Running Docker as a Service - Environment Variables-CodePudding

I am attempting to run my docker container in my linux server and configure it as a systemd unit to manage itself. My /etc/systemd/system/system.service file features this line:

[Unit]
Description=Your Container Name
After=docker.service
Requires=docker.service
StartLimitInterval=200
StartLimitBurst=10

[Service]
TimeoutStartSec=0
Restart=always
RestartSec=2
ExecStartPre=-/usr/bin/docker exec %n stop
ExecStartPre=-/usr/bin/docker rm %n
ExecStartPre=/usr/bin/bash -c 'docker login -u AWS -p $(aws ecr get-login-password --region eu-west-1) 0123456789.dkr.ecr.eu-west-1.amazonaws.com'
ExecStartPre=/usr/bin/docker pull 0123456789.dkr.ecr.eu-west-1.amazonaws.com/your-container:latest
ExecStart=/usr/bin/docker run --rm --name %n 0123456789.dkr.ecr.eu-west-1.amazonaws.com/your-container:latest -e env_var1=abc -e env_var2=def

[Install]
WantedBy=multi-user.target

This has proven problematic because when I restart the service and check the status it shows this error:

● docker.name.service - name
   Loaded: loaded (/etc/systemd/system/docker.name.service; disabled; vendor preset: disabled)
   Active: failed (Result: start-limit) since Thu 2022-03-10 19:28:06 UTC; 6min ago
  Process: 11029 ExecStart=/usr/bin/docker run --rm --name %n 0123456789.dkr.ecr.eu-west-1.amazonaws.com/your-container:latest -e env_var1=abc -e env_var2=def (code=exited, status=127)
  Process: 11018 ExecStartPre=/usr/bin/docker pull 0123456789.dkr.ecr.eu-west-1.amazonaws.com/your-container:latest (code=exited, status=0/SUCCESS)
  Process: 10984 ExecStartPre=/usr/bin/bash -c docker login -u AWS -p $(aws ecr get-login-password --region eu-west-1) 0123456789.dkr.ecr.eu-west-1.amazonaws.com/your-container:latest (code=exited, status=0/SUCCESS)
  Process: 10973 ExecStartPre=/usr/bin/docker rm %n (code=exited, status=1/FAILURE)
  Process: 10951 ExecStartPre=/usr/bin/docker exec %n stop (code=exited, status=1/FAILURE)
 Main PID: 11029 (code=exited, status=127)
Process: 8174 ExecStart=/usr/bin/docker run --rm --name %n 0123456789.dkr.ecr.eu-west-1.amazonaws.com/your-container:latest -e env_var1=abc -e env_var2=def (code=exited, status=127)

Removing the docker -e options env_var1=abc -e env_var2=def and restarting the service then allows the service to start correctly. How do I get these environment variables to be passed to the docker container from the service? It is critical they are.

CodePudding user response：

docker run considers everything after the image name to be a command that's passed to the container, overriding whatever is configured in the Dockerfile with CMD.

To provide environment variables to the container itself, your -e options need to appear before the image name:

ExecStart=/usr/bin/docker run --rm --name %n  -e env_var1=abc -e env_var2=def 0123456789.dkr.ecr.eu-west-1.amazonaws.com/your-container:latest