Release: Scripts to change versions in all go.mod files and push tags upstream.

Examplar invocations:

Edit go.mod files such that all etcd modules are pointing on given version:

```
% DRY_RUN=false TARGET_VERSION="v3.5.13" ./scripts/release_mod.sh update_versions
```

Tag latest commit with current version number for all the modules and push upstream:
```
% DRY_RUN=true REMOTE_REPO="origin" ./scripts/release_mod.sh push_mod_tags
```

scripts/release_mod.sh

@@ -0,0 +1,124 @@
+#!/usr/bin/env bash
+
+# Examples:
+
+# Edit go.mod files such that all etcd modules are pointing on given version:
+#
+# % DRY_RUN=false TARGET_VERSION="v3.5.13" ./scripts/release_mod.sh update_versions
+
+# Tag latest commit with current version number for all the modules and push upstream:
+#
+# % DRY_RUN=false REMOTE_REPO="origin" ./scripts/release_mod.sh push_mod_tags
+
+set -e
+
+DRY_RUN=${DRY_RUN:-true}
+
+if ! [[ "$0" =~ scripts/release_mod.sh ]]; then
+  echo "must be run from repository root"
+  exit 255
+fi
+
+source ./scripts/test_lib.sh
+
+# _cmd prints help message
+function _cmd() {
+  log_error "Command required: ${0} [cmd]"
+  log_info "Available commands:"
+  log_info "  - update_versions  - Updates all cross-module versions to \${TARGET_VERSION} in the local client."
+  log_info "  - push_mod_tags    - Tags HEAD with all modules versions tags and pushes it to \${REMOTE_REPO}."
+}
+
+# maybe_run [cmd...] runs given command depending on the DRY_RUN flag.
+function maybe_run() {
+  if ${DRY_RUN}; then
+    log_warning -e "# DRY_RUN:\n  % ${*}"
+  else
+    run "${@}"
+  fi
+}
+
+# update_module_version [v2version] [v3version]
+#   Updates versions of cross-references in all internal references in current module.
+function update_module_version() {
+  local v3version="${1}"
+  local v2version="${2}"
+  local modules
+  modules=$(run go list -f '{{if not .Main}}{{if not .Indirect}}{{.Path}}{{end}}{{end}}' -m all)
+
+  v3deps=$(echo "${modules}" | grep -E "${REPO}/.*/v3")
+  for dep in ${v3deps}; do
+    maybe_run go mod edit -require "${dep}@${v3version}"
+  done
+
+  v2deps=$(echo "${modules}" | grep -E "${REPO}/.*/v2")
+  for dep in ${v2deps}; do
+    maybe_run go mod edit -require "${dep}@${v2version}"
+  done
+}
+
+# Updates all cross-module versions to ${TARGET_VERSION} in local client.
+function update_versions_cmd() {
+  assert_no_git_modifications || return 2
+
+  if [ -z "${TARGET_VERSION}" ]; then
+    log_error "TARGET_VERSION environment variable not set. Set it to e.g. v3.5.10-alpha.0"
+    return 2
+  fi
+
+  local v3version="${TARGET_VERSION}"
+  local v2version
+  # converts e.g. v3.5.0-alpha.0 --> v2.305.0-alpha.0
+  # shellcheck disable=SC2001
+  v2version="$(echo "${TARGET_VERSION}" | sed 's|^v3.\([0-9]*\).|v2.30\1.|g')"
+
+  log_info "DRY_RUN       : ${DRY_RUN}"
+  log_info "TARGET_VERSION: ${TARGET_VERSION}"
+  log_info ""
+  log_info "v3version: ${v3version}"
+  log_info "v2version: ${v2version}"
+
+  run_for_modules update_module_version "${v3version}" "${v2version}"
+}
+
+function push_mod_tags_cmd {
+  assert_no_git_modifications || return 2
+
+  if [ -z "${REMOTE_REPO}" ]; then
+    log_error "REMOTE_REPO environment variable not set"
+    return 2
+  fi
+  log_info "REMOTE_REPO:  ${REMOTE_REPO}"
+
+  # Any module ccan be used for this
+  local master_version
+  master_version=$(go list -f '{{.Version}}' -m "${REPO}/api/v3")
+  local tags=()
+
+  for module in $(modules); do
+    local version
+    version=$(go list -f '{{.Version}}' -m "${module}")
+    local path
+    path=$(go list -f '{{.Path}}' -m "${module}")
+    local subdir="${path//${REPO}\//}"
+    local tag
+    if [ -z "${version}" ]; then
+      tag="${master_version}"
+      version="${master_version}"
+    else
+      tag="${subdir///v[23]/}/${version}"
+    fi
+
+    log_info "Tags for: ${module} version:${version} tag:${tag}"
+    maybe_run git tag -f "${tag}"
+    tags=("${tags[@]}" "${tag}")
+  done
+  maybe_run git push -f "${REMOTE_REPO}" "${tags[@]}"
+}
+
+"${1}_cmd"
+
+if "${DRY_RUN}"; then
+  log_info
+  log_warning "WARNING: It was a DRY_RUN. No files were modified."
+fi

