docker ADD with symlinks - docker

When I do sudo docker build -t test -f 7.1/Dockerfile . docker fails on step 8/10:
Step 8/10 : ADD etc/php /usr/local/etc/php
ADD failed: file not found in build context or excluded by .dockerignore: stat etc/php: file does not exist
I don't understand. etc/php is symlinked to another directory. Shouldn't that work?
If I do ls -latr etc/php I get this:
lrwxrwxrwx 1 scbn scbn 43 Sep 11 17:48 etc/php -> /home/neubert/devops/containers/common/etc/php
If I do cd etc/php && ls -latr I get this:
total 84
drwxr-xr-x 2 scbn scbn 4096 Jan 3 2021 conf.d
drwxr-xr-x 5 scbn scbn 4096 Jan 3 2021 ..
-rw-r--r-- 1 scbn scbn 70125 Jan 26 2021 php.ini
drwxr-xr-x 3 scbn scbn 4096 Jan 26 2021 .

$ docker build --help
Usage: docker build [OPTIONS] PATH | URL | -
Here, PATH | URL | - is so called build context, you usually use ., but it could be other path. When docker build, it will tar all the contents in build context, then pass it to docker engine. So, the COPY in Dockerfile could just reference the item in build context.
For your scenario:
lrwxrwxrwx 1 scbn scbn 43 Sep 11 17:48 etc/php -> /home/neubert/devops/containers/common/etc/php
Above I guess the symbol link etc/php is in your build context, while the real folder /home/neubert/devops/containers/common/etc/php not, so build fail, you have to in some way assure the real targe also in build context.

Related

Why does docker image content differ from the container created from it?

Following is the Dockerfile for the image,
FROM jenkins/jenkins:lts-jdk11
USER jenkins
RUN jenkins-plugin-cli --plugins "blueocean:1.25.2 http_request" && ls -la /var/jenkins_home
When this is built using docker build -t ireshmm/jenkins:lts-jdk11 ., following is the output,
Sending build context to Docker daemon 3.072kB
Step 1/3 : FROM jenkins/jenkins:lts-jdk11
---> 9aee0d53624f
Step 2/3 : USER jenkins
---> Using cache
---> 49d657d24299
Step 3/3 : RUN jenkins-plugin-cli --plugins "blueocean:1.25.2 http_request" && ls -la /var/jenkins_home
---> Running in b459c4c48e3e
Done
total 20
drwxr-xr-x 3 jenkins jenkins 4096 Jan 22 16:49 .
drwxr-xr-x 1 root root 4096 Jan 12 15:46 ..
drwxr-xr-x 3 jenkins jenkins 4096 Jan 22 16:49 .cache
-rw-rw-r-- 1 jenkins root 7152 Jan 12 15:42 tini_pub.gpg
Removing intermediate container b459c4c48e3e
---> 5fd5ba428f1a
Successfully built 5fd5ba428f1a
Successfully tagged ireshmm/jenkins:lts-jdk11
When create a container and list files docker run -it --rm ireshmm/jenkins:lts-jdk11 ls -la /var/jenkins_home, following is the output:
total 40
drwxr-xr-x 3 jenkins jenkins 4096 Jan 22 16:51 .
drwxr-xr-x 1 root root 4096 Jan 12 15:46 ..
-rw-r--r-- 1 jenkins jenkins 4683 Jan 22 16:51 copy_reference_file.log
drwxr-xr-x 2 jenkins jenkins 16384 Jan 22 16:51 plugins
-rw-rw-r-- 1 jenkins root 7152 Jan 12 15:42 tini_pub.gpg
Question: Why do the contents of /var/jenkins_home differ while building the image and the inside the container created from it given that no command is run after listing the files while building image? How can that happen?
The jenkins/jenkins:lts-jdk11 has an ENTRYPOINT that runs /usr/local/bin/jenkins.sh, which among other things creates the copy_reference_file.log file:
$ grep -i copy_reference /usr/local/bin/jenkins.sh
: "${COPY_REFERENCE_FILE_LOG:="${JENKINS_HOME}/copy_reference_file.log"}"
touch "${COPY_REFERENCE_FILE_LOG}" || { echo "Can not write to ${COPY_REFERENCE_FILE_LOG}. Wrong volume permissions?"; exit 1; }
echo "--- Copying files at $(date)" >> "$COPY_REFERENCE_FILE_LOG"
find "${REF}" \( -type f -o -type l \) -exec bash -c '. /usr/local/bin/jenkins-support; for arg; do copy_reference_file "$arg"; done' _ {} +
The ENTRYPOINT scripts runs whenever you start a container from that image (before any command you've provided on the command line).

