Differences

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--- cloud:recipe:coding [2020/05/14 08:26] – chudler
+++ cloud:recipe:coding [2020/05/14 18:32] (current) – chudler
@@ Line 2: / Line 2: @@
 This document gives a quick introduction to using the Openstack Python client to discover and consume compute resources.
-Before beginning, get an account as described in the [[ cloud:intro | Introduction ]]
+Before beginning, get an account as described in the [[ cloud:intro | Introduction ]]. This is the right place to read about writing python scripts. A companion document shows how to use the [[ cloud:cli | Command Line ]].
 ======Installation======
@@ Line 15: / Line 15: @@
 </code>
+=====Configuration=====
+Obtain your configuration from the [[ https://overcloud.cs.uchicago.edu/project/api_access/clouds.yaml/ | Web Interface ]]. The preceding link is for authenticated and authorized users only. Please read [[ cloud:intro | Intro ]] for access. After logging in to the web interface at [[ https://overcloud.cs.uchicago.edu ]], click the menu on the left side, Project->API Access. On the right side of the top of the page, click "Download Openstack RC File"->"Openstack clouds.yaml file".
+Save the clouds.yaml file to the current working directory, or see the [[ https://docs.openstack.org/openstacksdk/latest/user/config/configuration.html#config-files | Upstream Docs ]] about config file search order:
+<code>
+USER_CONFIG_DIR
+    Linux: ~/.config/openstack
+    OSX: ~/Library/Application Support/openstack
+    Windows: C:\Users\USERNAME\AppData\Local\OpenStack\openstack
+SITE_CONFIG_DIR
+    Linux: /etc/openstack
+    OSX: /Library/Application Support/openstack
+    Windows: C:\ProgramData\OpenStack\openstack
+</code>
+====Sample Configuration File====
+<code>
+clouds:
+  openstack:
+    auth:
+      auth_url: https://overcloud.cs.uchicago.edu:5000
+      username: "CNetID"
+      password: "sekret"
+      project_id: YOUR PROJECT UUID
+      project_name: "CNetID"
+      user_domain_name: "CS_LDAP"
+    region_name: "RegionOne"
+    interface: "public"
+    identity_api_version: 3
+</code>
+The main flaw here is that you are taking risks by storing your University credentials in a file. Instead, you can use the API or web interface to create an Application Credential. For example,
+<code>
+openstack application credential create --secret sekret --role member --expiration 2020-10-10:10:10:10 --restricted myapp
+</code>
+=====Testing and Usage=====
+Ensure you can load the python module
+<code>
+python -m openstack version
+</code>
+Check your configuration
+<code>
+python -m openstack.config.loader
+</code>
+Check the exact error if one is displayed. For example, if you see
+<code>
+keystoneauth1.exceptions.auth_plugins.MissingRequiredOptions: Auth plugin requires parameters which were not given: auth_url
+</code>
+You have failed to provide a configuration file. This is different from a syntax error, but not so different from a permission problem, for example.
+======Demo Code======
+The following Python code shows how to create and destroy a server, and obtain information about Networks, Images, and Flavors. Consult the [[ https://docs.openstack.org/openstacksdk/latest/user/index.html#api-documentation | API Resource Documentation ]] to see what else is possible.
+For your learning, contrast this with the equivalent actions that are taken in the [[ cloud:cli | Command Line Usage Guide ]].
+<code Python>
+import openstack
+from openstack.config import loader
+# to enable debug logging
+# openstack.enable_logging(True)
+config = loader.OpenStackConfig()
+cloud = openstack.connect(cloud='openstack')
+flavor = cloud.get_flavor_by_ram(2048)
+# print(flavor.name)
+image = cloud.get_image('20.04')
+# pretty print
+# cloud.pprint(image)
+network = cloud.get_network('campus37')
+try:
+    server = cloud.create_server('myserver', image=image, flavor=flavor, network=network, wait=True, auto_ip=True)
+finally:
+    cloud.delete_server('myserver', wait=True, delete_ips=True)
+</code>