dynamic port assignment while creating user session

src/oci_cli/cli_setup_bootstrap.py

@@ -15,6 +15,7 @@
 import oci._vendor.jwt as jwt
 import oci
 import oci.regions as regions
+import socket
 import os
 import sys
 import uuid
@@ -39,6 +40,15 @@
 @cli_util.help_option
 @click.pass_context
 @cli_util.wrap_exceptions
+def is_port_available(port):
+    try:
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+            s.bind(('',port))
+        return True
+    except OSError as e:
+        return False    
+
+
 def bootstrap_oci_cli(ctx, profile_name, config_location):
     region_param = ctx.obj['region'] if ctx.obj['region'] else ''
     user_session = create_user_session(region=region_param)
@@ -109,24 +119,56 @@ def bootstrap_oci_cli(ctx, profile_name, config_location):
     oci iam region list --config-file {config_file} --profile {profile}
 """.format(config_file=config_location, profile=profile_name))
 
-
-def create_user_session(region='', tenancy_name=None):
+@click.command()
+@click.option('-e', '--env-port', default=None, envvar='BOOTSTRAP_PORT', help='Specify the port to use (can be set via BOOTSTRAP_PORT environment variable)')
+def create_user_session(env_port,region='', tenancy_name=None,):
     if region == '':
         region = cli_setup.prompt_for_region()
-
-    # try to set up http server so we can fail early if the required port is in use
+
     try:
-        server_address = ('', BOOTSTRAP_SERVICE_PORT)
-        httpd = StoppableHttpServer(server_address, StoppableHttpRequestHandler)
+        env_port1 = os.getenv('BOOTSTRAP_PORT')
+        port_number=env_port1 or env_port
+
+        if not port_number.isdigit():
+            click.echo("Invalid port number")
+            raise ValueError("Invalid port number")
+
+        if env_port is None:
+            boot_strap_service_port = is_port_available(BOOTSTRAP_SERVICE_PORT)
+            if boot_strap_service_port:
+                click.echo("Default port {} is available, establishing connection...".format(BOOTSTRAP_SERVICE_PORT))
+                server_address = ('', int(BOOTSTRAP_SERVICE_PORT))
+                httpd = StoppableHttpServer(server_address, StoppableHttpRequestHandler)
+                click.echo("Connected to default port {}.".format(BOOTSTRAP_SERVICE_PORT))
+            else:
+                click.echo("Could not complete bootstrap process because default port {} is already in use.".format(
+                    BOOTSTRAP_SERVICE_PORT))
+        elif env_port1:
+            if is_port_available(int(env_port1)):
+                click.echo("Port {} passed as env. variable is available, establishing connection...".format(env_port1))
+                server_address = ('', int(env_port1))
+                httpd = StoppableHttpServer(server_address, StoppableHttpRequestHandler)
+                click.echo("Connected to port {}".format(env_port1))
+            else:
+                click.echo("Could not complete bootstrap process because port {} is already in use.".format(env_port))
+
+        elif env_port:
+            if is_port_available(int(env_port)):
+                click.echo("Port {} passed as env. variable is available, establishing connection...".format(env_port))
+                server_address = ('', int(env_port))
+                httpd = StoppableHttpServer(server_address, StoppableHttpRequestHandler)
+                click.echo("Connected to port {}".format(env_port))
+
+            else:
+                click.echo("Could not complete bootstrap process because port {} is already in use.".format(env_port))
+
+        else:
+            click.echo("No input of port received. Exiting...")
+            sys.exit(0)
     except OSError as e:
         if e.errno == errno.EADDRINUSE:
-            click.echo("Could not complete bootstrap process because port {port} is already in use.".format(
-                port=BOOTSTRAP_SERVICE_PORT)
-            )
-
-            sys.exit(1)
-
-        raise e
+            click.echo("Could not complete bootstrap process. Failed to find an empty port")
+            sys.exit(0)
 
     # create new key pair
     # this key pair is used to get the initial token and also uploaded as a new API key for the user