audit2allow - Adding and managing custom rules, error when attempting to add - centos7

I am still a complete noob when it comes to managing selinux and custom rules. I understand the concept to a certain degree (only letting applications certain permissions to certain resources, rather than just RWX based on user:group of the process and files)
I usually use this snippet when I need to let things work properly. If I have an issue in the code somewhere, whether it's accessing files, ports, or performing other tasks, this generally unblocks it from being a problem. Probably not the best route, but it works for what I need.
I would like to figure out how to manage it better, but I can't seem to find any information on managing current/custom/default rules and add them another way. I know there's also some boolean settings that can be toggled/set using setsebool, but other than that I'm a bit lost.
This is what I generally run (as root) when attempting to allow whatever I'm doing.
sudo grep nginx /var/log/audit/audit.log | audit2allow -m nginx > nginx.te
sudo grep nginx /var/log/audit/audit.log | audit2allow -M nginx
# Make this policy package active
sudo semodule -i nginx.pp
# Cleanup
sudo rm -f nginx.te && sudo rm -f nginx.pp
When I run the third line to make the policy package active, I get the following error:
Failed to resolve typeattributeset statement at /etc/selinux/targeted/tmp/modules/100/redis/cil:82
semodule: Failed!
I cannot open the file either, because /etc/selinux/targeted/tmp/ doesn't exist afterwards.

Related

How to use Dockerfile COPY command to copy files from parent directories [duplicate]

