Building a Static WordPress

Photo by Vidsplay from StockSnap

Now that I have Nginx in Front of WordPress, I thought the next logic step was to try and hide my WordPress even more. What exactly would this mean? In my mind, I figured that I would restrict access to all of the backend functions of my WordPress site to just my IP Addresses. From there, I would simply serve static versions of the content.

Part of the reason that I can do this is because my site is mostly static. I don’t allow comments or other dynamic plugins. The site is only used to publish my blog posts and that’s about it. I also setup WordPress to use the permalink format of /%year%/%monthnum%/%post_id%/

First Step, Mirror the Site to a Private Repo

Just as the heading states, I needed to first get all of my content available outside of WordPress. Luckily, I realized that I had a few previous blog posts:

that could help me accomplish the initial steps. I won’t completely bore you with the details contained in these posts. I’m going to assume that you can get a basic idea of how to setup the private repo using Creating a Private GitHub Repo. You can setup your repo however you like but for future planning purposes, I decided to create a html directory inside of it to house the website files. My initial repo looked like the following:

 % ls -al
 total 8
 drwxr-xr-x   5 salgatt  staff   160 Dec 31 08:46 .
 drwxr-xr-x  49 salgatt  staff  1568 Jan  7 12:32 ..
 drwxr-xr-x  15 salgatt  staff   480 Jan  7 09:05 .git
 -rw-r--r--   1 salgatt  staff    18 Dec 30 18:57 README.md
 drwxr-xr-x   4 salgatt  staff   128 Jan  5 21:31 html 

With the private repo created, I needed to get all of my content into the repo for later use by Nginx. I just did a wget to pull only the page content down. The reason I did this is because there were a number of js and css files that are required for the admin pages and possibly for other “things” that I might not use right away:

 % cd html
 % wget --mirror --follow-tags=a,img --no-parent https://blog.shellnetsecurity.com
 --2021-01-07 16:37:24--  https://blog.shellnetsecurity.com/
 Resolving blog.shellnetsecurity.com (blog.shellnetsecurity.com)... 157.230.75.245
 Connecting to blog.shellnetsecurity.com (blog.shellnetsecurity.com)|157.230.75.245|:443... connected.
 HTTP request sent, awaiting response... 200 OK
 Length: 17266 (17K) [text/html]
 Saving to: ‘blog.shellnetsecurity.com/index.html’
 

 blog.shellnetsecurity.com/index.html       100%[=======================================================================================>]  16.86K  --.-KB/s    in 0.09s   
...
 --2021-01-07 16:37:41--  https://blog.shellnetsecurity.com/author/salgatt/page/2/
 Connecting to blog.shellnetsecurity.com (blog.shellnetsecurity.com)|157.230.75.245|:443... connected.
 HTTP request sent, awaiting response... 200 OK
 Length: 41746 (41K) [text/html]
 Saving to: ‘blog.shellnetsecurity.com/author/salgatt/page/2/index.html’
 

 blog.shellnetsecurity.com/author/salgatt/p 100%[=======================================================================================>]  40.77K  --.-KB/s    in 0.1s    
 

 2021-01-07 16:37:44 (398 KB/s) - ‘blog.shellnetsecurity.com/author/salgatt/page/2/index.html’ saved [41746/41746]
 

 FINISHED --2021-01-07 16:37:44--
 Total wall clock time: 19s
 Downloaded: 56 files, 2.7M in 3.4s (821 KB/s) 

My wget command runs the –mirror command to ummm mirror the site. I do the –follow-tags=a,img so that I only nab the html plus images and follow only href tags. Finally, I want to stay within my site and not download any other sites’ content by issuing –no-parent. With that, I now have a blog.shellnetsecurity.com directory in my repo’s html directory.

 % ls -al
 total 0
 drwxr-xr-x   4 salgatt  staff  128 Jan  5 21:31 .
 drwxr-xr-x   5 salgatt  staff  160 Dec 31 08:46 ..
 drwxr-xr-x  18 salgatt  staff  576 Jan  7 08:38 blog.shellnetsecurity.com 

Now, I need to get all of my static content into the repo as well. In order to do that, I just did a simple copy of the static files from my container running wordpress using kubectl cp:

 % kubectl cp -n wordpress wordpress-85589d5658-48ncz:/opt/wordpress/wp-content ./blog.shellnetsecurity.com/wp-content
 tar: Removing leading `/' from member names
 % kubectl cp -n wordpress wordpress-85589d5658-48ncz:/opt/wordpress/wp-includes ./blog.shellnetsecurity.com/wp-includes
 tar: Removing leading `/' from member names 

These copy commands grab ALL files in these two directories. The idea is that I’m grabbing the js and css for any plugins running in my WordPress and any theme related files. Since these directories contain PHP files and other files I don’t need in my static repo, I remove them with a nice little find command:

 % find blog.shellnetsecurity.com/wp-includes -type f -not -name '*.js' -not -name '*.css' -not -name '*.jpg' -not -name '*.png' -delete
 % find blog.shellnetsecurity.com/wp-content -type f -not -name '*.js' -not -name '*.css' -not -name '*.jpg' -not -name '*.png' -delete 

At this point, I now have a repo that should have all of the content ready to go. I commit all of the changes and push the changes to main.

