Staging and Committing Changes in Git and GitHub

Staging Files
As we generate new solution artifacts they need to be added to the repository, integrated with work by other team members and tested to ensure that no defects were introduced by our changes. Until we add the files to the repository they are considered untracked files even though they are present in a folder in the repo. Simply creating files in the folder structure of the local repository is not sufficient.

Create in local repo folder structure

After creating a new file, we can use git status to check the status of files in the repository’s directory structure. Untracked files will be displayed in red. Red bad Green good!

Use git Status to see untracked files

Depending on the number of files we have created we can use git add with various options to track one or more untracked files. If we create a single file (or a short list of files) we can use git add <filename(s)> to Stage a particular file or list of files

Stage single file or list of files with git add <filename(s)>

If we create multiple files in a single directory we can use git add . to Stage all files in the current directory but not sub directories. We can use git status at any time to determine if there are any untracked files or uncommitted changes in the local repository.

Create multiple untracked files and check status

Once we have determined that there are 2 untracked files and tracked file with a changes to be committed we can use git add . (git add –all) to add all track all new files in the current directory (or all files in current and subdirectories)

Stage all files in current directory
Git add .

If we create multiple files in multiple subdirectories we can use git add –all to stage all files in the directory tree with a single command

Committing changes to the Local Repository
Once we have created or edited files and Staged the changes then we can commit the changes to the repository. However, if we attempt to commit without authenticating against the repository we will get a warning message

Please tell me who you are

We can add the email and username info using the git config command

Use git config to add email and user name

Committing changes to the Local Repository
If we attempt to commit without adding a commit message we will be prompted to enter a commit message in the dreaded vim editor as in the image below. If you find yourself in this editor, enter your message then press <esc> to exit edit mode then type 😡 <enter> to exit the editor

Enter Added Echo Util Class, Unit and Acceptance Tests

Adding a Commit Message

Once we have added our commit message and have pressed <esc> then typed 😡 <enter> to save and exit the editor we will then see our commit message followed by details about the files committed to the repository as in the image below.

Commit complete

Pushing Changes to a Remote Repository
In order to share our changes with other team members we need to push our changes to a remote repository. With a small team and little to no branching pushing changes to a remote repo is as simple as running git push origin master. This command pushes changes from the current branch in the local repo to the master branch of the remote repo

git push origin master

The get push origin master command only works if you cloned your remote repository to the local repository or if you have configured the remote repo in advance. Even if you cloned or configured the remote repo in advance if you are not already logged into the remote repo you will be prompted to log in when you execute git push origin master

Authenticate to remote repo for push to complete

Once you have authenticated, the commit will complete and a status message will be displayed showing the number of files committed as well as the source and destination branch.

Push complete

In the next post we will clone this remote repo to a new local repo on a different computer pull the changes add a couple of new files commit and push our changes before we move into branching and merging.

Creating a Git Repository

There are a few ways to create a Git Repository but before we talk about How let’s talk about Why.
Why do we need a Git Repository or any Repository for that matter? And What is a Git Repository anyway? In its simplest for a Git Repository is simply a folder that contains files that we want to keep track of. As changes are made to the files the modifications and different versions of the files are tracked and changes are committed to the repository. This is very useful when there are many different team members working on the same set of files. For this reason, tools like Git are commonly referred to as Version Control systems. Historically systems such a Git, SVN and Subversion have been used to store Source Code for software applications so they have also been referred to as Source Code Management SCM or Software Configuration Management Systems. However, with the recent push to streamline Software Delivery Life Cycles (SDLC) there has been a move to place ALL solution related artifacts in Version Control. This allows for configuration of Continuous Integration, Automated Testing, easier automated deployments and simplified scrips.

So that makes the why do we need a Git Repository question easier to answer. A Git repository provides a central source of truth as to the current, tested and ready to deploy version of the application. A Git repository also provides a central source from which to build and deploy our solutions from as well as providing the ability to isolate changes made to different features or by different developers to their own isolated branch of the repository.

So now that we know what it is and why we need one lets look at how to create a Git Repository.

Git Init

If we are starting a brand new project and do not yet have a repository we can convert and existing directory into a repository using the Git Init command.
Git Init initialized the directory as a Git Repository and creates a hidden folder called .Git as a sub directory of the directory being initialized.

Git Clone

If we already have a remote repository in GitHub we clone that repository to create a local workspace with files we can edit.


Cloning a repository is a fast way for new team member to quickly get a new workstation setup and start being productive immediately.

Simply copy the URL of the Remote repository you wish to clone then run git clone <past URL here>. Depending on the size of the repository the cloning process takes a matter of seconds.

