'az functionapp deploy' with zip file sends wrong content-type

[zerodogg]

Describe the bug

When deploying a zip file from 'az functionapp deploy' it sends the content type as application/octet-stream which causes azure to return a HTTP 415 "Unsupported Media Type". It should send application/zip.

Related command

az functionapp deploy --resource-group XXX --name XXX --src-path XXX.zip

Errors

An error occurred during deployment. Status Code: 415, Please visit …/api/deployments/latest to get more information about your deployment

Issue script & Debug output

Expected behavior

Zip gets deployed

Environment Summary

azure-cli 2.87.0

core 2.87.0
telemetry 1.1.0

Extensions:
ssh 2.0.6

Dependencies:
msal 1.36.0
azure-mgmt-resource 24.0.0

Python location '/usr/local/Cellar/azure-cli/2.87.0/libexec/bin/python'
Config directory '/Users/…/.azure'
Extensions directory '/Users/…/.azure/cliextensions'

Python (Darwin) 3.13.14 (main, Jun 10 2026, 12:24:04) [Clang 17.0.0 (clang-1700.6.4.2)]

Legal docs and information: aka.ms/AzureCliLegal

Your CLI is up-to-date.

Additional context

This patch fixes it:

--- a/src/azure-cli/azure/cli/command_modules/appservice/custom.py
+++ b/src/azure-cli/azure/cli/command_modules/appservice/custom.py
@@ -11361,7 +11361,10 @@ def _build_deploymentstatus_url(cmd, resource_group_name, webapp_name, slot, dep

 def _get_ondeploy_headers(params):
     if params.src_path:
-        content_type = 'application/octet-stream'
+        if params.artifact_type == "zip":
+            content_type = 'application/zip'
+        else:
+            content_type = 'application/octet-stream'
     elif params.src_url:
         content_type = 'application/json'
     else:

[yonzhan]

functionapp

[a0x1ab]

Bug Analysis

az functionapp deploy --src-path <file>.zip always sets the deployment
Content-Type header to application/octet-stream, regardless of the
artifact type. For zip deployments, Azure's Kudu/SCM deployment API expects
application/zip and returns HTTP 415 Unsupported Media Type when it
receives application/octet-stream instead.

Root cause: _get_ondeploy_headers() in
src/azure-cli/azure/cli/command_modules/appservice/custom.py hardcodes
application/octet-stream whenever params.src_path is set, without looking
at params.artifact_type.

Fix: when params.src_path is set and params.artifact_type == "zip",
send Content-Type: application/zip; otherwise keep
application/octet-stream for other artifact types (war, jar, ear, static,
startup, script, etc.).

The issue reporter attached a reference patch (note it has a syntax error —
missing : after the if — so it won't compile as-is; write valid Python):

def _get_ondeploy_headers(params):
    if params.src_path:
        if params.artifact_type == "zip":
            content_type = 'application/zip'
        else:
            content_type = 'application/octet-stream'
    elif params.src_url:
        content_type = 'application/json'
    ...

Please add/adjust a unit test covering the zip case (asserting
Content-Type: application/zip) and confirm the previous behavior is
unchanged for other artifact types.

Use this EXACT PR title: [AppService] Fix #33688: az functionapp deploy: Fix wrong Content-Type header for zip deployments

PR title & description format (required)

This repo enforces a PR format (guide). Please author the PR exactly as follows or CI's Check the Format of Pull Request Title and Content will fail.

Use this EXACT PR title (copy verbatim, do not reword):

[AppService] Fix #33688: `az functionapp deploy`: Fix wrong Content-Type header for zip deployments

Keep the backticks around the command and the Fix #33688: prefix. You may only adjust the wording after the command (the final summary) if the fix changes; the [AppService] prefix, issue link, and backticked command must stay.

Description — follow the PR template and fill in:

• Link the issue — start the Description with a closing keyword so the PR auto-links and closes it: Fixes #33688.
• Related command — the az ... command this affects.
• Description (mandatory) — why the bug happens, what you changed, and the resulting behavior.
• Testing Guide — example command(s) showing the fix works.
• History Notes — leave the title to drive the history note, or add extra lines in the same format (component in brackets + the command in backticks), e.g. [AppService] `az <command>`: <note>.
• Keep the template checklist and tick the items you've satisfied.

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Posted by agent-assist (autonomous bug-fix pipeline).