Serve the Static Repo

Like I said before, I’m not going to clutter this post with the details that can be found in Building a Kubernetes Container That Synchs with Private Git Repo. Assuming you have this all ready to go, I’m going to cut straight to the configuration portion. I’m assuming the nginx container is mounting the private repo at /dir/wordpress_static. I am also going to build upon the nginx configmap that was created in Adding Nginx in Front of WordPress. I’m first going to change the root directory to be the static WordPress blog:

         root /dir/wordpress_static/html/blog.shellnetsecurity.com; 

I also need to change some of my original reverse proxy mappings to serve most content from static but still leave a few requests go to my WordPress

         location /status {
                 return 200 "healthy\n";
         }
 
         location / {
                 try_files $uri $uri/ /index.html;
         }
 
         location /sitemap {
                 proxy_pass https://wordpress;
                 proxy_ssl_verify off;
                 proxy_set_header Host blog.shellnetsecurity.com;
                 proxy_set_header X-Forwarded-For $remote_addr;
         }
 
         location /wp-sitemap {
                 proxy_pass https://wordpress;
                 proxy_ssl_verify off;
                 proxy_set_header Host blog.shellnetsecurity.com;
                 proxy_set_header X-Forwarded-For $remote_addr;
         }
 
         location /wp-json {
                 allow 1.1.1.1;
                 allow 2.2.2.2;
                 deny all;
                 proxy_pass https://wordpress;
                 proxy_ssl_verify off;
                 proxy_set_header Host blog.shellnetsecurity.com;
                 proxy_set_header X-Forwarded-For $remote_addr;
         }
 
         location /wp-login {
                 allow 1.1.1.1;
                 allow 2.2.2.2;
                 deny all;
                 proxy_pass https://wordpress; 
                 proxy_ssl_verify off;
                 proxy_set_header Host blog.shellnetsecurity.com;
                 proxy_set_header X-Forwarded-For $remote_addr;
         }
 
         location /admin {
                 allow 1.1.1.1;
                 allow 2.2.2.2;
                 deny all;
                 proxy_pass https://wordpress;
                 proxy_ssl_verify off;
                 proxy_set_header Host blog.shellnetsecurity.com;
                 proxy_set_header X-Forwarded-For $remote_addr;
         }
 
         location /wp-admin {
                 allow 1.1.1.1;
                 allow 2.2.2.2;
                 deny all;
                 proxy_pass https://wordpress;
                 proxy_ssl_verify off;
                 proxy_set_header Host blog.shellnetsecurity.com;
                 proxy_set_header X-Forwarded-For $remote_addr;
         }

Through some trial and error, I found that I needed to have all of the following paths allowed for my admin functionalities:

  • /wp-admin
  • /admin
  • /wp-login
  • /wp-json

Since these are required for admin functions, I have made sure to run my IP restrictions on them and only allow my addresses to access them. For now, I am managing my sitemaps from within WordPress so I also allowed requests from any clients to go directly to my WordPress server still (something I’ll correct in a future post when I talk about automation). Aside from these exceptions, I’m using try_files to find the other content. This means that requests for any other content will be sent into the root directive, aka /dir/wordpress_static/html/blog.shellnetsecurity.com, aka the private repo! Notice the trailing /index.html on the directive? That just means that I’ll serve /index.html whenever the page isn’t found.

With that, I am now serving content from my mirrored content that is running from the private repo. I can still manage my WordPress site like I normally do from the backend and generate content and make changes and life is mostly good.

I am an idiot

Yes, you don’t need to tell me this! I know there are some obvious flaws in what I’ve setup like:

  • What happens when I post a new article?!
  • What do I do when WordPress is upgraded?
  • What happens when a plugin is upgraded?
  • Do you know that doing a wget for just pages won’t download pretty little images?
  • Did you know that serving /index.html for css/jpg/png/js files is ugly?
  • This manual process is terrible!

I know! I have already begun to tackle these and I’ll have more details on that when I write my Automating Static WordPress Updates (Currently in Draft). As a sneak peak to all of this, there’s a really cool WordPress plugin that will send various notifications to Slack. Oh the fun that we will have when talking about using Slack as a message bus and writing and app and and …. ok I’ll contain my excitement for now!

Automatically Rebuild Image on Docker Hub

This post focuses on me being lazy. In the previous post, I talked about building a custom image and posting it to the Docker Hub. I have also talked about creating a Git repo and storing everything in it thus far. What if we could make a commit rebuild our image for us? As luck would have it, you can do this!

This post is going to focus on making that very simple change to your Docker Hub repository so that every commit causes the image to be rebuilt to the latest. How fun!

Connecting Docker Hub to Your Git Account

The major thing to accomplish here is configuring Docker Hub to monitor Git. In order to do that, you’ll need to first sign into your Docker Hub account. This should bring you to the main page where you see the list of repos you maintain:

From there, click on the repo that you plan to configure. In my case, it’s the testnginximage repo. On the resulting screen, click on the Builds link to reveal the below page:

Click on the Link to GitHub button, to open your preferences to configure linked accounts.

Click the Connect link on this screen, to link to your GitHub account. If you are already signed into GitHub, Docker Hub will automatically connect to whatever account you are signed in with. If you are not already signed into GitHub, you’ll see the below login to GitHub screen:

Login to the GitHub account you used to store your Dockerfile we created in the previous post. Once connected, you’ll return to your Docker Hub profile with your GitHub account connected and the account name used listed:

At this point, you now have your Docker Hub and GitHub accounts connected. The next step will be to enable automatic builds.

Enabling Automatic Builds in Docker Hub

With Docker Hub and GitHub connected, the next step is to tell Docker Hub which repo to use and where the Dockerfile is located. In order to do that, go back to your repo and once again, click on the Build link. Within the Build screen, again, click on the Link to GitHub button. This time, the button should say “Connected” on it as shown below:

On the resulting page, configure the username and repo you would like to use as your source. Since I have been building everything in my mysamplerepo repo, I’m choosing this from the drop down:

In my prior examples, I created the Dockerfile in the nginxdocker directory within my mysamplerepo. Assuming you have done the same, scroll down the page and set the Build Context to be the nginxdocker in the Build Rules. This Build Context would be the path from the root of your repo that contains the Dockerfile. If you’ve placed your Dockerfile in a different path within your repo, make sure you have Build Context configured for that particular path.