docker-compose build fail with file not found

I would like to ask a question regarding the docker-compose.yml and Dockerfile.
Following is the situation I have met.
I first use docker image build (docker image build -t test .) and docker run (docker run -p 8888:8080 -p 8889:8009 8883:8443 -v tomcat8:/usr/local/tomcat8 --name test test) to test whether my Dockerfile is ready to go, and it is working.
Dockerfile
FROM ubuntu:latest
ENV HOME /usr/local/tomcat8
RUN apt-get -y update && apt-get -y install unzip wget openjdk-8-jdk
COPY ./installERDDAP.sh $HOME/installERDDAP.sh
COPY . $HOME/
RUN chmod +x $HOME/installERDDAP.sh
WORKDIR $HOME
RUN ./installERDDAP.sh
EXPOSE 8080 8443 8009
CMD ["catalina.sh","run"]
So that I script the docker-compose.yml, like below
docker-compose.yml
version: '3'
services:
erddap:
build:
context: ./
dockerfile: Dockerfile
image: erddap_dev:2.02
container_name: erddap
restart: always
ports:
- "8888:8080"
- "8883:8443"
- "8889:8009"
volumes:
- ./tomcat8:/usr/local/tomcat8
However, the error message popup and said that the file catalina.sh does not exist. When I get into the container, well, that is true. There are no files existed. But if I put RUN ls -la in the Dockerfile, I do see the files are listed, like below.
Step 12/14 : RUN ls -la
---> Running in fed4870bd617
total 176
drwxr-xr-x. 1 root root 4096 Sep 11 20:08 .
drwxr-xr-x. 1 root root 21 Sep 11 20:08 ..
drwxrwxr-x. 8 root root 166 Sep 11 19:31 .git
-rw-rw-r--. 1 root root 12 Sep 11 07:50 .gitignore
-rw-r--r--. 1 root root 165 Sep 11 20:08 .wget-hsts
-rw-r-----. 1 root root 19318 Jun 30 21:53 BUILDING.txt
-rw-r-----. 1 root root 5408 Jun 30 21:53 CONTRIBUTING.md
-rw-rw-r--. 1 root root 640 Sep 11 20:03 Dockerfile
-rw-r-----. 1 root root 57011 Jun 30 21:53 LICENSE
-rw-r-----. 1 root root 1726 Jun 30 21:53 NOTICE
-rw-r-----. 1 root root 3255 Jun 30 21:53 README.md
-rw-r-----. 1 root root 7136 Jun 30 21:53 RELEASE-NOTES
-rw-r-----. 1 root root 16262 Jun 30 21:53 RUNNING.txt
drwxr-x---. 2 root root 4096 Sep 11 20:08 bin
-rwxr-x---. 2 root root 25245 Jun 30 21:50 catalina.sh
drwx------. 2 root root 238 Jun 30 21:53 conf
drwxr-xr-x. 3 root root 20 Sep 11 20:08 content
drwxr-xr-x. 2 root root 6 Sep 11 20:08 data
drwxrwxr-x. 5 root root 44 Sep 11 03:46 doc
-rw-rw-r--. 1 root root 320 Sep 11 19:49 docker-compose.yml
-rwxrwxr-x. 1 root root 1030 Sep 11 19:41 installERDDAP.sh
drwxr-x---. 2 root root 4096 Sep 11 20:08 lib
drwxr-x---. 2 root root 6 Jun 30 21:49 logs
drwxr-xr-x. 2 root root 66 Sep 11 20:08 tarz
drwxr-x---. 2 root root 30 Sep 11 20:08 temp
drwxrwxr-x. 4 root root 29 Sep 11 19:41 tomcat8
drwxr-x---. 7 root root 99 Sep 11 20:08 webapps
drwxr-x---. 2 root root 6 Jun 30 21:49 work
Removing intermediate container fed4870bd617
Interestingly, these files are not also showing up in my volume directory. Could please someone tells me where am I wrong?
Thanks
1st Updates:
According to the suggestion below, if I commended out the volumes within docker-compose.yml or if I added WORKDIR / in front of the CMD command, none of them are working.
If I modified CMD commend in Dockfile from CMD ["catalina.sh","run"] to CMD ["./catalina.sh","run"] is not working, too. But if I changed to CMD ["/usr/local/tomcat8/catalina.sh","run"], the build process is completed. But the errors than become
Attaching to erddap
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
erddap | Cannot find /usr/local/bin/setclasspath.sh
erddap | This file is needed to run this program
2nd Updates:
installERDDAP.sh
#!/bin/bash
mkdir tarz
wget -q https://ftp.wayne.edu/apache/tomcat/tomcat-8/v8.5.57/bin/apache-tomcat-8.5.57.tar.gz -O ./tarz/apache-tomcat-8.5.57.tar.gz
tar -xf ./tarz/apache-tomcat-8.5.57.tar.gz -C /usr/local/tomcat8 --strip 1
mkdir data
ln ./bin/catalina.sh catalina.sh
From what I can tell your bind mount may be "overriding/hiding" your container files. If your "./tomcat8" directory is not empty it will basically "override/hide" the files in your container. I would remove the volume declaration to validate if this is the case, if so then you would need to clear out your "./tomcat8" directory and when you run the container again it should populate it with the files in the container, from then forward your local directory will again "override/hide" your container files.
In your docker file before the line CMD ["catalina.sh","run"] put WORKDIR / And change "catalina.sh" to "./catalina.sh"

