Friday, November 10, 2017

SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch


SSL_CTX_use_PrivateKey_file("/opt/nginx/ssl/server.key") failed (SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch


To match CSR key and generated SSL certificate
echo "--Certificate:" && openssl x509 -noout -modulus -in ssl_certificate_file && echo "--Key:" && openssl rsa -noout -modulus -in csr_key_file
 Here change ssl_certificate_file and csr_key_file with your own file names.

With this command, you can get 2 modules. And if this both modules value looks same then it should work else key and SSL certificate is not correct.

You can also compare serial key from your order of SSL certificate:
openssl x509 -in ssl_certificate.cer -serial -noout

If it will not match then Reissue certificate or check your key or SSL if it is an old one.

Wednesday, September 06, 2017

How to install Docker on Ubuntu 16.04

Nowadays, docker is going to use globally. As a developer, it will help me a lot with this:

  • Escape app dependency
  • works with any technology
  • Easy to share via repo
Here are few steps for easy installation of Docker in Ubuntu 16.04

Install packages to allow apt to use a repository over HTTPS:
sudo apt-get install apt-transport-https ca-certificates curl software-properties-common
Add the GPG key for the official Docker repository to the system:
curl -fsSL | sudo apt-key add -
Add the Docker repository to APT sources:
sudo add-apt-repository "deb [arch=amd64] $(lsb_release -cs) stable"

Now update the package for Docker
sudo apt-get update
Now, Install Docker with:
sudo apt-get install -y docker-ce
Check if Docker is running or not with
sudo systemctl status docker
Now you can check that if you are able to access and download Docker images from Docker hub or not with "Hello World" image
docker run hello-world

If it will give you permission error due to sudo then add sudo with command

If image is not searchable on locally then it will get it from Docker hub

Sachin New 

Sachin 10 Oct 

Steve Single Product 

Thursday, July 06, 2017

NoMethodError: undefined method `last_comment' for #

I found this error for rake new version:
rake aborted!
NoMethodError: undefined method `last_comment' for #<Rake::Application:0x000000027b6798>
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/rspec-core-2.99.2/lib/rspec/core/rake_task.rb:143:in `initialize'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/rspec-rails-2.99.0/lib/rspec/rails/tasks/rspec.rake:11:in `new'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/rspec-rails-2.99.0/lib/rspec/rails/tasks/rspec.rake:11:in `<top (required)>'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/activesupport- `load'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/activesupport- `block in load'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/activesupport- `load_dependency'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/activesupport- `load'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/rspec-rails-2.99.0/lib/rspec-rails.rb:10:in `block in <class:Railtie>'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `instance_exec'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `block in load_tasks'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `each'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `load_tasks'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `block in load_tasks'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `each'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `all'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `load_tasks'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `load_tasks'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/railties- `method_missing'
/home/sachin/rails_projects/sachin/Rakefile:7:in `<top (required)>'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/rake-12.0.0/exe/rake:27:in `<top (required)>'
(See full trace by running task with --trace)


Rake 11.0.1 removes the methodlast_comment which Rails 2.3 rspec-core (< 3.4.4) uses. Therefore until/if a patch is released we need to pin rake to an older version in Gemfile:

`gem 'rake', '< 11.0'`

Then `bundle update rake`

It will resolve your issue.

Friday, June 02, 2017

Gem Load Error is: uninitialized constant Mysql2::Client::SECURE_CONNECTION on Ubuntu 16.04