Once you have this all configured, click on the Save and Build button at the bottom of the page. This should take you back to the Build page where you can monitor the status of the build.

Monitor the progress to make sure everything builds correctly. Once done, you should see a success status for the build.

Use a Commit to Generate a Build

Now that we have everything connected and working, let’s see if we can do a commit to our repo and confirm that the commit makes a build trigger. Let’s just make a simple change and no longer expose port 443 from for the image:

FROM ubuntu
  
 MAINTAINER Scott Algatt
  
 RUN apt-get update 
     && apt-get install -y nginx libnginx-mod-http-lua libnginx-mod-http-subs-filter software-properties-common
     && add-apt-repository -y universe 
     && add-apt-repository -y ppa:certbot/certbot 
     && apt-get update 
     && apt-get -y install certbot python-certbot-nginx 
     && apt-get clean 
     && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 COPY ./conf/nginx.conf /etc/nginx/nginx.conf
 COPY ./conf/site.conf /etc/nginx/sites-available/default
  
 EXPOSE 80
 CMD ["nginx"]

With that change, let’s do a commit and push:

$ git commit -a
 [master 0e01193] Removing port 443
  Committer: Scott <scott@iMacs-iMac.local>
  
  2 files changed, 2 deletions(-)
$ git push origin master
 Counting objects: 6, done.
 Delta compression using up to 4 threads.
 Compressing objects: 100% (6/6), done.
 Writing objects: 100% (6/6), 499 bytes | 499.00 KiB/s, done.
 Total 6 (delta 3), reused 0 (delta 0)
 remote: Resolving deltas: 100% (3/3), completed with 3 local objects.
 To github.com:algattsm/mysamplerepo.git
    1d4d448..0e01193  master -> master

After performing the commit, refresh your Build page in Docker Hub and you should see a build trigger:

This means that you’ll be able to simply use your GitHub to generate a new image anytime you like! This also means that with every commit, you’ll be exposing the latest version of your image on Docker Hub.

Referenced File

In case you want to make sure you have the correct file, here would be the only file I referenced in this post:

Deploying Nginx + PHP + git-sync on Kubernetes

In my previous post, I explained how to setup a simple nginx instance that could be used to sync to a private Git repo. The only drawback is that this setup will only serve static pages. What if you wanted to be able to run a server with dynamic code like PHP? I’m glad you asked! In this post, we’ll update our config to include a php-fpm instance to allow us to serve PHP pages.

I have planned these articles out so that they build on each other. With that in mind, I’m assuming you have followed my articles to date and therefore we’ll be simply extended the current deployment.

If you’re impatient like me, just scroll to the bottom and download the full files.

Setting Up The PHP-FPM Instance

First we need to get our PHP-FPM yaml setup. By default, php-fpm runs on port 9000. This means we need a service definition to expose this to the cluster. This will also need access to the git repo we created so we’ll add in the git container spec. Instead of running the nginx image, we’ll run the php-fpm image. In order to make life easy on ourselves, I’m going to use the webserver.yaml from my previous post as a template. I’m going to make the following changes to it:

  1. Replace any reference of “webserver” with “phpfpm”.
  2. Change the following in the service definition
    1. change the port name from http to phpfpm
    2. change the port number from 80 to 9000
  3. Remove the ConfigMap
    1. Remove the definition of it from the top of the file
    2. Remove the references to it in the spec volumes and the container volumeMounts
  4. Change the image of the second container from nginx:latest to php:fpm
  5. Change the containerPort from 80 to 9000

If we’ve done this all correctly, we should have a yaml that looks similar to the below:

apiVersion: v1
  
 kind: Service
 metadata:
   name: phpfpm
   labels:
     tier: backend
 spec:
   selector:
     app: phpfpm
     tier: backend
   ports:  
   - name: phpfpm
     port: 9000
 ---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: phpfpm
   labels:
     tier: backend
 spec:
   replicas: 1
   selector:
     matchLabels:
       app: phpfpm
       tier: backend
   template:
     metadata:
       labels:
         app: phpfpm
         tier: backend
     spec:
       securityContext:
         fsGroup: 65533 # to make SSH key readable
       volumes:
       - name: dir
         emptyDir: {}
       - name: git-secret
         secret:
           secretName: github-creds
           defaultMode: 288
       containers:
       - env:
         - name: GIT_SYNC_REPO
           value: git@github.com:<some user>/mysamplerepo.git
         - name: GIT_SYNC_BRANCH
           value: master
         - name: GIT_SYNC_SSH
           value: "true"
         - name: GIT_SYNC_PERMISSIONS
           value: "0777"
         - name: GIT_SYNC_DEST
           value: www
         - name: GIT_SYNC_ROOT
           value: /git
         name: git-sync
         image: k8s.gcr.io/git-sync:v3.1.1
         securityContext:
           runAsUser: 65533 # git-sync user
         volumeMounts:
         - name: git-secret
           mountPath: /etc/git-secret
         - name: dir
           mountPath: /git
       - name: phpfpm
         image: php:fpm
         ports:
         - containerPort: 9000
         volumeMounts:
         - name: dir
           mountPath: /usr/share/nginx 

We can now save this yaml and apply it to our cluster:

# kubectl apply -f phpfpm.yaml 
 service/phpfpm unchanged
 deployment.apps/phpfpm configured

Assuming all went well, we should now have our webserver and phpfpm containers up and running:

# kubectl get pod
 NAME                         READY   STATUS    RESTARTS   AGE
 phpfpm-b46969c5f-zzh6d       2/2     Running   0          103s
 webserver-8fb84dc86-7xw4w    2/2     Running   0          10s

That’s just lovely but what next?

