add rust-version.sh script

ci/read-cargo-variable.sh

@@ -0,0 +1,14 @@
+# source this file
+
+readCargoVariable() {
+  declare variable="$1"
+  declare Cargo_toml="$2"
+
+  while read -r name equals value _; do
+    if [[ $name = "$variable" && $equals = = ]]; then
+      echo "${value//\"/}"
+      return
+    fi
+  done < <(cat "$Cargo_toml")
+  echo "Unable to locate $variable in $Cargo_toml" 1>&2
+}

ci/rust-version.sh

@@ -0,0 +1,74 @@
+#!/usr/bin/env bash
+
+# Source:
+# https://github.com/solana-labs/solana-accountsdb-plugin-postgres/blob/master/ci/rust-version.sh
+
+#
+# This file maintains the rust versions for use by CI.
+#
+# Obtain the environment variables without any automatic toolchain updating:
+#   $ source ci/rust-version.sh
+#
+# Obtain the environment variables updating both stable and nightly, only stable, or
+# only nightly:
+#   $ source ci/rust-version.sh all
+#   $ source ci/rust-version.sh stable
+#   $ source ci/rust-version.sh nightly
+
+# Then to build with either stable or nightly:
+#   $ cargo +"$rust_stable" build
+#   $ cargo +"$rust_nightly" build
+#
+
+if [[ -n $RUST_STABLE_VERSION ]]; then
+  stable_version="$RUST_STABLE_VERSION"
+else
+  # read rust version from rust-toolchain.toml file
+  base="$(dirname "${BASH_SOURCE[0]}")"
+  # pacify shellcheck: cannot follow dynamic path
+  # shellcheck disable=SC1090,SC1091
+  source "$base/../ci/read-cargo-variable.sh"
+  stable_version=$(readCargoVariable channel "$base/../rust-toolchain.toml")
+fi
+
+if [[ -n $RUST_NIGHTLY_VERSION ]]; then
+  nightly_version="$RUST_NIGHTLY_VERSION"
+else
+  nightly_version=2022-04-01
+fi
+
+
+export rust_stable="$stable_version"
+export rust_stable_docker_image=solanalabs/rust:"$stable_version"
+
+export rust_nightly=nightly-"$nightly_version"
+export rust_nightly_docker_image=solanalabs/rust-nightly:"$nightly_version"
+
+[[ -z $1 ]] || (
+  rustup_install() {
+    declare toolchain=$1
+    if ! cargo +"$toolchain" -V > /dev/null; then
+      echo "$0: Missing toolchain? Installing...: $toolchain" >&2
+      rustup install "$toolchain"
+      cargo +"$toolchain" -V
+    fi
+  }
+
+  set -e
+  cd "$(dirname "${BASH_SOURCE[0]}")"
+  case $1 in
+  stable)
+    rustup_install "$rust_stable"
+    ;;
+  nightly)
+    rustup_install "$rust_nightly"
+    ;;
+  all)
+    rustup_install "$rust_stable"
+    rustup_install "$rust_nightly"
+    ;;
+  *)
+    echo "$0: Note: ignoring unknown argument: $1" >&2
+    ;;
+  esac
+)