Once you have initialized or cloned your repository you can then begin to add files edit and commit your changes. See the next post in this series for details on adding files and committing staged changes.

DevOps Case study links

•GE Case Study
•AWS Sydney Australia
•GE Oil and Gas Presentation
•GE, AWS adoption Developer Division Case Study

•Interview with Sam Guckenheimer on Microsoft’s Journey to Cloud Cadence
•ALM Devops features
•Microsoft Continuous Delivery Discussion

•Rakuten and Microsoft talk Devops in Real World
•Detailed retrospective

• Knight Capital Case Study
•Knight Capital Group Wikipedia
•Loss Swamps Trading Firm
•Knight Capital Group Comments
•Knight Capital Says Trading Glitch cost it $440M

Open Source Development: Installing Java, Maven, Git and Gnome on Ubuntu

Before you can begin building that groundbreaking new app you have been dreaming about you first need to get your development environment setup. The following steps represent the path of least resistance to get a development environment setup and begin development of your new killer app. The tools mentioned will also allow your new software delivery pipeline to be automated with another tool or 2 and some additional configuration.

Operating System
First we need an OS to host all of our tools and for our purposes that OS will be Ubuntu Server 18.04 host on the AWS Cloud. Once we have our AWS EC2 Instance up and running we can use PuTTY to SSH into our server.

Once we have our AWS EC2 Instance up and running we can use Putty to SSH into our server and finish up the configuration of the new server.

When we open the connection for the first time we will be prompted to add the servers host key to the cache if we trust the server and intend to connect to it again in the future. We do trust the server as we just created it and we also intend to connect to it again in the future so click “Yes”.

Once we click “Yes” we are successfully connected to our new Ubuntu Server in AWS.

Server Configuration

Now we can complete the configuration of our new server to allow us to install and use our development tools. First, we will run “sudo apt-get update” to download the package lists from the repositories and “update” them to get information about the newest versions of packages and any dependencies they may have.

Configure passwords and create developers account

Next, we will set a password for the root user so that we can login to the console later if needed

Now we can create a new account to use when we connect to the server to do development. To accomplish this, we will use the command “sudo adduser developer”.

Once the user has been created we will add them to the admin group using the command “sudo usermod -aG admin developer”

Runtime Environment

Now that we have our server up and running and have configured our users we can begin installing the tools. First we will need to load the Java Runtime environment with the command “sudo apt install default-jre”. This will install the latest version of the runtime. It is important to note that while the latest version of the runtime is what we want to use for any new development it may still be necessary to load a specific version of the runtime to support a particular tool. For example Jenkins requires that version 8 be installed otherwise the installation will fail. For this reason we will install the version required by Jenkins as well by first adding the repository with the command “sudo add-apt-repository ppa:webupd8team/java”

Then we will execute the command “sudo apt install oracle-java8-installer” to complete the Java 8 installation.

Build Tool

We will use maven to build our solution and specify dependencies in Eclipse projects. We will use the command “sudo apt install maven” to install Maven.

Version Control

Once Maven has installed successfully we can install Git with the following command “sudo apt install git”.

Then we can add our developer user to Git with the command git config –global “developer”

Using the git config –global ” “ command we can include an email address for our developer.

Install Jenkins for Continuous Integration

Jenkins can be used for many things from Continuous Integration to Continuous Delivery and Deployment depending on the plugins employed. Since Jenkins has so many uses in optimizing our software delivery pipeline we will install now and complete final configuration in a later post. The command to install Jenkins (after we have install the appropriate runtime version) is “wget -q -O – | sudo apt-key add –” to add the repository. Then “sudo sh -c ‘echo deb binary/ > /etc/apt/sources.list.d/jenkins.list'” to refresh the list.

Then we will need a “sudo apt-get update” to get latest. And finally “sudo apt install jenkins” to install Jenkins. After the install completes we can use “systemctl status jenkins” to verify installation was successful.

Note: The installation is case sensitive and Jenkins must have a lowercase “j”

Graphical User Interface

Before installing anything else we will install the Gnome GUI so that we can remote into this server and use the GUI to navigate between tools and locate files. To install Gnome we will first add the repository “sudo add-apt-repository ppa:gnome3-team/gnome3” then perform an update “sudo apt-get update” and finally install Gnome “sudo apt-get install gnome-shell ubuntu-gnome-desktop”

Install RDP and Open Ports

Once we have all system level tools installed we can install xRDP and open the Web and RDP ports so that we can connect to our server remotely. To install xRDP we can use the “sudo apt install xrdp” command and then use “” to enable it

Then open ports 3389 and 8080 with the commands “sudo ufw allow 3389” and “sudo ufw allow 8080”

Now we can use Remote Desktop to connect to our server and install the Integrated Development Environment use the Marketplace in the GUI

A dialog will notify you that the identity of the remote computer cannot be verified. Since we just created this server we will check the “Don’t ask me again for connections to this computer” checkbox then click “Yes”

Then we can login as the developer user we created earlier.

