deploy-apps.sh

#!/usr/bin/env bash
set -euo pipefail

DEPLOYMENT_FILE="deployment.yaml"
DEPLOYMENTS_GLOB=(./*/"$DEPLOYMENT_FILE")
STARTING_PROMPT="Available deployments:"
SELECTION_PROMPT="Type to check deployments (again to uncheck, ENTER when done): "
NOT_FOUND_ERROR="Error! Not found: "
SELECTION_CHAR="X"

g_selections=()        # Used to track what deployments the user has already selected
g_invalidSelections=() # Used to track what response tokens did not match to a deployment
g_deploymentFiles=()   # Used to track the pathname of deployment.yaml files
g_deploymentDirs=()    # Used to track the dirs which contain a deployment.yaml file

# This function gets called once before building any of the deployments are built
function preBuildSteps() {
    eval "$(minikube -p parca-demo docker-env)"
}

# This function gets called once for each deployment the user selected to build
#
# arg 1: the directory the deployment is found
# arg 2: the path to the deployment file
function buildSteps() {
    printf 'Building the "%s" demo\n' "${1}"
    make -C "$1" build
    kubectl apply -f "$2"
}

# This function collects the names and the deployment.yaml files for each deployment
function findDeployments() {
    local file

    for file in "${DEPLOYMENTS_GLOB[@]}"; do
        if [ -e "$file" ]; then # Make sure it isn't an empty match
            g_deploymentFiles+=("$file")
            g_deploymentDirs+=("$(basename "$(dirname "$file")")")
            g_selections+=("") # mark as not selected
        fi
    done
}

# This function checks if a deployment is already selected or not then toggles it
#
# arg 1: the 0-based deployment index to toggle
function toggleSelection() {
    if [ "${g_selections[$1]}" == "" ]; then
        g_selections[$1]="$SELECTION_CHAR"
    elif [ "${g_selections[$1]}" == "$SELECTION_CHAR" ]; then
        g_selections[$1]=""
    fi
}

# This function parses a user's string response token by checking if there are any
# deployments with the same name and returns its 0-based index
#
# arg 1: user's response token
function findDeploymentIndexFromString() {
    local i

    for i in "${!g_deploymentDirs[@]}"; do
        if [ "${g_deploymentDirs[$i]}" == "$1" ]; then
            echo "$i"
        fi
    done
}

# This function parses a user's valid integer response token by changing their
# 1-based index to a 0-based index
#
# arg 1: user's response token
function findDeploymentIndexFromInteger() {
    if [ 1 -le "$1" ] && [ "$1" -le "${#g_selections[@]}" ]; then
        echo "$(($1 - 1))"
    fi
}

# This function attempts to match the user's response token to a valid deployment
# configuration. It calls the appropriate function depending on if the token is
# an integer or a string
#
# arg 1: user's response token
function findDeploymentIndex() {
    local deploymentIndex

    deploymentIndex=$(findDeploymentIndexFromInteger "$1")
    if [ "$deploymentIndex" ]; then
        echo "$deploymentIndex"
        return
    fi

    deploymentIndex=$(findDeploymentIndexFromString "$1")
    if [ "$deploymentIndex" ]; then
        echo "$deploymentIndex"
        return
    fi
}

# This function parses the user's whitespace-delimited response. It identifies which
# tokens are valid and keeps track of which ones aren't
#
# vargs: array of user's response tokens
function parseResponse() {
    local item

    g_invalidSelections=()

    for item in "$@"; do
        local deploymentIndex

        deploymentIndex=$(findDeploymentIndex "$item")
        if [ "$deploymentIndex" ]; then
            toggleSelection "$deploymentIndex"
        else
            g_invalidSelections+=("$item")
        fi
    done
}

# This function parses the arguments that were provided to this script in the terminal.
# It identifies which tokens are valid and keeps track of which ones aren't.
#
# vargs: array of script's arguments
function parseArguments() {
    local item

    for item in "$@"; do
        local deploymentIndex

        deploymentIndex=$(findDeploymentIndexFromString "$item")
        if [ "$deploymentIndex" ]; then
            toggleSelection "$deploymentIndex"
        else
            g_invalidSelections+=("$item")
        fi
    done
}

# This function prints the list of deployments a user can select alongside an index
# and a text-based checkbox to indicate if it selected already
function printDeploymentOptions() {
    local i

    echo # blank line
    echo "$STARTING_PROMPT"
    for i in "${!g_deploymentDirs[@]}"; do
        printf "%3s [%1s] %s\n" "$((i + 1))" "${g_selections[$i]}" "${g_deploymentDirs[$i]}"
    done
}

# This function prints the list of invalid selections the user made
function printInvalidSelections() {
    if [ "${#g_invalidSelections[@]}" -ne 0 ]; then
        echo "$NOT_FOUND_ERROR ${g_invalidSelections[*]}"
        return 1
    fi
}

# This function displays the list of deployments to the users and records their
# input in a loop until they pass an empty line
function promptForDeploymentSelection() {
    local response

    while true; do
        printDeploymentOptions
        printInvalidSelections && true # Don't exit if there were invalid selections

        read -p "$SELECTION_PROMPT" -ra response
        if [ "${#response[@]}" -eq 0 ]; then
            break # no response received
        fi

        parseResponse "${response[@]}"
    done
}

# This function loops though all selected deployments and builds them
function buildSelectedDeployments() {
    local i

    for i in "${!g_selections[@]}"; do
        if [ "${g_selections[i]}" == "$SELECTION_CHAR" ]; then
            buildSteps "${g_deploymentDirs[$i]}" "${g_deploymentFiles[$i]}"
        fi
    done
}

# This function build the deployments specified as arguments to this script if there are
# any available. Otherwise, it will prompt the user to select some.
#
# vargs: array of script's arguments
function selectDeploymentsFromArgumentsElsePrompt() {
    if [ "$#" -ne 0 ]; then
        parseArguments "$@"
        printInvalidSelections
    else
        promptForDeploymentSelection
    fi
}

findDeployments
selectDeploymentsFromArgumentsElsePrompt "$@"
preBuildSteps
buildSelectedDeployments