We've all been there - you go to restart Nginx after some configuration changes, only to discover your nginx.conf file is empty or corrupted. Maybe your cat walked across the keyboard, maybe you had a late-night coding session gone wrong, or perhaps the filesystem decided to play tricks on you.


When Nginx is running, it maintains its complete configuration in memory. This means even if your configuration files are gone, the running process still knows exactly how it was configured. Here's how to extract it:


This method dumps the actual configuration tree from memory:

# Install gdb if needed
sudo apt-get install gdb

# Find the Nginx master process ID
ps aux | grep nginx | grep master

# Attach gdb to the process
sudo gdb -p [nginx-master-pid]

# In gdb, run:
(gdb) call (void)Ngx_Dump_Config()

# The output will show the complete configuration
# Press Ctrl+D to exit gdb

For a quicker but less complete solution:
strings /proc/$(pgrep -f "nginx: master")/environ | grep -A50 "NGINX_CONF"

If you have the debug module compiled in:
kill -USR1 $(cat /var/run/nginx.pid)
# Check error log for dumped configuration
tail -f /var/log/nginx/error.log

Once you've extracted the configuration, you'll need to:

Save it to a new file (e.g., nginx.conf.recovered)
Validate it with: nginx -t -c /path/to/nginx.conf.recovered
Replace your missing config file

To avoid this situation in the future:
# Use version control
git init /etc/nginx
git add /etc/nginx/*
git commit -m "Initial nginx config"

# Set up automatic backups
sudo cp -a /etc/nginx /etc/nginx.backup-$(date +%Y%m%d)

Be aware that:

Some dynamic modules might not show in the dumped config
Comments will be lost in the recovery process
If Nginx was started with -g parameters, those won't appear



We've all been there - you go to restart Nginx only to discover your meticulously crafted configuration file has mysteriously vanished. Whether it was an accidental rm, a failed editor session, or filesystem corruption, the result is the same: panic sets in when you realize you don't have backups.
If your Nginx process is still running (and thankfully it often is in these situations), you can recover the complete configuration directly from memory. Here's how:

# Install gdb if needed
sudo apt-get install gdb

# Attach to running nginx master process
sudo gdb -p $(cat /var/run/nginx.pid)

# In gdb shell:
(gdb) call (void)system("nginx -T")
(gdb) detach
(gdb) quit

For systems without gdb, try this alternative:

# Find all open configuration files
sudo ls -l /proc/$(cat /var/run/nginx.pid)/fd/ | grep conf

# Then use strace to capture the config
sudo strace -e trace=open -p $(cat /var/run/nginx.pid) 2>&1 | grep nginx.conf

For the most thorough recovery when other methods fail:

# Create memory dump
sudo gcore -o /tmp/nginx_dump $(cat /var/run/nginx.pid)

# Search dump for configuration strings
strings /tmp/nginx_dump.* | grep -A20 -B20 "server {"

Once recovered, implement these safeguards:

# Version control your configs
git init /etc/nginx
git add /etc/nginx/*
git commit -m "Initial nginx config"

# Create automated backups
sudo crontab -e
# Add:
@daily tar -czf /backup/nginx-$(date +\%Y\%m\%d).tar.gz /etc/nginx

Before restarting with recovered config:

nginx -t -c /path/to/recovered.conf