/bin/sh: app: not found

/ # which chasquid-util
/usr/local/bin/chasquid-util
/ # chasquid-util
/bin/sh: chasquid-util: not found
/ # /usr/local/bin/chasquid-util
/bin/sh: /usr/local/bin/chasquid-util: not found
/ # ls -al /usr/local/bin/
total 27432
drwxr-xr-x 1 root root 4096 Jul 26 16:18 .
drwxr-xr-x 1 root root 4096 Jul 26 16:18 ..
-rwxr-xr-x 1 root root 11721005 Jul 26 16:18 chasquid
-rwxr-xr-x 1 root root 5510494 Jul 26 16:18 chasquid-util
-rwxr-xr-x 1 root root 2910713 Jul 26 16:18 mda-lmtp
-rwxr-xr-x 1 root root 4767277 Jul 26 16:18 smtp-check
-rwxr-xr-x 1 root root 3164845 Jul 26 16:18 spf-check
/ #
Given your context, this typically means you are missing a shared library. With alpine, it's typically glibc since they ship with libmusl. You can check this with:
ldd chasquid-util
I've got several other reasons for this listed in my DC 2018 slidedeck:
Did you run the intended command? (e.g. docker run --rm my_image -it echo hello world will run the command -it)
Is docker trying to run a json string? (any json paring errors will show up as executing the json as a string)
Does the file exist... in the path and inside the container? (can't run stuff from the host inside a container without building it into the image or mounting a volume)
If it is a shell script, check the first line (e.g. #!/bin/bash)
Check for windows linefeeds on linux shell scripts (look for ^M or \r with different editors)
If it is a binary, there is likely a missing library (use ldd to check)

How to remove data from docker volume?