How can I include files from outside of Docker's build context using the "ADD" command in the Docker file?
From the Docker documentation:
The path must be inside the context of the build; you cannot ADD
../something/something, because the first step of a docker build is to
send the context directory (and subdirectories) to the docker daemon.
I do not want to restructure my whole project just to accommodate Docker in this matter. I want to keep all my Docker files in the same sub-directory.
Also, it appears Docker does not yet (and may not ever) support symlinks: Dockerfile ADD command does not follow symlinks on host #1676.
The only other thing I can think of is to include a pre-build step to copy the files into the Docker build context (and configure my version control to ignore those files). Is there a better workaround for than that?
The best way to work around this is to specify the Dockerfile independently of the build context, using -f.
For instance, this command will give the ADD command access to anything in your current directory.
docker build -f docker-files/Dockerfile .
Update: Docker now allows having the Dockerfile outside the build context (fixed in 18.03.0-ce). So you can also do something like
docker build -f ../Dockerfile .
I often find myself utilizing the --build-arg option for this purpose. For example after putting the following in the Dockerfile:
ARG SSH_KEY
RUN echo "$SSH_KEY" > /root/.ssh/id_rsa
You can just do:
docker build -t some-app --build-arg SSH_KEY="$(cat ~/file/outside/build/context/id_rsa)" .
But note the following warning from the Docker documentation:
Warning: It is not recommended to use build-time variables for passing secrets like github keys, user credentials etc. Build-time variable values are visible to any user of the image with the docker history command.
I spent a good time trying to figure out a good pattern and how to better explain what's going on with this feature support. I realized that the best way to explain it was as follows...
Dockerfile: Will only see files under its own relative path
Context: a place in "space" where the files you want to share and your Dockerfile will be copied to
So, with that said, here's an example of the Dockerfile that needs to reuse a file called start.sh
Dockerfile
It will always load from its relative path, having the current directory of itself as the local reference to the paths you specify.
COPY start.sh /runtime/start.sh
Files
Considering this idea, we can think of having multiple copies for the Dockerfiles building specific things, but they all need access to the start.sh.
./all-services/
/start.sh
/service-X/Dockerfile
/service-Y/Dockerfile
/service-Z/Dockerfile
./docker-compose.yaml
Considering this structure and the files above, here's a docker-compose.yml
docker-compose.yaml
In this example, your shared context directory is the runtime directory.
Same mental model here, think that all the files under this directory are moved over to the so-called context.
Similarly, just specify the Dockerfile that you want to copy to that same directory. You can specify that using dockerfile.
The directory where your main content is located is the actual context to be set.
The docker-compose.yml is as follows
version: "3.3"
services:
service-A
build:
context: ./all-service
dockerfile: ./service-A/Dockerfile
service-B
build:
context: ./all-service
dockerfile: ./service-B/Dockerfile
service-C
build:
context: ./all-service
dockerfile: ./service-C/Dockerfile
all-service is set as the context, the shared file start.sh is copied there as well the Dockerfile specified by each dockerfile.
Each gets to be built their own way, sharing the start file!
On Linux you can mount other directories instead of symlinking them
mount --bind olddir newdir
See https://superuser.com/questions/842642 for more details.
I don't know if something similar is available for other OSes.
I also tried using Samba to share a folder and remount it into the Docker context which worked as well.
If you read the discussion in the issue 2745 not only docker may never support symlinks they may never support adding files outside your context. Seems to be a design philosophy that files that go into docker build should explicitly be part of its context or be from a URL where it is presumably deployed too with a fixed version so that the build is repeatable with well known URLs or files shipped with the docker container.
I prefer to build from a version controlled source - ie docker build
-t stuff http://my.git.org/repo - otherwise I'm building from some random place with random files.
fundamentally, no.... -- SvenDowideit, Docker Inc
Just my opinion but I think you should restructure to separate out the code and docker repositories. That way the containers can be generic and pull in any version of the code at run time rather than build time.
Alternatively, use docker as your fundamental code deployment artifact and then you put the dockerfile in the root of the code repository. if you go this route probably makes sense to have a parent docker container for more general system level details and a child container for setup specific to your code.
I believe the simpler workaround would be to change the 'context' itself.
So, for example, instead of giving:
docker build -t hello-demo-app .
which sets the current directory as the context, let's say you wanted the parent directory as the context, just use:
