chore: add latest tag action

.github/workflows/latest-release-tag.yml

@@ -0,0 +1,32 @@
+name: Tags
+on:
+  release:
+    types: [published] # This makes it run only when a new released is published
+
+jobs:
+  latest-release:
+    name: Add/update tag to new release
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    - name: Check for latest tag
+      id: latest-tag
+      run: |
+        source ./scripts/tag_latest_release.sh $(echo ${{ github.event.release.tag_name }}) --dry-run
+
+        if ${SKIP_TAG}
+        then
+          echo "::set-env name=skip_tag::true"
+        fi
+
+    - name: Run latest-tag
+      uses: EndBug/latest-tag@latest
+      if: (! env.skip_tag )
+      with:
+        description: Superset latest release
+        tag-name: latest
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -81,6 +81,7 @@ ghostdriver.log
 testCSV.csv
 .terser-plugin-cache/
 apache-superset-*.tar.gz*
+release.json
 
 # Translation binaries
 messages.mo

RELEASING/README.md

@@ -329,3 +329,5 @@ Finally, so the Github UI reflects the latest release, you should create a relea
 tag corresponding with the new version. Go to https://github.com/apache/incubator-superset/tags,
 click the 3-dot icon and select `Create Release`, paste the content of the ANNOUNCE thread in the
 release notes, and publish the new release.
+
+At this point, a GitHub action will run that will check whether this release's version number is higher than the current 'latest' release. If that condition is true, this release sha will automatically be tagged as `latest` so that the most recent release can be referenced simply by using the 'latest' tag instead of looking up the version number. The existing version number tag will still exist, and can also be used for reference.

docs/src/pages/docs/installation/index.mdx

@@ -51,6 +51,12 @@ $ git clone https://github.com/apache/incubator-superset.git
 Once that command completes successfully, you should see a new `incubator-superset` folder in your
 current directory.
 
+We recommend that you check out and run the code from the last tagged release:
+
+```bash
+$ git checkout latest
+```
+
 ### 3. Launch Superset Through Docker Compose
 
 Navigate to the folder you created in step 1:
@@ -68,7 +74,7 @@ $ docker-compose up
 You should see a wall of logging output from the containers being launched on your machine. Once
 this output slows, you should have a running instance of Superset on your local machine!
 
-### 4. Login to Superset
+### 4. Log in to Superset
 
 Your local Superset instance also includes a Postgres server to store your data and is already
 pre-loaded with some example datasets that ship with Superset. You can access Superset now via your

docs/src/pages/docs/installation/installing_scratch.mdx

@@ -63,7 +63,7 @@ pip install --upgrade setuptools pip
 
 ### Python Virtual Environment
 
-We highly recommend installing Superset inside of a virtual environment. Python 3 ships with
+We highly recommend installing Superset inside of a virtual environment. Python ships with
 `virtualenv` out of the box but you can install it using:
 
 ```

scripts/tag_latest_release.sh

@@ -0,0 +1,123 @@
+#! /bin/bash
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+run_git_tag () {
+  if [ "$DRY_RUN" = "false" ] && [ "$SKIP_TAG" = "false" ]
+  then
+    git tag -a -f latest "${GITHUB_TAG_NAME}" -m "latest tag"
+    echo "${GITHUB_TAG_NAME} has been tagged 'latest'"
+  fi
+  exit 0
+}
+
+SKIP_TAG=false
+DRY_RUN=false
+
+# get params passed in with script when it was run
+# --dry-run is optional and returns the value of SKIP_TAG, but does not run the git tag statement
+# A tag name is required as a param. A SHA won't work. You must first tag a sha with a release number
+# and then run this script
+while [[ $# -gt 0 ]]
+do
+key="$1"
+
+case $key in
+    --dry-run)
+    DRY_RUN=true
+    shift # past value
+    ;;
+    *)    # this should be the tag name
+    GITHUB_TAG_NAME=$key
+    shift # past value
+    ;;
+esac
+done
+
+if [ -z "${GITHUB_TAG_NAME}" ]; then
+    echo "Missing tag parameter, usage: ./scripts/tag_latest_release.sh <GITHUB_TAG_NAME>"
+    exit 1
+fi
+
+# check that this tag only contains a proper semantic version
+if ! [[ ${GITHUB_TAG_NAME} =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]
+then
+  echo "This tag ${GITHUB_TAG_NAME} is not a valid release version. Not tagging."
+  SKIP_TAG=true
+  exit 0
+fi
+
+## split the current GITHUB_TAG_NAME into an array at the dot
+IFS=$'.'
+THIS_TAG_NAME=(${GITHUB_TAG_NAME})  || echo 'not found'
+
+# look up the 'latest' tag on git
+LATEST_TAG_LIST=$(git show-ref latest && git show --pretty=tformat:%d -s latest | grep tag:) || echo 'not found'
+
+# if 'latest' tag doesn't exist, then set this commit to latest
+if [[ -z "$LATEST_TAG_LIST" ]]
+then
+  # move on to next task
+  echo "there are no latest tags yet, so I'm going to start by tagging this sha as the latest"
+  run_git_tag
+fi
+
+## get all tags that use the same sha as the latest tag. split at comma.
+IFS=$','
+LATEST_TAGS=($LATEST_TAG_LIST)
+
+## loop over those tags and only take action on the one that isn't tagged 'latest'
+## that one will have the version number tag
+for (( i=0; i<${#LATEST_TAGS[@]}; i++ ))
+do
+  if [[ ${LATEST_TAGS[$i]} != *"latest"* ]]
+  then
+    ## extract just the version from this tag
+    LATEST_RELEASE_TAG=$(echo "${LATEST_TAGS[$i]}" | sed -E -e 's/tag:|\(|\)|[[:space:]]*//g')
+
+    # check that this only contains a proper semantic version
+    if ! [[ ${LATEST_RELEASE_TAG} =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]
+    then
+      echo "This tag ${LATEST_RELEASE_TAG} is not a valid release version. Looking for another."
+      continue
+    fi
+    echo "The current release with the latest tag is version ${LATEST_RELEASE_TAG}"
+
+    ## remove the sha from the latest tag and split into an array- split at the dot
+    IFS=$'.'
+    LATEST_RELEASE_TAG_SPLIT=(${LATEST_RELEASE_TAG})
+
+    for (( j=0; j<${#THIS_TAG_NAME[@]}; j++ ))
+    do
+      ## if this value is greater than the latest release, then tag it, if it's lower, then stop, if it's
+      ## the same then move on to the next index
+      if [[ ${THIS_TAG_NAME[$j]} -gt ${LATEST_RELEASE_TAG_SPLIT[$j]} ]]
+      then
+        echo "This release tag ${GITHUB_TAG_NAME} is the latest. Tagging it"
+        run_git_tag
+
+      elif [[ ${THIS_TAG_NAME[$j]} -lt ${LATEST_RELEASE_TAG_SPLIT[$j]} ]]
+      then
+        continue
+      fi
+    done
+  fi
+done
+
+echo "This release tag ${GITHUB_TAG_NAME} is not the latest. Not tagging."
+# if you've gotten this far, then we don't want to run any tags in the next step
+SKIP_TAG=true