• Duplicate exported resources on puppet by mistake

    We had a strange problem in our test environment the other day. There is a need to share an authorized key in order for the ssh connectivity to be available.

    The way we shared the file resource was straight forward.

      @@file {"/home/kafka/.ssh/authorized_keys":
        ensure => present,
        mode => '0600',
        owner => 'kafka',
        group => 'kafka',
        content => "${::sharedkey}",
        tag => "${::tagvalue}",
      }

    The tag value variable was a fact unique to each Kafka cluster.

    However, each time we executed puppet, the following error the following error was present:

    08:38:20 Error: Could not retrieve catalog from remote server: Error 500 on SERVER: Server Error: A duplicate resource was found while collecting exported resources, with the type and title File[/home/kafka/.ssh/authorized_keys] on node [node_name]

    We had a couple of days at our disposal to play with the puppet DB, nothing relevant came from it

    This behavior started after provisioning a second cluster named similar also with SSL enabled.

    After taking a look on the official Puppet documentation (https://puppet.com/docs/puppet/latest/lang_exported.html – check the caution clause), it was clear that the naming of resource should not be the same.

    The problem hadn’t appear on any of our clusters since now, so this was strange to say the least.

    For whatever reason, the tag was not taken into consideration.

    And we know that because resources shared on both nodes were put everywhere, there was no filtering.

    Solution:

    Quick fix was done with following modifications.

      @@file {"/home/kafka/.ssh/authorized_keys_${::clusterid}":
        path => "/home/kafka/.ssh/authorized_keys",
        ensure => present,
        mode => '0600',
        owner => 'kafka',
        group => 'kafka',
        content => "${::sharedkey}",
        tag => "${::clusterid}",
      }

    So now there is an individual file per cluster, and we also have a tag that is recognized in order to filter the shared file that we need on our server.

    Filtering will be done like File <<| tag == "${::clusterid}" |>>

    Cheers!

  • Strange problem in puppet run for Ubuntu

    Hi,

    Short sharing of a strange case.

    We’ve written a small manifest in order to distribute some python scripts. You can find the reference here: https://medium.com/metrosystemsro/new-ground-automatic-increase-of-kafka-lvm-on-gcp-311633b0816c

    When you try to run it on Ubuntu 14.04, there is this very strange error:

    Error: Failed to apply catalog: [nil, nil, nil, nil, nil, nil]

    The cause for this is as follows:

    Python 3.4.3 (default, Nov 12 2018, 22:25:49)
    [GCC 4.8.4] on linux (and I believe this is the default max version on trusty)

    In order to install the dependencies, you need python3-pip, so a short search returns following options:

    apt search python3-pip
    Sorting... Done
    Full Text Search... Done
    python3-pip/trusty-updates,now 1.5.4-1ubuntu4 all [installed]
      alternative Python package installer - Python 3 version of the package
    
    python3-pipeline/trusty 0.1.3-3 all
      iterator pipelines for Python 3

    If we want to list all the installed modules with pip3 list, guess what, it’s not working:

    Traceback (most recent call last):
       File "/usr/bin/pip3", line 5, in 
         from pkg_resources import load_entry_point
       File "/usr/local/lib/python3.4/dist-packages/pkg_resources/init.py", line 93, in 
         raise RuntimeError("Python 3.5 or later is required")
     RuntimeError: Python 3.5 or later is required

    So, main conclusion is that it’s not related to puppet, just the incompatibility between version for this old distribution.

    Cheers

  • Small addition for ‘cat’ in Python

    Hi,

    There was a issue on options that aggregate any other ones, like -A for my previous post

    In my view the easiest way to solve it is by storing the options in a tuple.

