Merge pull request fedimint#5605 from dpc/24-07-11-rel-notes-upgrade

chore: require acking v0.4 upgrade instructions via env var

devimint/src/vars.rs

@@ -118,6 +118,7 @@ declare_vars! {
         FM_API_SECRET: Option<String> = std::env::var("FM_API_SECRET").ok().or_else(|| FM_FORCE_API_SECRETS.get_active()); env: "FM_API_SECRET";
 
         FM_IN_DEVIMINT: String = "1".to_string(); env: FM_IN_DEVIMINT_ENV;
+        FM_SKIP_REL_NOTES_ACK: String = "1".to_string(); env: "FM_SKIP_REL_NOTES_ACK";
 
         FM_FED_SIZE: usize = fed_size; env: "FM_FED_SIZE";
         FM_OFFLINE_NODES: usize = offline_nodes; env: "FM_OFFLINE_NODES";

docs/RELEASE_NOTES-v0.4.md

@@ -0,0 +1,30 @@
+## Important Fedimint v0.4 Release Notes
+
+This document describes only critically important release notes.
+For all the non-critical release notes, see usual places (like github release pages).
+
+### Lock-step upgrade requirement
+
+Upgrading existing Federations that were created using previous (pre v0.4.x)
+versions of `fedimintd` requires stopping all peers at the exact same session count
+(mint's internal consensus height), and switching to new v0.4.x release at the same time,
+before starting them again.
+
+
+To schedule stopping your `fedimintd` at specific consensus height you can
+use `fedimin-cli` command:
+
+**Details to be described in the near feature. Check newer version of this document.**
+
+### Acknowledging
+
+To acknowledge that you are aware of requirements described above please set:
+
+```
+FM_REL_NOTES_ACK=0_4_xyz
+```
+
+in your `fedimintd` environment when running `fedimintd v0.4.x`.
+
+If you are a `fedimintd` integrator (e.g. wrap `fedimintd` in shell scripts, Dockerfiles, NixOS modules, etc.),
+please make sure the end user/operator of `fedimintd` is required to set it.

fedimintd/src/fedimintd.rs

@@ -5,7 +5,7 @@ use std::net::SocketAddr;
 use std::path::PathBuf;
 use std::time::Duration;
 
-use anyhow::{format_err, Context};
+use anyhow::{bail, format_err, Context};
 use clap::{Parser, Subcommand};
 use fedimint_core::admin_client::ConfigGenParamsRequest;
 use fedimint_core::config::{
@@ -39,7 +39,7 @@ use fedimint_wallet_server::common::config::{
 };
 use fedimint_wallet_server::WalletInit;
 use futures::FutureExt;
-use tracing::{debug, error, info};
+use tracing::{debug, error, info, warn};
 
 use crate::default_esplora_server;
 use crate::envs::{
@@ -215,6 +215,7 @@ impl Fedimintd {
         );
 
         handle_version_hash_command(code_version_hash);
+        check_release_notes_ack()?;
 
         let fedimint_version = env!("CARGO_PKG_VERSION");
 
@@ -464,6 +465,37 @@ impl Fedimintd {
     }
 }
 
+fn check_release_notes_ack() -> anyhow::Result<()> {
+    const VERSION: &str = "v0.4";
+    const FM_SKIP_REL_NOTES_ACK_ENV: &str = "FM_SKIP_REL_NOTES_ACK";
+    const FM_REL_NOTES_ACK_ENV: &str = "FM_REL_NOTES_ACK";
+    // the suffix here is to prevent people getting to smart and trying to
+    // automate-it-out change it for every release
+    const FM_REL_NOTES_CUR_VAL: &str = "0_4_xyz";
+
+    // This is here only for upgrade tests and other automated tests, where
+    // juggling different values might be impossible.
+    if is_env_var_set(FM_SKIP_REL_NOTES_ACK_ENV) {
+        warn!("Skipping release notes ack. This should never be happening in production");
+        return Ok(());
+    }
+
+    // The actual code-path we want end users to take
+    if std::env::var(FM_REL_NOTES_ACK_ENV).unwrap_or_default() == FM_REL_NOTES_CUR_VAL {
+        return Ok(());
+    }
+
+    eprintln!(
+        "This version of fedimintd has some criticallly important requirements you should be aware of."
+    );
+    eprintln!("Not following them will likely result in a consensus failure or other problems.");
+    eprintln!("To ensure you have read them, you must set specific environment variable to a specific value.");
+    eprintln!("Robustness and safety of your federations is our primary concern.");
+    eprintln!("See https://github.com/fedimint/fedimint/blob/releases/{VERSION}/docs/RELEASE_NOTES-{VERSION}.md");
+
+    bail!("Must acknowledge release notes. See details above.")
+}
+
 async fn run(
     opts: ServerOpts,
     task_group: &TaskGroup,