docker build -t hello-demo-app ..
You can also create a tarball of what the image needs first and use that as your context.
https://docs.docker.com/engine/reference/commandline/build/#/tarball-contexts
This behavior is given by the context directory that the docker or podman uses to present the files to the build process.
A nice trick here is by changing the context dir during the building instruction to the full path of the directory, that you want to expose to the daemon.
e.g:
docker build -t imageName:tag -f /path/to/the/Dockerfile /mysrc/path
using /mysrc/path instead of .(current directory), you'll be using that directory as a context, so any files under it can be seen by the build process.
This example you'll be exposing the entire /mysrc/path tree to the docker daemon.
When using this with docker the user ID who triggered the build must have recursively read permissions to any single directory or file from the context dir.
This can be useful in cases where you have the /home/user/myCoolProject/Dockerfile but want to bring to this container build context, files that aren't in the same directory.
Here is an example of building using context dir, but this time using podman instead of docker.
Lets take as example, having inside your Dockerfile a COPY or ADDinstruction which is copying files from a directory outside of your project, like:
FROM myImage:tag
...
...
COPY /opt/externalFile ./
ADD /home/user/AnotherProject/anotherExternalFile ./
...
In order to build this, with a container file located in the /home/user/myCoolProject/Dockerfile, just do something like:
cd /home/user/myCoolProject
podman build -t imageName:tag -f Dockefile /
Some known use cases to change the context dir, is when using a container as a toolchain for building your souce code.
e.g:
podman build --platform linux/s390x -t myimage:mytag -f ./Dockerfile /tmp/mysrc
or it can be a path relative, like:
podman build --platform linux/s390x -t myimage:mytag -f ./Dockerfile ../../
Another example using this time a global path:
FROM myImage:tag
...
...
COPY externalFile ./
ADD AnotherProject ./
...
Notice that now the full global path for the COPY and ADD is omitted in the Dockerfile command layers.
In this case the contex dir must be relative to where the files are, if both externalFile and AnotherProject are in /opt directory then the context dir for building it must be:
podman build -t imageName:tag -f ./Dockerfile /opt
Note when using COPY or ADD with context dir in docker:
The docker daemon will try to "stream" all the files visible on the context dir tree to the daemon, which can slowdown the build. And requires the user to have recursively permission from the context dir.
This behavior can be more costly specially when using the build through the API. However,with podman the build happens instantaneously, without needing recursively permissions, that's because podman does not enumerate the entire context dir, and doesn't use a client/server architecture as well.
The build for such cases can be way more interesting to use podman instead of docker, when you face such issues using a different context dir.
Some references:
https://docs.docker.com/engine/reference/commandline/build/
https://docs.podman.io/en/latest/markdown/podman-build.1.html
As is described in this GitHub issue the build actually happens in /tmp/docker-12345, so a relative path like ../relative-add/some-file is relative to /tmp/docker-12345. It would thus search for /tmp/relative-add/some-file, which is also shown in the error message.*
It is not allowed to include files from outside the build directory, so this results in the "Forbidden path" message."
Using docker-compose, I accomplished this by creating a service that mounts the volumes that I need and committing the image of the container. Then, in the subsequent service, I rely on the previously committed image, which has all of the data stored at mounted locations. You will then have have to copy these files to their ultimate destination, as host mounted directories do not get committed when running a docker commit command
You don't have to use docker-compose to accomplish this, but it makes life a bit easier
# docker-compose.yml
version: '3'
services:
stage:
image: alpine
volumes:
- /host/machine/path:/tmp/container/path
command: bash -c "cp -r /tmp/container/path /final/container/path"
setup:
image: stage
# setup.sh
# Start "stage" service
docker-compose up stage
# Commit changes to an image named "stage"
docker commit $(docker-compose ps -q stage) stage
# Start setup service off of stage image
docker-compose up setup
Create a wrapper docker build shell script that grabs the file then calls docker build then removes the file.
a simple solution not mentioned anywhere here from my quick skim:
have a wrapper script called docker_build.sh
have it create tarballs, copy large files to the current working directory
call docker build
clean up the tarballs, large files, etc
this solution is good because (1.) it doesn't have the security hole from copying in your SSH private key (2.) another solution uses sudo bind so that has another security hole there because it requires root permission to do bind.
I think as of earlier this year a feature was added in buildx to do just this.
If you have dockerfile 1.4+ and buildx 0.8+ you can do something like this
docker buildx build --build-context othersource= ../something/something .
