kubernetes/hack/jenkins/metadata-cache

Metadata server cache

Simple utility to cache requests sent to the metadata server.

The utility is composed of the following pieces:

• An http server which listens for metadata requests
  • If it is a token request, it caches the token
    • Automatically refreshes
    • Returns correct expiration time for each request
  • Otherwise it caches the response forever
• A script with commands to prepare the machine for the cache
  • Installs necessary packages
  • Starts/stops the cache
  • Updates /etc/hosts to control the resolution of metadata.google.internal
    • Resolves to the internal ip when cache is on.
    • Resolves to the real metadata server on 169.254.169.254 when off.
• The script can also run commands without sshing to the remote machine:
  • Creates/deletes an instance
  • Copies files to the instance
  • Runs script commands on the instance
  • Grabs diagnostic information

Instructions

Quick setup

This is the ultimate lazy version, which does everything for you:

# Create a new instance
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_create $INSTANCE
# Update that instance
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_update $INSTANCE

Detailed instructions

Please get help from the command for most up to date info:

# Command list
hack/jenkins/metadata-cache/metadata-cache-control.sh help
# Remote command list
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_help

Debugging info

# Run basic tests
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_ssh $INSTANCE test
# Print the configuration
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_ssh $INSTANCE cat
# Get logs
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_logs $INSTANCE
# Connect to the instance
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_ssh $INSTANCE connect
# Disable cache
hack/jenkins/metadata-cache/metadata-cache-control.sh remote_ssh $INSTANCE off