Add a couple of AWS exercises

Questions as well were added.

exercises/aws/solutions/budget_setup.md

@@ -0,0 +1,18 @@
+## AWS - Budget Setup
+
+### Objectives
+
+Setup a cost budget in your AWS account based on your needs.
+
+### Solution
+
+1. Go to "Billing"
+2. Click on "Budgets" in the menu
+3. Click on "Create a budget"
+4. Choose "Cost Budget" and click on "Next"
+5. Choose the values that work for you. For example, recurring monthly budget with a specific amount
+6. Insert a budget name and Click on "Next" 
+7. Set up an alert but clicking on "Add an alert threshold"
+  1. Set a threshold (e.g. 75% of budgeted amount)
+  2. Set an email where a notification will be sent
+8. Click on "Next" until you can click on "Create a budget"

exercises/aws/solutions/ec2_iam_roles.md

@@ -0,0 +1,21 @@
+## AWS EC2 - IAM Roles
+ 
+### Requirements
+ 
+1. Running EC2 instance without any IAM roles (so you if you connect the instance and try to run AWS commands, it fails)
+2. IAM role with "IAMReadOnlyAccess" policy
+ 
+### Objectives
+
+1. Attach a role (and if such role doesn't exists, create it) with "IAMReadOnlyAccess" policy to the EC2 instance
+2. Verify you can run AWS commands in the instance
+ 
+### Solution
+
+#### Console
+
+1. Go to EC2 service
+2. Click on the instance to which you would like to attach the IAM role
+3. Click on "Actions" -> "Security" -> "Modify IAM Role" 
+4. Choose the IAM role with "IAMReadOnlyAccess" policy and click on "Save"
+5. Running AWS commands now in the instance should work fine (e.g. `aws iam list-users`)

exercises/aws/solutions/launch_ec2_web_instance.md

@@ -0,0 +1,39 @@
+## AWS - Launch EC2 Web Instance
+
+### Objectives
+
+Launch one EC2 instance with the following requirements:
+
+1. Amazon Linux 2 image
+2. Instance type: pick up one that has 1 vCPUs and 1 GiB memory
+3. Instance storage should be deleted upon the termination of the instance
+4. When the instance starts, it should install:
+  1. Install the httpd package
+  2. Start the httpd service
+  3. Make sure the content of /var/www/html/index.html is `I made it! This is is awesome!`
+5. It should have the tag: "Type: web" and the name of the instance should be "web-1"
+6. HTTP traffic (port 80) should be accepted from anywhere
+
+### Solution
+
+1. Choose a region close to you 
+2. Go to EC2 service
+3. Click on "Instances" in the menu and click on "Launch instances"
+4. Choose image: Amazon Linux 2
+5. Choose instance type: t2.micro 
+6. Make sure "Delete on Termination" is checked in the storage section
+7. Under the "User data" field the following:
+
+```
+yum update -y
+yum install -y httpd
+systemctl start httpd
+systemctl enable httpd
+echo "<h1>I made it! This is is awesome!</h1>" > /var/www/html/index.html
+```
+8. Add tags with the following keys and values:
+  * key "Type" and the value "web"
+  * key "Name" and the value "web-1"
+9. In the security group section, add a rule to accept HTTP traffic (TCP) on port 80 from anywhere
+10. Click on "Review" and then click on "Launch" after reviewing.
+11. If you don't have a key pair, create one and download it.

exercises/aws/solutions/no_application.md

@@ -0,0 +1,21 @@
+## No Application :'(
+
+### Objectives
+
+Explain what might be possible reasons for the following issues:
+
+1. Getting "time out" when trying to reach an application running on EC2 instance
+2. Getting "connection refused" error
+
+### Solution
+
+1. 'Time out' Can be due to one of the following:
+
+  * Security group doesn't allow access
+  * No host (yes, I know. Not the first thing to check and yet...)
+  * Operating system firewall blocking traffic
+
+2. 'Connection refused' can happen due to one of the following:
+
+  * Application didn't launch properly or has some issue (doesn't listens on the designated port)
+  * Firewall replied with a reject instead of dropping the packets

exercises/aws/solutions/security_groups.md

@@ -0,0 +1,55 @@
+## AWS EC2 - Security Groups
+
+### Requirements 
+
+For this exercise you'll need:
+
+1. EC2 instance with web application
+2. Security group inbound rules that allow HTTP traffic
+
+### Objectives
+
+1. List the security groups you have in your account, in the region you are using
+2. Remove the HTTP inbound traffic rule
+3. Can you still access the application? What do you see/get?
+4. Add back the rule
+5. Can you access the application now?
+
+### Solution
+
+#### Console
+
+1. Go to EC2 service - > Click on "Security Groups" under "Network & Security"
+   You should see at least one security group. One of them is called "default"
+2. Click on the security group with HTTP rules and click on "Edit inbound rules".
+   Remove the HTTP related rules and click on "Save rules"
+3. No. There is a time out because we removed the rule allowing HTTP traffic.
+4. Click on the security group -> edit inbound rules and add the following rule:
+  * Type: HTTP
+  * Port range: 80
+  * Source: Anywhere -> 0.0.0.0/0
+5. yes
+
+#### CLI
+
+1. `aws ec2 describe-security-groups` -> by default, there is one security group called "default", in a new account
+2. Remove the rule:
+
+```
+aws ec2 revoke-security-group-ingress \
+    --group-name someHTTPSecurityGroup
+    --protocol tcp \
+    --port 80 \
+    --cidr 0.0.0.0/0
+```
+3. No. There is a time out because we removed the rule allowing HTTP traffic.
+4. Add the rule we remove:
+
+```
+aws ec2 authorize-security-group-ingress \
+    --group-name someHTTPSecurityGroup
+    --protocol tcp \
+    --port 80 \
+    --cidr 0.0.0.0/0
+```
+5. yes