Where is log output from cloud-init stored?

Question

Where does output from cloud-init (automatically runs scripts when starting up a virtual machine in the cloud, for example at Amazon EC2) go? I would like to know that my initialization scripts executed successfully.

There is a /var/log/cloud-init.log file, but it seems to contain only partial output (namely from the SSH key initialization).

score 21 · Accepted Answer · edited Jan 27 '17 at 17:25

Since cloud-init 0.7.5 (released on Apr 1 2014), all output from cloud-init is captured by default to /var/log/cloud-init-output.log. This default logging configuration was added in a commit from Jan 14 2014:

# this tells cloud-init to redirect its stdout and stderr to
# 'tee -a /var/log/cloud-init-output.log' so the user can see output
# there without needing to look on the console.
output: {all: '| tee -a /var/log/cloud-init-output.log'}

To add support for previous versions of cloud-init, you can manually add this configuration manually to your Cloud Config Data.

score 3 · Answer 2 · answered Jun 29 '12 at 13:46

3

I couldn't find way a "native" way for doing that. Before passing the script to cloud-init, I've simply (automatically) appended a >> /tmp/init-script-log 2>&1 to each line of the script, to forward stout and stderr to a file.

answered Jun 29 '12 at 13:46

Roberto Aloi

565
2
5
14

1

As Valko pointed out, neither `/var/log/cloud-init.log` nor `/var/log/cloud-init-output.log` captures output from user-data scripts. Roberto's solution here answers that concern. Another way I've seen this done is to preamble your user-data script to send all output to **syslog** with `exec 1> >(logger -s -t "WhateverNameYouWantToMakeSiftingLogMessagerEasier") 2>&1` – Toddius Zho Jan 29 '18 at 17:00

score 2 · Answer 3 · answered Feb 12 '21 at 10:41

2

The log is stored in systemd:

journalctl -u cloud-final

answered Feb 12 '21 at 10:41

Graham North

21
1

1

Welcome to Stackexchange, and thanks for your contribution. However, the question was asked ten years ago before systemd was widely used (or even before it existed). Even when systemd is used, I am not sure if your answer is correct. [cloudinit documentation](https://cloudinit.readthedocs.io/en/latest/topics/faq.html?highlight=log#where-are-the-logs) says something else. – berndbausch Feb 24 '21 at 09:48

score 1 · Answer 4 · answered Feb 19 '11 at 07:18

1

On my EC2 box (running the Amazon Linux AMI) it's stored in /var/log/cloud-init.log

answered Feb 19 '11 at 07:18

Edouard

11
1

2

Thanks, but it doesn't seem to contain output from user scripts. – Markus Miller Feb 19 '11 at 07:24

score 1 · Answer 5 · answered Sep 02 '15 at 01:19

1

On the Centos 7 AMI I am using, the output of my user data script is in /var/log/cloud-init-output.log.

answered Sep 02 '15 at 01:19

rakslice

445
3
11

score 0 · Answer 6 · answered May 23 '19 at 14:05

0

I've found log output in /var/log/messages (CentOS7 AWS AMI)

answered May 23 '19 at 14:05

mbo

101
1

score -5 · Answer 7 · answered Jan 29 '11 at 14:26

First of all let me congratulate you on using cloud-init, it's a quite amazing tool!

There's no way yet to setup a log level but by default cloud-init will run with DEBUG enabled.

It's still in heavy development, I expect it to be a lot better by the release of Ubuntu Natty

Where is log output from cloud-init stored?

7 Answers7