Setting up Codecov in Susper repository hosted on Github

In this blog post, I’ll be discussing how we setup codecov in Susper.

  • What is Codecov and in what projects it is being used in FOSSASIA?

Codecov is a famous code coverage tool. It can be easily integrated with the services like Travis CI. Codecov also provides more features with the services like Docker.

Projects in FOSSASIA like Open Event Orga Server, Loklak search, Open Event Web App uses Codecov. Recently, in the Susper project also the code coverage tool has been configured.

  • How we setup Codecov in our project repository hosted on Github?

The simplest way to setup Codecov in a project repository is by installing using the terminal command:

npm install --save-dev

Susper works on tech-stack Angular 2 (we have recently upgraded it to Angular v4.1.3) recently. Angular comes with Karma and Jasmine for testing purpose. There are many repositories of FOSSASIA in which Codecov has been configured like this. But with, Angular this case is a little bit tricky. So, using alone:

bash <(curl -s

won’t generate code coverage because of the presence of Karma and Jasmine. It will require two packages: istanbul as coverage reporter and jasmine as html reporter. I have discussed them below.

Install these two packages:

  • Karma-coverage-istanbul-reporter
  • npm install karma-coverage-istanbul-reporter --save-dev
  • Karma-jasmine html reporter
  • npm install karma-jasmine-html-reporter --save-dev

    After installing the, the package.json will be updated as follows:

  • "devDependencies": {
      "codecov": "^2.2.0",
      "karma-coverage-istanbul-reporter": "^1.3.0",
      "karma-jasmine-html-reporter": "^0.2.2",

    Add a script for testing:

  • "scripts": {
       "test": "ng test --single-run --code-coverage --reporters=coverage-istanbul"

    Now generally, the codecov works better with Travis CI. With the one line bash <(curl -s the code coverage can now be easily reported.

Here is a particular example of travis.yml from the project repository of Susper:

 - ng test --single-run --code-coverage --reporters=coverage-istanbul
 - ng lint
 - bash <(curl -s
 - bash ./

Update karma.config.js as well:

Module.exports = function (config) {
    plugins: [
    preprocessors: {
      'src/app/**/*.js': ['coverage']
    client {
      clearContext: false
    coverageIstanbulReporter: {
      reports: ['html', 'lcovonly'],
      fixWebpackSourcePaths: true
    reporters: config.angularCli && config.angularCli.codeCoverage
      ? ['progress', 'coverage-istanbul'],
      : ['progress', 'kjhtml'],

This karma.config.js is an example from the Susper project. Find out more here:
This is how we setup codecov in Susper repository. And like this way, it can be set up in other repositories as well which supports Angular 2 or 4 as tech stack.

Setting up Codecov in Susper repository hosted on Github

Creating a Script to Review loklak Apps

The Loklak applications site now has a functional store listing page where developers can showcase their apps and users and other developers can get all sorts of information about an app. However, for an app to be showcased properly on store listing page, the app must contain a properly configured app.json file and some necessary assets. But while creating an app a developer might miss out some vital information from app.json or forget to provide some of the required assets, which he will later come to know from his co-developers or reviewers.

Now this will cause inconvenience, both for the developer and reviewer. So to overcome this has now got a new script to review a given app. It checks whether the necessary fields are present in app.json or not. If present then it checks whether the fields are empty or not. If any invalid or missing information problem is encountered then it is reported to the developer along with information on what should be the actual case. If the app passes all the checks then the developer is informed that his app is ready to be published.

In order to use this script all the developer needs to do is open his app directory in terminal and execute the following command


This will present the developer with all the necessary informations.

How the script works?

Now let us delve into the working of the script. The initial call to the shell script calls a python script This python script performs all the checks on the app and displays necessary informations.

The first thing the script does is, it checks whether there is an app.json present in the app directory or not, if yes then the process continues otherwise it ends immediately with an error.

if "app.json" not in dir_contents:
    print_info("Please include a well configured app.json")
    print_problem("review failed")

Next it performs one of the most important checks. It verifies whether the name of the app and app directory name is same or not. If it is same then there is no problem else it shows the corresponding error message.

app_dir_name = os.getcwd().split("/")[-1]
    if app_dir_name != app_json.get("name"):
      print_problem("app directory name and name mentioned in app.json are different")
      print_info("app directory name and name mentioned in app.json must be same")
      problems_no += 1

Next the script checks whether there is an index.html present or not. Index.html is a must as it serves as the entry point of the app.

if “index.html” not in dir_contents:
print_problem(“index.html is missing”)
print_info(“app must contain index.html”)
problems_no += 1

After this the script checks whether a number of key fields are present or not. These field includes applicationCategory, oneLineDescription, author. If they are present, it checks whether the fields are empty or not. If the fields are either absent or empty, error is shown to the developer.

