Merge ~hloeung/influxdb-charm:master into influxdb-charm:master

[Haw Loeung]

Juju actions only available in Xenial and beyond

The juju actions required to interact with InfluxDB uses
python3-influxdb which is only available in Xenial and beyond. This
fixes that to not fail on prior series such as Trusty (LP: #1732015).

diff --git a/actions/create-database b/actions/create-database
index 96c9cb1..d2cd4bd 100755
--- a/actions/create-database
+++ b/actions/create-database
@@ -1,7 +1,6 @@
 #!/usr/bin/python3
 # Create a database
 
-import influxdb
 import requests
 import traceback
 
@@ -12,6 +11,12 @@ from charmhelpers.core.hookenv import (
     log,
 )
 
+try:
+    import influxdb
+except ImportError:
+    print("Missing python3-influxdb package")
+    exit(1)
+
 action = "create-database"
 
 try:
@@ -33,7 +38,7 @@ try:
     print("Create database: " + database)
     client.create_database(database)
     action_set({"created": database})
-except:
+except Exception:
     action_fail('Unhandled exception')
     tb = traceback.format_exc()
     action_set(dict(traceback=tb))
diff --git a/actions/create-user b/actions/create-user
index cae4df9..8ad8db3 100755
--- a/actions/create-user
+++ b/actions/create-user
@@ -1,7 +1,6 @@
 #!/usr/bin/python3
 # Create a database
 
-import influxdb
 import random
 import requests
 import string
@@ -14,6 +13,12 @@ from charmhelpers.core.hookenv import (
     log,
 )
 
+try:
+    import influxdb
+except ImportError:
+    print("Missing python3-influxdb package")
+    exit(1)
+
 action = "create-user"
 charset = string.ascii_lowercase + string.ascii_uppercase + string.digits
 password = ''.join(random.sample(charset, 16))
@@ -54,5 +59,5 @@ except influxdb.exceptions.InfluxDBClientError as e:
         action_fail("User {} already exists".format(user))
     else:
         unhandled_exception()
-except:
+except Exception:
     unhandled_exception()
diff --git a/actions/grant-privilege b/actions/grant-privilege
index 62626f1..87cfb0d 100755
--- a/actions/grant-privilege
+++ b/actions/grant-privilege
@@ -1,7 +1,6 @@
 #!/usr/bin/python3
 # Create a database
 
-import influxdb
 import requests
 import traceback
 
@@ -12,6 +11,12 @@ from charmhelpers.core.hookenv import (
     log,
 )
 
+try:
+    import influxdb
+except ImportError:
+    print("Missing python3-influxdb package")
+    exit(1)
+
 action = "grant-privilege"
 
 
@@ -45,5 +50,5 @@ try:
     client.grant_privilege(privilege, database, user)
     action_set({"granted": user, "privilege": privilege, "database": database})
     print("Granted {} {} on {}".format(user, privilege, database))
-except:
+except Exception:
     unhandled_exception()
diff --git a/layer.yaml b/layer.yaml
index 0dcf45c..c68c892 100644
--- a/layer.yaml
+++ b/layer.yaml
@@ -8,10 +8,14 @@ includes:
   - interface:influxdb-api
 options:
   basic:
+    # We need to use virtual env:
+    # https://github.com/juju-solutions/charms.reactive/issues/135
+    use_venv: true
+    include_system_packages: true
     packages:
-      # we need to specify these here due to https://github.com/juju-solutions/charms.reactive/issues/82
+      # We need to specify essential required packages:
+      # https://github.com/juju-solutions/charms.reactive/issues/82
       - build-essential
       - python3-setuptools
       - python3-wheel
       - python3-yaml
-      - python3-influxdb
diff --git a/reactive/influxdb.py b/reactive/influxdb.py
index ae04df9..24b51bf 100644
--- a/reactive/influxdb.py
+++ b/reactive/influxdb.py
@@ -42,6 +42,10 @@ def install_influx():
         subprocess.check_call(['influx', '--version'], stdin=subprocess.PIPE, stdout=subprocess.PIPE)
     except OSError:
         apt_install('influxdb-client')
+    series = host.lsb_release()['DISTRIB_CODENAME']
+    # python3-influxdb only exists in Ubuntu Xenial and beyond - LP: #1732015.
+    if series not in ('precise', 'trusty'):
+        apt_install('python3-influxdb')
 
 
 def apply_configs(fh, config):