initial import

.dockerignore

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+.python2.7
+*.iml
+*.md

.gitignore

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+.python2.7
+*.iml

.travis.yml

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+language: generic
+sudo: required
+services:
+  - docker
+before_script:
+  - docker login -u "${DOCKERHUB_USERNAME}" -p "${DOCKERHUB_PASSWORD}"
+script:
+  - .travis/build.sh
+after_script:
+  - |
+    if [[ "${TRAVIS_BRANCH}" == "master" ]]; then
+      docker run infolinks/github-release \
+          --token="${GITHUB_ACCESS_TOKEN}" \
+          --repo="${TRAVIS_REPO_SLUG}" \
+          --commit="${TRAVIS_COMMIT}"
+    fi

.travis/build.sh

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+#!/usr/bin/env bash
+
+set -e
+
+docker build -t infolinks/k8s-ingress-networks:${TRAVIS_COMMIT} .
+
+if [[ ${TRAVIS_TAG} =~ ^v[0-9]+$ ]]; then
+    docker tag infolinks/k8s-ingress-networks:${TRAVIS_COMMIT} infolinks/k8s-ingress-networks:${TRAVIS_TAG}
+    docker push infolinks/k8s-ingress-networks:${TRAVIS_TAG}
+    docker tag infolinks/k8s-ingress-networks:${TRAVIS_COMMIT} infolinks/k8s-ingress-networks:latest
+    docker push infolinks/k8s-ingress-networks:latest
+fi

CODE_OF_CONDUCT.md

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+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at dev@infolinks.com. The project team will review and investigate all complaints, and will respond in a way that it deems appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [http://contributor-covenant.org/version/1/4][version]
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/
+

CONTRIBUTING.md

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+# Contributing
+
+When contributing to this repository, please first discuss the change you wish to make via issue, email, or any other method with the owners of this repository before making a change. 
+
+Please note we have a code of conduct, please follow it in all your interactions with the project.
+
+## Pull Request Process
+
+1. Include updates to README.md with details of the change, including new environment variables or mounts, preferably with examples.
+2. Undocumented code will be rejected, as well as over-documented code :)
+

Dockerfile

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+FROM google/cloud-sdk:171.0.0-alpine
+MAINTAINER Arik Kfir <arik@infolinks.com>
+RUN apk --no-cache --update add jq && \
+    gcloud components install --quiet kubectl
+COPY update_ingresses.py scan-ingress-networks.sh /usr/local/bin/
+RUN chmod a+x /usr/local/bin/scan-ingress-networks.sh /usr/local/bin/update_ingresses.py
+ENTRYPOINT ["/usr/local/bin/scan-ingress-networks.sh"]

README.md

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 # k8s-ingress-networks
-Annotates Ingress resources with whitelisted CIDR ranges from configuration
+
+[![Build Status](https://travis-ci.org/infolinks/k8s-ingress-networks.svg?branch=master)](https://travis-ci.org/infolinks/k8s-ingress-networks)
+
+Container for continually ensuring that a Kubernetes Ingress resources is restricted only to a set of whitelisted
+networks (CIDR ranges) based on a list of named networks. 
+
+This container will:
+
+1. Search for a configuration map (whose name is provided as an environment variable) that will contain a mapping
+between network names and CIDR ranges.
+2. Watch Ingress resources with the annotation `ingress.infolinks.com/networks`
+3. For each such Ingress resource:
+    1. Build a CIDR list from the combined CIDR ranges of all networks referenced in `ingress.infolinks.com/networks`
+    2. Add/update the Kubernetes annotation `ingress.kubernetes.io/whitelist-source-range` with the CIDR list
+
+## Deployment
+
+When running externally to a Kubernetes cluster, make sure that you configure `kubectl` to properly access your cluster.
+
+If this container is running inside a Kubernetes cluster, you just need to make sure the `Pod` running this container 
+has the RBAC permissions to use `kubectl`.
+
+## Contributions
+
+Any contribution to the project will be appreciated! Whether it's bug
+reports, feature requests, pull requests - all are welcome, as long as
+you follow our [contribution guidelines for this project](CONTRIBUTING.md)
+and our [code of conduct](CODE_OF_CONDUCT.md).