if app_json.get("applicationCategory") == None:
    print_problem("key applicationCategory missing in app.json")
    print_info("app.json must contain key applicationCategory with category as value")
    problems_no += 1
    if app_json.get("applicationCategory") == "":
      print_problem("applicationCategory cannot be an empty string")
      problems_no += 1
  if app_json.get("oneLineDescription") == None:
    print_problem("key oneLineDescription missing in app.json")
    print_info("app.json must contain key oneLineDescription with a one line description of the app")
    problems_no += 1
    if app_json.get("oneLineDescription") == "":
      print_problem("oneLineDescription cannot be an empty string")
      problems_no += 1
  if app_json.get("author") == None:
    print_problem("author object missing in app.json")
    print_info("app.json must contain author object containing information about author")
    problems_no += 1
    author = app_json.get("author")
    if author.get("name") == None:
      print_problem("name of author is mssing in author object")
      print_info("name of author must be mentioned in author object")
      problems_no += 1
      if author.get("name") == "":
        print_problem("author name cannot be an empty string")
        problems_no += 1

After the above checks are performed, it checks whether the fields corresponding to the image assets are present or not and whether the assets being referred in app.json exist in the directory. If not, then the developer is informed about the same.

if app_json.get("promoImage") == None:
    print_problem("key promoImage missing in app.json")
    print_info("app.json must contain key promoImage with path of promo image as value")
    problems_no += 1
    if os.path.isfile(app_json.get("promoImage")) == False:
      if app_json.get("promoImage") == "":
        print_problem("promoImage cannot be an empty string")
        print_problem(app_json.get("promoImage") + " does not exists")
      problems_no += 1
  if app_json.get("appImages") == None:
    print_problem("key appImages missing in app.json")
    print_info("app.json must contain key appImages with paths of preview images as value")
    problems_no += 1
    for image in app_json.get("appImages"):
      if os.path.isfile(image) == False:
        if image == "":
          print_problem("appImages cannot contain empty strings")
          print_problem(image +" does not exists")
        problems_no += 1

Finally after all the checks are performed, the developer is informed whether his or her app is ready to be published or not. The number of errors are also presented along with all other details.

if problems_no > 0:
    print_problem("Number of problems detected : " + str(problems_no))
    print_problem("App cannot be published")
    print_info("Please check")
    print_success("App is ready for publishing")
    print_info("Check to publish your app")

Here is an sample output for a faulty app

Here is an sample output for app which is ready to go.

The script is presently functional and can be used to review your apps before sending it for being published on However there are a number of things which are presently not checked like version,,, etc. These checks will be included soon.

Creating a Script to Review loklak Apps

Creating a command line tool to initiate loklak app development

There are various apps presently hosted on, which shows several interesting and awesome stuff that can be done using the loklak API. Now the question is how to create a loklak app? Well previously there were two ways to create a loklak app, you could either create an app from scratch creating all the necessary files including index.html (app entry point), app.json (required for maintaining app metadata and store listing),, and other necessary files, or you could use the boilerplate app which provides you with a ready to go app template which you have to edit to create your app.

Recently there has been a new addition to the repository, a command line tool called loklakinit, built with python which will automate the process of initiating a loklak app on the go. The tool creates the entire loklak app directory structure including app.json with all the necessary details (as provided by the user) and defaults, index.html, a css and js subdirectory with a style.css and script.js in the respective folders, file, file and file with proper references in app.json.

All that the developer needs to do is, execute the following from the root of the repository.


This will start the process and initiate the app.

Creating loklakinit tool

Now let us delve into the code. So what actually the script does? How it works? Well the tool acts very much like the popular npm init command. At first the script creates a dictionary which stores the defaults for app.json. Next the script takes a number of inputs from the user and predicts some default values, if the user refuses to provide any input for a particular parameter then the default value for that parameter is used.

app_json = collections.OrderedDict()

app_json["@context"] = ""
app_json["@type"] = "SoftwareApplication"
app_json["permissions"] = "/api/search.json"
app_json["name"] = "myloklakapp"
app_json["headline"] = "My first loklak app"
app_json["alternativeHeadline"] = app_json["headline"]
app_json["applicationCategory"] = "Misc"
app_json["applicationSubCategory"] = ""
app_json["operatingSystem"] = ""
app_json["promoImage"] = "promo.png"
app_json["appImages"] = ""
app_json["oneLineDescription"] = ""
app_json["getStarted"] = ""
app_json["appUse"] = ""
app_json["others"] = ""

author = collections.OrderedDict()
author["@type"] = "Person"
author["name"] = ""
author["email"] = ""
author["url"] = ""
author["sameAs"] = "" 

app_json["author"] = author

The first part of the script inserts some default values into the app_json dictionary. Now what is an OrderedDict? Well, it is nothing but a python dictionary in which the order in which the keys are inserted is maintained. A ordinary python dictionary does not maintain the order of the keys.

