Scripts for releasing. (#576)

* Scripts for releasing.

- fixes #510

* fix review comments.

Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>

RELEASING.md

@@ -0,0 +1,36 @@
+# Release Process
+
+## Pre-Release
+Update go.mod for submodules to depend on the new release which will happen
+in the next step. This will create build failure for those who depend
+on the master branch instead or released version. But they shouldn't be
+depending on the master. So it is not a concern.
+
+1. Run the pre-release script. It creates a branch pre_release_<tag> to make the changes.
+2. Verify the changes.
+3. Push the changes to upstream.
+4. Create a PR on github and merge the PR once approved.
+
+    ```
+    ./pre-release.sh -t <new tag>
+    git diff master
+    git push
+    ```
+
+
+## Tag
+Now create a new Tag on the commit hash of the changes made in pre-release step.
+Use the same tag as used in the pre-release step.
+
+1. Run the tag.sh script.
+2. Push tags upstream. Make sure you run this for all sub-modules as well.
+
+    ```
+    ./tag.sh -t <new tag> -c <commit-hash>
+    git push upstream <new tag>
+    git push upstream <submodules-path/new tag>
+    ```
+
+## Release
+Now create a release for the new tag on github. tag.sh script generates commit logs since
+last release. Use that to draft the new release.

pre_release.sh

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+#!/bin/sh
+
+set -e
+
+help()
+{
+   printf "\n"
+   printf "Usage: $0 -t tag\n"
+   printf "\t-t Unreleased tag. Update all go.mod with this tag.\n"
+   exit 1 # Exit script after printing help
+}
+
+while getopts "t:" opt
+do
+   case "$opt" in
+      t ) TAG="$OPTARG" ;;
+      ? ) help ;; # Print help
+   esac
+done
+
+# Print help in case parameters are empty
+if [ -z "$TAG" ]
+then
+   printf "Tag is missing\n";
+   help
+fi
+
+# Validate semver
+SEMVER_REGEX="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)(\\-[0-9A-Za-z-]+(\\.[0-9A-Za-z-]+)*)?(\\+[0-9A-Za-z-]+(\\.[0-9A-Za-z-]+)*)?$"
+if [[ "${TAG}" =~ ${SEMVER_REGEX} ]]; then
+	printf "${TAG} is valid semver tag.\n"
+else
+	printf "${TAG} is not a valid semver tag.\n"
+	exit -1
+fi
+
+TAG_FOUND=`git tag --list ${TAG}`
+if [ ${TAG_FOUND} = ${TAG} ] ; then
+        printf "Tag ${TAG} already exists\n"
+        exit -1
+fi
+
+
+cd $(dirname $0)
+
+# Update go.mod
+git checkout -b pre_release_${TAG} master
+PACKAGE_DIRS=$(find . -mindepth 2 -type f -name 'go.mod' -exec dirname {} \; | egrep -v 'tools' | sed 's/^\.\///' | sort)
+
+for dir in $PACKAGE_DIRS; do
+	sed -i .bak "s/opentelemetry.io\/otel\([^ ]*\) v[0-9]*\.[0-9]*\.[0-9]/opentelemetry.io\/otel\1 ${TAG}/" ${dir}/go.mod
+	rm -f ${dir}/go.mod.bak
+done
+
+# Run lint to update go.sum
+make lint
+
+# Add changes and commit.
+git add .
+make ci
+git commit -m "Prepare for releasing $TAG"
+
+printf "Now run following to verify the changes.\ngit diff master\n"
+printf "\nThen push the changes to upstream\n"

tag.sh

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+#!/bin/bash
+
+set -e
+
+help()
+{
+   printf "\n"
+   printf "Usage: $0 -t tag -c commit-hash\n"
+   printf "\t-t New tag that you would like to create\n"
+   printf "\t-c Commit hash to associate with the new tag\n"
+   exit 1 # Exit script after printing help
+}
+
+while getopts "t:c:" opt
+do
+   case "$opt" in
+      t ) TAG="$OPTARG" ;;
+      c ) COMMIT_HASH="$OPTARG" ;;
+      ? ) help ;; # Print help
+   esac
+done
+
+# Print help in case parameters are empty
+if [ -z "$TAG" ] || [ -z "${COMMIT_HASH}" ]
+then
+   printf "Some or all of the parameters are missing\n";
+   help
+fi
+
+# Validate semver
+SEMVER_REGEX="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)(\\-[0-9A-Za-z-]+(\\.[0-9A-Za-z-]+)*)?(\\+[0-9A-Za-z-]+(\\.[0-9A-Za-z-]+)*)?$"
+
+
+if [[ "${TAG}" =~ ${SEMVER_REGEX} ]]; then
+        printf "${TAG} is valid semver tag.\n"
+else
+        printf "${TAG} is not a valid semver tag.\n"
+        exit -1
+fi
+
+cd $(dirname $0)
+
+# Check if the commit-hash is valid
+COMMIT_FOUND=`git log -50 --pretty=format:"%H" | grep ${COMMIT_HASH}`
+if [ "${COMMIT_FOUND}" != "${COMMIT_HASH}" ] ; then
+	printf "Commit ${COMMIT_HASH} not found\n"
+	exit -1
+fi
+
+# Check if the tag doesn't alread exists.
+TAG_FOUND=`git tag --list ${TAG}`
+if [ "${TAG_FOUND}" = "${TAG}" ] ; then
+	printf "Tag ${TAG} already exists\n"
+	exit -1
+fi
+
+# Save most recent tag for generating logs
+TAG_CURRENT=`git tag | grep '^v' | tail -1`
+
+PACKAGE_DIRS=$(find . -mindepth 2 -type f -name 'go.mod' -exec dirname {} \; | egrep -v 'tools' | sed 's/^\.\///' | sort)
+
+# Create tag for root module
+git tag -a "${TAG}" -m "Version ${TAG}" ${COMMIT_HASH}
+
+# Create tag for submodules
+for dir in $PACKAGE_DIRS; do
+	git tag -a "${dir}/${TAG}" -m "Version ${dir}/${TAG}" ${COMMIT_HASH}
+done
+
+# Generate commit logs
+printf "New tag ${TAG} created.\n"
+printf "\n\n\nChange log since previous tag ${TAG_CURRENT}\n"
+printf "======================================\n"
+git --no-pager log --pretty=oneline ${TAG_CURRENT}..${TAG}
+