migrations: add migration for adding registry-qps and registry-burst

Adds a migration for two new settings `settings.kubernetes.registry-qps`
and `settings.kubernetes.registry-burst`

Release.toml

@@ -41,4 +41,5 @@ version = "1.0.8"
 "(1.0.8, 1.1.0)" = [
     "migrate_v1.1.0_kubelet-server-tls-bootstrap.lz4",
     "migrate_v1.1.0_kubelet-cloud-provider.lz4",
+    "migrate_v1.1.0_kubelet-registry-qps-registry-burst.lz4",
 ]

sources/Cargo.toml

@@ -55,6 +55,7 @@ members = [
     "api/migration/migrations/v1.0.8/add-bootstrap-containers",
     "api/migration/migrations/v1.1.0/kubelet-server-tls-bootstrap",
     "api/migration/migrations/v1.1.0/kubelet-cloud-provider",
+    "api/migration/migrations/v1.1.0/kubelet-registry-qps-registry-burst",
 
     "bottlerocket-release",
 

sources/api/migration/migrations/v1.1.0/kubelet-registry-qps-registry-burst/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "kubelet-registry-qps-registry-burst"
+version = "0.1.0"
+authors = ["Tianhao Geng <tianhg@amazon.com>"]
+license = "Apache-2.0 OR MIT"
+edition = "2018"
+publish = false
+# Don't rebuild crate just because of changes to README.
+exclude = ["README.md"]
+
+[dependencies]
+migration-helpers = { path = "../../../migration-helpers" }

sources/api/migration/migrations/v1.1.0/kubelet-registry-qps-registry-burst/src/main.rs

@@ -0,0 +1,24 @@
+#![deny(rust_2018_idioms)]
+
+use migration_helpers::common_migrations::AddSettingsMigration;
+use migration_helpers::{migrate, Result};
+use std::process;
+
+/// We added two new settings for configuring kubelet, `settings.kubernetes.registry-qps`
+/// and `settings.kubernetes.registry-burst`
+fn run() -> Result<()> {
+    migrate(AddSettingsMigration(&[
+        "settings.kubernetes.registry-qps",
+        "settings.kubernetes.registry-burst",
+    ]))
+}
+
+// Returning a Result from main makes it print a Debug representation of the error, but with Snafu
+// we have nice Display representations of the error, so we wrap "main" (run) and print any error.
+// https://github.com/shepmaster/snafu/issues/110
+fn main() {
+    if let Err(e) = run() {
+        eprintln!("{}", e);
+        process::exit(1);
+    }
+}