Timemachine/mc-router
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Corrected docker/swarm discovery from previous refactoring (#446)

Browse Source
This commit is contained in:
Geoff Bourne
2025-08-23 13:39:01 -05:00
committed by GitHub
parent 4055f39b19
commit 35500a758b
9 changed files with 95 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files
.devcontainer/devcontainer.json
+35
View File
@@ -0,0 +1,35 @@
// For format details, see https://aka.ms/devcontainer.json. For config options, see the
// README at: https://github.com/devcontainers/templates/tree/main/src/go
{
"name": "Go",
// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
"image": "golang:1.24-bookworm",
// Features to add to the dev container. More info: https://containers.dev/features.
"features": {
// For in-docker discovery testing
"ghcr.io/devcontainers/features/docker-outside-of-docker:1": {}
},
// Use 'forwardPorts' to make a list of ports inside the container available locally.
"forwardPorts": [
25565
],
containerEnv: {
"GOROOT": "/usr/local/go"
},
// Configure tool-specific properties.
"customizations": {
"jetbrains": {
"backend": "IntelliJ",
"plugins": [
"org.jetbrains.plugins.go"
]
},
"vscode": {
"extensions": [
"golang.go"
]
}
}
}
DEVELOPMENT.md
+8
View File
@@ -0,0 +1,8 @@
## Developing Docker discovery on non-Linux
This works best with the included devcontaner setup, which includes attaching the host's docker socket to the dev container at `/var/run/docker.sock`.
On Windows, can create the devcontainer using:
![image.png](docs/create-dev-container.png)
README.md
+14 -15
View File
@@ -103,8 +103,6 @@ The [multi-architecture image published at Docker Hub](https://hub.docker.com/re
The diagram below shows how this `docker-compose.yml` configures two Minecraft server services named `vanilla` and `forge`, which also become the internal network aliases. _Notice those services don't need their ports exposed since the internal networking allows for the inter-container access._
```yaml
version: "3.8"
services:
vanilla:
image: itzg/minecraft-server
@@ -141,20 +139,21 @@ To test out this example, add these two entries to my "hosts" file:
### Using Docker auto-discovery
When running `mc-router` in a Docker environment you can pass the `--in-docker` or `--in-docker-swarm`
command-line argument and it will poll the Docker API periodically to find all the running
containers/services for Minecraft instances. To enable discovery you have to set the `mc-router.host`
label on the container. These are the labels scanned:
When running `mc-router` in a Docker environment you can pass the `--in-docker` or `--in-docker-swarm` command-line argument or set the environment variables `IN_DOCKER` or `IN_DOCKER_SWARM` to "true". With that, it will poll the Docker API periodically to find all the running containers/services for Minecraft instances. To enable discovery, you have to set the `mc-router.host` label on the container.
- `mc-router.host`: Used to configure the hostname the Minecraft clients would use to
connect to the server. The container/service endpoint will be used as the routed backend. You can
use more than one hostname by splitting it with a comma.
- `mc-router.port`: This value must be set to the port the Minecraft server is listening on.
The default value is 25565.
- `mc-router.default`: Set this to a truthy value to make this server the default backend.
Please note that `mc-router.host` is still required to be set.
- `mc-router.network`: Specify the network you are using for the router if multiple are
present in the container/service. You can either use the network ID, it's full name or an alias.
When using in Docker, make sure to volume mount the Docker socket into the container, such as
```yaml
volumes:
- /var/run/docker.sock:/var/run/docker.sock:ro
```
These are the labels scanned:
- `mc-router.host`: Used to configure the hostname the Minecraft clients would use to connect to the server. The container/service endpoint will be used as the routed backend. You can use more than one hostname by splitting it with a comma.
- `mc-router.port`: This value must be set to the port the Minecraft server is listening on. The default value is 25565.
- `mc-router.default`: Set this to a truthy value to make this server the default backend. Please note that `mc-router.host` is still required to be set.
- `mc-router.network`: Specify the network you are using for the router if multiple are present in the container/service. You can either use the network ID, it's full name or an alias.
#### Example Docker deployment
cmd/mc-router/main.go
+5 -1
View File
@@ -24,6 +24,7 @@ func showVersion() {
type CliConfig struct {
Version bool `usage:"Output version and exit"`
Debug bool `usage:"Enable debug logs"`
Trace bool `usage:"Enable trace logs"`
ServerConfig server.Config `flatten:"true"`
}
@@ -40,7 +41,10 @@ func main() {
os.Exit(0)
}
if cliConfig.Debug {
if cliConfig.Trace {
logrus.SetLevel(logrus.TraceLevel)
logrus.Trace("Trace logs enabled")
} else if cliConfig.Debug {
logrus.SetLevel(logrus.DebugLevel)
logrus.Debug("Debug logs enabled")
}
docs/create-dev-container.png
BIN
View File
Binary file not shown.