while True :

  app_name = raw_input("name (" + app_json["name"] + ") : ")
  if app_name :
    app_json["name"] = app_name

  app_context = raw_input("@context (" + app_json["@context"] + ") : ")
  if app_context :
    app_json["@context"] = app_context

  app_type = raw_input("@type (" + app_json["@type"] + ") : ")
  if app_type :
    app_json["@type"] = app_type

  app_permissions = raw_input("permissions (" + app_json["permissions"] + ") : ")
  if app_permissions :
    app_json["permissions"] = app_permissions.split(",")

  app_headline = raw_input("headline (" + app_json["headline"] + ") : ")
  if app_headline :
    app_json["headline"] = app_headline
    app_json["alternativeHeadline"] = app_headline

  app_alternative_headline = raw_input("alternative headline (" + app_json["alternativeHeadline"] + ") : ")
  if app_alternative_headline :
    app_json["alternativeHeadline"] = app_alternative_headline

  app_category = raw_input("application category (" + app_json["applicationCategory"] + ") : ")
  if app_category :
    app_json["applicationCategory"] = app_category

  app_sub_category = raw_input("sub category : ")
  if app_sub_category :
    app_json["applicationSubCategory"] = app_sub_category

  app_os = raw_input("application operating system (" + app_json["operatingSystem"] + ") : ")
  if app_os :
    app_json["operatingSystem"] = app_os

  app_promo_image = raw_input("promo image (" + app_json["promoImage"] + ") : ")
  if app_promo_image :
    app_json["promoImage"] = app_promo_image

  app_images = raw_input("app preview images (values can be separted by comma) : ")
  if app_images :
    app_json["appImages"] = app_images.split(",")

  app_description = raw_input("one line description : ")
  if app_description :
    app_json["oneLineDescription"] = app_description

  author["name"] = raw_input("author name : ")

  author_type = raw_input("author type (" + author["@type"] + ") : ")
  if author_type :
    author["@type"] = author_type

  author["email"] = raw_input("email : ")

  author["url"] = raw_input("url : ")
  author["sameAs"] = author["url"]

  author["sameAs"] = raw_input("same as : ")

  app_json["author"] = author

  print json.dumps(app_json, indent=2)

  confirm = raw_input("confirm (yes) : ")

  if confirm.lower() != "no" :

The next part of the script asks for various inputs from the developer which he or she can either provide or skip, if an input skipped then the default value is used. However for some parameters like author name, url etc, no default value is used, the developer must provide those values later by editing the app.json file. Once all the inputs are taken, the script outputs the json object created, if the output is alright then the developer may press enter and the process will continue, otherwise the developer may enter ‘no’ and once again the script will start taking inputs.

Once the final app_json is created, next part is creating the actual directory structure with the default files. This is done as shown below.

index_html = open("index.html", 'w')
index_html.write("<!-- entry point of the app, on launching the appliccation" +
                  "this page will be displayed -->")

app_json_file = open("app.json", 'w')
app_json_file.write(json.dumps(app_json, indent=2))

get_started_md = open("", 'w')
get_started_md.write("<!-- getting started with the app -->")

app_use_md = open("", 'w')
app_use_md.write("<!-- use of this app -->")

others_md = open("", 'w')
others_md.write("<!-- other relevant information about this app -->")

style_css = open("css/style.css", 'w')
style_css.write("/* css to style the app */")

script_js = open("js/script.js", 'w')
script_js.write("// javascript logic for the app")

print "done"

A new directory is created in the root of the repository, the name of the directory is same as the app name. Python’s os module is used to create the directory and subdirectories. Inside the directory, app.json file is created in which app_json dictionary is dumped as a json object.
After this the other default files are created. These include index.html, js/script.js, css/style.css, and After everything is done script exits and the developer is all set to start with his development.

Finally is used to call

#!/usr/bin/env bash

python bin/

This allows users to initiate the script by just executing bin/ from root of the repository. The entire source code for this script can be found here (python code) and here (bash script)

Creating a command line tool to initiate loklak app development

Enhancing Github profile scraper service in loklak

The Github profile scraper is one of the several scrapers present in the loklak project, some of the other scrapers being Quora profile scraper, WordPress profile scraper, Instagram profile scraper, etc.Github profile scraper scrapes the profile of a given github user and provides the data in json format. The scraped data contains user_id, followers, users following the given user, starred repositories of an user, basic information like user’s name, bio and much more. It uses the popular Java Jsoup library for scraping.

The entire source code for the scraper can be found here.

Changes made

The scraper previously provided very limited information like, name of the user, description, starred repository url, followers url, following url, user_id, etc. One of the major problem was the api accepted only the profile name as a parameter and it returned the entire data, that is, the scraper scraped all the data even if the user did not ask for it. Moreover the service provided certain urls as data for example starred repository url, followers url, following url instead of providing the actual data present at those urls.

