Category: Server Maintenance

How to remove git token on git project after a failed git pull

After doing a git pull is it possible you have an error because your Git Token is not valid anymore, here is an exemple:

# git pull
remote: HTTP Basic: Access denied
fatal: Authentication failed for 'https://gitlab-ci-token:YOURTOKEN@gitlab.com/YOURPROJECT.git/'

In order to do the git pull we want to use our credential with the LOGIN / PASSWORD that we use to access GitLab.

Solution 1 : Git pull one time with login (temporary)

# git pull https://gitlab.com/YOURPROJECT.git

Solution 2 : Change the origin URL to HTTPS (permanent)

# git remote set-url origin https://gitlab.com/YOURPROJECT.git
# git pull

It will ask your login and password for the git pull and will not use the git token anymore.

Kill Node.JS service by port / Arrêter un service Node.JS avec son port

🇬🇧Dear all, is it possible you want to kill a Node.JS service with your linux machine, that is running on a specific port

Il est possible que vous voulez arrêter un processus Node.JS sur un port précis sur votre machine linux🇫🇷

Here is the magic command to find and kill the Node.JS process

Voici la commande magique qui permet de trouver et arrêter de processus avec son port

netstat -pluton
It looks like the name of the famous planet / Moyen mémo-technique on pense à cette p’tite planete

Then you should be able to find the process (PID) with the port associated

Vous devriez avec cette commande trouver le nom du processus (PID) avec le port associé

PORT 4000:

Start Google Cloud instance VM from a shared image from another Project / Organization

If you have multiple projects or organization and you want to clone a machine that is already configured, you can create an image of the instance of the machine.
But, you will have to share the access to the external project and organization.
Here is how to do it :

Share the image to the organization in the Images and in IAM

In both IAM and Image (VM) you will have to share the access Compute Image User

Start the VM using the shared image from another project / organization

gcloud compute instances create INSTANCE-NAME --image SHARED-IMAGE-NAME --image-project PROJECT-NAME --zone ZONE --tags http-server
  • INSTANCE-NAME : Name of the VM instance you are creating (that will appear in the VM list)
  • SHARED-IMAGE-NAME : The name of the image you shared to the organization
  • PROJECT-NAME : The name if the project where is the image you shared to the organization
  • ZONE : The geographical zone of the VM

Now the machine is started from an image from another organization and project !

Renew automatically HTTPS SSL certificates with cron and Certbot

Use the command crontab -e to edit the crontab (recurring tasks), and insert the following line:

0 0 1 * * /usr/bin/certbot renew --pre-hook “service nginx stop” --post-hook “service nginx start” --quiet > /etc/letsencrypt/renewals.log

It will renew all the certificates, the 1st of each month (0 0 1 * *), and will stop nginx before the renewal and start nginx after the renewal so it can works.
It will work on all the linux servers.

AWS Amplify : Babel error building React.JS app

Is it possible you may have an error with babel on AWS Amplify, while deploying your React.JS app:

If you click on Frontend you should be able to see the logs :

2022-01-14T17:18:36.441Z [INFO]: $ react-scripts build
2022-01-14T17:18:37.352Z [INFO]: Creating an optimized production build...
2022-01-14T17:18:38.431Z [INFO]: Failed to compile.
2022-01-14T17:18:38.433Z [INFO]: ./src/index.js
                                 Error: [BABEL] /codebuild/output/src483533555/src/app/src/index.js: Cannot find module '@babel/helper-define-map'
                                 Require stack:
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/plugin-transform-classes/lib/transformClass.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/plugin-transform-classes/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/available-plugins.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/plugins-compat-data.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/normalize-options.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/create.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/@babel/core/lib/config/files/plugins.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/@babel/core/lib/config/files/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/@babel/core/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/babel-loader/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/loader-runner/lib/loadLoader.js
                                 - /codebuild/output/src483533555/src/app/node_modules/loader-runner/lib/LoaderRunner.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/NormalModule.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/NormalModuleFactory.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/Compiler.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/webpack.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/scripts/build.js (While processing: "/codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/index.js")
2022-01-14T17:18:38.451Z [WARNING]: error Command failed with exit code 1.
2022-01-14T17:18:38.451Z [INFO]: info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
2022-01-14T17:18:38.461Z [ERROR]: !!! Build failed
2022-01-14T17:18:38.461Z [ERROR]: !!! Non-Zero Exit Code detected
2022-01-14T17:18:38.461Z [INFO]: # Starting environment caching...
2022-01-14T17:18:38.461Z [INFO]: # Uploading environment cache artifact...
2022-01-14T17:18:38.534Z [INFO]: # Environment caching completed
Terminating logging...

In order to solve the @babel errors, you will need to install all the @babel packages:

NPM

npm install babel-core babel-loader babel-preset-env 
babel-preset-react babel-polyfill babel-runtime @babel/helpers 
@babel/helper-builder-react-jsx-experimental @babel/helper-builder-react-jsx 
@babel/helper-define-map @babel/helper-plugin-utils @babel/helper-regex

YARN

yarn add babel-core babel-loader babel-preset-env 
babel-preset-react babel-polyfill babel-runtime @babel/helpers 
@babel/helper-builder-react-jsx-experimental @babel/helper-builder-react-jsx 
@babel/helper-define-map @babel/helper-plugin-utils @babel/helper-regex

In order to run your React.JS project on Amplify, here is all the babel packages I installed to solve all problems:

  • babel-core
  • babel-loader
  • babel-preset-env
  • babel-preset-react
  • babel-polyfill
  • babel-runtime
  • @babel/helpers
  • @babel/helper-builder-react-jsx
  • @babel/helper-builder-react-jsx-experimental
  • @babel/helper-define-map
  • @babel/helper-plugin-utils
  • @babel/helper-regex

After, that, you should be able to see your React.JS app online with Amplify:

Public Images for your React / Angular app on Google Cloud

We often need images in our React or Angular app, but putting them in the project is not clean.
So we can use Google Cloud with Cloud Storage for the images on your app.

