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Common Delegate Scripts

You can use the delegateINIT_SCRIPT environment variable to run startup scripts on the host, container, or pod on installation or restart.

For information on using theINIT_SCRIPT environment variable to run scripts, see Run Initialization Scripts on Delegates.

This topic provides information on script availability and some common delegate scripts you can declare in theINIT_SCRIPT environment variable.

Utilities​

The delegate ships with tar and cURL. To use other utilities you'll need to add them to the beginning of your scripts.

For example, for unzip and wget:

microdnf install unzip  
microdnf install wget  
...

Terraform​

# Install TF  
microdnf install unzip
curl -O -L https://releases.hashicorp.com/terraform/1.3.5/terraform_1.3.5_darwin_amd64.zip
unzip terraform_1.3.5_darwin_amd64.zip
mv ./terraform /usr/bin/
# Check TF install
terraform --version

Upgrade Terraform​

##terraform update  
microdnf install unzip  
microdnf install wget  
set +x  
apt-get update  
apt-get install wget  
apt-get -y install git  
wget https://releases.hashicorp.com/terraform/1.1.9/terraform_1.3.5_darwin_amd64.zip apt-get install unzip  
unzip terraform_1.3.5_darwin_amd64.zip  
cp terraform /usr/bin/  
terraform --version

Install Terraform and Terragrunt​

#Terraform  
microdnf install unzip
curl -O -L https://releases.hashicorp.com/terraform/1.3.5/terraform_1.3.5_darwin_amd64.zip
unzip terraform_1.3.5_darwin_amd64.zip
mv ./terraform /usr/bin/
# Check TF install
terraform --version 
  
#Terragrunt  
microdnf install unzip  
microdnf install wget  
wget https://github.com/gruntwork-io/terragrunt/releases/download/v0.28.0/terragrunt_linux_amd64  
yes | mv terragrunt_linux_amd64 terragrunt  
chmod u+x terragrunt  
yes | mv terragrunt /usr/local/bin/terragrunt  
terragrunt --version

Helm 2​

Use the following script to install Helm 2 and Tiller in the delegate cluster:

If you are using remote Helm charts with your Harness Kubernetes Service, use the helm init --client-only option. For more information, see Helm charts.

# Add the Helm version that you want to install  
HELM_VERSION=v2.14.0  
# v2.13.0  
# v2.12.0  
# v2.11.0  
  
export DESIRED_VERSION=${HELM_VERSION}  
  
echo "Installing Helm $DESIRED_VERSION ..."  
  
curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get | bash  
  
# If Tiller is already installed in the cluster   
helm init --client-only  
  
# If Tiller is not installed in the cluster  
# helm init

DESIRED_VERSION is used by a function in the Helm install script.If Helm is being installed in a cluster outside of the Delegate's cluster ensure that the kubeconfig in the Delegate cluster is pointing to the correct cluster using:

kubectl config current-context cluster_name

If you are using TLS for communication between Helm and Tiller, ensure that you use the --tls parameter with your commands. For more information, see Command Flags in Helm Deploy step in the Helm Deployment guide, and see  Using SSL Between Helm and Tiller from Helm, and the section Securing your Helm Installation in that document.Here is an example of how to add a Helm chart from a private repo using secrets repoUsername and repoPassword from Harness Secrets Management.

# Other installation method  
# curl https://raw.githubusercontent.com/helm/helm/master/scripts/get > get_helm.sh  
# chmod 700 get_helm.sh  
# ./get_helm.sh  
  
curl https://raw.githubusercontent.com/helm/helm/master/scripts/get | bash  
  
helm init --client-only  
  
helm repo add --username ${secrets.getValue("repoUsername")} --password ${secrets.getValue("repoPassword")} nginx https://charts.bitnami.com/bitnami  
  
helm repo update

Helm 3​

You do not need to use the INIT_SCRIPT environment variable for Helm 3. Harness provides support for Helm 3 for delegates that connect to the target Kubernetes cluster.

For more information, see Upgrade to Helm 3 Charts in Kubernetes Services and Upgrade Native Helm 2 Deployments to Helm 3.

Pip​

Ensure that you run apt-get update before running any apt-get commands.

apt-get update  
# Install pip  
apt-get -y install python-pip  
# Check pip install  
pip -v

Unzip​

Ensure that you run apt-get update before running any apt-get commands.

apt-get update  
# Install Unzip  
apt-get install unzip

AWS CLI​

The following script installs the AWS CLI version 2 on the Delegate host.

# Install AWS CLI  
microdnf install unzip  
curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"  
unzip awscliv2.zip  
./awscli-bundle/install -b ~/bin/aws  
# install  
sudo ./aws/install  
# Check AWS CLI install  
aws --version

AWS Describe Instance​

The following script describes the EC2 instance based on its private DNS hostname, which is also the name in the Delegate's Hostname field:

aws ec2 describe-instances --filters "Name=network-interface.private-dns-name,Values=ip-10-0-0-205.ec2.internal" --region "us-east-1"

The value for the Values parameter is simply the Hostname of the Delegate.

AWS List All Instances in a Region​

The following script will list all of the EC2 instances in the region you supply:

aws ec2 describe-instances --query 'Reservations[*].Instances[*].[InstanceId,State.Name,InstanceType,PrivateIpAddress,PublicIpAddress,Tags[?Key==`Name`].Value[]]' --region "us-east-1" --output json | tr -d '\n[] "' | perl -pe 's/i-/\ni-/g' | tr ',' '\t' | sed -e 's/null/None/g' | grep '^i-' | column -t

Git CLI​

Ensure that you run apt-get update before running any apt-get commands.

apt-get update  
# Install Git with auto approval  
yes | apt-get install git  
# Check git install  
git --version

Cloud Foundry CLI​

Harness supports Cloud Foundry CLI version 6 only. Support for version 7 is pending.See Install Cloud Foundry CLI Versions on the Harness Delegate.

Docker Installation​

To install Docker on the Delegate, use the following script:

apt-get update  
apt-get install -y apt-utils dnsutils docker

Ensure that you run apt-get update before running any apt-get commands.

PowerShell​

You can run PowerShell scripts on a Harness Delegate, even though the Delegate must be run on Linux. Linux supports PowerShell using PowerShell core.

For steps on creating your script, see Installing PowerShell on Linux from Microsoft.

Whatever scripts you run must be supported by the version of PowerShell you install.

Here is an example for Ubuntu 16.04:

# Download the Microsoft repository GPG keys  
wget -q https://packages.microsoft.com/config/ubuntu/16.04/packages-microsoft-prod.deb  
  
# Register the Microsoft repository GPG keys  
sudo dpkg -i packages-microsoft-prod.deb  
  
# Update the list of products  
sudo apt-get update  
  
# Install PowerShell  
sudo apt-get install -y powershell  
  
# Start PowerShell  
pwsh

If apt-get is not installed on your Delegate host, you can use snap (snap install powershell --classic). See Install PowerShell Easily via Snap in Ubuntu 18.04.

Import a Self-Signed Certificate​

See Add Self-Signed Certificates for Delegate Connections.