Debugging tips and tricks

Author: Olivier Gambier

DEBUGGING.md

@@ -0,0 +1,49 @@
+# TLDR
+
+## Basics
+
+`docker info`
+
+`docker version`
+
+Have docker daemon started in debug mode: `docker -d -D`
+
+
+## Your private registry
+
+Copy your launch command (eg: `docker run registry...`).
+
+Copy your configuration file, if you are not using the default one.
+
+Restart your private registry in debug mode (add `-e DEBUG=true` to your docker launch command).
+
+`curl -svn --trace-time https://MYREGISTRY/_ping`
+
+## Testing the speed of the official registry
+
+```
+VICTIM=tianon/speedtest
+LAYER=71e62a8beff35bb692f64fb2e04bf1d6d19f5262500ad05dd95b1a95dcb5599d
+SIGNATURE="`curl -iv -o/dev/null -H "X-Docker-Token: true" "https://registry.hub.docker.com/v1/repositories/$VICTIM/images" 2>&1 | awk '{print $3}' | grep signature | tr -d "\r\n"`"
+CF_URL="`curl -iv -o/dev/null -H "Authorization: Token $SIGNATURE" https://registry-1.docker.io/v1/images/$LAYER/layer 2>&1 | awk '{print $3}' | grep cloudfront | sed -e 's/\r\n//g' | tr -d "\r\n"`"
+echo "*************"
+echo "CF delivery:"
+echo "*************"
+time curl  -svnoo --trace-time "${CF_URL}"
+
+echo "*************"
+echo "Resolving:"
+echo "*************"
+dig resolver-identity.cloudfront.net
+
+echo "*************"
+echo "RAW S3:"
+echo "*************"
+time curl -svnoo --trace-time http://kamilc-us-west-1.s3.amazonaws.com/test200m
+
+echo "*************"
+echo "RAW HTTP:"
+echo "*************"
+time curl -svnoo --trace-time http://mirrors.sonic.net/centos/7/isos/x86_64/CentOS-7.0-1406-x86_64-NetInstall.iso
+
+```

FAQ.md

@@ -24,3 +24,5 @@ Please insert the following into your bug report:
 Please, no "this happens to me as well" comments on tickets - not helpful.
 
 On the other hand, if you do have any useful information to provide, by all means do. 
+
+Also see [debugging](DEBUGGING.md) for more indepth information about troubleshooting and performance testing.