    Here is the snippet

    run_options = []
    try:
        opts, args = getopt.gnu_getopt(sys.argv[1:-1], 'AbeEnstTv', ['show-all', 'number-nonblank', 'show-ends', 'number', 'show-blank', 'squeeze-blank' 'show-tabs', 'show-nonprinting', 'help', 'version'])
    except getopt.GetoptError:
         print("Something went wrong")
         sys.exit(2)
    for opt, arg in opts:
        if opt in ('-A','--show-all'):
            run_options.append('E')
            run_options.append('T')
        elif opt in ('-b', '--number-nonblank'):
            run_options.append('b')
        elif opt in ('-n', '--number'):
            run_options.append('n')
        elif opt in ('-E', '--show-ends'):
            run_options.append('E')
        elif opt in ('-s', '--squeeze-blank'):
            run_options.append('s')
        elif opt in ('-T', '--show-tabs'):
            run_options.append('T')
     
    final_run_options = tuple(run_options)
    for element in final_run_options:
        if element == 'b':
            content_list = number_nonempty_lines(content_list)
        elif element == 'n':
            content_list = number_all_lines(content_list)   
        elif element == 'E':
            content_list = display_endline(content_list)
        elif element == 's':
            content_list = squeeze_blanks(content_list)
        elif element == 'T':
            content_list = show_tabs(content_list)

    So basically, you store the actual cases in a list which you convert to a tuple to eliminate duplicates. Once you have the final case, you parse it and change the actual content option by option.

    I didn’t have the time to test it but there is no big reason why it should’t work.

    Cheers

  • Linux ‘cat’ in Python – almost complete

    Morning,

    Since I am striving to find useful content to post more often, I took homework for a ‘cat’ written in Python.

    It’s not elegant, and it’s not the best version but it works.

    # -*- coding: utf-8 -*-
    """
    Created on Wed Dec 25 10:28:39 2019
    @author: Sorin
    """
    import sys,getopt,os
    if os.path.isabs(sys.argv[-1:][0]):
        FILENAME= sys.argv[-1:][0]
    else:
        FILENAME = os.getcwd() + "\\" + sys.argv[-1:][0]
    
    def read_content(filename):
        try:
            f = open(filename, "r+")
            content = f.read()
            f.close()
        except IOError as e:
                print("File could not be opened:", e)
                sys.exit(3)
        return content
        
    def transform_content():
        content = read_content(FILENAME)
        content_list = content.split('\n')
        return content_list
    def number_nonempty_lines(content_list):
        i = 0
        for line in content_list:
            if line != '':
                content_list[i] = str(i) + " " + line
            i = i + 1
        return content_list
    def squeeze_blanks(content_list):   
        i = 0
        duplicate_index = []
        for line in content_list:
            if (line == "" or line == "$")  or (str.isdigit(line.split(' ')[0]) and (line.split(' ')[-1] == "" or line.split(' ')[-1] == "$")):
               duplicate_index.append(i+1)
            i = i + 1
        delete_index = []
        for j in range(len(duplicate_index) - 1):
            if  duplicate_index[j] + 1 == duplicate_index[j+1]:
                delete_index.append(duplicate_index[j])
        for element in delete_index:
            content_list.pop(element)
        return content_list    
            
    def number_all_lines(content_list):
        i = 0
        for line in content_list:
            content_list[i] = str(i) + " " + line
            i = i + 1
        return content_list
    
    def display_endline(content_list):
       return [line + "$" for line in content_list]
    
    def show_tabs(content_list):
        print(content_list)
        content_list = [ line.replace('\t','^I') for line in content_list]
        return content_list
    
    content_list =transform_content()
    try:
        opts, args = getopt.gnu_getopt(sys.argv[1:-1], 'AbeEnstTv', ['show-all', 'number-nonblank', 'show-ends', 'number', 'show-blank', 'squeeze-blank' 'show-tabs', 'show-nonprinting', 'help', 'version'])
    except getopt.GetoptError:
         print("Something went wrong")
         sys.exit(2)
    for opt, arg in opts:
        if opt in ('-A','--show-all'):
            content_list = display_endline(content_list)
            content_list = show_tabs(content_list)
        elif opt in ('-b', '--number-nonblank'):
           content_list = number_nonempty_lines(content_list)
        elif opt in ('-n', '--number'):
           content_list = number_all_lines(content_list)
        elif opt in ('-E', '--show-ends'):
            content_list = display_endline(content_list)
        elif opt in ('-s', '--squeeze-blank'):
            content_list = squeeze_blanks(content_list)
        elif opt in ('-T', '--show-tabs'):
            content_list = show_tabs(content_list)
    print('\n'.join(content_list))

    Further improvements will be also posted. I must confess that there are still a couple of things to be fixed, like not running the same options twice, and the issue of putting it to work on very large files, but it will do in this form for now.