Configuring Nginx for PHP

At this point, we basically have two unassociated containers that are living independently in the same cluster. The only common bond is that they have the same set of files synched from the Git Repo. Next, we need to tell nginx to handle PHP requests and where to send them. This will require us to update our Nginx configMap. We do this by adding a location statement to handle php files like so:

      location ~ .php$ {
           try_files $uri =404;
           fastcgi_split_path_info ^(.+.php)(/.+)$;
           fastcgi_pass phpfpm:9000;
           fastcgi_index index.php;
           include fastcgi_params;
           fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
           fastcgi_param PATH_INFO $fastcgi_path_info;
       }

There’s lots going on here in this file but some important items to note. Nginx acts like a reverse proxy when handling PHP files. It simply takes the request and sends to php-fpm. The php-fpm service finds the request file locally, executes PHP on it, and sends the resulting processed output from PHP back to Nginx. Here is the full updated configMap:

apiVersion: v1
 kind: ConfigMap
 metadata:
   name: webserver-config
   labels:
     tier: backend
 data:
   config :
     server {
         listen       80;
         server_name  localhost;
  
         location / {
             root   /usr/share/nginx/www/html;
             index  index.html index.htm;
         }
  
         error_page   500 502 503 504  /50x.html;
         location = /50x.html {
             root   /usr/share/nginx/www/html;
         }
  
       location ~ .php$ {
           root /usr/share/nginx/www/html;
           try_files $uri =404;
           fastcgi_split_path_info ^(.+.php)(/.+)$;
           fastcgi_pass phpfpm:9000;
           fastcgi_index index.php;
           include fastcgi_params;
           fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
           fastcgi_param PATH_INFO $fastcgi_path_info;
       }
  
     }

Let’s apply this to our cluster:

# kubectl apply -f configmap.yaml 
 configmap/webserver-config configured

With the new configuration running, we’ll need Nginx to reload it. There’s a number of different ways we could do this but I’m going to use a hack that will allow us to test the config and then restart. First step, I want to make sure the new config will work for us:

# kubectl exec -it webserver-8fb84dc86-7xw4w -c webserver -- /usr/sbin/nginx -t
 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
 nginx: configuration file /etc/nginx/nginx.conf test is successful

It looks like the configuration is acceptable so let’s reload Nginx.

# kubectl exec -it webserver-8fb84dc86-7xw4w -c webserver -- /usr/sbin/nginx -s reload
 2019/12/28 14:01:32 [notice] 2804#2804: signal process started

We should now be ready to commit a PHP file to our repo and test.

Testing Our Configuration

Let’s create a simple PHP file in the html directory of our. 

We’ll jump onto the web server, install curl and test:

# kubectl exec -it webserver-8fb84dc86-7xw4w -c webserver -- /bin/bash
 root@webserver-8fb84dc86-7xw4w:/# apt update
 Hit:1 http://deb.debian.org/debian buster InRelease
 Hit:2 http://deb.debian.org/debian buster-updates InRelease
 Hit:3 http://security-cdn.debian.org/debian-security buster/updates InRelease
 Reading package lists... Done
 Building dependency tree       
 Reading state information... Done
 All packages are up to date.
 root@webserver-8fb84dc86-7xw4w:/# apt install curl
 Reading package lists... Done
 Building dependency tree       
 Reading state information... Done
 curl is already the newest version (7.64.0-4).
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
 root@webserver-8fb84dc86-7xw4w:/# curl localhost/index.php
  
 hello world from php

A great question to ask is how does php-fpm know which file and where that file exists? Like I said, great question.

This is handled by the fastcgi_param SCRIPT_FILENAME entry. This means that Nginx is going to tell php-fpm that it should try to load the $document_root$fastcgi_script_name file for the request. If you look at our configMap, we define document root as /usr/share/nginx/www/html. Assuming a request comes for index.php into Nginx, Nginx will tell php-fpm to also load /usr/share/www/html/index.php. In an environment where Nginx + PHP live on the same host, this doesn’t appear to be a problem because that file will exist for sure. In our configuration, we running two separate hosts aka containers. So we need to make sure the file exists on both servers in the same location. That’s the easy part! It does! Reason being, we’re using gitsynch on both containers and mounting that synched directory to the same location!

Full Working Configs

In case you want to just cheat and load the configurations, feel free to download them and play around:

Building a Kubernetes Container That Synchs with Private Git Repo

My previous post explained how to create a private git repo. On its own, that post is roughly useless unless you planned to maintained some private copy of your project so nobody can see it. In this post, we’re going to put that private repo to use in a Kubernetes environment. A basic assumption is that you already have a Kubernetes environment setup.

Adding Another SSH Key to the Repo

The first step would be to add another SSH Key to our repo. The purpose of this key is to be used to configure access from the container to the repo. We’ll load the SSH key into Kubernetes as a secret. We can’t set a password on this key or we might get prompted for the password during container build and that’s not useful. Also, since the key will not have a password, we won’t give it Read / Write access to our repo.