Then in your docker file you can use the from command to add the context
ADD –from=othersource . /stuff
See this related post https://www.docker.com/blog/dockerfiles-now-support-multiple-build-contexts/
Workaround with links:
ln path/to/file/outside/context/file_to_copy ./file_to_copy
On Dockerfile, simply:
COPY file_to_copy /path/to/file
I was personally confused by some answers, so decided to explain it simply.
You should pass the context, you have specified in Dockerfile, to docker when
want to create image.
I always select root of project as the context in Dockerfile.
so for example if you use COPY command like COPY . .
first dot(.) is the context and second dot(.) is container working directory
Assuming the context is project root, dot(.) , and code structure is like this
sample-project/
docker/
Dockerfile
If you want to build image
and your path (the path you run the docker build command) is /full-path/sample-project/,
you should do this
docker build -f docker/Dockerfile .
and if your path is /full-path/sample-project/docker/,
you should do this
docker build -f Dockerfile ../
An easy workaround might be to simply mount the volume (using the -v or --mount flag) to the container when you run it and access the files that way.
example:
docker run -v /path/to/file/on/host:/desired/path/to/file/in/container/ image_name
for more see: https://docs.docker.com/storage/volumes/
I had this same issue with a project and some data files that I wasn't able to move inside the repo context for HIPAA reasons. I ended up using 2 Dockerfiles. One builds the main application without the stuff I needed outside the container and publishes that to internal repo. Then a second dockerfile pulls that image and adds the data and creates a new image which is then deployed and never stored anywhere. Not ideal, but it worked for my purposes of keeping sensitive information out of the repo.
In my case, my Dockerfile is written like a template containing placeholders which I'm replacing with real value using my configuration file.
So I couldn't specify this file directly but pipe it into the docker build like this:
sed "s/%email_address%/$EMAIL_ADDRESS/;" ./Dockerfile | docker build -t katzda/bookings:latest . -f -;
But because of the pipe, the COPY command didn't work. But the above way solves it by -f - (explicitly saying file not provided). Doing only - without the -f flag, the context AND the Dockerfile are not provided which is a caveat.
How to share typescript code between two Dockerfiles
I had this same problem, but for sharing files between two typescript projects. Some of the other answers didn't work for me because I needed to preserve the relative import paths between the shared code. I solved it by organizing my code like this:
api/
Dockerfile
src/
models/
index.ts
frontend/
Dockerfile
src/
models/
index.ts
shared/
model1.ts
model2.ts
index.ts
.dockerignore
Note: After extracting the shared code into that top folder, I avoided needing to update the import paths because I updated api/models/index.ts and frontend/models/index.ts to export from shared: (eg export * from '../../../shared)
Since the build context is now one directory higher, I had to make a few additional changes:
Update the build command to use the new context:
docker build -f Dockerfile .. (two dots instead of one)
Use a single .dockerignore at the top level to exclude all node_modules. (eg **/node_modules/**)
Prefix the Dockerfile COPY commands with api/ or frontend/
Copy shared (in addition to api/src or frontend/src)
WORKDIR /usr/src/app
COPY api/package*.json ./ <---- Prefix with api/
RUN npm ci
COPY api/src api/ts*.json ./ <---- Prefix with api/
COPY shared usr/src/shared <---- ADDED
RUN npm run build
This was the easiest way I could send everything to docker, while preserving the relative import paths in both projects. The tricky (annoying) part was all the changes/consequences caused by the build context being up one directory.
One quick and dirty way is to set the build context up as many levels as you need - but this can have consequences.
If you're working in a microservices architecture that looks like this:
./Code/Repo1
./Code/Repo2
...
You can set the build context to the parent Code directory and then access everything, but it turns out that with a large number of repositories, this can result in the build taking a long time.
An example situation could be that another team maintains a database schema in Repo1 and your team's code in Repo2 depends on this. You want to dockerise this dependency with some of your own seed data without worrying about schema changes or polluting the other team's repository (depending on what the changes are you may still have to change your seed data scripts of course)
The second approach is hacky but gets around the issue of long builds:
Create a sh (or ps1) script in ./Code/Repo2 to copy the files you need and invoke the docker commands you want, for example:
#!/bin/bash
rm -r ./db/schema
mkdir ./db/schema
cp -r ../Repo1/db/schema ./db/schema
docker-compose -f docker-compose.yml down
docker container prune -f
docker-compose -f docker-compose.yml up --build
In the docker-compose file, simply set the context as Repo2 root and use the content of the ./db/schema directory in your dockerfile without worrying about the path.
Bear in mind that you will run the risk of accidentally committing this directory to source control, but scripting cleanup actions should be easy enough.