The scraper contained only one big function where all the scraping was performed. The code was not modular.

The scraper has been enhanced in the ways mentioned below.

  • The entire code has been refactored.Code scraping user specific data has been separated from code scraping organization specific data. Also separate method has been created for accessing the Github API.
  • Apart from profile parameter, the api now accepts another parameter called terms. It is a list of fields the user wants information on. In this way the scraper scrapes only that much data which is required by the user. This allows better response time and prevents unnecessary scraping.
  • The scraper now provides more information like user gists, subscriptions, events, received_events and repositories.

Code refactoring

The code has been refactored to smaller methods. ‘getDataFromApi’ method has been designed to access Github API. All the other methods which want to make request to now calls ‘getDatFromApi’ method with required parameter. The method is shown below.

private static JSONArray getDataFromApi(String url) {
       URI uri = null;
       try {
           uri = new URI(url);
       } catch (URISyntaxException e1) {

       JSONTokener tokener = null;
       try {
           tokener = new JSONTokener(uri.toURL().openStream());
       } catch (Exception e1) {
       JSONArray arr = new JSONArray(tokener);
       return arr;


For example if we want to make a request to the endpoint then we can use the above method and we will get a JSONArray in return.

All the code which scrapes user related data has been moved to ‘scrapeGithubUser’ method. This method scrapes basic user information like full name of the user, bio, user name, atom feed link, and location.

String fullName = html.getElementsByAttributeValueContaining("class", "vcard-fullname").text();
githubProfile.put("full_name", fullName);
String userName = html.getElementsByAttributeValueContaining("class", "vcard-username").text();
githubProfile.put("user_name", userName);
String bio = html.getElementsByAttributeValueContaining("class", "user-profile-bio").text();
githubProfile.put("bio", bio);
String atomFeedLink = html.getElementsByAttributeValueContaining("type", "application/atom+xml").attr("href");
githubProfile.put("atom_feed_link", "" + atomFeedLink);
String worksFor = html.getElementsByAttributeValueContaining("itemprop", "worksFor").text();
githubProfile.put("works_for", worksFor);
String homeLocation = html.getElementsByAttributeValueContaining("itemprop", "homeLocation").attr("title");
githubProfile.put("home_location", homeLocation);


Next it returns other informations like starred repositories information, followers information, following information and information about the organizations the user belongs to but before fetching such data it checks whether such data is really needed. In this way unnecessary api calls are prevented.

if (terms.contains("starred") || terms.contains("all")) {
            String starredUrl = GITHUB_API_BASE + profile + STARRED_ENDPOINT;
            JSONArray starredData = getDataFromApi(starredUrl);
            githubProfile.put("starred_data", starredData);
            int starred = Integer.parseInt(html.getElementsByAttributeValue("class", "Counter").get(1).text());
            githubProfile.put("starred", starred);
        if (terms.contains("follows") || terms.contains("all")) {
            String followersUrl = GITHUB_API_BASE + profile + FOLLOWERS_ENDPOINT;
            JSONArray followersData = getDataFromApi(followersUrl);
            githubProfile.put("followers_data", followersData);
            int followers = Integer.parseInt(html.getElementsByAttributeValue("class", "Counter").get(2).text());
            githubProfile.put("followers", followers);
        if (terms.contains("following") || terms.contains("all")) {
            String followingUrl = GITHUB_API_BASE + profile + FOLLOWING_ENDPOINT;
            JSONArray followingData = getDataFromApi(followingUrl);
            githubProfile.put("following_data", followingData);
            int following = Integer.parseInt(html.getElementsByAttributeValue("class", "Counter").get(3).text());
            githubProfile.put("following", following);
        if (terms.contains("organizations") || terms.contains("all")) {
            JSONArray organizations = new JSONArray();
            Elements orgs = html.getElementsByAttributeValue("itemprop", "follows");
            for (Element e : orgs) {
                JSONObject obj = new JSONObject();
                String label = e.attr("aria-label");
                obj.put("label", label);
                String link = e.attr("href");
                obj.put("link", "" + link);
                String imgLink = e.children().attr("src");
                obj.put("img_link", imgLink);
                String imgAlt = e.children().attr("alt");
                obj.put("img_Alt", imgAlt);
            githubProfile.put("organizations", organizations);


Similarly ‘scrapeGithubOrg’ is used to scrape information related to Github organization.

API usage

The API can be used in the ways shown below.

  • api/githubprofilescraper.json?profile=<profile_name> : This is equivalent to api/githubprofilescraper.json?profile=<profile_name>&terms=all :This will return all the data the scraper is currently capable of collecting.
  • api/githubprofilescraper.json?profile=<profile_name>&terms=<list_containing_required_fields> : This will return the basic information about a profile and data on selective fields as mentioned by the user.

