Hi, The default log analytics configuration through the azure monitor has a fixed schema for the Gateway Logs. Is it possible to write custom log messages to log analytics from Azure APIM?

@Nagashree Balasundaram Thanks for reaching out. you can log a custom header value in Log Analytics, using the following built-in ‘Additional Settings – Headers To Log’ functionality under setting tab. At the API (All Operations) level, maneuver to the Settings tab and scroll down to the Diagnostics Logs section. On the Azure Monitor tab, configure the required settings. Here is what I configured for my API/APIM service. Under the Additional Settings section, I have configured adding a Frontend Request Header called Test Once configured, ensure that you click on the Save button Now, test with a sample API call to see whether the APIM service is receiving this custom request header. For testing purpose, in my environment, I manually added the Request Header Test along with a dummy value for it, invoked the API operation and then checked the Ocp-Apim trace to verify whether the APIM service is receiving it as an incoming header. Maneuver to the Logs pane and verify APIManagementGatewayLogs, You can observe the custom header Test being logged as shown in my sample below: To benefit the community find the right answers, please do mark the post which was helpful by clicking on ‘ Accept Answer’ & ‘Up-Vote’.

Custom Log messages from APIM to log analytics

Accepted answer

JananiRamesh-MSFT 21,471 Reputation points

2022-06-30T17:19:38.62+00:00
@Nagashree Balasundaram Thanks for reaching out. you can log a custom header value in Log Analytics, using the following built-in ‘Additional Settings – Headers To Log’ functionality under setting tab.

At the API (All Operations) level, maneuver to the Settings tab and scroll down to the Diagnostics Logs section.

On the Azure Monitor tab, configure the required settings. Here is what I configured for my API/APIM service.

Under the Additional Settings section, I have configured adding a Frontend Request Header called Test

Once configured, ensure that you click on the Save button

Now, test with a sample API call to see whether the APIM service is receiving this custom request header.

For testing purpose, in my environment, I manually added the Request Header Test along with a dummy value for it, invoked the API operation and then checked the Ocp-Apim trace to verify whether the APIM service is receiving it as an incoming header.

Maneuver to the Logs pane and verify APIManagementGatewayLogs, You can observe the custom header Test being logged as shown in my sample below:

To benefit the community find the right answers, please do mark the post which was helpful by clicking on ‘Accept Answer’ & ‘Up-Vote’.
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1 person found this answer helpful.
Nagashree Balasundaram 731 Reputation points

2022-06-30T18:17:47.863+00:00

@JananiRamesh-MSFT , sorry if i wasn't clear. I want to log certain variables extracted in the policies, or custom messages from policy execution. The Gateway Logs has a fixed schema where you log the request payload bytes and the headers based on the selection you have shown above from Azure monitor. This doesnt help to log custom messages from policies.

Sujithreddy Komma 571 Reputation points Microsoft Employee

2022-07-01T11:00:22.65+00:00

Hi nagashree,

Can you Please try using the Trace policy in you code
For example it will be like below

<trace source="PetStore API" severity="verbose">
<message>@((string)context.Variables["clientConnectionID"])</message>
<metadata name="Operation Name" value="New-Order"/>
</trace>

This will help you push the information into application insights like below

i am not sure it will push to Azure Monitor as well. you can try and let us know

JananiRamesh-MSFT 21,471 Reputation points

2022-07-01T11:15:07.3+00:00

@Nagashree Balasundaram Thanks for getting back, I don't think there is a way to log variables extracted from policy to Log Analytics this can be achieved if you try to log to Application insights by writing a trace policy @Sujithreddy Komma Trace policy will work only for Application insights and not for log analytics.
Please let me know incase of further queries, I would be happy to assist you.

Sujithreddy Komma 571 Reputation points Microsoft Employee

2022-07-01T11:19:55.84+00:00

@JananiRamesh-MSFT :Thanks for the above

Nagashree Balasundaram 731 Reputation points

2022-07-05T16:59:07.867+00:00

@Sujithreddy Komma , @JananiRamesh-MSFT - thank you for the responses. I tried including the trace policy in APIM - I dont see it in Appinsights under Traces. I have Appinsights configured for the APIM as below and the appinsights transactions are showing 0 traces. Is there anything else that is missed?
<trace source="CUID-V3" severity="verbose">
<message>@((string)context.Variables["token"])</message>
<metadata name="Operation Name" value="Validate-Token" />
</trace>
APIM trace after adding the trace policy shows it was successfully executed

JananiRamesh-MSFT 21,471 Reputation points

2022-07-13T13:14:39.873+00:00

Hi @Nagashree Balasundaram Apologies for the delay in response, I tried reproducing the same at my end am able to get those values in application insights as shown below

could you please verify again ?

To benefit the community find the right answers, please do mark the post which was helpful by clicking on ‘Accept Answer’ & ‘Up-Vote’.

Nagashree Balasundaram 731 Reputation points

2022-07-13T15:49:20+00:00

Thank you @JananiRamesh-MSFT . I had verbosity set to "information" in appinsights. After updating it to "verbose" I am able to view it under appinsights traces.
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Custom Log messages from APIM to log analytics

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