add option 'snapshots'

README.md

@@ -1,4 +1,8 @@
-**tip** is a Docker GitHub Action written in Python. **tip** allows to keep a pre-release and its artifacts up to date with latest builds. Combined with a workflow that is executed periodically, **tip** allows to provide a fixed release name for users willing to use daily/nightly artifacts of a project.
+**tip** is a Docker GitHub Action written in Python.
+
+**tip** allows to keep a GitHub Release of type pre-release and its artifacts up to date with latest builds. Combined with a workflow that is executed periodically, **tip** allows to provide a fixed release name for users willing to use daily/nightly artifacts of a project.
+
+Furthermore, when any [semver](https://semver.org) compilant tagged commit is pushed, **tip** can create a release and upload assets.
 
 # Usage
 
@@ -35,11 +39,9 @@ jobs:
           README.md
 ```
 
-Note that the tag and the pre-release need to be created manually the first time. The workflow above will fail if the release does not exist.
-
 # Options
 
-All options can be optionally provided as environment variables: `INPUT_TOKEN`, `INPUT_FILES`, `INPUT_TAG` and/or `INPUT_RM`.
+All options can be optionally provided as environment variables: `INPUT_TOKEN`, `INPUT_FILES`, `INPUT_TAG`, `INPUT_RM` and/or `INPUT_SNAPSHOTS`.
 
 ## token (required)
 
@@ -56,3 +58,7 @@ The default tag name for the tip/nightly pre-release is `tip`, but it can be opt
 ## rm
 
 Set option `rm` to `true` for systematically removing previous artifacts (e.g. old versions). Otherwise (by default), all previours artifacts are preserved or overwritten.
+
+## snapshots
+
+Whether to create releases from any tag or to treat some as snapshots. By default, all the tags with non-empty `prerelease` field (see [semver.org: Is there a suggested regular expression (RegEx) to check a SemVer string?](https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string)) are considered snapshots; neither a release is created nor assets are uploaded.

action.yml

@@ -15,6 +15,10 @@ inputs:
     description: 'Whether to delete all the previous artifacts, or only replacing the ones with the same name'
     required: false
     default: false
+  snapshots:
+    description: 'Whether to create releases from any tag or to treat some as snapshots'
+    required: false
+    default: true
 runs:
   using: 'docker'
   image: 'Dockerfile'

tip.py

@@ -1,7 +1,9 @@
 #!/usr/bin/env python3
 
-from os import environ, getenv
+import re
+import sys
 from sys import argv, stdout
+from os import environ, getenv
 from subprocess import check_call
 from glob import glob
 from pathlib import Path
@@ -55,14 +57,45 @@ print("· Get Release handler")
 
 tag = getenv('INPUT_TAG', 'tip')
 
+env_tag = None
+gh_ref = environ['GITHUB_REF']
+is_prerelease = True
+is_draft = False
+
+if gh_ref[0:10] == 'refs/tags/':
+    env_tag = gh_ref[10:]
+    if env_tag != tag:
+        semver = re.search(r"^(?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)\.(?P<patch>0|[1-9]\d*)(?:-(?P<prerelease>(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+(?P<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$", env_tag)
+        if semver.group('prerelease') is None:
+            # is a regular semver compilant tag
+            is_prerelease = False
+            tag = env_tag
+        elif getenv('INPUT_SNAPSHOTS', 'true') == 'true':
+            # is semver compilant prerelease tag, thus a snapshot (we skip it)
+            sys.exit()
+
+gh_tag = None
 try:
     gh_tag = gh_repo.get_git_ref('tags/%s' % tag)
 except Exception as e:
     stdout.flush()
-    # TODO: create the tag/release, instead of raising an exception
-    raise(Exception("Tag '%s' does not exist!" % tag))
-
+    pass
+if gh_tag:
+    try:
         gh_release = gh_repo.get_release(tag)
+    except Exception as e:
+        gh_release = gh_repo.create_git_release(tag, tag, "", draft=True, prerelease=is_prerelease)
+        is_draft = True
+        pass
+else:
+    err_msg = "Tag/release '%s' does not exist and could not create it!" % tag
+    if 'GITHUB_SHA' not in environ:
+        raise(Exception(err_msg))
+    try:
+        gh_release = gh_repo.create_git_tag_and_release(tag,  "", tag, "", environ['GITHUB_SHA'], 'commit', draft=True, prerelease=is_prerelease)
+        is_draft = True
+    except Exception as e:
+        raise(Exception(err_msg))
 
 print("· Upload artifacts")
 
@@ -99,17 +132,19 @@ for artifact in artifacts:
 stdout.flush()
 print("· Update Release reference (force-push tag)")
 
-if ('GITHUB_SHA' in environ) and ('GITHUB_REF' in environ) and environ['GITHUB_REF'] != 'refs/tags/%s' % tag:
-    sha = environ['GITHUB_SHA']
-    print("force-push '%s' to %s" % (tag, sha))
-    gh_repo.get_git_ref('tags/%s' % tag).edit(sha)
+if is_draft:
+    # Unfortunately, it seems not possible to update fields 'created_at' or 'published_at'.
+    print(" > Update (pre-)release")
+    gh_release.update_release(
+        gh_release.title,
+        "" if gh_release.body is None else gh_release.body,
+        draft=False,
+        prerelease=is_prerelease,
+        tag_name=gh_release.tag_name,
+        target_commitish=gh_release.target_commitish
+    )
 
-    # TODO: alternatively, update the title/body of the release (while keeping the tag or not)
-    # gh_release.update_release(
-    #     gh_release.title,
-    #     gh_release.body,
-    #     draft=False,
-    #     prerelease=True,
-    #     tag_name=gh_release.tag_name,
-    #     target_commitish=gh_release.target_commitish
-    # )
+if ('GITHUB_SHA' in environ) and (env_tag is None):
+    sha = environ['GITHUB_SHA']
+    print(" > Force-push '%s' to %s" % (tag, sha))
+    gh_repo.get_git_ref('tags/%s' % tag).edit(sha)