While I am trying to create DB with rake db:create then I am getting this error:

rake aborted!
Bundler::GemRequireError: There was an error while trying to load the gem 'mysql2'.
Gem Load Error is: uninitialized constant Mysql2::Client::SECURE_CONNECTION
Backtrace for gem load error is:
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/mysql2-0.3.16/lib/mysql2/client.rb:12:in `<class:Client>'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/mysql2-0.3.16/lib/mysql2/client.rb:2:in `<module:Mysql2>'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/mysql2-0.3.16/lib/mysql2/client.rb:1:in `<top (required)>'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/mysql2-0.3.16/lib/mysql2.rb:10:in `require'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/mysql2-0.3.16/lib/mysql2.rb:10:in `<top (required)>'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/bundler-1.15.1/lib/bundler/runtime.rb:82:in `require'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/bundler-1.15.1/lib/bundler/runtime.rb:82:in `block (2 levels) in require'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/bundler-1.15.1/lib/bundler/runtime.rb:77:in `each'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/bundler-1.15.1/lib/bundler/runtime.rb:77:in `block in require'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/bundler-1.15.1/lib/bundler/runtime.rb:66:in `each'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/bundler-1.15.1/lib/bundler/runtime.rb:66:in `require'
/home/sachin/.rvm/gems/ruby-1.9.3-p545@oomph-sachin/gems/bundler-1.15.1/lib/bundler.rb:108:in `require'
/home/sachin/rails_projects/sachin/config/application.rb:8:in `<top (required)>'


Update your Gemfile to version 0.3.20

     gem 'mysql2', '~> 0.3.20'

Then run "bundle update mysql2" and then try it will work!

Wednesday, October 28, 2015

Redirect rules for nginx server block

If you want server_name without www then follow this
server {
 listen 80 default_server;
 passenger_enabled on;
 passenger_app_env production;
 root /home/sachin/testapp/public;
server {
listen 80;
return 301 $scheme://$request_uri;
If you want server_name with www then follow this
server {
 listen 80 default_server;
 passenger_enabled on;
 passenger_app_env production;
 root /home/sachin/testapp/public;
server {
 listen 80;
 return 301 $scheme://$request_uri;
Ref. taken from here. 

Install Ruby from source code

You can install ruby with following steps:
sudo apt-get update
sudo apt-get install build-essential libssl-dev libyaml-dev libreadline-dev openssl curl git-core zlib1g-dev bison libxml2-dev libxslt1-dev libcurl4-openssl-dev nodejs libsqlite3-dev sqlite3
Create a temporary folder for the Ruby source files:
mkdir ~/ruby
Move to the new folder:
cd ~/ruby
Download the latest stable Ruby source code. (
If 2.1 then
If 2.2 then
Decompress the downloaded file:
If 2.1 then
tar -xzf ruby-2.1.1.tar.gz
If 2.2 then
tar -xzf ruby-2.2.0.tar.gz
Select the extracted directory:
cd ruby-2.2.0
Run the configure script. This will take some time as it checks for dependencies and creates a new Makefile, which will contain steps that need to be taken to compile the code:
Run the make utility which will use the Makefile to build the executable program. This step can take a bit longer:
Now, run the same command with the install parameter. It will try to copy the compiled binaries to the /usr/local/bin folder. This step requires root access to write to this directory. It will also take a bit of time:
sudo make install
Ruby should now be installed on the system. We can check it with the following command, which should print the Ruby version:
ruby -v
Finally, we can delete the temporary folder:
rm -rf ~/ruby

Deploy Ruby On Rails Application with Nginx server using Phusion Passenger gem

Here I will show you that how to deploy ruby on rails application with passenger and nginx on digitalocean OR amazon aws server.

Here I have used Ubuntu as operating system.

First of all you can login with root user. For deploy application its better to create new user.

Step 1.) create new user for our application. 
adduser sachin(username)
Step 2.) Give that user to sudo permission so that user will able to do some administrative work
gpasswd -a sachin sudo
Step 3.) Generate ssh key for root user
Step 4.) Then read generated key with this and copy it somewhere else or clipboard for further use
cat ~/.ssh/
Step 5.) Now you can login into created new user(sachin)
su - sachin
Step 6.) Then we can add root user's key into this user's authorization key and for that we can follow this pattern:
mkdir .ssh
chmod 700 .ssh/
nano .ssh/authorized_keys 
Now insert your public key (which should be in your clipboard or anywhere else you have copied earlier in step 4) by pasting it into the editor. 
chmod 600 .ssh/authorized_keys
With exit you will logout from user(sachin) and now you are into root user.

