Building a Container that Loops: Difference between revisions
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(2 intermediate revisions by the same user not shown) | |||
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<syntaxhighlight lang='bash'> | <syntaxhighlight lang='bash'> | ||
#!/bin/ | #!/bin/bash | ||
function sigint() { | |||
echo "process got SIGINT and it is exiting ..." | |||
run=false | |||
} | |||
function sigterm() { | |||
echo "process got SIGTERM and it is exiting ..." | |||
run=false | |||
} | |||
trap 'sigint' INT | |||
trap 'sigterm' TERM | |||
while | while ${run}; do | ||
sleep 1 | |||
done | |||
</syntaxhighlight> | </syntaxhighlight> | ||
Line 59: | Line 74: | ||
==Log into the Container== | ==Log into the Container== | ||
docker exec -it /bin/bash | docker exec -it bcff8efd8a9a /bin/bash | ||
==Execute the Probe== | ==Execute the Probe== | ||
docker exec bcff8efd8a9a /opt/probe |
Latest revision as of 20:16, 29 January 2018
Internal
Overview
This is a simple container based on centos base image whose command sleep-loos, allowing the container to "hang around" without doing much. It also carry a "probe" script that can be exercised externally.
Procedure
Create the Image
Place the scripts (loop and probe) in an empty directory that will serve as build context.
loop:
#!/bin/bash
function sigint() {
echo "process got SIGINT and it is exiting ..."
run=false
}
function sigterm() {
echo "process got SIGTERM and it is exiting ..."
run=false
}
trap 'sigint' INT
trap 'sigterm' TERM
while ${run}; do
sleep 1
done
probe:
#!/bin/sh
echo "executed in $(uname -n)"
Dockerfile:
FROM centos:latest
COPY loop probe /opt
CMD /opt/loop
The build command:
cd workarea docker build -t centos-loop:1 .
The image thus created can be listed in the local registry:
docker images REPOSITORY TAG IMAGE ID CREATED SIZE centos-loop 1 89c2ce131758 About a minute ago 207MB centos latest ff426288ea90 9 days ago 207MB
Run the Container
docker run -d centos-loop:1
docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES bcff8efd8a9a centos-loop:1 "/bin/sh -c /opt/loop" 2 minutes ago Up 2 minutes brave_yonath
Log into the Container
docker exec -it bcff8efd8a9a /bin/bash
Execute the Probe
docker exec bcff8efd8a9a /opt/probe