Side by Side

After

Width:  |  Height:  |  Size: 175 KiB

examples/docker-discovery/compose.yml
+23
View File
@@ -0,0 +1,23 @@
services:
router:
image: itzg/mc-router
environment:
IN_DOCKER: true
ports:
- "25565:25565"
volumes:
- /var/run/docker.sock:/var/run/docker.sock:ro
vanilla:
image: itzg/minecraft-server
environment:
EULA: "TRUE"
labels:
mc-router.host: "vanilla.example.com"
paper:
image: itzg/minecraft-server
environment:
EULA: "TRUE"
TYPE: PAPER
labels:
mc-router.host: "paper.example.com"
server/docker.go
+5 -13
View File
@@ -15,8 +15,7 @@ import (
)
type IDockerWatcher interface {
Start(socket string, timeoutSeconds int, refreshIntervalSeconds int, autoScaleUp bool, autoScaleDown bool) error
Stop()
Start(ctx context.Context, socket string, timeoutSeconds int, refreshIntervalSeconds int, autoScaleUp bool, autoScaleDown bool) error
}
const (
@@ -34,7 +33,6 @@ type dockerWatcherImpl struct {
autoScaleUp bool
autoScaleDown bool
client *client.Client
contextCancel context.CancelFunc
}
func (w *dockerWatcherImpl) makeWakerFunc(_ *routableContainer) ScalerFunc {
@@ -57,7 +55,7 @@ func (w *dockerWatcherImpl) makeSleeperFunc(_ *routableContainer) ScalerFunc {
}
}
func (w *dockerWatcherImpl) Start(socket string, timeoutSeconds int, refreshIntervalSeconds int, autoScaleUp bool, autoScaleDown bool) error {
func (w *dockerWatcherImpl) Start(ctx context.Context, socket string, timeoutSeconds int, refreshIntervalSeconds int, autoScaleUp bool, autoScaleDown bool) error {
var err error
w.autoScaleUp = autoScaleUp
@@ -83,9 +81,7 @@ func (w *dockerWatcherImpl) Start(socket string, timeoutSeconds int, refreshInte
ticker := time.NewTicker(refreshInterval)
containerMap := map[string]*routableContainer{}
var ctx context.Context
ctx, w.contextCancel = context.WithCancel(context.Background())
logrus.Trace("Performing initial listing of Docker containers")
initialContainers, err := w.listContainers(ctx)
if err != nil {
return err
@@ -104,6 +100,7 @@ func (w *dockerWatcherImpl) Start(socket string, timeoutSeconds int, refreshInte
for {
select {
case <-ticker.C:
logrus.Trace("Listing Docker containers")
containers, err := w.listContainers(ctx)
if err != nil {
logrus.WithError(err).Error("Docker failed to list containers")
@@ -145,6 +142,7 @@ func (w *dockerWatcherImpl) Start(socket string, timeoutSeconds int, refreshInte
}
case <-ctx.Done():
logrus.Debug("Stopping Docker monitoring")
ticker.Stop()
return
}
@@ -303,12 +301,6 @@ func (w *dockerWatcherImpl) parseContainerData(container *dockertypes.Container)
return
}
func (w *dockerWatcherImpl) Stop() {
if w.contextCancel != nil {
w.contextCancel()
}
}
type routableContainer struct {
externalContainerName string
containerEndpoint string
server/docker_swarm.go
+3 -12
View File
@@ -26,7 +26,6 @@ type dockerSwarmWatcherImpl struct {
autoScaleUp bool
autoScaleDown bool
client *client.Client
contextCancel context.CancelFunc
}
func (w *dockerSwarmWatcherImpl) makeWakerFunc(_ *routableService) ScalerFunc {
@@ -49,7 +48,7 @@ func (w *dockerSwarmWatcherImpl) makeSleeperFunc(_ *routableService) ScalerFunc
}
}
func (w *dockerSwarmWatcherImpl) Start(socket string, timeoutSeconds int, refreshIntervalSeconds int, autoScaleUp bool, autoScaleDown bool) error {
func (w *dockerSwarmWatcherImpl) Start(ctx context.Context, socket string, timeoutSeconds int, refreshIntervalSeconds int, autoScaleUp bool, autoScaleDown bool) error {
var err error
w.autoScaleUp = autoScaleUp
@@ -75,9 +74,7 @@ func (w *dockerSwarmWatcherImpl) Start(socket string, timeoutSeconds int, refres
ticker := time.NewTicker(refreshInterval)
serviceMap := map[string]*routableService{}
var ctx context.Context
ctx, w.contextCancel = context.WithCancel(context.Background())
logrus.Trace("Performing initial listing of Docker containers")
initialServices, err := w.listServices(ctx)
if err != nil {
return err
@@ -99,7 +96,7 @@ func (w *dockerSwarmWatcherImpl) Start(socket string, timeoutSeconds int, refres
services, err := w.listServices(ctx)
if err != nil {
logrus.WithError(err).Error("Docker failed to list services")
return
continue
}
visited := map[string]struct{}{}
@@ -332,9 +329,3 @@ func (w *dockerSwarmWatcherImpl) parseServiceData(service *swarm.Service, networ
ok = true
return
}
func (w *dockerSwarmWatcherImpl) Stop() {
if w.contextCancel != nil {
w.contextCancel()
}
}
server/server.go
+2 -6
View File
@@ -142,21 +142,17 @@ func NewServer(ctx context.Context, config *Config) (*Server, error) {
// TODO convert to RouteFinder
if config.InDocker {
err = DockerWatcher.Start(config.DockerSocket, config.DockerTimeout, config.DockerRefreshInterval, config.AutoScale.Up, config.AutoScale.Down)
err = DockerWatcher.Start(ctx, config.DockerSocket, config.DockerTimeout, config.DockerRefreshInterval, config.AutoScale.Up, config.AutoScale.Down)
if err != nil {
return nil, fmt.Errorf("could not start docker integration: %w", err)
} else {
defer DockerWatcher.Stop()
}
}
// TODO convert to RouteFinder
if config.InDockerSwarm {
err = DockerSwarmWatcher.Start(config.DockerSocket, config.DockerTimeout, config.DockerRefreshInterval, config.AutoScale.Up, config.AutoScale.Down)
err = DockerSwarmWatcher.Start(ctx, config.DockerSocket, config.DockerTimeout, config.DockerRefreshInterval, config.AutoScale.Up, config.AutoScale.Down)
if err != nil {
return nil, fmt.Errorf("could not start docker swarm integration: %w", err)
} else {
defer DockerSwarmWatcher.Stop()
}
}