[kamal-proxy](https://github.com/basecamp/kamal-proxy) is a custom minimal proxy designed specifically for Kamal. It has some advantages over Traefik: 1. Imperative deployments - we tell it to switch from container A to container B, and it waits for container B to start then switches. No need to poll for health checks ourselves or mess around with forcing health checks to fail. 2. Support for multiple apps - as much as possible, configuration is supplied at runtime by the deploy command, allowing us to have multiple apps share a proxy without conflicting config. 3. First class support for Kamal operations - rather than trying to work out how to make Traefik do what we want, we can build features directly into the proxy, making configuration simpler and avoiding obscure errors
28 lines
942 B
Bash
Executable File
28 lines
942 B
Bash
Executable File
#!/bin/bash
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install_kamal() {
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cd /kamal && gem build kamal.gemspec -o /tmp/kamal.gem && gem install /tmp/kamal.gem
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}
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# Push the images to a persistent volume on the registry container
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# This is to work around docker hub rate limits
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push_image_to_registry_4443() {
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# Check if the image is in the registry without having to pull it
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if ! stat /registry/docker/registry/v2/repositories/$1/_manifests/tags/$2/current/link > /dev/null; then
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hub_tag=$1:$2
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registry_4443_tag=registry:4443/$1:$2
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docker pull $hub_tag
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docker tag $hub_tag $registry_4443_tag
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docker push $registry_4443_tag
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fi
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}
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install_kamal
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push_image_to_registry_4443 nginx 1-alpine-slim
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push_image_to_registry_4443 basecamp/kamal-proxy latest
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push_image_to_registry_4443 busybox 1.36.0
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# .ssh is on a shared volume that persists between runs. Clean it up as the
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# churn of temporary vm IPs can eventually create conflicts.
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rm -f /root/.ssh/known_hosts
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