Cannot chmod file on Openshift online v3 : Operation not permitted

I am migrating a Django application from Openshift v2 to v3 (In case you don't know, RedHat is shutting down v2 on September 30th, see: https://blog.openshift.com/migrate-to-v3-v2-eol/)
So, I am following this blog post to help me: https://blog.openshift.com/migrating-django-applications-openshift-3/ . I am new to all these Docker / Kubernetes concepts the new version is build upon.
I was able to make some progress : I managed to get a successful build of my app. Yet it crashes at deployment time:
---> Running application from script (app.sh) ...
/usr/libexec/s2i/run: line 42: /opt/app-root/src/app.sh: Permission denied
Indeed, app.sh has lost its x permission. I log into the failing container as debug and see it:
> oc debug dc/<my app>
> (app-root)sh-4.2$ ls -l /opt/app-root/src/app.sh
-rw-rw-r--. 1 default root 127 Sep 6 21:20 /opt/app-root/src/app.sh
The blog posts states "Ensure that the app.sh file is executable by running chmod +x app.sh.", which I did on my local repo. Whatever, I want to do it again directly in the pod, but it doesn't work:
(app-root)sh-4.2$ chmod +x /opt/app-root/src/app.sh
chmod: changing permissions of ‘/opt/app-root/src/app.sh’: Operation not permitted
So, how can I set the x permission to app.sh ? Thank you
Without looking into more details, any S2I builder image will gladly use your custom supplied run script to start the application in an alternative way.
Create .s2i/bin/ (mind the dot) in your source code directory, place the run script into it and rebuild the app in OpenShift - it will automatically use your custom run script upon deployment.
This is the preferred way of starting applications using custom commands in OpenShift.
Regarding your immediate problem, there is a very simple reason why you can not change the permissions of the script: you were trying to modify the permissions in the deployed pod, and not the builder pod. Deployed pods run using different UIDs, usually somewhere in the range of 100000000, and definitely do not match the file ownership as generated by the build. Hence permission denied.
The root cause of your problem (app.sh losing executable permissions) must be in the way the build process installs those files, and indeed looking at the /usr/libexec/s2i/assemble script in the base image does seem to reveal the culprit. The last two lines are:
# set permissions for any installed artifacts
fix-permissions /opt/app-root
If you wanted to change this part of the build instead of using a custom run script, I suggest you then create .s2i/bin/assemble in your project's source code and make it look sort of like this:
#!/bin/bash
echo "Running stock build:"
${STI_SCRIPTS_PATH}/assemble
echo "Fixing the mess:"
chmod 755 /opt/app-root/src/app.sh
This will fix whatever the stock build process does to file permissions, and will do it using the same UID as the rest of the build, so file ownership shouldn't be an issue.
as I stumbled upon this issue myself I've found a way to resolve it.
You have to make your file app.sh executable and push it in your repo as such.
If git does not track this modification as it did for me, you have to use: git update-index --chmod=+x app.sh for it to work.

(AWS) Security implications of adding an exclusion for user:wsgi in sudoers

While setting up a script to convert documents to PDF using libreoffice on AWS, I can't get libreoffice to --convert-to pdfwithout sudo as perhaps the user wsgi does not have write permissions to the /opt/python/current/app directory.
So I plan to solve this by appending the following line to the /etc/sudoers file:
wsgi ALL = NOPASSWD: /opt/libreoffice5.3/program/soffice.bin
As I want to automate this while deploying, in my .ebextensions/01_packages.config I have
container_commands:
01_edit_sudoers_only_once:
command: "echo 'wsgi ALL = NOPASSWD: /opt/libreoffice5.3/program/soffice.bin' >> /etc/sudoers"
test: "test ! -f .sudoers_edited"
02_mark_sudoers_as_edited:
command: "touch .sudoers_edited"
Is there a potential security issue with this?
There is a significant potential security issue with giving a web service process the ability to invoke things with sudo.
Giving it permission to write to directories containing code would also be unsafe.
You really need to identify what's being denied and why that matters. If error messages aren't sufficiently clear, you could use strace to observe the processes system calls and the resulting errors.