Generate the SSH Key

As before, we’re going to run the ssh-keygen command but we’ll specify the file where to save the key and just simply hit enter at the password prompt so that it’s not password protected.

imacs-imac:~ scott$ ssh-keygen -t rsa
 Generating public/private rsa key pair.
 Enter file in which to save the key (/Users/scott/.ssh/id_rsa): /Users/scott/.ssh/GH_RO_key_rsa
 Enter passphrase (empty for no passphrase): 
 Enter same passphrase again: 
 Your identification has been saved in /Users/scott/.ssh/GH_RO_key_rsa.
 Your public key has been saved in /Users/scott/.ssh/GH_RO_key_rsa.pub.
 The key fingerprint is:
 SHA256:0v0koHVNHdJbt4j2PaNorHa25dXgNl0sQjJB8R3ClPA scott@imacs-imac.lan
 The key's randomart image is:
 +---[RSA 2048]----+
 |         .===+o. |
 |           *o+o.o|
 |        o + E ooo|
 |       + + * ..o |
 |      o S + + + o|
 |       .   + + Bo|
 |          . o.=.=|
 |         . *oo.. |
 |        ..=...   |
 +----[SHA256]-----+
 imacs-imac:~ scott$ 

Upload the Key to our Git Repo

With our new SSH Key created, we’ll want to once again take the contents of the .pub file aka GH_RO_key_rsa.pub if you’re following along and paste that into our repo’s Deploy Keys like below:

Be sure that Allow write access is NOT selected and paste in the contents of the pub file to the Key box. Next, click Add Key. You should now have two keys listed:

Configuring Kubernetes

Now that we have our new Read Only key added to the repo, it’s time to setup Kubernetes. This is going to be a simple configuration so that we can display static HTML pages on our Kubernetes cluster.

Add SSH Key to Kubernetes

In order to have Kubernetes be able to use the SSH key, we need to add it as a secret that we’ll reference in our pod deployment. The first step is to create a known hosts file to be used along with the key so we don’t have to worry about acknowledging any new key messages.

~# ssh-keyscan github.com > /tmp/known_hosts
 # github.com:22 SSH-2.0-babeld-778045a0
 # github.com:22 SSH-2.0-babeld-778045a0
 # github.com:22 SSH-2.0-babeld-778045a0
 ~# 

This copies the ssh key from github into the /tmp/known_hosts file. Next, we need to get the contents of our private key file. When we pasted the key into GitHub, we were working with the public key file..aka the .pub file…Since Kubernetes will need to authenticate using this key, it’ll need the private key file…aka the GH_RO_key_rsa file. We’ll use the kubectl command to add the key into Kubernetes:

~# kubectl create secret generic github-creds --from-file=ssh=.ssh/GH_RO_key_rsa --from-file=known_hosts=/tmp/known_hosts
 secret/github-creds created
 ~# 

Creating the Web Server Deployment

Now we’re going to create a YAML file to configure and setup everything. The start of that YAML file will be to configure Kubernetes to open a port that directs traffic to port 80 of our resulting pod. From there, we’ll need to setup a pod that runs two separate containers. One container will be our git-synch application and the other will be nginx. We could get into some “complex” discussions and added costs of running a PVC or some other Kubernetes shared storage but we’re only dealing with a small web site that is synched with github so we’re gonna simply leverage local storage on each node by defining two volumes:

      volumes:
       - name: dir
         emptyDir: {}
       - name: git-secret
         secret:
           secretName: github-creds
           defaultMode: 288

This creates two volumes dir and git-secret. The dir is simply an empty directory volume that we’ll be filling with our files that we synch from Github. The git-secret is the SSH Key we added above. This needs to be made available to our git-synch container. 

In the nginx container, we’re going to mount the dir volume as /usr/share/nginx. The default nginx image looks for web content, aka document root, in /usr/share/nginx/html. Therefore, we’re going mount the repo as /usr/share/nginx. We mount the dir volume to /git as this is where we’re going to write our synched data.

You can see all of these configurations in the git-synch container configuration such as the target location for our synched files as well as the secret to use.

      containers:
       - env:
         - name: GIT_SYNC_REPO
           value: git@github.com:<some user>/mysamplerepo.git
         - name: GIT_SYNC_BRANCH
           value: master
         - name: GIT_SYNC_SSH
           value: "true"
         - name: GIT_SYNC_PERMISSIONS
           value: "0777"
         - name: GIT_SYNC_DEST
           value: www
         - name: GIT_SYNC_ROOT
           value: /git
         name: git-sync
         image: k8s.gcr.io/git-sync:v3.1.1
         securityContext:
           runAsUser: 65533 # git-sync user
         volumeMounts:
         - name: git-secret
           mountPath: /etc/git-secret
         - name: dir
           mountPath: /git

You’ll want to make sure you change the GIT_SYNC_REPO to match the value of your clone/download link in Github. The GIT_SYNC_DEST should match the name of your repo.

Here is the full config for reference:

apiVersion: v1
 kind: Service
 metadata:
   name: webserver
   labels:
     tier: backend
 spec:
   selector:
     app: webserver
     tier: backend
   ports:  
   - name: http
     port: 80
 ---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: webserver
   labels:
     tier: backend
 spec:
   replicas: 1
   selector:
     matchLabels:
       app: webserver
       tier: backend
   template:
     metadata:
       labels:
         app: webserver
         tier: backend
     spec:
       securityContext:
         fsGroup: 65533 # to make SSH key readable
       volumes:
       - name: dir
         emptyDir: {}
       - name: git-secret
         secret:
           secretName: github-creds
           defaultMode: 288
       containers:
       - env:
         - name: GIT_SYNC_REPO
           value: git@github.com:<some user>/mysamplerepo.git
         - name: GIT_SYNC_BRANCH
           value: master
         - name: GIT_SYNC_SSH
           value: "true"
         - name: GIT_SYNC_PERMISSIONS
           value: "0777"
         - name: GIT_SYNC_DEST
           value: www
         - name: GIT_SYNC_ROOT
           value: /git
         name: git-sync
         image: k8s.gcr.io/git-sync:v3.1.1
         securityContext:
           runAsUser: 65533 # git-sync user
         volumeMounts:
         - name: git-secret
           mountPath: /etc/git-secret
         - name: dir
           mountPath: /git
       - name: webserver
         image: nginx:latest
         ports:
         - containerPort: 80
         volumeMounts:
         - name: dir
           mountPath: /usr/share/nginx