For example – api/githubprofilescraper.json?profile=djmgit&terms=followers,following,organizations

The above request will return data about followers, following, and organizations apart from basic profile information. Thus the scraper will scrape only those data that is required by the user.

Future scope

‘scrapeGithubUser’ is still lengthy and it can be further broken down into smaller methods. The part of the method which scrapes basic user information like name, bio, etc can be moved to a separate method. This will further increase code readability and maintainability.

Now we have a much more functional and enhanced Github profile scraper which provides more data than the previous one.

Enhancing Github profile scraper service in loklak

Link one repository’s subdirectory to another

Loklak, a distributed social media message search server, generates its documentation automatically using Continuous Integration. It generates the documentation in the gh-pages branch of its repository. From there, the documentation is linked and updated in the gh-pages branch of repository.

The method with which Loklak links the documentations from their respective subprojects to the repository is by using `subtrees`. Stating the git documentation,

“Subtrees allow subprojects to be included within a subdirectory of the main project, optionally including the subproject’s entire history. A subtree is just a subdirectory that can be committed to, branched, and merged along with your project in any way you want.”

What this means is that with the help of subtrees, we can link any project to our project keeping it locally in a subdirectory of our main repository. This is done in such a way that the local content of that project can easily be synced with the original project through a simple git command.


A representation of how Loklak currently uses subtrees to link the repositories is as follows.

git clone --quiet --branch=gh-pages [email protected]/ central-docs
cd central docs

git subtree pull --prefix=server gh-pages --squash -m "Update server subtree"

git subtree split:

The problem with the way documentation is generated currently is that the method is very bloated. The markup of the documentation is first compiled in each sub-projects’s repository and then aggregated in the repository. What we intend to do now is to keep all the markup documentation in the docs folder of the respective repositories and then create subtrees from these folders to a master repository. From the master repository, we then intend to compile the markups to generate the HTML pages.

Intended Implementation:

To implement this we will be making use of subtree split command.

    1. Run the following command in the subprojects repository. It creates a subtree from the docs directory and moves it to a new branch documentation.
git subtree --prefix=docs/ split -b documentation
    1. Clone the master repository. (This is the repository we intend to link the subdirectory with.)
git clone --quiet --branch=master [email protected]:loklak/ loklak_docs
cd loklak_docs
    1. Retrieve the latest content from the subproject.
      • During the first run.
git subtree add --prefix=raw/server ../loklak_server documentation --squash -m "Update server subtree"
      • During following runs.
git subtree pull --prefix=raw/server ../loklak_server documentation --squash -m "Update server subtree"
    1. Push changes.
git push -fq origin master > /dev/null 2>&1
Link one repository’s subdirectory to another

Continuous Deployment Implementation in Loklak Search

In current pace of web technology, the quick response time and low downtime are the core goals of any project. To achieve a continuous deployment scheme the most important factor is how efficiently contributors and maintainers are able to test and deploy the code with every PR. We faced this question when we started building loklak search.

As Loklak Search is a data driven client side web app, GitHub pages is the simplest way to set it up. At FOSSASIA apps are developed by many developers working together on different features. This makes it more important to have a unified flow of control and simple integration with GitHub pages as continuous deployment pipeline.

So the broad concept of continuous deployment boils down to three basic requirements

  1. Automatic unit testing.
  2. The automatic build of the applications on the successful merge of PR and deployment on the gh-pages branch.
  3. Easy provision of demo links for the developers to test and share the features they are working on before the PR is actually merged.

Automatic Unit Testing

At Loklak Search we use karma unit tests. For loklak search, we get the major help from angular/cli which helps in running of unit tests. The main part of the unit testing is TravisCI which is used as the CI solution. All these things are pretty easy to set up and use.

Travis CI has a particular advantage which is the ability to run custom shell scripts at different stages of the build process, and we use this capability for our Continuous Deployment.

Automatic Builds of PR’s and Deploy on Merge

This is the main requirement of the our CD scheme, and we do so by setting up a shell script. This file is in the project repository root.

There are few critical sections of the deploy script. The script starts with the initialisation instructions which set up the appropriate variables and also decrypts the ssh key which travis uses for pushing the repo on gh-pages branch (we will set up this key later).

  • Here we also check that we run our deploy script only when the build is for Master Branch and we do this by early exiting from the script if it is not so.