From this point we can use the Marketplace to search for and install additional tools using the GUI.

Technical Debt Pay It Forward

Pay it Forward

You can pay now or pay later but trust me you’re gonna pay! I’m talking about Technical Debt… Technical Debt like any other Debt has Interest, so you can pay now or pay later but if you pay later it will be much more expensive. See this post on the Increasing cost of Technical Debt for more info. 

The increasing cost of technical debt
Increasing cost of technical debt

The short version is defects are said to have a 1x cost at design time but costs increase exponentially as you build, test approaching production. The simple point is that the earlier that we find and resolve issues and defects the less it costs. Anything that we can do simplify or speed up this process of finding and documenting defects reduces our Debt. We want to make a Shift Left in quality by moving quality checks closer to the beginning of the delivery pipeline where defects are cheaper to fix. By creating Test Cases based on the customer requirements and success criteria we can ensure that our tests are mapped to business value. This is no substitute for Unit Tests written at the Function or Method level as used in Unit Testing.  Plan for chaos, write test to detect it and buffer team capacity to fix it (more on that in a future post).

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Blockchain Part 4: Decentralized Applications (Dapps)

While cryptocurrencies in general and Bitcoin in particular are the primary application that brought blockchain into the limelight, the potential of blockchain in the enterprise extends far beyond cryptocurrencies. As we’ll see in subsequent blogs, companies in financial, energy, medical, supply chain management, logistics, cloud computing, etc. are now investing in and launching proof of concepts to get ahead of the coming operations and technology changes in their enterprise systems.

The real power of blockchain will be realized as the technology gets adopted by industries such as:

  • Healthcare
  • Banking & Finance
  • Logistics
  • Ecommerce
  • Cloud Computing

Some of the startups launching Decentralized Applications
(Dapps) include Storj, which is a decentralized storage solution. There’s also technical conversation about how to launch domain name server (DNS) on blockchain to prevent denial of service (DoS) attacks.

Blockchain is rapidly gaining adoption in the enterprise. A significant percentage of fortune 500 companies are either building external facing commercial blockchain platforms (Microsoft, Amazon, Oracle, etc) or deploying proof of concept within their operations. This means that –

  • How to introduce blockchain to your organization especially teams already using DevOps
  • Knowledge base for blockchain solutions and strategies
  • Increased demand for blockchain developers
  • Timeline for blockchain widespread blockchain adoption

We will be exploring these topics in subsequent articles

Blockchain Part 3: Why Blockchain is the Next Platform for Applications

Blockchains are comprised of single blocks chained together to form a single chain or single main chain and multiple side chains.

  • Single (Main) Chain

    As the name implies is a single on the main chain in the blockchain. Here, the main chain validates and processes all blocks and transactions.

  • Multi (Side) Chain

    Because all transaction or requests must be verified prior to execution, it can put a tremendous overhead on the processing power of the main chain. So, there is a new technology being adopted (Ethereum already has this implemented) that allows a fork in the main chain into a side chain or child chain.

    A side chain is usually defined for one specific task. There can be multiple side chains where each is performing a different task. Side chains are implemented in order to maximize transaction (keep in mind that could be requests for action) processing efficiency.


    Suppose DevOps requirement is to put change management on the main chain. Side chains can be created to optimize for transactions that require monitoring and immediate response (such as approvals) and another side chain for processes that are time consuming and require team/operational coordination such as testing.

Fig 1. Main chain and side chain

In this scenario, we see that branches can be created from the main chain in the blockchain. Example, if the main chain represents the overall business objective, and the branches or side chains represent processes, business groups or divisions. A transaction in the main chain can call on processes in the side chain to be executed, validated and reported back to the main chain. This methodology can alleviate some of the overhead that can slow down the main chain.

Blockchain Part 2: What is Blockchain

Blockchain Part 2: What is Blockchain?

Blockchain is an append-only electronic distributed ledger database technology. The protocol ensures that each block of data is tamper proof, secure, decentralized, verified and fingerprinted (or hashed) before it is appended to the chain.

For example: Currently, most enterprise companies like Facebook, Amazon and Microsoft run a data monopoly, meaning that all user data that are collected are stored in a central database controlled by the entity. The user has little to no control on how that data is used, shared, stored, updated, etc.