    Cheers

  • Reset Cinnamon desktop interface

    Hi,

    I recently had an issue with Cinnamon interface, more exactly, my menu panel dissapeared.

    After some quick searches on the net, I found this command:

    gsettings reset-recursively org.cinnamon

    It seems to do the trick.

    Cheers

  • Automatic increase of Kafka LVM on GCP

    I wrote an article for my company that was published on Medium regarding the topic in the subject. Please see the link

    https://medium.com/metrosystemsro/new-ground-automatic-increase-of-kafka-lvm-on-gcp-311633b0816c

    Thanks

  • Using GCP recommender API for Compute engine

    Let’s keep it short. If you want to use Python libraries for Recommender API, this is how you connect to your project.

    from google.cloud.recommender_v1beta1 import RecommenderClient
    from google.oauth2 import service_account
    def main():
        credential = service_account.Credentials.from_service_account_file('account.json')
        project = "internal-project"
        location = "europe-west1-b"
        recommender = 'google.compute.instance.MachineTypeRecommender'
        client = RecommenderClient(credentials=credential)
        name = client.recommender_path(project, location, recommender)
       
        elements = client.list_recommendations(name,page_size=4)
        for i in elements:
            print(i)
    
    main()

    credential = RecommenderClient.from_service_account_file(‘account.json’) will not return any error, just hang.

    That’s all folks!

  • ELK query using Python with time range

    Short post. Sharing how you make an ELK query from Python using also timestamp:

    es=Elasticsearch([{'host':'[elk_host','port':elk_port}])
    
    query_body_mem = {
        "query": {
            "bool" : {
                "must" : [
                        {
                            "query_string" : {
                            "query": "metricset.module:system metricset.name:memory AND tags:test AND host.name:[hostname]"
                        }
                    },
                    {
                             "range" : {
                                "@timestamp" : {
                                    "gte" : "now-2d",
                                    "lt" :  "now"
                }
            
            }
       
                    }
                ]
            }
       
        }
        
    }
    
    res_mem=es.search(index="metricbeat-*", body=query_body_mem, size=500)
    df_mem = json_normalize(res_mem['hits']['hits'])
    

    And that’s all!

    Cheers

  • Multiple field query in ELK from Python

    Morning,

    There are a lot of pages on how to query ELK stack from Python client library, however, it’s still hard to grab a useful pattern.

    What I wanted is to translate some simple query in Kibana like redis.info.replication.role:master AND beat.hostname:*test AND tags:test into a useful Query DSL JSON.

    It’s worth mentioning that the Python library uses this DSL. Once you have this info, things get much simpler.

    Well, if you search hard enough, you will find a solution, and it should look like.

    another_query_body = {
        "query": {
            "query_string" : {
                "query": "(master) AND (*test) AND (test)",
                "fields": ["redis.info.replication.role", "beat.hostname" , "tags"]
            }
        }
    }

    As you probably guessed, each field maps to a query entry.

    Cheers

  • Getting interactive help in IPython

    Hello,

    I want to share with you a simple trick that I saw in a training course related to objects and classes functionality in IPython.

    If you want to see a short description of the object or class you are using in your notebook please use , for example, if you just imported Elasticsearch from the elasticsearch module, the following

    And if you want more details, you can use it like this, it will actually show you the code 🙂

    I tried to do that also with DataFrame but it seems that it works only on already created objects

    And for the more detailed look, you can try it yourself.

    Here is also a link to more experienced people https://jakevdp.github.io/PythonDataScienceHandbook/01.01-help-and-documentation.html

    Cheers!