Using Elasticsearch Rest API from Kibana web Dev Console to test ingest-pipeline

When using Elasticsearch with a Kibana instance, the user can take advantage of the Kibana web interface to test or query data from the Elasticsearch indexes really easy and fast with the REST APIs. Developing, testing or experimenting is easy in the Kibana Dev tools Console, where indexes could be created, deleted, populated and many more without the need of anything except a modern browser. The Elasticsearch REST API is here –, which points always to the current (latest) version of the Elasticseach version and the versions may be changed, for example, here is the link for the 7.17 branch. Using the Dev Tools Console is simpler even than the curl from the command-line, because the user does not need to add additional (curl or not) arguments and parameters for authentication, headers, metadata for data typing and so on. Just type the API commands and add data if they need. In fact, in the Elasticsearch site most examples use the REST API, so it is just as easy as copy and past in the console text area.

SCREENSHOT 1) Log in the Kibana instance and then navigate to the Dev tools on the left menu and then choose Console.

main menu
Management Dev Tools Console

SCREENSHOT 2) The console shows the last state, which in this case is empty, because it is opened for the first time.

Write the REST API in the left and execute by click over the play button and expect the output in JSON format in the right.

main menu
Dev tools Console overview

Keep on reading!

Moving existing Elasticsearch and Kibana installation from CentOS 7 to CentOS Stream 9

main menu
install Elasticsearch and Kibana

Despite having only two additional installed software under CentOS 7 it is not a good idea to just try upgrading only CentOS 7 to CentOS Stream 9. There is no clear and supported path for upgrading from CentOS 7 to CentOS Stream 9 and even to the older one CentOS 8 (or CentOS Stream 8). The best way is to just make a clean install of CentOS Stream 9 and copy all the Elasticsearch and Kibana files and this article is how to do it without problems.
Here is the plan to move the existing installation of Elasticsearch and Kibana services from CentOS 7 to CentOS Stream 9:

  1. Make a clean install of CentOS Stream 9
  2. Update the current Elasticsearch and Kibana installations to their last versions (from their branch or minor versions).
  3. Add Elasticsearch and Kibana repositories to the new system. Tune the system crypto policies.
  4. Install Elasticsearch and Kibana software packages, but do not start the services.
  5. Copy Elasticsearch and Kibana important files such as the index directory and the configuration directories. Check the user and group IDs of the files.
  6. Start the Elasticsearch and Kibana services.

In this example, the installation of the new server is just starting a new LXC container, which will host the Elasticsearch and Kibana services. There is no difference between using a container or a physical machine. With LXC container it is easier to copy the needed files such as the Elasticsearch index files, which may be tens of terabytes or more, and various configuration files.

STEP 1) Make a clean install of CentOS Stream 9

Check out the following article on the purpose – Network installation of CentOS Stream 9 (20220606.0) – minimal server installation or if LXC container is preferred – Run LXC CentOS Stream 9 container with bridged network under CentOS Stream 9.

Creating a LXC container of CentOS Stream 9 is really simple and fast:

[root@srv ~]# lxc-create --template download -n -- --dist centos --release 9-Stream --arch amd64
The cached copy has expired, re-downloading...
Downloading the image index
Downloading the rootfs
Downloading the metadata
The image cache is now ready
Unpacking the rootfs

You just created a Centos 9-Stream x86_64 (20230511_19:27) container.

Then tune the network following the above article. It is a good idea when configuring the network to preserve the original UUIDs and network addresses (MAC address, too) of the LXC containers network and the inner container’s interface.
So copy the UUID from /var/lib/lxc/loganalyzer-old/rootfs/etc/sysconfig/network-scripts/ifcfg-eth0 to the CentOS Stream 9 network configuration – /var/lib/lxc/loganalyzer/rootfs/etc/NetworkManager/system-connections/ethernet-eth0.nmconnection, which uses NetworkManager. And the LXC container’s MAC address: the variable from /var/lib/lxc/loganalyzer/config to /var/lib/lxc/loganalyzer/config.
The last step is to run the newly installed system. No errors in the output signals for a successful start-up of the LXC container with the name loganalyzer.

[root@srv ~]# lxc-start -n loganalyzer
[root@srv ~]# 

STEP 2) Upgrade the current Elasticsearch and Kibana installations to their last versions (from their branch or minor versions).