scan-ingress-networks.sh

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+#!/usr/bin/env bash
+
+CONFIG_MAP_NAMESPACE=${CONFIG_MAP_NAMESPACE}
+if [[ -z "${CONFIG_MAP_NAMESPACE}" ]]; then
+    echo "Environment variable 'CONFIG_MAP_NAMESPACE' not defined" >&2
+    exit 1
+fi
+
+CONFIG_MAP_NAME=${CONFIG_MAP_NAME}
+if [[ -z "${CONFIG_MAP_NAME}" ]]; then
+    echo "Environment variable 'CONFIG_MAP_NAME' not defined" >&2
+    exit 1
+fi
+
+while true; do
+    NETWORKS=$(kubectl get "configmap/${CONFIG_MAP_NAME}" -n "${CONFIG_MAP_NAMESPACE}" --output=json | jq '.data | map_values(. | split(","))')
+    if [[ $? != 0 ]]; then
+        exit 1
+    fi
+
+    RESTRICTED_INGRESSES=$(kubectl get ingress --all-namespaces --output=json | jq '
+                [
+                    .items[] |
+                    {
+                        "namespace": .metadata.namespace,
+                        "name": .metadata.name,
+                        "networks": (.metadata.annotations["ingress.infolinks.com/networks"] // "") | split(","),
+                        "whitelist": (.metadata.annotations["ingress.kubernetes.io/whitelist-source-range"] // "") | split(",")
+                    }
+                ]')
+    if [[ $? != 0 ]]; then
+        exit 1
+    fi
+
+    # example resulting context:
+    # {
+    #   "networks": {
+    #     "arik": [ "81.218.196.247/32", "31.168.217.84/32" ],
+    #     "office": [ "212.143.214.138/32", "82.80.146.176/32" ]
+    #   },
+    #   "ingresses": [
+    #     {
+    #       "namespace": "app",
+    #       "name": "echoserver",
+    #       "networks": [ "arik", "office" ],
+    #       "whitelist": [ "1.2.3.4/5", "6.7.8.9/0" ]
+    #     },
+    #     {
+    #       "namespace": "app",
+    #       "name": "echoserver",
+    #       "networks": [],
+    #       "whitelist": [ "0.0.0.0/0" ]
+    #     }
+    #   ]
+    # }
+    echo -nE "{ \"networks\": ${NETWORKS}, \"ingresses\": ${RESTRICTED_INGRESSES} }" | $(dirname $0)/update_ingresses.py
+    if [[ $? != 0 ]]; then
+        echo "Updating Ingress resources failed!" >&2
+        exit 1
+    fi
+
+    # rinse & repeat
+    sleep 10
+    if [[ $? != 0 ]]; then
+        echo "Interrupted" >&2
+        exit 0
+    fi
+done

update_ingresses.py

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+#!/usr/bin/env python2
+import json
+import subprocess
+
+import sys
+
+# URL constants
+WHITELIST_ANN_NAME = 'ingress.kubernetes.io/whitelist-source-range'
+
+
+def main():
+    # read JSON from stdin
+    try:
+        context = json.loads('\n'.join(sys.stdin.readlines()))
+    except:
+        sys.stderr.write("Failed reading JSON from stdin!\n")
+        sys.stderr.flush()
+        raise
+
+    # iterate ingresses, and for each one, construct the list of whitelisted CIDRs (from its whitelisted networks)
+    # then annotate the ingress to whitelist only the CIDRs collected from those whitelisted networks
+    networks = context['networks']
+    for ing in context['ingresses']:
+        ing_namespace = ing['namespace']
+        ing_name = ing['name']
+        ing_actual_whitelist = ing['whitelist']
+
+        # collect CIDRs from the ingress's whitelisted networks
+        if ing['networks']:
+            ing_desired_whitelist = []
+            for network_name in ing['networks']:
+                ing_desired_whitelist.extend(networks[network_name] if network_name in networks else [])
+        else:
+            ing_desired_whitelist = ["0.0.0.0/0"]
+
+        # if actual & desired whitelists are different, update ingress
+        if ing_actual_whitelist != ing_desired_whitelist:
+            print "Ingress '%s/%s' has differing actual & desired CIDR whitelist:" % (ing_namespace, ing_name)
+            print "   Actual: %s" % ing_actual_whitelist
+            print "  Desired: %s" % ing_desired_whitelist
+            whitelist_string = ','.join(ing_desired_whitelist)
+            subprocess.check_call(
+                "kubectl annotate --namespace=\"%s\" ingress/%s --overwrite %s=\"%s\"" % (ing_namespace,
+                                                                                          ing_name,
+                                                                                          WHITELIST_ANN_NAME,
+                                                                                          whitelist_string),
+                shell=True)
+
+
+if __name__ == "__main__":
+    main()