CodeDeploy AfterInstall hook does not exit after starting Go server

Question

I have a simple Go server. Code below. server.go

package main

import (
    "fmt"
    "log"
    "net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hi there, I love %s!", r.URL.Path[1:])
}

func main() {
    http.HandleFunc("/", handler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

I have an EC2 server with CodeDeploy agent and everything in place. All I am trying to do is, once I push and merge new code with master branch of my Github repo, CodeDeploy should deploy the revisions to my EC2 server In-Place and below is my appspec.yml (which is at the root of my repo)

appspec.yml

version: 0.0
os: linux
files:
  - source: /
    destination: /home/ubuntu/go/myproject
hooks:
  AfterInstall:
  - location: after-install.sh
    runas: ubuntu

after-install.sh script below. Pretty simple, after the revision is deployed to myproject folder in EC2, cd into the folder and start the go server.

#!/bin/bash

cd $HOME/go/myproject
/usr/local/go/bin/go run server.go &

Problem: With the above, revisions are perfectly deployed and the server is started and I can hit the public dns on port 8080 from my browser and see the changes. However, CodeDeploy keeps running and never shows that deployment is completed.

Is there anything I should do for CodeDeploy to gracefully complete after starting the Go server?

What stage does it get stuck in? Also is it behind a load balancer that is configured with CodeDeploy? — Chris Williams
Gets stuck in AfterInstall hook after the after-install.sh is executed since, I see the server get started. No the EC2 is not behind a load balancer for now. In the CodeDeploy console, I see the spinner keeps spinning, probably will do that since default timeout is 3600 and then fail. — Aakash
If you run the after install script yourself does it also hang? — Chris Williams

Chris Williams Chris Williams · Accepted Answer · 2020-07-28T17:06:43

According to the documentation you should not do this.

You cannot simply add an ampersand (&) in after-install.sh to run sleep.sh in the background.

If the below was your hook file

#!/bin/bash
# Do not do this.
/tmp/sleep.sh &

You would need to add > /dev/null 2> /dev/null < /dev/null before the &, like below

#!/bin/bash
/tmp/sleep.sh > /dev/null 2> /dev/null < /dev/null &

For your file it should be update to look like the below

#!/bin/bash

cd $HOME/go/myproject
/usr/local/go/bin/go run server.go > /dev/null 2> /dev/null < /dev/null &

CodeDeploy AfterInstall hook does not exit after starting Go server

1 Answers