# Pull requests and commits to other branches shouldn't try to deploy.
if [ "$TRAVIS_PULL_REQUEST" != "false" -o "$TRAVIS_BRANCH" != "$SOURCE_BRANCH" ]; then
echo "Skipping deploy; The request or commit is not on master"
exit 0


  • We also store important information regarding the deploy keys which are generated manually and are encrypted using travis.
# Save some useful information
REPO=`git config remote.origin.url`
SSH_REPO=${REPO/https:\/\/\//[email protected]:}
SHA=`git rev-parse --verify HEAD`

# Decryption of the deploy_key.enc
openssl aes-256-cbc -K $ENCRYPTED_KEY -iv $ENCRYPTED_IV -in deploy_key.enc -out deploy_key -d

chmod 600 deploy_key
eval `ssh-agent -s`
ssh-add deploy_key


  • We clone our repo from GitHub and then go to the Target Branch which is gh-pages in our case.
# Cloning the repository to repo/ directory,
# Creating gh-pages branch if it doesn't exists else moving to that branch
git clone $REPO repo
cd repo
git checkout $TARGET_BRANCH || git checkout --orphan $TARGET_BRANCH
cd ..

# Setting up the username and email.
git config "Travis CI"


  • Now we do a clean up of our directory here, we do this so that fresh build is done every time, here we protect our files which are static and are not generated by the build process. These are CNAME and 404.html
# Cleaning up the old repo's gh-pages branch except CNAME file and 404.html
find repo/* ! -name "CNAME" ! -name "404.html" -maxdepth 1  -exec rm -rf {} \; 2> /dev/null
cd repo

git add --all
git commit -m "Travis CI Clean Deploy : ${SHA}"


  • After checking out to our Master Branch we do an npm install to install all our dependencies here and then do our project build. Then we move our files generated by the ng build to our gh-pages branch, and then we make a commit, to this branch.
git checkout $SOURCE_BRANCH
# Actual building and setup of current push or PR.
npm install
ng build --prod --aot
git checkout $TARGET_BRANCH
mv dist/* .
# Staging the new build for commit; and then committing the latest build
git add .
git commit --amend --no-edit --allow-empty


  • Now the final step is to push our build files to gh-pages branch and as we only want to put the build there if the code has actually changed, we make sure by adding that check.
# Deploying only if the build has changed
if [ -z `git diff --name-only HEAD HEAD~1` ]; then

echo "No Changes in the Build; exiting"
exit 0

# There are changes in the Build; push the changes to gh-pages
echo "There are changes in the Build; pushing the changes to gh-pages"

# Actual push to gh-pages branch via Travis
git push --force $SSH_REPO $TARGET_BRANCH


Now this 70 lines of code handle all our heavy lifting and automates a large part of our CD. This makes sure that no incorrect builds are entering the gh-pages branch and also enabling smoother experience for both developers and maintainers.

The important aspect of this script is ability to make sure Travis is able to push to gh-pages. This requires the proper setup of Keys, and it definitely is the trickiest part the whole setup.

  • The first step is to generate the SSH key. This is done easily using terminal and ssh-keygen.
$ ssh-keygen -t rsa -b 4096 -C "[email protected]


  • I would recommend not using any passphrase as it will then be required by Travis and thus will be tricky to setup.
  • Now, this generates the RSA public/private key pair.
  • We now add this public deploy key to the settings of the repository.
  • After setting up the public key on GitHub we give the private key to Travis so that Travis is able to push on GitHub.
  • For doing this we use the Travis Client, this helps to encrypt the key properly and send the key and iv to the travis. Which then using these values is able to decrypt the private key.
$ travis encrypt-file deploy_key
encrypting deploy_key for domenic/travis-encrypt-file-example
storing result as deploy_key.enc
storing secure env variables for decryption

Please add the following to your build script (before_install stage in your .travis.yml, for instance):

    openssl aes-256-cbc -K $encrypted_0a6446eb3ae3_key -iv $encrypted_0a6446eb3ae3_key -in super_secret.txt.enc -out super_secret.txt -d

Pro Tip: You can add it automatically by running with --add.

Make sure to add deploy_key.enc to the git repository.
Make sure not to add deploy_key to the git repository.
Commit all changes to your .travis.yml.


  • Make sure to add deploy_key.enc to git repository and not to add deploy_key to git.

And after all these steps everything is done our client-side web application will deploy on every push on the master branch.

These steps are required only one time in project life cycle. At loklak search, we haven’t touched the since it was written, it’s a simple script but it does all the work of Continuous Deployment we want to achieve.

Generation of Demo Links and Test Deployments

This is also an essential part of the continuous agile development that developers are able to share what they have built and the maintainers to review those features and fixes. This becomes difficult in a web application as the fixes and features are more often than not visual and attaching screenshots with every PR become the hassle. If the developers are able to deploy their changes on their gh-pages and share the demo links with the PR then it’s a big win for development at a faster pace.

Now, this step is highly specific for Angular projects while there are are similar approaches for React and other frameworks as well, if not we can build the page easily and push our changes to gh-pages of our fork.

