First run of az-cli is slow

[lanni-energinet]

Description

For quite some time we have been impacted by poor performance due to the nature of az-cli's command and module caching on it's first run. It would seem that az-cli was not written with ephemeral runners in mind, and it doesn't look like they could change this easily. Hence why we are opening this issue here.

We can see that the issue is fixed on windows images as a simple warmup has been implemented

runner-images/images/windows/scripts/build/Install-AzureCli.ps1

Line 22 in c5c9a7c

# Warm-up Azure CLI

Can you please implement a simple warm up like on the windows runners?

From a sample of our logs we have measured the following impact
Minimum 2 s
Maximum 31 s
Average 5 s

We estimate wasting roughly 6500 minutes per month which is more than 10% of our of total usage

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 20.04
• Ubuntu 22.04
• Ubuntu 24.04
• macOS 11
• macOS 12
• macOS 13
• macOS 13 Arm64
• macOS 14
• macOS 14 Arm64
• Windows Server 2019
• Windows Server 2022

Image version and build link

https://github.com/actions/runner-images/releases/tag/ubuntu22%2F20240609.1

Is it regression?

no

Expected behavior

A build-in warmup in the ubuntu image creation similar to the windows image

Actual behavior

No warmup

Repro steps

None needed

[kishorekumar-anchala]

HI @lanni-energinet ,

Thank you for bringing this issue to us, we are investigating on this issue and we will update you on this issue after our findings.