Authorization Credentials Stripped --- django, elastic beanstalk, oauth

I implemented a REST api in django with django-rest-framework and used oauth2 for authentication.
I tested with:
curl -X POST -d "client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET&grant_type=password&username=YOUR_USERNAME&password=YOUR_PASSWORD" http://localhost:8000/oauth2/access_token/
and
curl -H "Authorization: Bearer <your-access-token>" http://localhost:8000/api/
on localhost with successful results consistent with the documentation.
When pushing this up to an existing AWS elastic beanstalk instance, I received:
{ "detail" : "Authentication credentials were not provided." }
I like the idea of just having some extra configuration on the standard place. In your .ebextensions directory create a wsgi_custom.config file with:
files:
"/etc/httpd/conf.d/wsgihacks.conf":
mode: "000644"
owner: root
group: root
content: |
WSGIPassAuthorization On
As posted here: https://forums.aws.amazon.com/message.jspa?messageID=376244
I thought the problem was with my configuration in django or some other error type instead of focusing on the differences between localhost and EB. The issue is with EB's Apache settings.
WSGIPassAuthorization is natively set to OFF, so it must be turned ON. This can be done in your *.config file in your .ebextensions folder with the following command added:
container_commands:
01_wsgipass:
command: 'echo "WSGIPassAuthorization On" >> ../wsgi.conf'
Please let me know if I missed something or if there is a better way I should be looking at the problem. I could not find anything specifically about this anywhere on the web and thought this might save somebody hours of troubleshooting then feeling foolish.
I use a slightly different approach now. sahutchi's solution worked as long as env variables were not changed as Tom dickin pointed out. I dug a bit deeper inside EB and found out where the wsgi.conf template is located and added the "WSGIPassAuthorization On" option there.
commands:
WSGIPassAuthorization:
command: sed -i.bak '/WSGIScriptAlias/ a WSGIPassAuthorization On' config.py
cwd: /opt/elasticbeanstalk/hooks
That will always work, even when changing environment variables. I hope you find it useful.
Edit: Seems like lots of people are still hitting this response. I haven't used ElasticBeanstalk in a while, but I would look into using Manel Clos' solution below. I haven't tried it personally, but seems a much cleaner solution. This one is literally a hack on EBs scripts and could potentially break in the future if EB updates them, specially if they move them to a different location.
Though the above solution is interesting, there is another way. Keep the wsgi.conf VirtualHost configuration file you want to use in .ebextensions, and overwrite it in a post deploy hook (you can't do this pre-deploy because it will get re-generated (yes, I found this out the hard way). If you do this, to reboot, make sure to use the supervisorctl program to restart so as to get all your environment variables set properly. (I found this out the hard way as well.)
cp /tmp/wsgi.conf /etc/httpd/conf.d/wsgi.conf
/usr/local/bin/supervisorctl -c /opt/python/etc/supervisord.conf restart httpd
exit 0
01_python.config:
05_fixwsgiauth:
command: "cp .ebextensions/wsgi.conf /tmp"

Redmine custom logo not appearing

I have installed Redmine and I've been playing around with a few themes. I am having trouble installing a custom logo. I add the new file in the correct folder and reference it in the correct stylesheet but when I inspect it in the browser it says "Failed to load the given URL"
I also tried making changes to the base.html.erb file and this did not show up either.
Simple changes to the stylesheet do work however.
Thanks for your help :)
Man, doing anything with Redmine customization is not easy but I finally got it. I followed this tutorial, http://www.redmine.org/projects/redmine/wiki/Howto_add_a_logo_to_your_Redmine_banner
However this did not actually work on my system so I added a few commands of my own. If these commands do not work then try adding sudo in front of them. THis will prompt you for the admin password.
Near the end, the tut tells you to do this in command line:
chown redmine:redmine /opt/redmine/public/images/logo.png
Now I am using Apache so my path would look more like this
chown apache:apache /var/www/redmine/public/images/logo.png
Anyway I tried that and it still had no effect, now the additions I was doing was either under public/images or public/themes so I chose to just target the public folder. This may be bad practice when going live but I am only working locally on a virtual machine.
Here is what worked:
chown -R apache:apache /var/www/redmine/public
chmod -R 775 apache:apache /var/www/redmine/public
The -R stands for recursive so it effects the child files too. chmod 775 allows read, write, execute permission for Owner & Group, and only read, execute permissions for Other.
Restart your server after that (the command could be slightly different depending on your setup, refer to the tut)
/etc/init.d/httpd restart
This was very confusing for me at first so let me know if anyone needs more clarification on the subject. I am using Redmine installed on a CentOS virtual box.