Step 7.)  Then again login in sachin user
su - sachin (Make sure you do all later operation with this user)
Step 8.) Set Up Your Domain(Optional)
In order to ensure that your site will be up and visible, you need to set up your DNS records to point your domain name towards your new server. You can find more information on setting up a hostname by following the link. 
Step 9.) Now you need to setup environment for ruby as well rails. We can install ruby from latest source code as well rvm.

Step 10.) Now we need to setup passenger with nginx
        First, install a PGP key:
sudo apt-key adv --keyserver --recv-keys 561F9B9CAC40B2F7
Create an APT source file (you will need sudo privileges):
sudo nano /etc/apt/sources.list.d/passenger.list
And insert the following line in the file:
deb trusty main
Press CTRL+x to exit, type y to save the file, and then press ENTER to confirm the file location.
Change the owner and permissions for this file:
sudo chown root: /etc/apt/sources.list.d/passenger.list
sudo chmod 600 /etc/apt/sources.list.d/passenger.list
Update the APT cache:
sudo apt-get update
Finally, install Passenger with Nginx:
sudo apt-get install nginx-extras passenger
        Note : If you have used rvm then don't do this:
This step will overwrite our Ruby version to an older one. To resolve this, simply remove the incorrect Ruby location and create a new symlink to the correct Ruby binary file:
sudo rm /usr/bin/ruby
sudo ln -s /usr/local/bin/ruby /usr/bin/ruby 
Step 11.) Setup the web server
Open the Nginx configuration file:
sudo nano /etc/nginx/nginx.conf
Find the following lines, in the http block:
# passenger_root /usr/lib/ruby/vendor_ruby/phusion_passenger/locations.ini;
# passenger_ruby /usr/bin/ruby;
Uncomment both of them. Update the path in the passenger_ruby line. They should look like this:
passenger_root /usr/lib/ruby/vendor_ruby/phusion_passenger/locations.ini;
passenger_ruby /usr/local/bin/ruby;
Then save file.

You will get path for passenger_root with
passenger-config --root
You will get path for passenger_ruby with
which ruby 
Note: For passenger_ruby
If you have used ruby source code then keep as it is
If you have used rvm without gemset then it should like this:
passenger_ruby /home/sachin/.rvm/gems/ruby-2.2.0/wrappers/ruby
If you have used rvm with gemset named testapp then it should be like this:
passenger_ruby /home/sachin/.rvm/gems/ruby-2.2.0@testapp/wrappers/ruby
Step 12.) Now we need to configure nginx
First, We need to disable the default Nginx configuration. Open the Nginx config file:
sudo nano /etc/nginx/sites-available/default
Find the lines:
listen 80 default_server;
listen [::]:80 default_server ipv6only=on;
Comment them out, like this:
# listen 80 default_server;
# listen [::]:80 default_server ipv6only=on;
then Save the file.

        Now, create an Nginx configuration file for our app:
sudo nano /etc/nginx/sites-available/testapp
        Add the following server block. The settings are explained below.(Nginx redirect rules)
        If you have domain name then set it as server_name else add ip address for the server_name. If you are using more then one application with same server with different domain the don't add default_server into listen 80
server {
listen 80 default_server;
passenger_enabled on;
passenger_app_env production;
root /home/sachin/testapp/public;
         Then create a symlink for it:
sudo ln -s /etc/nginx/sites-available/testapp /etc/nginx/sites-enabled/testapp 

Step 13.) Reload & Restart nginx
Reload: sudo nginx -s reload
Restart: sudo service nginx restart

Friday, August 21, 2015

requirements_debian_update_system ruby-2.2.2 error

Today I got new laptop with Ubuntu 15.04 and I was trying to install ruby on rails with rvm.
I have successfully installed rvm and I can see that rvm is installed properly.
But when I have tried to install ruby within rvm using command 'rvm install 2.2.2' then I got below error.

