add documentation

Signed-off-by: Markus Blaschke <[email protected]>

Author: mblaschke

README.md

@@ -1,3 +1,4 @@
 # Go Common library for webdevops projects
 
 * [azuresdk](/azuresdk/README.md)
+* [prometheus](/prometheus/README.md)

azuresdk/README.md

@@ -76,16 +76,19 @@ Example configuration:
 }
 ```
 
-### Tag handling
+## Tag manager
 
 Tag can be dynamically added to metrics and processed though filters
 
-format is: `tagname?filter1` or `tagname?filter1&filter2`
+format is: `tagname?option1` or `tagname?option1&option2`
 
-| Tag filter | Description                 |
-|------------|-----------------------------|
-| `toLower`  | Lowercasing Azure tag value |
-| `toUpper`  | Uppercasing Azure tag value |
+| Tag option | Description                                                                                                     |
+|------------|-----------------------------------------------------------------------------------------------------------------|
+| `name`     | Name of target label                                                                                            |
+| `toLower`  | Lowercasing Azure tag value                                                                                     |
+| `toUpper`  | Uppercasing Azure tag value                                                                                     |
+| `inherit`  | If tag is not set, try to fetch from parent structure (Resource -> ResourceGroup -> Subscription)               |
+| `source`   | Defines where the tag value should be fetched from, allowed values: `resource`, `resourceGroup`, `subscription` |
 
 ## AzureTracing metrics
 

prometheus/README.md

@@ -0,0 +1,13 @@
+# Prometheus common library webdevops projects
+
+## Collector
+
+### Caching
+
+Prometheus collector offers a caching mechanism for faster restart with different backends defined by the cache spec:
+
+| Cache spec                                                                           | Description                                                          |
+|--------------------------------------------------------------------------------------|----------------------------------------------------------------------|
+| `file://path/to/cache/`                                                              | Use local filesystem to cache data (use PVC inside Kubernetes!)      |
+| `azblob://{storageAccountName}.blob.core.windows.net/{containerName}/{optionalPath}` | Use Azure StorageAccount to save cache data (with optional sub path) |
+| `k8scm://{namespace}/{configMapName}`                                                | Use Kubernetes ConfigMap to save cache data                          |