With out configuration file all ready to go, we’ll use kubectl to apply the file:

~# kubectl apply -f webserver.yaml 
 service/webserver created
 deployment.apps/webserver created
 ~# 

After some time, we should be able to check the status and see the pod is online and the service is setup:

~# kubectl get pod
 NAME                         READY   STATUS    RESTARTS   AGE
 webserver-686854f667-cwq5f   2/2     Running   5          3m46s
 ~# kubectl get svc
 NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
 kubernetes   ClusterIP   10.152.183.1     <none>        443/TCP   149m
 webserver    ClusterIP   10.152.183.195   <none>        80/TCP    5m28s
 ~# 

Testing the Deployment

With everything deployed, we should have a web server up and running that is serving our git repo from the previous post. Without getting into deploying an ingress server and such, let’s take a short cut to test out our deployment. We can do this by connecting to the web server and doing a curl. First, we connect to the web server container:

# kubectl exec -it webserver-686854f667-cwq5f -c webserver /bin/bash

The above command will connect you to a shell in the container. By default, the nginx image does not have curl installed so we’ll need to install this to test further. Install curl using the below commands:

root@webserver-686854f667-cwq5f:/# apt update;apt -y install curl

With curl installed, let’s connect to the local web server:

root@webserver-686854f667-cwq5f:/# curl localhost
 <html>
 <head><title>403 Forbidden</title></head>
 <body>
 <center><h1>403 Forbidden</h1></center>
 <hr><center>nginx/1.17.6</center>
 </body>
 </html>

That does not seem right…I broke something…didn’t I? Oh wait, I know let’s try…

root@webserver-686854f667-cwq5f:/# curl localhost/html/
 <html>
 <body>
 hello world!
 </body>
 </html>

That works better. Looks like we need to fix something here but first let’s see if making a change to the repo works. Let’s cheat and use the github file editor and make a change to the index.html file like the below:

If we run our curl again, survey says….

root@webserver-686854f667-cwq5f:/# curl localhost/html/
 <html>
 <body>
 hello world! Test #2
 </body>
 </html>

Boom! Just like that it’s working. Kinda…

Fixing Our Deployment

In case the problem isn’t quite obvious, we are attempting to mount the git repo in a location that nginx isn’t quite looking for. It’s a bad idea to mount the entire git repo as the document root since it could allow people to look at your .git directory and possibly other files that you didn’t consider. In order to fix our deployment and secure just a little further we’re going to first adjust the nginx configuration with a Kubernetes configmap:

apiVersion: v1
 kind: ConfigMap
 metadata:
   name: webserver-config
   labels:
     tier: backend
 data:
   config :
     server {
         listen       80;
         server_name  localhost;
     
         location / {
             root   /usr/share/nginx/www/html;
             index  index.html index.htm;
         }
     
         error_page   500 502 503 504  /50x.html;
         location = /50x.html {
             root   /usr/share/nginx/www/html;
         }
    
     }

This configmap supplies nginx with a new configuration for the default site that tells nginx that the document root is now located in /usr/share/nginx/www/html. We also made some changes to the original webserver.yaml to add this new configuration as well as changing the mount point for git and nginx. The full configuration is here.

apiVersion: v1
 kind: ConfigMap
 metadata:
   name: webserver-config
   labels:
     tier: backend
 data:
   config :
     server {
         listen       80;
         server_name  localhost;
         location / {
             root   /usr/share/nginx/www/html;
             index  index.html index.htm;
         }
         error_page   500 502 503 504  /50x.html;
         location = /50x.html {
             root   /usr/share/nginx/www/html;
         }
     }
 ---
 apiVersion: v1
 kind: Service
 metadata:
   name: webserver
   labels:
     tier: backend
 spec:
   selector:
     app: webserver
     tier: backend
   ports:  
   - name: http
     port: 80
 ---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: webserver
   labels:
     tier: backend
 spec:
   replicas: 1
   selector:
     matchLabels:
       app: webserver
       tier: backend
   template:
     metadata:
       labels:
         app: webserver
         tier: backend
     spec:
       securityContext:
         fsGroup: 65533 # to make SSH key readable
       volumes:
       - name: dir
         emptyDir: {}
       - name: git-secret
         secret:
           secretName: github-creds
           defaultMode: 288
       - name: config
         configMap:
           name: webserver-config
           items:
           - key: config
             path: default.conf
       containers:
       - env:
         - name: GIT_SYNC_REPO
           value: git@github.com:<some user>/mysamplerepo.git
         - name: GIT_SYNC_BRANCH
           value: master
         - name: GIT_SYNC_SSH
           value: "true"
         - name: GIT_SYNC_PERMISSIONS
           value: "0777"
         - name: GIT_SYNC_DEST
           value: www
         - name: GIT_SYNC_ROOT
           value: /git
         name: git-sync
         image: k8s.gcr.io/git-sync:v3.1.1
         securityContext:
           runAsUser: 65533 # git-sync user
         volumeMounts:
         - name: git-secret
           mountPath: /etc/git-secret
         - name: dir
           mountPath: /git
       - name: webserver
         image: nginx:latest
         ports:
         - containerPort: 80
         volumeMounts:
         - name: dir
           mountPath: /usr/share/nginx
         - name: config
           mountPath: /etc/nginx/conf.d

Let’s apply this updated configuration using kubectl:

root@do-nyc04:/tmp# kubectl apply -f webserver.yaml 
 configmap/webserver created
 service/webserver unchanged
 deployment.apps/webserver configured

