Refactor promql_api after project structure change

Refactored prompql_api after project structure change.
Fix review comments and make a better read me.

Change-Id: I40b7b2da40d85e9f297d4bb87d8633c71bdd1ec0
Issue-ID: ONAPARC-452
Signed-off-by: Rajamohan Raj <rajamohan.raj@intel.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/vnfs/DAaaS/lib/promql_api/README.md b/vnfs/DAaaS/lib/promql_api/README.md
new file mode 100644
index 00000000..de64fe0b
--- /dev/null
+++ b/vnfs/DAaaS/lib/promql_api/README.md
@@ -0,0 +1,65 @@
+## What does this API do ?
+This api as of now provides a function which takes in a lits of 'LABELS' of prometheus
+and returns the corresponding result_sets in a list.
+
+For eg:
+If the labels is
+
+```
+LABELS = ['irate(collectd_cpufreq{exported_instance="otconap7",cpufreq="1"}[2m])']
+```
+
+The return is:
+
+```
+[{'metric': {'cpufreq': '1',
+             'endpoint': 'collectd-prometheus',
+             'exported_instance': 'otconap7',
+             'instance': '172.25.103.1:9103',
+             'job': 'collectd',
+             'namespace': 'edge1',
+             'pod': 'plundering-liger-collectd-wz7xg',
+             'service': 'collectd'},
+  'value': [1559177169.415, '119727200']}]
+```
+
+## How to use this API ?
+
+```
+1. Copy the directory 'promql_api' to your working directory. 
+```
+
+```
+2. Import the API function: query
+from promql_api.prom_ql_api import query
+```
+
+```
+3. have a global or local variable as 'LABELS'
+LABELS = ['irate(collectd_cpufreq{exported_instance="otconap7",cpufreq="1"}[2m])']
+```
+
+```
+4. Store the result set in a list:
+list_of_result_sets = query(LABELS)
+```
+
+## Troubleshooting tips
+
+* Check the sample file - sample_promql_query.py in the repo ( sample-apps/m3db_promql)
+* Make sure the file "__init__.py" is present in promql_api directory after you copy the directory.
+* Make sure environment variables like "DATA_ENDPOINT" are correctly set.
+* Logs are generated in the directory where the query function is called.
+* sample log file - promql_api.log
+
+```
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: set_log_config :: INFO :: Set the log configs.
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: load_and_validate_env_vars :: INFO :: Loading the env variables ...
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: load_and_validate_env_vars :: ERROR :: Env var: DATA_ENDPOINT not         found !
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: query :: INFO :: Forming the get request ...
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: query :: INFO :: API request::: URL: http://172.25.103.1:30090/api/v1/    query
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: query :: INFO :: API request::: params: {'query':                         'irate(collectd_cpufreq{exported_instance="otconap7",cpufreq="1"}[2m])'}
+ 05-30-2019 08:47:53PM ::connectionpool.py :: _new_conn :: DEBUG :: Starting new HTTP connection (1): 172.25.103.1   05-30-2019 08:47:53PM ::connectionpool.py :: _make_request :: DEBUG :: http://172.25.103.1:30090 "GET /api/v1/      query?query=irate%28collectd_cpufreq%7Bexported_instance%3D%22otconap7%22%2Ccpufreq%3D%221%22%7D%5B2m%5D%29 HTTP/1. 1" 200 370
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: query :: INFO :: ::::::::::RESULTS:::::::::::::                           irate(collectd_cpufreq{exported_instance="otconap7",cpufreq="1"}[2m])
+ 05-30-2019 08:47:53PM ::prom_ql_api.py :: query :: INFO :: {'metric': {'cpufreq': '1', 'endpoint': 'collectd-       prometheus', 'exported_instance': 'otconap7', 'instance': '172.25.103.1:9103', 'job': 'collectd', 'namespace':      'edge1', 'pod': 'plundering-liger-collectd-wz7xg', 'service': 'collectd'}, 'value': [1559249299.084, '236300']}
+ ```