502 bad gateway apache proxy multi site config

installation
1

I have a site “forum.6figureswithchris.com” it was working fine behind a proxy port 8080 and I have apache on port 80 but suddenly it gives “502 bad gateway”

##this is the all-in-one, standalone Discourse Docker container template
##
## After making changes to this file, you MUST rebuild
## /var/discourse/launcher rebuild app
##
## BE *VERY* CAREFUL WHEN EDITING!
## YAML FILES ARE SUPER SUPER SENSITIVE TO MISTAKES IN WHITESPACE OR ALIGNMENT!
## visit http://www.yamllint.com/ to validate this file as needed



templates:
  - "templates/postgres.template.yml"
  - "templates/redis.template.yml"
  - "templates/web.template.yml"
  - "templates/web.ratelimited.template.yml"
## Uncomment these two lines if you wish to add Lets Encrypt (https)
  #- "templates/web.ssl.template.yml"
  #- "templates/web.letsencrypt.ssl.template.yml"

## which TCP/IP ports should this container expose?
## If you want Discourse to share a port with another webserver like Apache or nginx,
## see https://meta.discourse.org/t/17247 for details
expose:
  - "8080:80"   # http
  #- "444:443" # https

params:
  db_default_text_search_config: "pg_catalog.english"

  ## Set db_shared_buffers to a max of 25% of the total memory.
  ## will be set automatically by bootstrap based on detected RAM, or you can override
  #db_shared_buffers: "256MB"

  ## can improve sorting performance, but adds memory usage per-connection
  #db_work_mem: "40MB"

  ## Which Git revision should this container use? (default: tests-passed)
  #version: tests-passed

env:
  LANG: en_US.UTF-8
  # DISCOURSE_DEFAULT_LOCALE: en

  ## How many concurrent web requests are supported? Depends on memory and CPU cores.
  ## will be set automatically by bootstrap based on detected CPUs, or you can override
  #UNICORN_WORKERS: 3

  ## TODO: The domain name this Discourse instance will respond to
  ## Required. Discourse will not work with a bare IP number.
  DISCOURSE_HOSTNAME: 'forum.7figureswithchris.com'
  ## Uncomment if you want the container to be started with the same
  ## hostname (-h option) as specified above (default "$hostname-$config")
  #DOCKER_USE_HOSTNAME: true

  ## TODO: List of comma delimited emails that will be made admin and developer
  ## on initial signup example 'user1@example.com,user2@example.com'
  DISCOURSE_DEVELOPER_EMAILS: 'admin@epcmarketer.com,admin@6figureswithchris.com,admin@7figureswithchris.com,admin@chrisfrevillereview.com,admin@chrisfrevillereviews.com,admin@christopherfreville.com'

  ## TODO: The SMTP mail server used to validate new accounts and send notifications
  # SMTP ADDRESS, username, and password are required
  # WARNING the char '#' in SMTP password can cause problems!
  DISCOURSE_SMTP_ADDRESS: host.epcmarketer.com
  #DISCOURSE_SMTP_PORT: 587
  DISCOURSE_SMTP_USER_NAME: admin@epcmarketer.com
  DISCOURSE_SMTP_PASSWORD: **no#**
  DISCOURSE_SMTP_ENABLE_START_TLS: false
  DISCOURSE_SMTP_OPENSSL_VERIFY_MODE: none
# no # in password

  ## If you added the Lets Encrypt template, uncomment below to get a free SSL certificate
  #LETSENCRYPT_ACCOUNT_EMAIL: me@example.com

  ## The CDN address for this Discourse instance (configured to pull)
  ## see https://meta.discourse.org/t/14857 for details
  #DISCOURSE_CDN_URL: //discourse-cdn.example.com

## The Docker container is stateless; all data is stored in /shared
volumes:
  - volume:
      host: /var/discourse/shared/standalone
      guest: /shared
  - volume:
      host: /var/discourse/shared/standalone/log/var-log
      guest: /var/log