Let’s now reconnect and test our configuration:

root@do-nyc04:/tmp# kubectl get pod -o wide
 NAME                         READY   STATUS    RESTARTS   AGE    IP             NODE              NOMINATED NODE   READINESS GATES
 webserver-8fb84dc86-5chm5    2/2     Running   0          17s    10.244.1.53    pool-sfo01-ssy1   <none>           <none>
 root@do-nyc04:/tmp# kubectl exec -it webserver-8fb84dc86-5chm5 -c webserver /bin/bash
 root@webserver-8fb84dc86-5chm5:/# apt update;apt -y install curl
 Get:1 http://deb.debian.org/debian buster InRelease [122 kB]
 Get:2 http://deb.debian.org/debian buster-updates InRelease [49.3 kB]             
 Get:3 http://security-cdn.debian.org/debian-security buster/updates InRelease [65.4 kB]
 Get:4 http://deb.debian.org/debian buster/main amd64 Packages [7908 kB]
 Get:5 http://deb.debian.org/debian buster-updates/main amd64 Packages [5792 B]
 Get:6 http://security-cdn.debian.org/debian-security buster/updates/main amd64 Packages [167 kB]
 Fetched 8317 kB in 2s (3534 kB/s)                         
 Reading package lists... Done
 Building dependency tree       
 Reading state information... Done
 All packages are up to date.
 Reading package lists... Done
 Building dependency tree       
 Reading state information... Done
 The following additional packages will be installed:
 ...
 128 added, 0 removed; done.
 Setting up libgssapi-krb5-2:amd64 (1.17-3) ...
 Setting up libcurl4:amd64 (7.64.0-4) ...
 Setting up curl (7.64.0-4) ...
 Processing triggers for libc-bin (2.28-10) ...
 Processing triggers for ca-certificates (20190110) ...
 Updating certificates in /etc/ssl/certs...
 0 added, 0 removed; done.
 Running hooks in /etc/ca-certificates/update.d...
 done.
  
 root@webserver-8fb84dc86-5chm5:/# curl localhost
 <html>
 <body>
 hello world! Test #2
 </body>
  
 </html>

Great news! It looks like it’s fixed. Just to make sure things are working still, let’s make another change and see if it publishes.

root@webserver-8fb84dc86-5chm5:/# curl localhost
 <html>
 <body>
 hello world! Everything must be cleaned up at this point
 </body>
 </html>

W00t! Looks like everything is working and as we expect. Although, this configuration is mostly useless unless you are actually within the Kubernetes cluster. For the next article, I’ll provide some options and a hack for exposing this web server to the world.

Creating a Private GitHub Repo

The first step in my adventure was to first create a location to store my web content. The mostly likely location for this was GitHub. The process for signing up for a GitHub account is pretty easy so I won’t bother going through that process here. I’m going to assume that you figured that part out and I will begin with that assumption.

 Setting Up a Private GitHub Repo

Once you have your account, you’ll need to next setup your very first repo. Login to GitHub and click on the “New” button to create a repo
On the resulting screen:
  1. Enter a name for your repo
  2. Enter a description if you like
  3. We’re creating a private repo here because we don’t want anyone messing with it or having access to it (more on that in a future post).
  4. Let’s also initialize the repo with a blank README. This way you can add notes to the repo later if you have anything specific to remind yourself of

The configuration should look something like this:

  1. Click the Create repository button and like magic you have your very own Private repo!
Make note of the “Private” listed at the top of the repo. This lets you know that the repo is not available to the public on GitHub. Only those that have been specifically granted access will be permitted to view the contents and make changes.

Granting Access to the Repo Via Deploy Keys

Now that we have this private repo created, we need to be able to grant access to it for anyone or anything that will want to make changes to it. In order to do this, we’re going to generate a SSH key on our client machine so that we can have access via CLI (Sorry, I work is much from CLI as possible). These instructions will help you generate the ssh key and add it to the repo’s settings.

Generating the SSH Keys

First, we’ll need to generate our ssh keys that we intend to use for the repo. To do this, pop open a terminal window and run the ssh-keygen command as shown below. We’re going to make this key capable or performing Read and Write operations in our repo so be sure to supply a password when generating the key.

imacs-imac:~ scott$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/scott/.ssh/id_rsa):
Created directory '/Users/scott/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /Users/scott/.ssh/id_rsa.
Your public key has been saved in /Users/scott/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:o16ykEsBSueHW4G/Qu4a/5U26nfYsdrdbAUkxN60xFk scott@imacs-imac.lan
The key's randomart image is:

+---[RSA 2048]----+
|          o.. oE |
|    .      o *   |
| ..o .    . * .  |
|..o.o .    . +   |
|.  +.+  S     .  |
|  o +o…o     . |
| . ++.o=+ o   .  |
|  +..++*o+. o.   |
| ..o+++.o. ..o   |
+----[SHA256]-----+

This is generating a new ssh key that is protected by a password. The key will be called id_rsa and be located in the default location of ~/.ssh.

Adding the SSH Key to Our Repo

Now that we have our SSH Key, we will need to give it permissions to our repo. We go back to our repo on GitHub and click on the Settings link towards the top of the screen. From there, click on the Deploy Keys link on the left navigation menu. You should be looking at a screen similar to the below page:

Click the Add Deploy Key button on the Deploy keys page. Go back to your CLI (or however you wanna get the contents of the file) and dump the contents of your public key file (aka the one that ends in .pub). The private one (aka the one WITHOUT .pub should not be shared with anyone). You can see below how I’ve gotten the contents using cat.

