44 lines
1.6 KiB
Markdown
44 lines
1.6 KiB
Markdown
# Docker Swarm Usage
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## Healthcheck
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The [Docker Image](../Dockerfile) includes a Healthcheck with the following options:
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```
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--interval=30s
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```
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> Specifies the time interval at which the health check should be performed. In this case, the health check will be performed every 30 seconds.
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<br>
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```
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--timeout=10s
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```
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> Specifies the amount of time to wait for a response from the health check command. If the response does not arrive within 10 seconds, the health check will be considered a failure.
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<br>
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```
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--start-period=5s
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```
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> Specifies the amount of time to wait before starting the health check process. In this case, the health check process will begin 5 seconds after the container is started.
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<br>
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```
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--retries=3
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```
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> Specifies the number of times Docker should retry the health check before considering the container to be unhealthy.
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<br>
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The CMD instruction is used to define the command that will be run as part of the health check.
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In this case, the command is `wget --quiet --tries=1 --spider http://localhost:3000/ || exit 1`. This command will attempt to connect to `http://localhost:3000/`
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and if it fails it will exit with a status code of `1`. If this command returns a status code other than `0`, the health check will be considered a failure.
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Overall, this HEALTHCHECK instruction is defining a health check process that will run every 30 seconds, wait up to 10 seconds for a response,
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begin 5 seconds after the container is started, and retry up to 3 times.
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The health check will consist of attempting to connect to http://localhost:3000/ and will consider the container to be unhealthy if it is unable to connect.
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