToV5<Runtime>,
 	pallet_core_fellowship::migration::MigrateV0ToV1<Runtime, fellowship::FellowshipCoreInstance>,
 	pallet_core_fellowship::migration::MigrateV0ToV1<Runtime, ambassador::AmbassadorCoreInstance>,
+	ambassador::migrations::TruncateHeadAmbassadors,
 	// permanent
 	pallet_xcm::migration::MigrateToLatestXcmVersion<Runtime>,
 );