## Plugins go here
## see https://meta.discourse.org/t/19157 for details
hooks:
  after_postgres:
     - exec: sudo -u postgres createdb discourse_dbase1 || exit 0
     - exec: sudo -u postgres createdb discourse_dbase2 || exit 0
     - exec: sudo -u postgres createdb discourse_dbase3 || exit 0
     - exec: sudo -u postgres createdb discourse_dbase4 || exit 0
     - exec: sudo -u postgres createdb discourse_dbase5 || exit 0
     - exec:
          stdin: |
            grant all privileges on database discourse_dbase1 to discourse;
            grant all privileges on database discourse_dbase2 to discourse;
            grant all privileges on database discourse_dbase3 to discourse;
            grant all privileges on database discourse_dbase4 to discourse;
            grant all privileges on database discourse_dbase5 to discourse;
          cmd: sudo -u postgres psql discourse_dbase1
          raise_on_fail: false
          cmd: sudo -u postgres psql discourse_dbase2
          raise_on_fail: false
          cmd: sudo -u postgres psql discourse_dbase3
          raise_on_fail: false
          cmd: sudo -u postgres psql discourse_dbase4
          raise_on_fail: false
          cmd: sudo -u postgres psql discourse_dbase5
          raise_on_fail: false

     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase1 <<< "alter schema public owner to discourse;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase1 <<< "create extension if not exists hstore;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase1 <<< "create extension if not exists pg_trgm;"'

     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase2 <<< "alter schema public owner to discourse;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase2 <<< "create extension if not exists hstore;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase2 <<< "create extension if not exists pg_trgm;"'

     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase3 <<< "alter schema public owner to discourse;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase3 <<< "create extension if not exists hstore;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase3 <<< "create extension if not exists pg_trgm;"'

     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase4 <<< "alter schema public owner to discourse;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase4 <<< "create extension if not exists hstore;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase4 <<< "create extension if not exists pg_trgm;"'

     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase5 <<< "alter schema public owner to discourse;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase5 <<< "create extension if not exists hstore;"'
     - exec: /bin/bash -c 'sudo -u postgres psql discourse_dbase5 <<< "create extension if not exists pg_trgm;"'
  after_code:
    - exec:
        echo: "hey!"

  before_bundle_exec:
    - file:
        path: /var/www/discourse/config/multisite.yml
        contents: |
         discourse_instance2:
           adapter: postgresql
           database: discourse_dbase2
           pool: 25
           timeout: 5000
           db_id: 2
           host_names:
             - forum.6figureswithchris.com
         discourse_instance3:
           adapter: postgresql
           database: discourse_dbase3
           pool: 25
           timeout: 5000
           db_id: 3
           host_names:
             - forum.chrisfrevillereview.com
         discourse_instance4:
           adapter: postgresql
           database: discourse_dbase4
           pool: 25
           timeout: 5000
           db_id: 4
           host_names:
             - forum.chrisfrevillereviews.com
         discourse_instance5:
           adapter: postgresql
           database: discourse_dbase5
           pool: 25
           timeout: 5000
           db_id: 5
           host_names:
             - forum.christopherfreville.com
  after_bundle_exec:
    - exec: cd /var/www/discourse && sudo -E -u discourse bundle exec rake multisite:migrate


## Any custom commands to run after building
run:
  - exec: echo "Beginning of custom commands"

  ## If you want to set the 'From' email address for your first registration, uncomment and change:
  ## After getting the first signup email, re-comment the line. It only needs to run once.
  #- exec: rails r "SiteSetting.notification_email='info@unconfigured.discourse.org'"
  - exec: echo "End of custom commands"

Here are the outputs of “free -m” and “df -m”:
total used free shared
buff/cache available
Mem: 1873 1263 64 48 545 338
Swap: 1999 1177 822

Filesystem     1M-blocks  Used Available Use% Mounted on
/dev/vda3          38221 27744      8514  77% /
devtmpfs             927     0       927   0% /dev
tmpfs                937     1       937   1% /dev/shm
tmpfs                937    10       928   1% /run
tmpfs                937     0       937   0% /sys/fs/cgroup
tmpfs                188     0       188   0% /run/user/0
/dev/loop0          3904   514      3186  14% /tmp
overlay            38221 27744      8514  77% /var/lib/docker/overlay2/b217295203dbf619158c49bd476d34ea83f121737016f263af1777318d43232b/merged
shm                  512     1       512   1% /var/lib/docker/containers/683ec51e28f18b77d9053e63203decaf4b8141cc0749a066f0909476c870b57c/mounts/shm

Here is a snippet of httpd.conf:

<VirtualHost 72.52.244.147:80>
ServerName forum.6figureswithchris.com
DocumentRoot /home/mercury/forum.6figureswithchris.com
ProxyPreserveHost On
ProxyRequests Off
ProxyPass / http://0.0.0.0:8080/
ProxyPassReverse / http://0.0.0.0:8080/

and here is the httpd error_log file snippet:

[Thu Jul 05 22:32:15.028092 2018] [proxy:error] [pid 46868] [client 123.201.41.40:57760] AH00898: Error reading from remote server returned by /favicon.ico, referer: http://forum.6figureswithchris.com/
[Thu Jul 05 22:32:16.034055 2018] [proxy_http:error] [pid 46868] (104)Connection reset by peer: [client 123.201.41.40:57760] AH01102: error reading status line from remote server 0.0.0.0:8080, referer: http://forum.6figureswithchris.com/
[Thu Jul 05 22:32:16.034106 2018] [proxy:error] [pid 46868] [client 123.201.41.40:57760] AH00898: Error reading from remote server returned by /502.shtml, referer: http://forum.6figureswithchris.com/

The things I have tried:
1)Rebuilding app, restarting vps, completely reinstalling everything from scratch

2)Tried adding to httpd.conf and failed with all these:
Timeout 2400
ProxyTimeout 2400
ProxyBadHeader Ignore
ProxyPass / http://0.0.0.0:8080/ retry=1 acquire=3000 timeout=600 Keepalive=On

3)./launcher cleanup
Image of error:
Screenshot_7

2

Is there a specific reason you’re using apache2 instead of nginx?

Have you checked apache2 logs to figure out what is making it angry?

3

Here are the apache logs. The apache was default in the system, so I used it. Is it possible to use nginx just for discourse alongwith apache?

4

If You have the right understanding then everything is achievable but that would just increase the complexity of the setup! I wonder why You are forwarding requests to 0.0.0.0 instead of localhost or something similar!

5

I tried

  1. my ip addrress: it gives

    [Fri Jul 06 15:39:42.586174 2018] [proxy:error] [pid 66519] (110)Connection timed out: AH00957:
    HTTP: attempt to connect to 72.52.244.147:8080 (72.52.244.147) failed

this error

  1. localhost: it gives same error as 0.0.0.0

P.S. When I modify virtualhost to 8080 instead of 80 port and access forum.6figureswithchris.com:8080 the site works! So the main error is in the port only

6

So You should consider looking at other vhosts for apache2 if some other vhost is trying to reserve the same IP:PORT if so, release the IP from that vhost and try port 80 again.

7

I just checked and found out that there are several vhosts with same ip:port but with different server names.
I deleted my vhost directive and used the one created with cpanel and added proxy code there and restarted httpd service but the results were same: 502 error

8

Ohh! Allright! I only understand now. I’m sorry but I won’t be of much help as my general troubleshooting suggestions don’t work with cpanel. I’d suggest you move your discourse to a separate server instead.

9

Ohk, thanks anyways. btw the server is centos vps and it has like 5 cpanel for 5 websites.

10

You’re running probably a very puzzled variant as in my experience there is a lot of struggle getting discourse to work on centOS let alone cpanel which is neither recommended nor easy to get going.

11

i know right. but it was working for 5 days completely ok but suddenly this error showed up. Is there any other way to check if memory is free? I read many threads saying its a memory error for sure

12

This is not a memory issue if you can get it working on an alternative port :wink:

13

Oh. Any other ideas? I am really stuck in this one I have spent 3 days completely just trying to solve this.

14

As I’ve suggested earlier, drop the idea of running it alongside cpanel

Just spin up a $5 droplet on DO and install afresh. It will be the most certainly works kind of solution I can give you right now.

3 Likes
15

If it was working before, I suspect it’s a Discourse problem. Have you rebuilt lately? Are you using any non-official plugins?

16

How can it be that it works fine on other ports but not on port 80 though? I suspect it’s cpanel and it’s firewall doing weird things.

17

I had rebuilt once and it caused problems. But I did a complete clean install of everything related docker and discourse exactly as I did earlier, the problem still persists.

18

yeah i think maybe firewall is blocking or apache not letting it connect on port 80 something like that

19

Apache is listening on port 80 and forwarding all requests to port 8080 to make the forum available to the rest of the world.

20

Oh. I am checking mod_proxy right now , if its misconfigured or something