Wait for kubernetes deployments to complete

README

Wait for kubernetes deployments to complete.
Two variants - s1.sh and s2.sh.

Usage:
./sX.sh
./sX.sh some-namespace

Both variants make just one pass through the list of deployments, so if another 
deployment is started while the script is running, the result may not be
correct.

Variant #1 may behave incorrectly if one of the pids gets reused. E.g. if the 
first deployment check instantly fails and the next check gets the same pid and
succeeds, the script will report success. Or if the pid is reused by a process
that's not a child of the current shell, wait will behave as if the deployment
check failed. This is quite unlikely to happen, but it is possible.

Variant #2 is slower.

The return code is 0 on success, or whatever `timeout ... kubectl rollout status`
returned for a timed out/failed deployment. Variant #2 could also return 1 on a
timeout that occured between calls to kubectl. 

s1.sh

#!/usr/bin/env bash

set -eEo pipefail
shopt -s inherit_errexit >/dev/null 2>&1 || true

# Wait for all deployments to namespace $1 (or "default"), time out after 60s.
wait_for_deployments() {
    local -r ns="${1:-default}" timeout=60
    local -a deployments pids
    local pid
    read -ra deployments <<<"$(kubectl get deployment --namespace "$ns" -o jsonpath='{.items[*].metadata.name}')"
    for deployment in "${deployments[@]}"; do
        timeout "$timeout" kubectl rollout status -w "deployment/$deployment" --namespace "$ns" >/dev/null &
        pids+=("$!")
    done
    for pid in "${pids[@]}"; do
        wait "$pid" || return "$?"
    done
}

wait_for_deployments "$1"

s2.sh

#!/usr/bin/env bash

set -eEo pipefail
shopt -s inherit_errexit >/dev/null 2>&1 || true

# Wait for all deployments to namespace $1 (or "default"), time out after 60s.
wait_for_deployments() {
    local -r ns="${1:-default}" timeout=60
    local -a deployments
    local start_time countdown
    read -ra deployments <<<"$(kubectl get deployment --namespace "$ns" -o jsonpath='{.items[*].metadata.name}')"
    start_time="$SECONDS"
    for deployment in "${deployments[@]}"; do
        countdown=$((timeout - SECONDS + start_time))
        if [[ "$countdown" -gt 0 ]]; then
            timeout "$countdown" kubectl rollout status -w "deployment/$deployment" --namespace "$ns" >/dev/null || return "$?"
        else
            return 1
        fi
    done
}

wait_for_deployments "$1"

I came up with very something similar:

...
for yaml in ${directory_patched}/*rollouts*/*; do
    timeout ${ROLLOUT_WAIT_TIME} kubectl rollout status -f ${yaml} --namespace ${PROJECT_NAME}
done

For my use case is pretty enough... But if you want to wait for all of them then you should use countdown. Yeah!