Multiple progs try to install new packages with apt

[vkameswaran]

It may not be a big issue. Various progs install new packages with apt while preparing the VM host. They conflict and cause failures. It would be beneficial to resolve this issue without displaying an exception message.

---STDOUT---


---STDERR---
E: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 3042 (apt-get)
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?
	from host/bin/prep_host.rb:93:in `<main>'

[greptile-apps-local]

To resolve the issue of multiple programs (progs) trying to install new packages with apt concurrently and causing lock conflicts, consider implementing a locking mechanism in your scripts or checking for the apt lock status before attempting package installations. Here's a suggested approach for prep_host.rb and similar scripts that use apt-get for package installations:

1. Implement a Lock Check and Wait Loop: Before each apt-get command, add a loop to check if /var/lib/dpkg/lock-frontend is locked. If it is, wait for a short period before checking again. This can prevent the script from failing due to the lock being held by another process.

Example implementation in Ruby (to be adapted and added before apt-get commands):

while File.exist?('/var/lib/dpkg/lock-frontend') || File.exist?('/var/lib/dpkg/lock')
  puts 'Waiting for other apt operations to complete...'
  sleep 5
end

2. Centralize Package Installation: If possible, centralize package installations to a single script or section of your codebase to minimize the chances of concurrent apt-get calls. This might involve collecting all required packages and installing them in one go, rather than spreading apt-get install calls across multiple scripts.

3. Use flock to Synchronize: For shell scripts, consider using flock to ensure that only one instance of your package installation logic runs at a time. This is more robust and can be used to wrap calls to apt-get.

Example shell command:

flock /var/lib/dpkg/lock-frontend -c 'sudo apt-get update && sudo apt-get install -y my-package'

Implementing these strategies should help mitigate the issue without displaying an exception message, by ensuring that apt-get commands do not conflict with each other.

References

greptileai/ubicloud/prog/install_dnsmasq.rb
greptileai/ubicloud/rhizome/host/bin/prep_host.rb
greptileai/ubicloud/prog/setup_nftables.rb

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