Parse `key1=value1 key2=value2` in Kusto - azure

Question

I'm running Cilium inside an Azure Kubernetes Cluster and want to parse the cilium log messages in the Azure Log Analytics. The log messages have a format like
key1=value1 key2=value2 key3="if the value contains spaces, it's wrapped in quotation marks"
For example:
level=info msg="Identity of endpoint changed" containerID=a4566a3e5f datapathPolicyRevision=0
I couldn't find a matching parse_xxx method in the docs (e.g. https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/parsecsvfunction ). Is there a possibility to write a custom function to parse this kind of log messages?

Answer 1

Not a fun format to parse... But this should work:
let LogLine = "level=info msg=\"Identity of endpoint changed\" containerID=a4566a3e5f datapathPolicyRevision=0";
print LogLine
| extend KeyValuePairs = array_concat(
extract_all("([a-zA-Z_]+)=([a-zA-Z0-9_]+)", LogLine),
extract_all("([a-zA-Z_]+)=\"([a-zA-Z0-9_ ]+)\"", LogLine))
| mv-apply KeyValuePairs on
(
extend p = pack(tostring(KeyValuePairs[0]), tostring(KeyValuePairs[1]))
| summarize dict=make_bag(p)
)
The output will be:
| print_0 | dict |
|--------------------|-----------------------------------------|
| level=info msg=... | { |
| | "level": "info", |
| | "containerID": "a4566a3e5f", |
| | "datapathPolicyRevision": "0", |
| | "msg": "Identity of endpoint changed" |
| | } |
|--------------------|-----------------------------------------|

Answer 2

With the help of Slavik N, I came with a query that works for me:
let containerIds = KubePodInventory
| where Namespace startswith "cilium"
| distinct ContainerID
| summarize make_set(ContainerID);
ContainerLog
| where ContainerID in (containerIds)
| extend KeyValuePairs = array_concat(
extract_all("([a-zA-Z0-9_-]+)=([^ \"]+)", LogEntry),
extract_all("([a-zA-Z0-9_]+)=\"([^\"]+)\"", LogEntry))
| mv-apply KeyValuePairs on
(
extend p = pack(tostring(KeyValuePairs[0]), tostring(KeyValuePairs[1]))
| summarize JSONKeyValuePairs=parse_json(make_bag(p))
)
| project TimeGenerated, Level=JSONKeyValuePairs.level, Message=JSONKeyValuePairs.msg, PodName=JSONKeyValuePairs.k8sPodName, Reason=JSONKeyValuePairs.reason, Controller=JSONKeyValuePairs.controller, ContainerID=JSONKeyValuePairs.containerID, Labels=JSONKeyValuePairs.labels, Raw=LogEntry