.envrc-aws

#!/usr/bin/env bash
#  vim:ts=4:sts=4:sw=4:et
#
#  Author: Hari Sekhon
#  Date: 2021-07-27 12:42:32 +0100 (Tue, 27 Jul 2021)
#
#  vim:ts=4:sts=4:sw=4:et
#
#  https://github.com/HariSekhon/DevOps-Bash-tools
#
#  License: see accompanying Hari Sekhon LICENSE file
#
#  If you're using my code you're welcome to connect with me on LinkedIn and optionally send me feedback to help steer this or other code I publish
#
#  https://www.linkedin.com/in/HariSekhon
#

# ============================================================================ #
#                              A W S   D i r e n v
# ============================================================================ #

# https://direnv.net/man/direnv-stdlib.1.html

# See Also:
#
#   .envrc
#   .envrc-gcp
#   .envrc-kubernetes

# direnv stdlib - loads .envrc from parent dir up to /
#
# useful to accumulate parent and child directory .envrc settings eg. adding Kubernetes namespace, ArgoCD app etc.
#
# bypasses security authorization though - use with care
#source_up
#
# source_up must be loaded before set -u otherwise gets this error:
#
#   direnv: loading .envrc
#   /bin/bash: line 226: $1: unbound variable

set -euo pipefail
[ -n "${DEBUG:-}" ] && set -x
srcdir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# XXX: Edit - crucial to set to the right environment, the rest of the inferred settings below depend on this
if [ -z "${CI:-}" ]; then
    export AWS_PROFILE="default"
fi

AWS_ACCOUNT_ID="$(aws sts get-caller-identity --query Account --output text || aws configure get sso_account_id || :)"
export AWS_ACCOUNT_ID
AWS_DEFAULT_REGION="$(aws configure get region || :)"  # use region configured in profile by default
AWS_DEFAULT_REGION="${AWS_DEFAULT_REGION:-eu-west-2}"  # XXX: Edit default fallback region
export AWS_DEFAULT_REGION
export AWS_DEFAULT_OUTPUT=json

# XXX: Edit, or remove if only have 1 cluster in account, will auto-determine below
export EKS_CLUSTER="mycluster"

# If EKS_CLUSTER isn't set and there is only one EKS cluster in this account and region, then use it - smart, but slower, prefer setting it explicitly for speed
if [ -z "${EKS_CLUSTER:-}" ]; then
    eks_clusters=()
    while IFS='' read -r line; do
        eks_clusters+=("$line")
    #done < <(aws eks list-clusters --output=json | jq -r '.clusters[]')
    done < <(aws eks list-clusters --query 'clusters[]' --output text)
    if [ "${#eks_clusters[@]}" -eq 1 ]; then
        export EKS_CLUSTER="${eks_clusters[*]}"
    fi
fi

if [ -n "${EKS_CLUSTER:-}" ]; then
    # kubectl context is easily created by running adjacent aws_kube_creds.sh script first
    export EKS_CONTEXT="arn:aws:eks:$AWS_DEFAULT_REGION:$AWS_ACCOUNT_ID:cluster/$EKS_CLUSTER"

    # XXX: safer to inline .envrc-kubernetes if you're worried about changes to it bypassing 'direnv allow' authorization
    # shellcheck disable=SC1090
    . "$srcdir/.envrc-kubernetes" "$EKS_CONTEXT"
fi

# better to load this dynamically from credentials, using functions in .bash.d/aws.sh
#export AWS_ACCESS_KEY_ID=...
#export AWS_SECRET_ACCESS_KEY=...
#export AWS_SESSION_TOKEN=...

#export AWS_CONFIG_FILE=~/.aws/config
#export AWS_SHARED_CREDENTIALS_FILE=~/.aws/credentials
#export AWS_MAX_ATTEMPTS=3

# to quickly export prefixed AWS environment keys if they exist for simple overrides, see examples below
aws_access_key_env(){
    env="$1"
    for key in AWS_ACCESS_KEY_ID AWS_SECRET_ACCESS_KEY; do
        varname="${env}_${key}"
        if [ -n "${!varname:-}" ]; then
            export "$key"="${!varname}"
        fi
    done
}

#aws_access_key_env "DEV"
#aws_access_key_env "STAGING"
#aws_access_key_env "PROD"
#aws_access_key_env "MGMT"