sachinlenovo@sachinlenovo-g-5070:~$ rvm install 2.2.2
Searching for binary rubies, this might take some time.
No binary rubies available for: ubuntu/15.04/x86_64/ruby-2.2.2.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
Checking requirements for ubuntu.
Installing requirements for ubuntu.
Updating system...................
Error running 'requirements_debian_update_system ruby-2.2.2',
showing last 15 lines of /home/sachinlenovo/.rvm/log/1440068704_ruby-2.2.2/update_system.log
++ case "${TERM:-dumb}" in
++ case "$1" in
++ [[ -t 2 ]]
++ return 1
++ printf %b 'There has been error while updating '\''apt-get'\'', please give it some time and try again later.
404 errors should be fixed for rvm to proceed. Check your sources configured in:
There has been error while updating 'apt-get', please give it some time and try again later.
404 errors should be fixed for rvm to proceed. Check your sources configured in:

++ return 100
Requirements installation failed with status: 100.

Then I found solution like this:

RVM will refuse to work, if apt-get update has any errors and it doesn't behave well. If your system's apt sources have an invalid repository than apt-get update gives you 404 or GPG error. This confused me for some time because this invalid or faulty repository has no connection with Ruby as well RVM. and after referring some documentation and solutions I came to know below scenario:

So for check the errors you have to run this command and need to find that which ppa is firing errors:
sudo apt-get update | grep "Failed"
then it will give you result like this:

W: Failed to fetch vivid main  404  Not Found                                                                                      W: .......                                                         
E: Some index files failed to download. They have been ignored, or old ones used instead.

Then for resolve this error you have to press Windows key and need to search "Software & Updates" 

Then open it and go into Other Software there you can see some URLs which is failed while update.

Then uncheck that urls from this and close this window then you can do 
sudo apt-get update 
and then you can install ruby with
rvm install 2.2.2

Thursday, July 30, 2015

PG::DuplicateColumn: ERROR: column already exists


PG::DuplicateColumn: ERROR:  column of relation table_name already exists

I am using Ruby On Rails with Postgresql and I faced this issue while I am doing migration.

sachin@sachin:~/demo_app$ rake db:migrate
== 20150710135824 AddStatusToUser: migrating =========================
-- add_column(:users, :status, :integer)
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

PG::DuplicateColumn: ERROR:  column "status" of relation "users" already exists
: ALTER TABLE "users" ADD COLUMN "status" integer/home/sachin/.rvm/gems/ruby-2.0.0-p598@demo_app/gems/activerecord-4.1.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in `async_exec'


Error indicates that in users table status column is already available. Then I found that earlier I have added same migration and then I have done rake db:migrate that time. So That time this column is created. And now I have added again. That's why I am facing this issue.

So here solution is: We need to remove existing column and then need to do migration. 

For that I have found this ways to resolve this issue:

1.) With ruby on rails,

        Open terminal and run "rails db" command it will connect with database. Then you can drop that added columns from here.

        You need to run this command for alter table:
        ALTER TABLE users DROP COLUMN status;

2.) Open postgresql console for drop column. 
         Open terminal and run "psql -U postgres" command then it will open psql console.Then you can drop that added columns from here.

        You need to run this command for alter table:
        ALTER TABLE users DROP COLUMN status;

3.) Add condition in migration

        if column_exists? :table_name, :column_name
                remove_column :table_name, :column_name

Thursday, November 27, 2014

Nginx 413 Request Entity Too Large

Nginx 413 Request Entity Too Large


You are trying to upload file/video below max range for client request:
For solve this problem increase it in your nginx.conf file.

Nginx conf file will be located at /etc/nginx/nginx.conf. If it does not exist there, it may also be at /usr/local/nginx/conf/nginx.conf or /usr/local/etc/nginx/nginx.conf.

Then open it in your favourite editor and set your required (here i need 20M) value for server or http or location

    # set client body size to 20M #
    client_max_body_size 20M;