tools: add a script to generate draft release changelog

This utility script helps in generated formatted and consistent
change log including:
       1- group logs per daemon
       2- standarize daemon names (lowercase, end with d)
       3- capitalize all log lines
       4- no merge commits

caveat: comments are assumed to be in the form

   daemon-name : message

Sample Output:

```
sharpd
    Follow the practice on cli design for json output
    Install route supports nexthop-seg6 (step3)
    Install_routes_helper support zapi_route flags (step1)

snapcraft
    Add missing dependency
    Add pathd to frr snap daemons
    Change base to ubuntu 18.04 and libyang 2.0.7

staticd
    Convert typedef to enum
    Fix distance processing
    Fix late initialization of blackhole type
    Output config using nb callbacks instead of operational data
```

Signed-off-by: Jafar Al-Gharaibeh <jafar@atcorp.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/tools/release_notes.py b/tools/release_notes.py
new file mode 100755
index 0000000000..7481cc18c3
--- /dev/null
+++ b/tools/release_notes.py
@@ -0,0 +1,93 @@
+#!/usr/bin/python3
+#
+# 2021 Jafar Al-Gharaibeh, ATCorp
+#
+# Generate a draft FRR release notes
+#
+
+import sys
+import os
+import getopt
+import subprocess
+
+def run(cmd):
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+    rv = proc.communicate("")[0].decode("UTF-8")
+    proc.wait()
+    return rv
+
+
+def usage(n):
+    print(os.path.basename(__file__), " [-b <branch>] [-t <tag> ]")
+    print("    Generate one line logs for non merge commits")
+    print("   -branch: branch name to use, default to HEAD")
+    print("   -tag   : generate logs up to this tag, default to latest tag")
+    sys.exit(n)
+
+
+def main(argv):
+    branch = tag = None
+    try:
+        opts, args = getopt.getopt(argv, "hb:t:", ["branch=", "tag="])
+    except getopt.GetoptError:
+        usage(2)
+    for opt, arg in opts:
+        if opt == "-h":
+            usage(0)
+        elif opt in ("-b", "--branch"):
+            branch = arg
+        elif opt in ("-t", "--tag"):
+            tag = arg
+
+    if branch is None:
+        branch = "HEAD"
+    if tag is None:
+        tag = run(["git", "describe", "--abbrev=0"]).strip("\n")
+
+    chnglog = run(
+        ["git", "log", "--no-merges", "--pretty=format:'%s%d'", tag + ".." + branch]
+    )
+    chnglog = chnglog.split("\n")
+
+    chnglist = []
+    daemons = [
+        "babel",
+        "bgp",
+        "eigrp",
+        "nhrp",
+        "ospf",
+        "ospf6",
+        "pbr",
+        "pim",
+        "rip",
+        "ripng",
+        "sharp",
+        "vrrp",
+        "zebra",
+    ]
+
+    for line in chnglog:
+        line = line.strip("'")
+        colon = line.partition(":")
+        label = colon[0].strip().lower()
+        if label in daemons:
+            label = label + "d"
+        comment = colon[2].strip().capitalize()
+        chnglist.append(label + ":" + comment)
+
+    chnglist.sort()
+    lastlabel = ""
+    for line in chnglist:
+        colon = line.partition(":")
+        label = colon[0]
+        comment = colon[2]
+        if label != lastlabel:
+            print("")
+            print(label)
+            lastlabel = label
+
+        print("   ", comment)
+
+
+if __name__ == "__main__":
+    main(sys.argv[1:])