For example, if the current Elasticsearch is version 7. It is good to upgrade it to the latest version from 7.x before proceeding with the next steps.
The current installed versions of Elasticsearch and Kibana software are from the branch 77.17.4-1 and the latest version is 7.17.10-1.
Check in the old system with (CentOS 7):

[root@loganalyzer-old ~]# yum list installed|egrep -e "(elasticsearch|kibana)"
elasticsearch.x86_64               7.17.4-1                               @elasticsearch
kibana.x86_64                      7.17.4-1                               @elasticsearch

Keep on reading!

Installing single node Elasticsearch 7.16 and Kibana 7.16 behind nginx web server under CentOS 8

This article will show how to install two big software – Elasticsearch to store information and Kibana to visualize the information under CentOS 8. Elasticsearch is ideal to store big data such as logs from user activities or server logs – one central repository for data, which is structured properly and it could be easily accessed and manipulated with various software.
Kibana is used mainly for visualizing the data stored in the Elasticseach server and manage the Elasticsearch service by the web. ste

Here is a simple example: send the web servers logs in Elasticsearch and visual statistical data with Kibana.

Using the rpm repository for the two software is the best option for installation and in future upgrades.

STEP 1) Install the CentOS 8.

How to install CentOS 8 could be found here – How to do a network installation of CentOS 8 (8.0.1950) – minimal server installation.
Or if a container approach is needed, there is a how to with LXC containerRun LXC CentOS 8 container with bridged network under CentOS 8.

STEP 2) Install the Elasticsearch.

This installation and configuration is for single node server setup.
First, create a rpm repository file /etc/yum.repos.d/elasticsearch.repo and fill it with the Elasticsearch repository information:

name=Elasticsearch repository for 7.x packages

Then import the Elasticsearch GPG key and install the Elasticsearch software:

[root@loganalyzer ~]# rpm --import
[root@loganalyzer ~]# dnf install elasticsearch
Last metadata expiration check: 0:00:19 ago on 11.12.2021 (Sat) 12:43:24 UTC.
Dependencies resolved.
 Package            Architecture             Version                     Repository                                Size
 elasticsearch      x86_64                   7.16.0-1                    elasticsearch                             327 M

Transaction Summary
Install  1 Package

Total download size: 327 M
Installed size: 526 M
Is this ok [y/N]: y
Downloading Packages:
elasticsearch-7.16.0-x86_64.rpm                                                                                 43 MB/s | 327 MB     00:07    
Total                                                                                                           43 MB/s | 327 MB     00:07     
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                                                                                                     1/1 
  Running scriptlet: elasticsearch-7.16.0-1.x86_64                                                                                                                                       1/1 
Creating elasticsearch group... OK
Creating elasticsearch user... OK

  Installing       : elasticsearch-7.16.0-1.x86_64                                                                                                                                       1/1 
  Running scriptlet: elasticsearch-7.16.0-1.x86_64                                                                                                                                       1/1 
### NOT starting on installation, please execute the following statements to configure elasticsearch service to start automatically using systemd
 sudo systemctl daemon-reload
 sudo systemctl enable elasticsearch.service
### You can start elasticsearch service by executing
 sudo systemctl start elasticsearch.service

Created elasticsearch keystore in /etc/elasticsearch/elasticsearch.keystore

[/usr/lib/tmpfiles.d/elasticsearch.conf:1] Line references path below legacy directory /var/run/, updating /var/run/elasticsearch → /run/elasticsearch; please update the tmpfiles.d/ drop-in file accordingly.

  Verifying        : elasticsearch-7.16.0-1.x86_64                                                                                                                                       1/1 



The configuration files are placed in /etc/elasticsearch/:
Keep on reading!

Kibana server is not ready yet – and Waiting for that migration to complete in the logs

Now, living in the cloud and big data there is a time when the admin may need to save all their logs in a central place! Elasticsearch and Kibana look good for the job! And after months of hassle-free work of the Elasticsearch and Kibana, Elasticsearch just stopped working and after a restart and upgrade (Elasticsearch and Kibana) Kibana showed an error message:

Kibana server is not ready yet

And if you have tried the STOP/START of Kibana and Elasticsearch and Kibana would still show the above message here is what you should do:

  1. Check if the two services are running! Kibana and Elasticsearch, if some of them is missing start it.
  2. Search for the logs and especially Elasticsearch logs. The first place to check is systemd logs with journalctl program (systemctl status also will point out the problem showing last lines of the logs).
  3. Look for the last lines and if they include

    Another Kibana instance appears to be migrating the index

    This article is probably the right place to solve the issue and start your setup successful.

STEP 1) Running services and analyzing the logs.