imacs-imac:~ scott$ cat /Users/scott/.ssh/id_rsa.pub
 
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDCHVTkeP69+YLgiyWx9+DQ9TFftis6kiJMDTr/hi4nqzHlGdDUR78fy/kfAzU
Wu5cwaiuTpxvXtFK2FA+qrAoNqOzKecaVRv017PxznbRQhZ+FIfbKRua3Gt3rGSzrMvOErmL1He23jO5OZZAqpkt97E5kGO1gFmt
fb90moXDyE0GC6s/3dVcZdEDw+uge6toBF9BGO27lFtdwIs3x3rUj88BcACfi0D/0nkFxK3UjgaEuAcICpneKfVhd/jY5DnguCD5ST5lTi
Z/9hNDKfU4L1sQ0jz9gdmGhBpxpW3lRYWxBHadxKNYZFSI0IFO5VAFecNzgo/eSerIi2A9ahmTX 
scott@imacs-imac.lan

Copy the entire contents of this file and go back to the Add deploy key screen on GitHub. Paste the contents into the Key field. Give it a Title and be sure to check the Allow write access box as shown below:

Once that is done, click the Add key button to add the key. If you were successful, you should see something like the following:

Synching With Our Repo

Now that we have the repo setup and access granted, we’ll want to do our first commit to it. In order to do that, we first need to add our ssh repo key to our ssh agent. We do this by using the ssh-add -k command. This will prompt for the password you used when creating the key and upon successful authentication, your key will be added.

imacs-imac:~ scott$ ssh-add -k /Users/scott/.ssh/id_rsa
 Enter passphrase for /Users/scott/.ssh/id_rsa: 
 Identity added: /Users/scott/.ssh/id_rsa (scott@imacs-imac.lan)
 imacs-imac:~ scott$ 

With the key loaded, we should be able to clone our repo to our local machine. First we can cheat by getting the clone link for our repo. Go back to the main repo page by clicking on the name of the repo at the top of the page (next to the “Private” tag). This should bring you back to a page similar to this displaying your empty README.

Click the Clone or download button to reveal the link to your repo and then copy the link. The link should look something like:

 git@github.com:<my_git_user>/mysamplerepo.git

where my_git_user is your GitHub username. With that copied, let’s go back to our terminal and do a clone to get the repo on our local machine.

imacs-imac:~ scott$ git clone git@github.com:<my_git_user>/mysamplerepo.git
 Cloning into 'mysamplerepo'...
 The authenticity of host 'github.com (192.30.253.112)' can't be established.
 RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
 Are you sure you want to continue connecting (yes/no)? yes
 Warning: Permanently added 'github.com,192.30.253.112' (RSA) to the list of known hosts.
 remote: Enumerating objects: 3, done.
 remote: Counting objects: 100% (3/3), done.
 remote: Total 3 (delta 0), reused 0 (delta 0), pack-reused 0
 Receiving objects: 100% (3/3), done.
 imacs-imac:~ scott$ 

You should now have a directory called mysamplerepo on your machine.

imacs-imac:~ scott$ ls -al mysamplerepo/
 total 8
 drwxr-xr-x   4 scott  staff  136 Dec 20 15:41 .
 drwxr-xr-x+ 22 scott  staff  748 Dec 20 15:41 ..
 drwxr-xr-x  13 scott  staff  442 Dec 20 15:41 .git
 -rw-r--r--   1 scott  staff   14 Dec 20 15:41 README.md

Now we’ve got a local copy of our repo…yaaaaay!

Committing Our First Change From Local Machine

Now that we’ve got our repo, we’ll want to next set this up for some feature articles. The first step is to create an html directory within the repo and add a simple html file to it.

imacs-imac:mysamplerepo scott$ mkdir html
 imacs-imac:mysamplerepo scott$ cd html/
 imacs-imac:html scott$ vi index.html

Inside the index.html, I put our obligatory “hello world” for now.

<html>
 <body>
 hello world
 </body>
 </html>

Save the contents of the file (:wq) for those following along with CLI. From there, we’ll need to add our untracked files…aka git add and then commit the changes and push them to the repo.

imacs-imac:html scott$ cd ..
 imacs-imac:mysamplerepo scott$ git add .
 imacs-imac:mysamplerepo scott$ git commit -a
 [master 6d43978] Creating our first deployment
  Committer: Scott <scott@imacs-imac.lan>
 Your name and email address were configured automatically based
 on your username and hostname. Please check that they are accurate.
 You can suppress this message by setting them explicitly. Run the
 following command and follow the instructions in your editor to edit
 your configuration file:
  
     git config --global --edit
  
 After doing this, you may fix the identity used for this commit with:
  
     git commit --amend --reset-author
  
  1 file changed, 5 insertions(+)
  create mode 100644 html/index.html
 imacs-imac:mysamplerepo scott$ git push origin master
 Warning: Permanently added the RSA host key for IP address '140.82.113.4' to the list of known hosts.
 Counting objects: 4, done.
 Delta compression using up to 4 threads.
 Compressing objects: 100% (2/2), done.
 Writing objects: 100% (4/4), 368 bytes | 368.00 KiB/s, done.
 Total 4 (delta 0), reused 0 (delta 0)
 To github.com:algattsm/mysamplerepo.git
    89800ef..6d43978  master -> master
 imacs-imac:mysamplerepo scott$ 

I cheated and just moved up one directory so I’m sure to add the html directory and the contents of it to my commit. Running git add . will make sure we grab all of the new (aka untracked) files to the commit. Then the git commit -a says to comment all of our changes and we give a reason. Finally, the git push origin master commits all of changes to our repo. Let’s go check and see if this all happened properly.

If you go to GitHub in your browser again and refresh the page, you should see the html directory and it should contain the index.html file we created.

Looks like I did something right! Hopefully at this point, so did you.

What Does it all Mean and What’s Next?

Glad you asked. It’s means nothing at this point but it’s a step in the direction I took. At this point, you and I should be successful at creating a private repo and being able to publish content to it. High-five bro! Until the next article!