We use @angular/cli for building project then use angular-cli-ghpages npm package to actually push to gh-pages branch of the fork. These commands are combined and are provided as node command npm run deploy. And this makes our CD scheme complete.


Clearly, the continuous deployment scheme has a lot of advantages over the other methods especially in the client side web apps where there are a lot of PR’s. This essentially eliminates all the deployment hassles in a simple way that any deployment doesn’t require any manual interventions. The developers can simply concentrate on coding the application and maintainers can just simply review the PR’s by seeing the demo links and then merge when they feel like the PR is in good shape and the deployment is done all by the Shell Script without requiring the commands from a developer or a maintainer.


Loklak Search GitHub Repository:

Loklak Search Application:

Loklak Search TravisCI:

Deploy Script:

Further Resources

Continuous Deployment Implementation in Loklak Search

Build a simple Angular 4 message publisher


The differences between Angular 1, Angular 2 and Angular 4

AngularJS/Angular 1 is a very popular framework which is based on MVC model, and it was released in October, 2010.
Angular 2, also called Angular, is based on component and is completely different from Angular 1 , which was released in September 2016.
Angular 4 is simply an update of Angular 2, which is released in March, 2017.

Note that Angular 3 was skipped due to the version number conflicts.



1. Install TypeScript:

npm install -g typescript

2. Install code editor: vscode, sublime, intellij.

3. Use Google chrome and development tool to debug.

Install Angular CLI by command line

Angular CLI is a very useful tool which contains a brunch of commands to work with Angular 4. In order to install Angular CLI, the version of Node should be higher or equal to 6.9.0, and NPM need to higher or equal to 3.

npm install -g @angular/cli

Create a new Project

ng new loklak-message-publisher
cd loklak-message-publisher
ng serve

The command will launch web browser automatically in localhost:4200 to run the application. It will detect any change in files. Of course you can change the default port to others.
The basic project structure is like this:

package.json: standard node configuration file, which including the name, version and dependency of the configuration.

tsconfig.json: configuration file for TypeScript compiler.

typings.json: another configuration file for typescript, mainly used for type checking.

app folder contains the main ts file, boot.ts and app.component.ts.


Next we will show how to build a simple message publisher. The final application looks like this, we can post new tweets in the timeline, and remove any tweet by clicking ‘x’ button:

  • The first step in to create new elements in app.component.html file.

The HTML file look quite simple, we save the file and switch to browser, the application is like this:

A very simple interface! In next step we need to add some style for the elements. Edit the app.component.css file:

.block {
   width: 800px;
   border: 1px solid #E8F5FD;
   border-bottom: 0px;
   text-align: center;
   margin: 0 auto;
   padding: 50px;
   font-family: monospace;
   background-color: #F5F8FA;
   border-radius: 5px;

h1 {
   text-align: center;
   color: #0084B4;
   margin-top: 0px;

.post {
   width: 600px;
   height: 180px;
   text-align: center;
   margin: 0 auto;
   background-color: #E8F5FD;
   border-radius: 5px;

.addstory {
   width: 80%;
   height: 100px;
   font-size: 15px;
   margin-top: 20px;
   resize: none;
   -webkit-border-radius: 5px;
   -moz-border-radius: 5px;
   border-radius: 5px;
   border-color: #fff;
   outline: none;

.post button {
   height: 30px;
   width: 75px;
   margin-top: 5px;
   position: relative;
   left: 200px;
   background-color: #008CBA;
   border: none;
   color: white;
   display: inline-block;
   border-radius: 6px;
   outline: none;

.post button:active {
   border: 0.2em solid #fff;
   opacity: 0.6;

.stream-container {
   width: 600px;
   border-bottom: 1px solid #E8F5FD;
   background-color: white;
   padding: 10px 0px;
   margin: 0 auto;
   border-radius: 5px;

.tweet {
   border: 1px solid;
   border-color: #E8F5FD;
   border-radius: 3px;

p {
   text-align: left;
   text-indent: 25px;
   display: inline-block;
   width: 500px;

span {
   display: inline-block;
   width: 30px;
   height: 30px;
   font-size: 30px;
   cursor: pointer;
   -webkit-text-fill-color: #0084B4;

The app is almost finished, so excited! Now we want to add some default tweets that will be shown up in our application.
Let’s open the app.component.ts file, add an array in class AppComponent.

Then in the app.component.html file, we add ngFor to instantiates a tweets in the page.

After we finished this step, all the tweets are displayed in our application. Now we have to implement ‘tweet’ button and delete button. We define addTweet and removeTweet functions in app.component.ts file.

For the addTweet function, we need to modify html to define the behavior of textarea and tweet button:

For removeTweet function, we add id for each tweet we posted, and combine delete span with removeTweet function, which pass the id of tweet.