There are many advantages of using Cloud Storage to expose public images :
– Real time maintenance (upload, delete, change, …)
– You don’t need any commit on your git (if you commit images on your Github / Gitlab for example)
– Clean project, only code files
– Light project repository to commit, images are heavy quickly

Create a Bucket

First, you need to create a Bucket (it’s like a big folder) if you don’t already have one.

Switch to Uniform access control

Then, to make your Bucket public, go to the Permissions tab, and change the access control to Uniform :

You should click Switch to Uniform, so you don’t have to make public each file one by one
You can see, if you upload your first image, that it’s not public yet

Add public access using by adding a Reader role for allUsers

You can then add the access of Object Reader to allUsers
Then you can see it’s Public to Internet and you are able to copy URL

You can now use you image anywhere, it’s on internet and anyone can see it with the URL, so you can use it to store images for your React / Angular app, all images will work.

Use Crontab for automating recurring tasks on Fedora/CentOS

You can use a tool that is called “Crontab” for recurring tasks automation. It is available for all the Linux systems and still the most used solution.

Edit the crontab configuration file

crontab -e

This will open vi, the default linux editor, that will allow you to edit the recurring tasks for a specific date and time.

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  *  user command to be executed

In vi the main commands used are:
– The escape key (:x! to save OR :q! to quit)
– a to append text
– i to insert text
– dd to remove the line
– x to delete the current selected character

Verify the date and time zone

You can verify the date and the time zone (most of the cloud machines are using the UTC time zone). you can use the following command “date”:

# date
Wed Aug  4 01:10:10 UTC 2021

Git commands on production server & Git issues

The following commands can be used on a production server.
In the case of a local machine development, use free software like GIT DESKTOP / SourceTree

First deployment in a folder

git clone <URL GITLAB/GITHUB HTTPS>

Updating / Getting last changes

git pull

The following commands respond to particular problems that may arise.

Changing the URL of a GIT Repository

This problem can occur if you are using GITLAB or GITHUB with SSH and you want to switch to HTTPS or vice versa, or following problems with the rights of an SSH key such as “remote: The project you were looking for could not be found.” and “fatal: Could not read from remote repository.”

Checking the repository URL:

git remote -v

Changing the URL of the repository:

git remote set-url origin <URL>

You cannot pull the changes “You have unstaged changes”

You may get the following error, indicating that some files have changed and need to be committed when you haven’t touched anything and just want to update the server:

Cannot pull with rebase: You have unstaged changes. 
Please commit or stash them. 

In order the solve this problem we should remove all the unstaged changes:

git reset --hard

You can now use the git pull command.

Back to the previous commit

git reset --hard HEAD^

Back to a specific commit

git reset --hard <ID COMMIT>

The commit ID is usually 7 digits and hexadecimal letters, example:
26b47fa

You can find it in the history tab of your GIT DESKTOP

Overwrite changes on the distant repository (local > remote)

git push --force origin master

Caution, delete on the distant repository, useful if you want to “delete” a commit that has been pushed.

Overwrite changes on the local repository (remote > local)

git reset --hard origin/master

Caution, deletes all the changes made not pushed to the remote git, useful if you want to “delete” the commits locally to have the same thing as on the remote git.

Install MariaDB on a Fedora/CentOS/RedHat server

If you have your own server, the first thing you may want to do with your backend shoud be to install a database server on it.

Here is step by step how to install a MySQL/MariaDB (almost the same) database on your server:
Install the MariaDB service:

yum install mariadb mariadb-server

Create your user access – change the username and password you want:

mysql
CREATE USER username@'%' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON *.* TO 'username'@'%' ;
flush privileges;

Verify the user has been created:

SELECT User FROM mysql.user;

You should be able to login on your database from you app and remotely.

CentOS : Fix ” HTTPS Error 404 – Not Found ” with YUM

If you want to install a package on CentOS with YUM is it possible that you might have the following error

Total download size: 20 M
Installed size: 60 M
Is this ok [y/d/N]: y
Downloading packages:
Delta RPMs disabled because /usr/bin/applydeltarpm not installed.
PACKAGE.x86 FAILED                                          
https://rpm.nodesource.com/pub_15.x/el/7/x86_64/PACKAGE.x86_64.rpm: [Errno 14] HTTPS Error 404 - Not Found
Trying other mirror.
To address this issue please refer to the below wiki article 

https://wiki.centos.org/yum-errors

If above article doesn't help to resolve this issue please use https://bugs.centos.org/.

Error downloading packages:
  2:PACKAGE.x86_64: [Errno 256] No more mirrors to try.

To solve this problem we should reset the sources used by YUM, the package manager of CentOS. To do so, you should use the following command:

yum clean all

It should clean the sources of the repos. You should now be able to install the packages you want with yum i <package>