scripts/test_lib.sh

@@ -1,11 +1,13 @@
 #!/usr/bin/env bash
 
-if [[ "$(go list)" != "go.etcd.io/etcd/v3" ]]; then
+REPO="go.etcd.io/etcd"
-  echo "must be run from 'go.etcd.io/etcd/v3' module directory"
+
+if [[ "$(go list)" != "${REPO}/v3" ]]; then
+  echo "must be run from '${REPO}/v3' module directory"
   exit 255
 fi
 
-ETCD_ROOT_DIR=$(go list -f '{{.Dir}}' "go.etcd.io/etcd/v3")
+ETCD_ROOT_DIR=$(go list -f '{{.Dir}}' "${REPO}/v3")
 
 ####   Convenient IO methods #####
 
@@ -48,6 +50,12 @@ function log_success {
   >&2 echo -n -e "${COLOR_NONE}"
 }
 
+function log_info {
+  >&2 echo -n -e "${COLOR_NONE}"
+  >&2 echo "$@"
+  >&2 echo -n -e "${COLOR_NONE}"
+}
+
 # From http://stackoverflow.com/a/12498485
 function relativePath {
   # both $1 and $2 are absolute paths beginning with /
@@ -105,6 +113,11 @@ function pkgs_in_module {
   go list -mod=mod "${1:-./...}";
 }
 
+# Prints subdirectory (from the repo root) for the current module.
+function module_subdir {
+  relativePath "${ETCD_ROOT_DIR}" "${PWD}"
+}
+
 ####    Running actions against multiple modules ####
 
 # run [command...] - runs given command, printing it first and
@@ -114,11 +127,11 @@ function pkgs_in_module {
 function run {
   local rpath
   local command
-  rpath=$(relativePath "${ETCD_ROOT_DIR}" "${PWD}")
+  rpath=$(module_subdir)
   # Quoting all components as the commands are fully copy-parsable:
   command=("${@}")
   command=("${command[@]@Q}")
-  if [ "${rpath}" != "." ]; then
+  if [[ "${rpath}" != "." && "${rpath}" != "" ]]; then
     repro="(cd ${rpath} && ${command[*]})"
   else 
     repro="${command[*]}"
@@ -147,15 +160,15 @@ function run_for_module {
 
 function modules() {
   modules=(
-    go.etcd.io/etcd/api/v3
+    "${REPO}/api/v3"
-    go.etcd.io/etcd/pkg/v3
+    "${REPO}/pkg/v3"
-    go.etcd.io/etcd/raft/v3
+    "${REPO}/raft/v3"
-    go.etcd.io/etcd/client/v2
+    "${REPO}/client/v2"
-    go.etcd.io/etcd/client/v3
+    "${REPO}/client/v3"
-    go.etcd.io/etcd/server/v3
+    "${REPO}/server/v3"
-    go.etcd.io/etcd/etcdctl/v3
+    "${REPO}/etcdctl/v3"
-    go.etcd.io/etcd/tests/v3
+    "${REPO}/tests/v3"
-    go.etcd.io/etcd/v3)
+    "${REPO}/v3")
   echo "${modules[@]}"
 }
 
@@ -313,3 +326,16 @@ function run_go_tool {
   run "${cmdbin}" "$@" || return 2
 }
 
+# assert_no_git_modifications fails if there are any uncommited changes.
+function assert_no_git_modifications {
+  log_callout "Making sure everything is committed."
+  if ! git diff --cached --exit-code; then
+    log_error "Found staged by uncommited changes. Do commit/stash your changes first."
+    return 2
+  fi
+  if ! git diff  --exit-code; then
+    log_error "Found unstaged and uncommited changes. Do commit/stash your changes first."
+    return 2
+  fi
+}
+