There are two things about Angular 4 we can learn from this tutorial:

  1. How to bind functions or variables to DOM elements, e.g. click function, ngModel.
  2. How to use the directives such as *ngFor to instantiate template.
Build a simple Angular 4 message publisher

Using LokLak to Scrape Profiles from Quora, GitHub, Weibo and Instagram

Most of us are really so curious to know about one’s social life. So taking this as a key point, LokLak has many profile scrapers in it. Profile scraper which are now available in LokLak  helps us to know about the posts, followers one has. Few of the profile scrapers available in LokLak are Quora Profile, GitHub Profile, Weibo Profile and Instagram Profile.

How do the scrapers work?

In loklak now we are using java to get the json objects of the scraped profile from different websites as mentioned above. So here is a simple explanation how one of the scraper works. In this post I am going to give you a gist about how Github Profile scraper API works:

In the github profile scraper one can search for a profile without logging in and know the contents like the followers, repositories, gists of that profile and many more.

The simple query which can be used is:

To scrape individual profiles:

To scrape organization profiles:

Jsoup is an API and it is a easiest way used by java developers for scraping the web i.e.,web scraping. This API is used for manipulating and extracting data using DOM, CSS like methods. So in here, the Jsoup API is helping us to extract the html data and with the help of the tags used in the html extracted data we are trying to get the relevant data which is needed.

How do we get the matching elements?

We here are using special methods like getElementsByAttributeValueContaining() of the org.jsoup.nodes.Element class to get the data. For instance, to get the email from the extracted data the code is written as:

String email = html.getElementsByAttributeValueContaining("itemprop", "email").text();
            if (!email.contains("@"))
                  email = "";
            githubProfile.put("email", email);


Here is the java code which imports and extracts data:

Imports the html file:

html = Jsoup.connect("" + profile).get();

Extracts the html file for individual user:

/*If Individual*/
           if (html.getElementsByAttributeValueContaining("class", "user-profile-nav").size() != 0) {
               scrapeGithubUser(githubProfile, terms, profile, html);
           if (terms.contains("gists") || terms.contains("all")) {
               String gistsUrl = GITHUB_API_BASE + profile + GISTS_ENDPOINT;
               JSONArray gists = getDataFromApi(gistsUrl);
               githubProfile.put("gists", gists);
           if (terms.contains("subscriptions") || terms.contains("all")) {
               String subscriptionsUrl = GITHUB_API_BASE + profile + SUBSCRIPTIONS_ENDPOINT;
               JSONArray subscriptions = getDataFromApi(subscriptionsUrl);
               githubProfile.put("subscriptions", subscriptions);
           if (terms.contains("repos") || terms.contains("all")) {
               String reposUrl = GITHUB_API_BASE + profile + REPOS_ENDPOINT;
               JSONArray repos = getDataFromApi(reposUrl);
               githubProfile.put("repos", repos);
           if (terms.contains("events") || terms.contains("all")) {
               String eventsUrl = GITHUB_API_BASE + profile + EVENTS_ENDPOINT;
               JSONArray events = getDataFromApi(eventsUrl);
               githubProfile.put("events", events);
          if (terms.contains("received_events") || terms.contains("all")) {
              String receivedEventsUrl = GITHUB_API_BASE + profile + RECEIVED_EVENTS_ENDPOINT;
              JSONArray receivedEvents = getDataFromApi(receivedEventsUrl);
              githubProfile.put("received_events", receivedEvents);

Extracts the html file for organization:

/*If organization*/
if (html.getElementsByAttributeValue("class", "orgnav").size() != 0) {
    scrapeGithubOrg(profile, githubProfile, html);

And this is the sample output:

For query:
  "data": [{
    "joining_date": "2016-04-12",
    "gists_url": "",
    "repos_url": "",
    "user_name": "kavithaenair",
    "bio": "GSoC'17 @loklak @fossasia ; Developer @fossasia ; Intern @amazon",
    "subscriptions_url": "",
    "received_events_url": "",
    "full_name": "Kavitha E Nair",
    "avatar_url": "",
    "user_id": "18421291",
    "events_url": "",
    "organizations": [
        "img_link": "",
        "link": "",
        "label": "fossasia",
        "img_Alt": "@fossasia"
        "img_link": "",
        "link": "",
        "label": "coala",
        "img_Alt": "@coala"
        "img_link": "",
        "link": "",
        "label": "loklak",
        "img_Alt": "@loklak"
        "img_link": "",
        "link": "",
        "label": "bvrit-wise-django-team",
        "img_Alt": "@bvrit-wise-django-team"
    "home_location": "\n    Hyderabad, India\n",
    "works_for": "",
    "special_link": "",
    "email": "",
    "atom_feed_link": ""
  "metadata": {"count": 1},
  "session": {"identity": {
    "type": "host",
    "name": "",
    "anonymous": true
Using LokLak to Scrape Profiles from Quora, GitHub, Weibo and Instagram