Troubleshooting

Upload Logs to Pastebin

Sometimes it helps to share your logs with someone who can help figure out problems.

First make sure you have the pastebin tool installed.

On CentOS: yum install -y fpaste

On Ubuntu: apt-get install -y pastebinit

Below are examples for Ubuntu and CentOS how to upload various files. You can tweak parameters as required.

Note that the long sed commands are there to hide IP addresses.

The command will return a URL link which you can share, that will open the logs in the browser.

** DO NOT COPY PASTE BLINDLY, edit commands as required before execution! **

Ubuntu Logs

Here are a few examples. You can change the log file name if required.

The two sed commands can be added in between any command to hide IP addresses: sed 's/\([0-9]\{1,3\}\.\)\{3,3\}[0-9]\{1,3\}/x.x.x.x/g'|sed  -r 's#:\[.*\]:([0-9]+)#:\[xxxx:xxxx:xxxx:xxxx\]:\1#g'.

# Example uploading last 200 lines of main syslog, hide IPv4 and IPv6 addresses
tail -200 /var/log/syslog | sed 's/\([0-9]\{1,3\}\.\)\{3,3\}[0-9]\{1,3\}/x.x.x.x/g'|sed  -r 's#:\[.*\]:([0-9]+)#:\[xxxx:xxxx:xxxx:xxxx\]:\1#g'| pastebinit -b pastebin.com -P

# Example uploading iri-playbook log
cat /tmp/iri-playbook-201801061902.log | pastebinit -b pastebin.com -P


# Example uploading last 200 lines of iota-pm service log
journalctl -u iota-pm --no-pager -n 200 | pastebinit -b pastebin.com -P

# Example uploading last 200 lines of iri service log
journalctl -u iri --no-pager -n 200 | pastebinit -b pastebin.com -P

CentOS Logs

Here are a few examples. You can change the log file name if required.

The two sed commands can be added in between any command to hide IP addresses: sed 's/\([0-9]\{1,3\}\.\)\{3,3\}[0-9]\{1,3\}/x.x.x.x/g'|sed  -r 's#:\[.*\]:([0-9]+)#:\[xxxx:xxxx:xxxx:xxxx\]:\1#g'.

# Example uploading last 200 lines of main syslog, hide IPv4 and IPv6 addresses
tail -200 /var/log/messages | sed 's/\([0-9]\{1,3\}\.\)\{3,3\}[0-9]\{1,3\}/x.x.x.x/g'|sed  -r 's#:\[.*\]:([0-9]+)#:\[xxxx:xxxx:xxxx:xxxx\]:\1#g'| fpaste -P "yes"

# Example uploading iri-playbook log
cat /tmp/iri-playbook-201801061902.log | fpaste -P "yes"


# Example uploading last 200 lines of iota-pm service log
journalctl -u iota-pm --no-pager -n 200 | fpaste -P "yes"

# Example uploading last 200 lines of iri service log
journalctl -u iri --no-pager -n 200 | fpaste -P "yes"

How to Handle Git Conflicts

This is by no means a git tutorial, and the method suggested here has nothing to do with how one should be using git.

Background

It is simply the case that updates are applied to configuration files over time. A user might have configured values that might later conflict with new updates.

I was looking for a quick solution for users who are not familiar with Linux or git. One idea was to rename all the variable files adding the extension .example and using those as the “source”.

The other solution is the one I am presenting here.

Backup My Changes

If you run a git pull and receive a message about conflicts, e.g.:

error: Your local changes to the following files would be overwritten by merge:
        somefile
Please, commit your changes or stash them before you can merge.
Aborting

This means you’ve applied changes in files which have already been updated upstream.

You can identify those files:

git status

And view the changes you’ve applied:

git diff

You can run the following command which will backup the files you’ve changed and allow to pull the updated versions:

mkdir -p /tmp/my-changes && for f in $(git status|grep modified|awk {'print $3'});do cp $f /tmp/my-changes/ ; git checkout -- $f ;done

This will copy any conflicting file into the directory /tmp/my-changes.

At this point you will not have any conflicts and be able to run git pull.