If kibana and elastisearch use systemd system to operate it is easy to access the logs with systemctl and journalctl
Check whether the kibana and elasticsearch are running with:

[root@loganalyzer ~]# ps ax|grep elasticsearch|grep -v grep
  258 ?        Ssl  836:31 /usr/share/elasticsearch/jdk/bin/java -Des.networkaddress.cache.ttl=60 -Des.networkaddress.cache.negative.ttl=10 -XX:+AlwaysPreTouch -Xss1m -Djava.awt.headless=true -Dfile.encoding=UTF-8 -Djna.nosys=true -XX:-OmitStackTraceInFastThrow -Dio.netty.noUnsafe=true -Dio.netty.noKeySetOptimization=true -Dio.netty.recycler.maxCapacityPerThread=0 -Dio.netty.allocator.numDirectArenas=0 -Dlog4j.shutdownHookEnabled=false -Dlog4j2.disable.jmx=true -Djava.locale.providers=COMPAT -Xms1g -Xmx1g -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/var/lib/elasticsearch -XX:ErrorFile=/var/log/elasticsearch/hs_err_pid%p.log -Xlog:gc*,gc+age=trace,safepoint:file=/var/log/elasticsearch/gc.log:utctime,pid,tags:filecount=32,filesize=64m -XX:MaxDirectMemorySize=536870912 -Des.path.home=/usr/share/elasticsearch -Des.path.conf=/etc/elasticsearch -Des.distribution.flavor=default -Des.distribution.type=rpm -Des.bundled_jdk=true -cp /usr/share/elasticsearch/lib/* org.elasticsearch.bootstrap.Elasticsearch -p /var/run/elasticsearch/ --quiet
  360 ?        Sl     0:00 /usr/share/elasticsearch/modules/x-pack-ml/platform/linux-x86_64/bin/controller
[root@loganalyzer ~]# ps ax|grep kibana|grep -v grep
 1284 ?        Ssl    4:32 /usr/share/kibana/bin/../node/bin/node /usr/share/kibana/bin/../src/cli -c /etc/kibana/kibana.yml

If one of the two services are missing you must start it! And second, each service should have only one instance (i.e. process)!
And check the kibana logs with journalctl

[root@loganalyzer ~]# journalctl -u kibana.service
Apr 24 23:09:31 loganalyzer kibana[1219]: {"type":"log","@timestamp":"2020-04-24T23:09:31Z","tags":["info","plugins","bfetch"],"pid":1219,"message":"Setting up plugin"}
Apr 24 23:09:31 loganalyzer kibana[1219]: {"type":"log","@timestamp":"2020-04-24T23:09:31Z","tags":["info","savedobjects-service"],"pid":1219,"message":"Waiting until all Elasticsearch nodes
 are compatible with Kibana before starting saved objects migrations..."}
Apr 24 23:09:31 loganalyzer kibana[1219]: {"type":"log","@timestamp":"2020-04-24T23:09:31Z","tags":["info","savedobjects-service"],"pid":1219,"message":"Starting saved objects migrations"}
Apr 24 23:09:31 loganalyzer kibana[1219]: {"type":"log","@timestamp":"2020-04-24T23:09:31Z","tags":["info","savedobjects-service"],"pid":1219,"message":"Creating index .kibana_task_manager_2
Apr 24 23:09:31 loganalyzer kibana[1219]: {"type":"log","@timestamp":"2020-04-24T23:09:31Z","tags":["warning","savedobjects-service"],"pid":1219,"message":"Unable to connect to Elasticsearch
. Error: [resource_already_exists_exception] index [.kibana_task_manager_2/O070AunfSyG6hwd6_pqqRA] already exists, with { index_uuid=\"O070AunfSyG6hwd6_pqqRA\" & index=\".kibana_task_manager
_2\" }"}
Apr 24 23:09:31 loganalyzer kibana[1219]: {"type":"log","@timestamp":"2020-04-24T23:09:31Z","tags":["warning","savedobjects-service"],"pid":1219,"message":"Another Kibana instance appears to
 be migrating the index. Waiting for that migration to complete. If no other Kibana instance is attempting migrations, you can get past this message by deleting index .kibana_task_manager_2 
and restarting Kibana."}

The systemctl status may be used, too. The error and the index are shown in the last lines of the status output – look below.

The problem here is there was a migration of index .kibana_task_manager_2, but it was abandoned because of unknown reason and now we should delete it to be able to use our kibana service. The index name might be with another name but it is the same problem.

STEP 2) Delete kibana index

Delete the kibana index in elasticsearch backend using curl and HTTP/HTTPS request such as:

[root@loganalyzer kibana]# curl -XDELETE

Keep on reading!