如何用Nomad在无Docker的Windows服务器执行MySQL初始化命令？

First, let's break down why your current setup isn't working: Nomad's exec driver on Windows runs the specified executable directly, not through a shell like cmd.exe or PowerShell. That means special shell syntax like the input redirect < gets passed as a literal argument to mysql instead of being interpreted as "read from this file"—which is why your parameters aren't behaving as expected.

Good news: Nomad absolutely supports one-time database initialization tasks! You just need to adjust your approach to work with how the exec driver operates. Here are two solid solutions:

Solution 1: Wrap the Command in cmd.exe to Handle Shell Syntax #

Since Windows shell features like redirects only work when run through cmd.exe, use it as your base command and pass the full mysql command as an argument with /c (this tells cmd to execute the string and exit):

job "gavin-setup" {
 datacenters = ["dc1"]
 group "gavin-setup-group" {
 task "setup" {
 driver = "exec"
 config = {
 command = "cmd.exe"
 args = [
 "/c",
 "mysql -hlocalhost -ugavin -pgavin_secret gavin_database < C:\\gavin\\config\\create.sql"
 ]
 }
 # Ensure this task only runs once (no retries if it fails)
 restart {
 attempts = 0
 mode = "fail"
 }
 }
 }
}

This way, cmd.exe parses the < redirect and feeds the contents of create.sql into mysql exactly as you intended.

Solution 2: Use MySQL's Built-in --init-file Parameter (Cleaner Approach) #

Instead of relying on shell redirects, use MySQL's native --init-file flag to tell it to execute the SQL script directly. This avoids needing to wrap the command in a shell entirely, which is more straightforward:

job "gavin-setup" {
 datacenters = ["dc1"]
 group "gavin-setup-group" {
 task "setup" {
 driver = "exec"
 config = {
 command = "mysql"
 args = [
 "-hlocalhost",
 "-ugavin",
 "-pgavin_secret",
 "gavin_database",
 "--init-file=C:\\gavin\\config\\create.sql"
 ]
 }
 # Prevent repeated execution of the initialization
 restart {
 attempts = 0
 mode = "fail"
 }
 }
 }
}

This is my go-to method because it eliminates potential edge cases with command escaping and keeps the task configuration focused on the actual database operation.

Bonus: Ensure Initialization Runs After MySQL is Ready #

If you're deploying MySQL alongside this initialization task, use Nomad's depends_on block to guarantee the setup only runs once MySQL is healthy and accepting connections. Here's a combined example:

job "mysql-and-setup" {
 datacenters = ["dc1"]
 group "mysql-group" {
 task "mysql" {
 driver = "exec"
 config = {
 command = "mysqld"
 args = ["--defaults-file=C:\\gavin\\config\\my.ini"]
 }
 # Define a service with a health check to confirm MySQL is up
 service {
 name = "mysql"
 port = "3306"
 check {
 type = "tcp"
 port = "3306"
 interval = "10s"
 timeout = "2s"
 }
 }
 }
 task "setup" {
 driver = "exec"
 config = {
 command = "mysql"
 args = [
 "-hlocalhost",
 "-ugavin",
 "-pgavin_secret",
 "gavin_database",
 "--init-file=C:\\gavin\\config\\create.sql"
 ]
 }
 # Wait for MySQL's health check to pass before running initialization
 depends_on {
 task = "mysql"
 condition = "healthy"
 }
 restart {
 attempts = 0
 mode = "fail"
 }
 }
 }
}

All these approaches let you run one-time database initialization tasks with Nomad's exec driver on Windows—no Docker required.

内容的提问来源于stack exchange，提问作者Gavin Palmer