Blockchain is an append-only electronic distributed ledger database. While the term “Blockchain” is relatively new, the underlying technologies have been in existence for 20+ years. Blockchain relies on the following existing technologies–

At a very high level, blockchain relies on the following existing technologies–

  • Cryptography – The fact that each blockchain record contains a unique cryptographic hash that is used to track that block, as well as others in the associated chain, means data cannot be modified (immutable). That makes it perfect for record keeping and auditing purposes.
  • Distributed Ledger Technology (DLT) – What makes a blockchain a special kind of ledger is that instead of being managed by a single centralized institution, such as a bank or government agency; rather, copes of the data are stored on multiple independent computers within a decentralized network. No single entity controls the ledger. Any of the computers on the network can make a change to the ledger, but only by following rules dictated by a “consensus protocol. Any changes made to the ledger are then broadcasted to all the nodes on the network. Then all nodes are updated to reflect those changes.
  • Consensus Algorithm – a mathematical algorithm that requires a majority of the other computers on the network to agree with the change. Consensus protocol comes in 2 flavors –
    • Permissioned and Permissionless

      Within this general framework are many variations. There are different kinds of consensus protocols, for example, and often disagreements over which kind is most secure. There are public, “permissionless” blockchain ledgers, to which in principle anyone can hitch a computer and become part of the network; these are what Bitcoin and most other cryptocurrencies belong to. There are also private, “permissioned” ledger systems that incorporate no digital currency. These might be used by a group of organizations that need a common record-keeping system but are independent of one another and perhaps don’t entirely trust one another—a manufacturer and its suppliers, for example.

  • Once a consensus generated by that algorithm has been achieved, all the computers on the network update their copies of the ledger simultaneously. If any of them tries to add an entry to the ledger without this consensus, or to change an entry retroactively, the rest of the network automatically rejects the entry as invalid.
  • Immutability – As mentioned above, data recorded on each block, once verified and accepted via consensus by all the nodes, cannot be modified or deleted. Any attempt to modify or delete a data on a block will render that block as well as the prior block non-compliant and therefore unacceptable.
  • Smart Contracts – are programmed instructions that are automatically executed when certain conditions are met. Smart contracts are similar to IF THEN ELSE statements embedded in contracts. Ex- do something (e.g., release code) if something else is true (test of code is completed and approved). Example, an attorney might create a smart contract “will” that is stored on a blockchain. In that case, in the event of an event, then the will is executed automatically, precisely as the owner stipulated without any human intervention or misunderstanding of the intent of the owner.
  • Trustless – Historically, society has relied on centralized authorities to establish trust between unknown parties in order to facilitate transactions and to execute contracts. These central authorities have served as custodians of trust for the millennia. Just imagine doing any business today without third party intermediaries. This is about to change thanks to blockchain. Because it is decentralized, transparent to all stakeholders and immutable, blockchain has trust built into its operations so it does not rely on a third party with a siloed and centralized database which are often subject to tempering and hacking.
  • Hashing – Takes the input on a given block in addition to the hash of the prior block and runs it through SHA-256 hashing algorithm and produces a new hash function that is then used to secure its place in the chain of blocks. This is one of the secure features of blockchain that makes it immutable and difficult to hack. If the content on a block is altered, then that block will be rejected by the blocks prior and after that block. So the only way to compromise a block is to solve a complex mathematical problem that alters the particular block and all other blocks before it along with all the decentralized block in the network. All these has to be done in a specific time limit for it to be accepted.

    How the hashing process works using the SHA-256 hash calculator

    Fig 2.

Part 1: Difference between Blockchain and Bitcoin —  Part 3: Why Blockchain is the next platform for Applications

Blockchain Part 1: Difference Between Blockchain vs Bitcoin (08/06/2018)

Edit: Interesting how much has changed in just 3 short months
Bitcoin is trading today 08/06/2018 at $7,632 ($3,941.67 11/25/2018) compared to August 16th, 2010, when it was trading at $0.07 per coin. Bitcoin actually went up to $15,825 per coin on December 2017. The meteoric rise in Bitcoin value and other cryptocurrencies has led to the misunderstanding that Bitcoin and Blockchain are one and the same thing. That would be similar to assuming that TCP/IP and email are the same thing.
While it is true that most people would probably never hear of blockchain without the current bitcoin buzz. The 2 are very different things.
Analogous to the early days of TCP/IP and the internet, it requires a compelling application like email or online commerce/payment in order to facilitate widespread adoption. Bitcoin happens to be the first viable application with compelling business disruption potential, investment incentives, financial rewards for investors, and global interests, to run on the Blockchain protocol.
While the term “Blockchain” is relatively new, some of the underlying technologies have been in existence for decades.

Fig 1.

Part 2: What is Blockchain