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Diffstat (limited to 'doc/rtd/topics/debugging.rst')
| -rw-r--r-- | doc/rtd/topics/debugging.rst | 57 |
1 files changed, 31 insertions, 26 deletions
diff --git a/doc/rtd/topics/debugging.rst b/doc/rtd/topics/debugging.rst index c2b47edc..cacc8a27 100644 --- a/doc/rtd/topics/debugging.rst +++ b/doc/rtd/topics/debugging.rst @@ -1,6 +1,6 @@ -********************** +******************************** Testing and debugging cloud-init -********************** +******************************** Overview ======== @@ -10,7 +10,7 @@ deployed instances. .. _boot_time_analysis: Boot Time Analysis - cloud-init analyze -====================================== +======================================= Occasionally instances don't appear as performant as we would like and cloud-init packages a simple facility to inspect what operations took cloud-init the longest during boot and setup. @@ -22,9 +22,9 @@ determine the long-pole in cloud-init configuration and setup. These subcommands default to reading /var/log/cloud-init.log. * ``analyze show`` Parse and organize cloud-init.log events by stage and -include each sub-stage granularity with time delta reports. + include each sub-stage granularity with time delta reports. -.. code-block:: bash +.. code-block:: shell-session $ cloud-init analyze show -i my-cloud-init.log -- Boot Record 01 -- @@ -41,9 +41,9 @@ include each sub-stage granularity with time delta reports. * ``analyze dump`` Parse cloud-init.log into event records and return a list of -dictionaries that can be consumed for other reporting needs. + dictionaries that can be consumed for other reporting needs. -.. code-block:: bash +.. code-block:: shell-session $ cloud-init analyze blame -i my-cloud-init.log [ @@ -56,10 +56,10 @@ dictionaries that can be consumed for other reporting needs. },... * ``analyze blame`` Parse cloud-init.log into event records and sort them based -on highest time cost for quick assessment of areas of cloud-init that may need -improvement. + on highest time cost for quick assessment of areas of cloud-init that may + need improvement. -.. code-block:: bash +.. code-block:: shell-session $ cloud-init analyze blame -i my-cloud-init.log -- Boot Record 11 -- @@ -73,31 +73,36 @@ Analyze quickstart - LXC --------------------------- To quickly obtain a cloud-init log try using lxc on any ubuntu system: -.. code-block:: bash +.. code-block:: shell-session + + $ lxc init ubuntu-daily:xenial x1 + $ lxc start x1 + $ # Take lxc's cloud-init.log and pipe it to the analyzer + $ lxc file pull x1/var/log/cloud-init.log - | cloud-init analyze dump -i - + $ lxc file pull x1/var/log/cloud-init.log - | \ + python3 -m cloudinit.analyze dump -i - - $ lxc init ubuntu-daily:xenial x1 - $ lxc start x1 - # Take lxc's cloud-init.log and pipe it to the analyzer - $ lxc file pull x1/var/log/cloud-init.log - | cloud-init analyze dump -i - - $ lxc file pull x1/var/log/cloud-init.log - | \ - python3 -m cloudinit.analyze dump -i - Analyze quickstart - KVM --------------------------- To quickly analyze a KVM a cloud-init log: 1. Download the current cloud image - wget https://cloud-images.ubuntu.com/daily/server/xenial/current/xenial-server-cloudimg-amd64.img + +.. code-block:: shell-session + + $ wget https://cloud-images.ubuntu.com/daily/server/xenial/current/xenial-server-cloudimg-amd64.img + 2. Create a snapshot image to preserve the original cloud-image -.. code-block:: bash +.. code-block:: shell-session $ qemu-img create -b xenial-server-cloudimg-amd64.img -f qcow2 \ test-cloudinit.qcow2 3. Create a seed image with metadata using `cloud-localds` -.. code-block:: bash +.. code-block:: shell-session $ cat > user-data <<EOF #cloud-config @@ -108,18 +113,18 @@ To quickly analyze a KVM a cloud-init log: 4. Launch your modified VM -.. code-block:: bash +.. code-block:: shell-session $ kvm -m 512 -net nic -net user -redir tcp:2222::22 \ - -drive file=test-cloudinit.qcow2,if=virtio,format=qcow2 \ - -drive file=my-seed.img,if=virtio,format=raw + -drive file=test-cloudinit.qcow2,if=virtio,format=qcow2 \ + -drive file=my-seed.img,if=virtio,format=raw 5. Analyze the boot (blame, dump, show) -.. code-block:: bash +.. code-block:: shell-session $ ssh -p 2222 ubuntu@localhost 'cat /var/log/cloud-init.log' | \ - cloud-init analyze blame -i - + cloud-init analyze blame -i - Running single cloud config modules @@ -136,7 +141,7 @@ prevents a module from running again if it has already been run. To ensure that a module is run again, the desired frequency can be overridden on the commandline: -.. code-block:: bash +.. code-block:: shell-session $ sudo cloud-init single --name cc_ssh --frequency always ... |