I prepared Docker image containing libraries needed for building my other project. I want to have a directory /myLibs with libraries from different projects, e.g:
/myLibs:
projectA
projectB
projectC
Dockerfile:
FROM my-base:1.0
VOLUME /myLibs
COPY projectA/bin/*.so* /myLibs/projectA/bin/
CMD /bin/bash
Built:
docker build -t my-libs:1.0 .
Then I want to update libs in this image every time when I rebuild projectA. So I prepared Dockerfile:
FROM my-libs:1.0 # I changed parent image, because /myLibs/projectB and /myLibs/projectC should remain
VOLUME /myLibs
RUN ls -al /myLibs && rm -rf /myLibs/projectA && ls -al /myLibs
RUN ls -al /myLibs
COPY projectA/bin/*.so* /myLibs/projectA/bin/
CMD /bin/bash
As a result I have old projectA libs in my volume:
Step 4 : RUN ls -al /myLibs && rm -rf /myLibs/projectA && ls -al /myLibs
---> Running in 1e3e25084e69
total 12
drwxr-xr-x 3 root root 4096 Jul 16 13:52 .
drwxr-xr-x 75 root root 4096 Jul 16 13:52 ..
drwxr-xr-x 4 root root 4096 Jul 16 13:51 projectA
total 8
drwxr-xr-x 2 root root 4096 Jul 16 13:52 .
drwxr-xr-x 75 root root 4096 Jul 16 13:52 ..
---> d5973da5965c
Removing intermediate container 1e3e25084e69
Step 5 : RUN ls -al /myLibs
---> Running in 1d93575b50c2
total 12
drwxr-xr-x 3 root root 4096 Jul 16 13:52 .
drwxr-xr-x 75 root root 4096 Jul 16 13:52 ..
drwxr-xr-x 4 root root 4096 Jul 16 13:51 projectA
---> 6d2a48a5b67b
How can I remove files from volume?
If you want to change the files on rebuild, you probably don't want to do it in the volume. The volume is generally for data you want to persist. Remember the volume mounting will occur after the container builds, so what's probably happening is the volume with the old data is mounting over any changes you are making in the image (re)build.
What are you using /myLibs for? If they are read-only files you want to set up in the build, you might be better off not using a volume and make them part of the image. If you want to modify them, it's probably better to manage that after the build - there is no real reason to rebuild the image if you are just changing files in a networked volume.

Edit apache configuration in docker

First time docker user here, I'm using this image: https://github.com/dgraziotin/osx-docker-lamp
I want to make the apache in that container to use a configuration file from the host system. How do I do that?
I know I can use nsenter, but I think my changes will get deleted when the container is turned off.
Thank you
The best solution is using VOLUME.
docker pull dgraziotin/lamp
You need to copy /etc/apache2/ from container to current directory in host computer. Then you can do this:
cd ~
mkdir conf
docker run -i -t --rm -v ~/conf:/tmp/conf dgraziotin/lamp:latest /bin/bash
On container do:
ls /tmp/conf
cd /etc/apache2/
tar -cf /tmp/conf/apache-conf.tar *
exit
On host computer:
cd conf
tar -xf apache-conf.tar
cd ..
# alter your configuration in this file and save
vi conf/apache2.conf
# run your container : daemon mode
docker run -d -p 9180:80 --name web-01 -v ~/conf:/etc/apache2 dgraziotin/lamp:latest
docker ps
To list conf content on Container use:
docker exec web-01 ls -lAt /etc/apache2/
total 72
-rw-r--r-- 1 root root 1779 Jul 17 20:24 envvars
drwxr-xr-x 2 root root 4096 Apr 10 11:46 mods-enabled
drwxr-xr-x 2 root root 4096 Apr 10 11:45 sites-available
-rw-r--r-- 1 root root 7136 Apr 10 11:45 apache2.conf
drwxr-xr-x 2 root root 4096 Apr 10 11:45 mods-available
drwxr-xr-x 2 root root 4096 Apr 10 11:44 conf-enabled
drwxr-xr-x 2 root root 4096 Apr 10 11:44 sites-enabled
drwxr-xr-x 2 root root 4096 Apr 10 11:44 conf-available
-rw-r--r-- 1 root root 320 Jan 7 2014 ports.conf
-rw-r--r-- 1 root root 31063 Jan 3 2014 magic
Use docker exec web-01 cat /etc/apache2/apache2.conf to list content inside Container.
One the WEB page to test your environment.
I hope this help you.
You should use a Dockerfile to generate a new image containing your desired configuration. For example:
FROM dgraziotin/lamp
COPY my-config-file /some/configuration/file
This assumes that there is a file my-config-file located in the same directory as the Dockerfile. Then run:
docker build -t myimage
And once the build completes you will have an image named myimage available locally.

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