Apply Changes

The next step is to identify the changes. You can view the files that have been backed up using ls -l /tmp/my-changes.

For each file in that directory find its corresponding (new) updated file: find -name filename.

To view the differeneces run diff /tmp/my-changes/my-old-file my-newfile. The command’s output might not be the prettiest; you can choose to handle the conflicts manually.

Once you are done applying your changes, you can proceed to run the playbook command you were about to apply.

HTTP Error 401 Unauthorized When Running Playbook

This is how the error would look like:

TASK [monitoring : create prometheus datasource in grafana] ************************************************************************************************
fatal: [localhost]: FAILED! => {"changed": false, "connection": "close", "content": "{\"message\":\"Basic auth failed\"}", "content_length": "31", "content_type": "application/json; charset=UTF-8", "date": "Fri, 29 Dec 2017 10:40:13 GMT", "json": {"message": "Basic auth failed"}, "msg": "Status code was not [200, 409]: HTTP Error 401: Unauthorized", "redirected": false, "status": 401, "url": "http://localhost:3000/api/datasources"}
     to retry, use: --limit @/opt/iri-playbook/site.retry

PLAY RECAP *************************************************************************************************************************************************

This can happen for a number of reasons. It is most probably a password mismatch between what the playbook sees in group_vars/all/iotapm.yml under the value iotapm_nginx_password and perhaps the iotapm_nginx_user too.

Solution A

Try to correct this by checking the password which is currently configured in grafana:

grep ^admin /etc/grafana/grafana.ini

The result should look like:

admin_user = iotapm
admin_password = hello123

You can try to override the password when running the playbook, appending it to the end of the ansible command, e.g.:

ansible-playbook -i inventory -v site.yml --tags=monitoring_role -e iotapm_nginx_password=hello123

Solution B

If Solution A doesn’t work, there’s a way to force-reset the password.

This solution also works if you haven’t installed Grafana via this tutorial and cannot login.

  1. Stop grafana-server:
systemctl stop grafana-server
  1. Delete grafana’s database:
rm -f /var/lib/grafana/grafana.db
  1. Edit /etc/grafana/grafana.ini, set correct values for admin_user and admin_password.
  2. Start grafana-server:
systemctl start grafana-server

Now you should be able to login to grafana.

Error Starting up Nelson After Upgrade

Checking nelson logs can reveal startup errors (e.g. journalctl -u nelson --no-pager -n40)

If you get an error that looks like this when starting up nelson:

Jan 29 20:57:40 vmi111112.shintaboserver.net nelson[3178]: 20:57:40.241        16600::NODE  terminating...
Jan 29 20:57:40 vmi111112.shintaboserver.net nelson[3178]: Unhandled Rejection at: Promise Promise {
Jan 29 20:57:40 vmi111112.shintaboserver.net nelson[3178]:   <rejected> Error: "toString()" failed
Jan 29 20:57:40 vmi111112.shintaboserver.net nelson[3178]:     at stringSlice (buffer.js:560:43)
Jan 29 20:57:40 vmi111112.shintaboserver.net nelson[3178]:     at Buffer.toString (buffer.js:633:10)
Jan 29 20:57:40 vmi111112.shintaboserver.net nelson[3178]:     at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:506:23) } reason: Error: "toString()" failed
Jan 29 20:57:40 vmi1111112.contaboserver.net nelson[3178]:     at stringSlice (buffer.js:560:43)

The nelson database might have become corrupt. You can remove it and it will re-create:

rm -rf /var/lib/nelson/data/neighbors.db

Start up nelson, and check the status again:

systemctl start nelson

Status:

systemctl status nelson

Error Starting or Restarting IRI

Examples of errors:

Hostname can’t be null

If you get this message in the logs:

java.lang.IllegalArgumentException: hostname can't be null

It is most likely you have a typo in one (or more) of the neighbors in your configuration file, or the entire line is invalid.

Make sure all neighbors adhere to the format examples:

tcp://some-node.myserver.com:15600
udp://10.20.30.40:14600
tcp://[2xxx:7xx:aaaf:111:2222:ff:ffff:xxxx]:12345