From 98cb350edc54e3ed1c727c0cafb48da2bbc947f0 Mon Sep 17 00:00:00 2001
From: Matt Thompson <mattt@defunct.ca>
Date: Fri, 23 Jun 2017 11:40:13 -0400
Subject: [PATCH] Only import os_utils when plugin is called

Currently, if a dependency of one of the os_ plugins is missing,
running monitorstack with no args returns (for example):

```
OpenStack plugins require access to the OpenStackSDK. \
    Please install "python-openstacksdk". \
    ERROR: No module named keystoneauth1.loading
```

This commit moves the os_utils import in the os_ plugins to within cli,
similar to what is being done in the kvm module.  This allows the
monitorstack cli to operate normally even if a plugin cannot be loaded.

Change-Id: I2ff1ad8c6365f6592191f09ea9c0d543f81e16ba
---
 monitorstack/plugins/os_block_pools_totals.py | 5 ++++-
 monitorstack/plugins/os_block_pools_usage.py  | 5 ++++-
 monitorstack/plugins/os_vm_quota_cores.py     | 5 ++++-
 monitorstack/plugins/os_vm_quota_instance.py  | 5 ++++-
 monitorstack/plugins/os_vm_quota_ram.py       | 5 ++++-
 monitorstack/plugins/os_vm_used_cores.py      | 5 ++++-
 monitorstack/plugins/os_vm_used_disk.py       | 5 ++++-
 monitorstack/plugins/os_vm_used_instance.py   | 5 ++++-
 monitorstack/plugins/os_vm_used_ram.py        | 5 ++++-
 9 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/monitorstack/plugins/os_block_pools_totals.py b/monitorstack/plugins/os_block_pools_totals.py
index 94fe228..683a0b1 100644
--- a/monitorstack/plugins/os_block_pools_totals.py
+++ b/monitorstack/plugins/os_block_pools_totals.py
@@ -17,7 +17,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get block storage totals from the available pools."""
@@ -33,6 +32,10 @@ def cli(ctx, config_file):
     """Get nova cores quotas."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_block_pools_usage.py b/monitorstack/plugins/os_block_pools_usage.py
index 2b566c6..f4635f4 100644
--- a/monitorstack/plugins/os_block_pools_usage.py
+++ b/monitorstack/plugins/os_block_pools_usage.py
@@ -17,7 +17,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get block storage usage from the available pools."""
@@ -33,6 +32,10 @@ def cli(ctx, config_file):
     """Get nova cores quotas."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_vm_quota_cores.py b/monitorstack/plugins/os_vm_quota_cores.py
index e3fd589..e7fbb19 100644
--- a/monitorstack/plugins/os_vm_quota_cores.py
+++ b/monitorstack/plugins/os_vm_quota_cores.py
@@ -17,7 +17,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get nova cores quotas."""
@@ -33,6 +32,10 @@ def cli(ctx, config_file):
     """Get nova cores quotas."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_vm_quota_instance.py b/monitorstack/plugins/os_vm_quota_instance.py
index 6b48b9b..652a2a1 100644
--- a/monitorstack/plugins/os_vm_quota_instance.py
+++ b/monitorstack/plugins/os_vm_quota_instance.py
@@ -17,7 +17,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get nova instance quotas."""
@@ -33,6 +32,10 @@ def cli(ctx, config_file):
     """Get nova instance quotas."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_vm_quota_ram.py b/monitorstack/plugins/os_vm_quota_ram.py
index 54a7e40..125656f 100644
--- a/monitorstack/plugins/os_vm_quota_ram.py
+++ b/monitorstack/plugins/os_vm_quota_ram.py
@@ -17,7 +17,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get nova ram quotas."""
@@ -33,6 +32,10 @@ def cli(ctx, config_file):
     """Get nova ram quotas."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_vm_used_cores.py b/monitorstack/plugins/os_vm_used_cores.py
index db05f07..8185446 100644
--- a/monitorstack/plugins/os_vm_used_cores.py
+++ b/monitorstack/plugins/os_vm_used_cores.py
@@ -19,7 +19,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get nova used cores."""
@@ -35,6 +34,10 @@ def cli(ctx, config_file):
     """Get nova used cores."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_vm_used_disk.py b/monitorstack/plugins/os_vm_used_disk.py
index a71111e..0d662f6 100644
--- a/monitorstack/plugins/os_vm_used_disk.py
+++ b/monitorstack/plugins/os_vm_used_disk.py
@@ -19,7 +19,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get nova used disk."""
@@ -35,6 +34,10 @@ def cli(ctx, config_file):
     """Get nova used disk."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_vm_used_instance.py b/monitorstack/plugins/os_vm_used_instance.py
index 511f719..9264694 100644
--- a/monitorstack/plugins/os_vm_used_instance.py
+++ b/monitorstack/plugins/os_vm_used_instance.py
@@ -19,7 +19,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get nova used instances."""
@@ -35,6 +34,10 @@ def cli(ctx, config_file):
     """Get nova used instances."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {
diff --git a/monitorstack/plugins/os_vm_used_ram.py b/monitorstack/plugins/os_vm_used_ram.py
index 1ce299b..a8967c9 100644
--- a/monitorstack/plugins/os_vm_used_ram.py
+++ b/monitorstack/plugins/os_vm_used_ram.py
@@ -19,7 +19,6 @@ import click
 
 from monitorstack import utils
 from monitorstack.cli import pass_context
-from monitorstack.utils import os_utils as ost
 
 
 DOC = """Get nova used ram."""
@@ -35,6 +34,10 @@ def cli(ctx, config_file):
     """Get nova used ram."""
     setattr(cli, '__doc__', DOC)
 
+    # Lower level import because we only want to load this module
+    # when this plugin is called.
+    from monitorstack.utils import os_utils as ost
+
     output = {
         'measurement_name': COMMAND_NAME,
         'meta': {