Add Networking, Images, Persistence tasks

Tasks/3.Networking/README.md

@@ -0,0 +1,9 @@
+# Practice - networking
+
+ - Run an nginx container "nginx1" in detached mode
+ - Run a busybox container "busy1" in interactive mode
+ - Try to ping the nginx container by name (You won’t be able to)
+ - Create a custom network **newnet** with a bridge driver
+ - Run another detached nginx container "nginx2", this time using **newnet**
+ - Run a new interactive busybox container "busy2", again using **newnet**
+ - Try pinging the new nginx container by name

Tasks/4.Building images/README.md

@@ -0,0 +1,22 @@
+# Practice - building images
+
+Your project utilizes microservices and Kuberenetes. On your cluster you have many containers (pods) with your services. There's a special container which runs Ubuntu and can access the other services' databases and other components. To access those components you install a few CLI tools on this special container. The problem - each time the cluster is re-deployed you must install the CLI tools again because they're not part of the container's base Ubuntu image.
+
+You want to automate this process by building a Dockerfile for this container using ubuntu:18.04 as your base image.
+
+To install those tools you normally use the following commands:
+
+- $ `DEBIAN_FRONTEND=noninteractive` # Env var required for postgres
+- $ `apt-get update && apt-get install -y postgresql` # Install postgres to access dbs
+- $ `apt-get install -y wget` # Install wget for downloading software packages
+- $ `apt-get install -y curl` # Install curl for running HTTP requests
+
+:whale: HINT: Research how to set environment variables inside Dockerfiles for the DEBIAN_FRONTEND variable.
+
+To build the image, navigate to your Dockerfile path and use
+ - `docker build –t "<name>:<tag>" .`
+
+Run a container from this image in interactive mode and verify the installations:
+ - `psql --version` # You should see the psql version
+ - `wget --version` # You should see the wget version and other info
+ - `curl 'http://example.com'` # You should see some html

Tasks/5.Using volumes/README.md

@@ -0,0 +1,17 @@
+# Practice - using volumes
+
+Run a container "mypsql" using **postgres:12** with options to:
+ - run the container in detached mode
+ - pass an environment variable `POSTGRES_PASSWORD=secretpass`
+ - create a named volume with `-v <name>:/var/lib/postgresql/data`
+
+Run a shell in the container and use psql to add a table and a record:
+ - $ `psql -U postgres`
+ - $ `create table public.films (id int PRIMARY KEY, name varchar(255));`
+ - $ `insert into films(id, name) values(1, 'Some movie');`
+
+Exit the container and delete it. Run a new container with the same options. Use ***the same*** volume name to re-use the existing volume.
+
+Run a shell inside the container and see if your data is still there:
+ - $ `psql –U postgres`
+ - $ `select * from public.films;`