5 ms·

I'd really-really need DNS for non-running containers, somehow. Nginx can't start if an upstream container is down, as its name won't be resolved.

bmelton 11y ago
I've had that problem too, and found that you can implement a "wait" command. If you're using Docker Compose, add this to your environment: environment: - WAIT_COMMAND=[ $(curl --write-out %{http_code} --silent --output /dev/null http://elastic:9200/_cat/health?h=st http://elastic:9200/_cat/health?h=st) = 200 ] - WAIT_START_CMD=python /code/lytten/main.py - WAIT_SLEEP=2 - WAIT_LOOPS=10 Then, create a 'wait' bash script in your app's source code that looks like this: !/bin/bash echo $WAIT_COMMAND echo $WAIT_START_CMD is_ready() { eval "$WAIT_COMMAND" } # wait until is ready i=0 while ! is_ready; do i=`expr $i + 1` if [ $i -ge $WAIT_LOOPS ]; then echo "$(date) - still not ready, giving up" exit 1 fi echo "$(date) - waiting to be ready" sleep 10 done #start the script exec $WAIT_START_CMD Then, finally, for your nginx container, add: command: sh /code/wait_to_start.sh to its specification
- Myrmornis 11y ago
  Just in case a shorter version appeals to you, I think you could rewrite it like this: timeout 60 bash -c 'until is_ready; do sleep 10; done' You'll need to `export -f is_ready` if it's a shell function. That's assuming you can use a timeout instead of number-of-retries. http://man7.org/linux/man-pages/man1/timeout.1.html http://man7.org/linux/man-pages/man1/timeout.1.html
  - bmelton 11y ago
    I was trying to find the source of where I got that bash script from, but couldn't, and then forgot about it within the editing window. I'll try to find it and provide that feedback. Thanks!
baq 11y ago
we've got consul set up in a way that points names to a known 503 service if its containers are not up.

bmelton 11y ago

I've had that problem too, and found that you can implement a "wait" command. If you're using Docker Compose, add this to your environment: environment: - WAIT_COMMAND=[ $(curl --write-out %{http_code} --silent --output /dev/null http://elastic:9200/_cat/health?h=st http://elastic:9200/_cat/health?h=st) = 200 ] - WAIT_START_CMD=python /code/lytten/main.py - WAIT_SLEEP=2 - WAIT_LOOPS=10 Then, create a 'wait' bash script in your app's source code that looks like this: !/bin/bash echo $WAIT_COMMAND echo $WAIT_START_CMD is_ready() { eval "$WAIT_COMMAND" } # wait until is ready i=0 while ! is_ready; do i=`expr $i + 1` if [ $i -ge $WAIT_LOOPS ]; then echo "$(date) - still not ready, giving up" exit 1 fi echo "$(date) - waiting to be ready" sleep 10 done #start the script exec $WAIT_START_CMD Then, finally, for your nginx container, add: command: sh /code/wait_to_start.sh to its specification

Myrmornis 11y ago
Just in case a shorter version appeals to you, I think you could rewrite it like this: timeout 60 bash -c 'until is_ready; do sleep 10; done' You'll need to `export -f is_ready` if it's a shell function. That's assuming you can use a timeout instead of number-of-retries. http://man7.org/linux/man-pages/man1/timeout.1.html http://man7.org/linux/man-pages/man1/timeout.1.html
- bmelton 11y ago
  I was trying to find the source of where I got that bash script from, but couldn't, and then forgot about it within the editing window. I'll try to find it and provide that feedback. Thanks!

baq 11y ago

we've got consul set up in a way that points names to a known 503 service if its containers are not up.