|Giles Bradshaw 4e0cd6e312||1 year ago|
|docker-squid||1 year ago|
|.gitignore||1 year ago|
|.versionrc||1 year ago|
|CHANGELOG.md||1 year ago|
|README.md||1 year ago|
|package.json||1 year ago|
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This is a direct copy of https://github.com/wrouesnel/docker-squid4
It’s been copied to push to docker hub with tags rather than just using “latest” so clients can control the version which is pulled.
This dockerfile builds a Squid 4 instance and includes all the necessary tooling to run it as a MITM (man-in-the-middle) SSL proxy.
There’s a number of reasons to do this - the big one being optimizing caching and delivery of objects during docker builds which might be downloading them from SSL protected endpoints.
It will require you to generate your own CA and set it as trusted.
The resulting docker image uses the following configuration environment variables:
ICP_PORTIf set, enables ICP on the given port for all users.
HTCP_PORTIf set, enables HTCP on the given port for all users.
MITM_PROXYIf set, tries to enable MITM SSL proxy functionality (requires CERT and KEY)
MITM_CERTIf set, the given PEM certificate is copied and used as the CA authority for MITM’ing connections.
MITM_KEYIf set, the given PEM certificate is copied and used as the signing key for the MITM CA.
docker-squid4Should be set to a unique value if you are chaining multiple proxy servers.
40000Cache size in megabytes. The cache defaults to
/var/cache/squid4. You should mount a volume here to make it persistent.
"1536 MB"Maximum object size to store in the cache. This is set high as one of my typical use cases is proxying distribution images.
"128 MB"Default memory cache size. I’ve no real clue what this should be, but RAM is plentiful so I like to keep it fairly large.
CACHE_PEERxCache peers for the squid instance may be specified with multiple CACHE_PEER environment variables. The suffix of each is used to determine ordering by the unix
EXTRA_CONFIGxExtra non-specific configuration lines to be appended after the main body of the configuration file. This is a good place for custom ACL parameters.
noIf set to
yesthen squid configuration templating is disabled entirely, allowing bind mounting the configuration file in manually instead. The certificate and SSL setup still runs normally.
DISABLE_CACHEDefault `` If set to
yesthen squid configuration templating removes all
cache_dirlines, setting squid to memory only cache.
NO_SSLv3,NO_TLSv1Allow overriding the default tls_outgoing_options supplied to OpenSSL. These are safe defaults, but if you’re in a really broken environment might not be usable.
By default squid in SSL MITM mode treats
cache_peer entries quite differently.
Because squid unwraps the CONNECT statement when bumping an SSL connection, but
does not rewrap it when communicating with peers, it requires all peers to connect
with SSL as well. This breaks compatibility with simple minded proxies.
To work around this, proxychains-ng (
proxychains4 internally) is built and
included in this image. If you need to use an upstream proxy with a MITM
squid4, you should launch the image in proxychains mode which intercepts squids
direct outbound connections and redirects them via CONNECT requests. This also
adds SOCKS4 and SOCKS5 proxy support if so desired.
proxychains is configured with the following environment variables. As with the
CONFIG_DISABLE prevents overwriting templated files.
PROXYCHAINDefault none. If set to
yesthen squid will be launched with proxychains. You should specify some proxies when doing this.
PROXYCHAIN_PROXYxUpstream proxies to be passed to the proxy chan config file. The suffix (
x) determines the order in which they are templated into the configuration file. The format is a space separated string like “http 127.0.0.1 3129”
strict_chain. Can be
dynamic_chainsensibly within this image. In
strict_chainmode, all proxies must be up. In
dynamic_chainmode proxies are used in order, but skipped if down. Disable configuration and bind a configuration file to /etc/proxychains.conf if you need more flexibility.
PROXYCHAIN_DNSDefault none. When set to
yes, turns on the
proxy_dnsoption for Proxychains.
In some corporate environments, its not possible to get reliable DNS outbound
proxychains-ng's DNS support won’t be able to provide for Squid4
to actually work. To address this, configuration is included to setup and use
The idea of the DNS-over-HTTPS client is that it will use your local proxy and network access to provide DNS service to Squid4.
yesthen enables and starts the DNS_OVER_HTTPS service.
127.0.0.153:53. Squid doesn’t support changing the port, so keep this in mind.
https://dns.google.com/resolve. AFAIK there’s no other options for this at the moment.
DNS_OVER_HTTPS_NO_PROXYDefault ``. List of DNS suffixes to not ever proxy via DNS_OVER_HTTPS.
DNS_OVER_HTTPS_PREFIX_SERVERDefault ``. Normal DNS server to try resolving first against.
DNS_OVER_HTTPS_SUFFIX_SERVERDefault ``. Normal DNS server to try resolving last against.
Since the DNS-over-HTTPS daemon is a separate Go binary, you may also need to
specify your internal proxy as an upstream to allow it to contact the HTTPS
DNS server - do this by passing the standard
parameters. Most likely these will be the same as your
directives (and probably only the 1).
The following command line will get you up and running quickly. It presumes you’ve generated a suitable CA certificate and are intending to use the proxy as a local MITM on your machine:
sudo mkdir -p /srv/squid/cache docker run -it -p 3128:127.0.0.1:3128 --rm \ -v /srv/squid/cache:/var/cache/squid4 \ -v /etc/ssl/certs:/etc/ssl/certs:ro \ -v /etc/ssl/private/local_mitm.pem:/local-mitm.pem:ro \ -v /etc/ssl/certs/local_mitm.pem:/local-mitm.crt:ro \ -e MITM_CERT=/local-mitm.crt \ -e MITM_KEY=/local-mitm.pem \ -e MITM_PROXY=yes \ squid
Note that it doesn’t really matter where we mount the certificate - the image launch script makes a copy as root to avoid messing with permissions anyway.
This is an example of a systemd unit file to persistly start squid4:
[Unit] Description=Squid4 Docker Container Documentation=http://wiki.squid.org After=network.target docker.service Requires=docker.service [Service] ExecStartPre=-/usr/bin/docker kill squid4 ExecStartPre=-/usr/bin/docker rm squid4 ExecStart=/usr/bin/docker run --net=host --rm \ -v /srv/squid/cache:/var/cache/squid4 \ -v /etc/ssl/certs:/etc/ssl/certs:ro \ -v /etc/ssl/private/local_mitm.pem:/local_mitm.pem:ro \ -v /etc/ssl/certs/local_mitm.pem:/local_mitm.crt:ro \ -e MITM_KEY=/local_mitm.pem \ -e MITM_CERT=/local_mitm.crt \ -e MITM_PROXY=yes \ --name squid4 \ squid [Install] WantedBy=multi-user.target