Guest24897
/
DockerCLI
mirror of https://github.com/docker/cli.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Permit '=' separator and '[ipv6]' in --add-host 

Fixes #4648

Make it easier to specify IPv6 addresses in the '--add-host' option by
permitting 'host=ip' in addition to 'host:ip', and allowing square
brackets around the address.

For example:

    --add-host=my-hostname:127.0.0.1
    --add-host=my-hostname:::1
    --add-host=my-hostname=::1
    --add-host=my-hostname:[::1]

To avoid compatibility problems, the CLI will replace an '=' separator
with ':', and strip brackets, before sending the request to the API.

Signed-off-by: Rob Murray <rob.murray@docker.com>
This commit is contained in:
robmry 2023-11-15 15:11:46 +00:00 committed by Rob Murray
parent af23916995
commit a682b8e655
6 changed files with 226 additions and 52 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
docs/reference/commandline/build.md
View File

@ -454,12 +454,12 @@ Specifying the `--isolation` flag without a value is the same as setting `--isol
### <a name="add-host"></a> Add entries to container hosts file (--add-host)
You can add other hosts into a container's `/etc/hosts` file by using one or
more `--add-host` flags. This example adds a static address for a host named
`docker`:
You can add other hosts into a build container's `/etc/hosts` file by using one
or more `--add-host` flags. This example adds static addresses for hosts named
`my-hostname` and `my_hostname_v6`:
```console
$ docker build --add-host docker:10.180.0.1 .
$ docker build --add-host my_hostname=8.8.8.8 --add-host my_hostname_v6=2001:4860:4860::8888 .
```
If you need your build to connect to services running on the host, you can use
@ -467,7 +467,15 @@ the special `host-gateway` value for `--add-host`. In the following example,
build containers resolve `host.docker.internal` to the host's gateway IP.
```console
$ docker build --add-host host.docker.internal:host-gateway .
$ docker build --add-host host.docker.internal=host-gateway .
```
You can wrap an IPv6 address in square brackets.
`=` and `:` are both valid separators.
Both formats in the following example are valid:
```console
$ docker build --add-host my-hostname:10.180.0.1 --add-host my-hostname_v6=[2001:4860:4860::8888] .
```
### <a name="target"></a> Specifying target build stage (--target)

30
docs/reference/commandline/run.md
View File

@ -746,22 +746,28 @@ section of the Docker run reference page.
You can add other hosts into a container's `/etc/hosts` file by using one or
more `--add-host` flags. This example adds a static address for a host named
`docker`:
`my-hostname`:
```console
$ docker run --add-host=docker:93.184.216.34 --rm -it alpine
$ docker run --add-host=my-hostname=8.8.8.8 --rm -it alpine
/ # ping docker
PING docker (93.184.216.34): 56 data bytes
64 bytes from 93.184.216.34: seq=0 ttl=37 time=93.052 ms
64 bytes from 93.184.216.34: seq=1 ttl=37 time=92.467 ms
64 bytes from 93.184.216.34: seq=2 ttl=37 time=92.252 ms
/ # ping my-hostname
PING my-hostname (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: seq=0 ttl=37 time=93.052 ms
64 bytes from 8.8.8.8: seq=1 ttl=37 time=92.467 ms
64 bytes from 8.8.8.8: seq=2 ttl=37 time=92.252 ms
^C
--- docker ping statistics ---
--- my-hostname ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 92.209/92.495/93.052 ms
```
You can wrap an IPv6 address in square brackets:
```console
$ docker run --add-host my-hostname=[2001:db8::33] --rm -it alpine
```
The `--add-host` flag supports a special `host-gateway` value that resolves to
the internal IP address of the host. This is useful when you want containers to
connect to services running on the host machine.
@ -779,11 +785,17 @@ $ echo "hello from host!" > ./hello
$ python3 -m http.server 8000
Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/) ...
$ docker run \
--add-host host.docker.internal:host-gateway \
--add-host host.docker.internal=host-gateway \
curlimages/curl -s host.docker.internal:8000/hello
hello from host!
```
The `--add-host` flag also accepts a `:` separator, for example:
```console
$ docker run --add-host=my-hostname:8.8.8.8 --rm -it alpine
```
### <a name="ulimit"></a> Set ulimits in container (--ulimit)
Since setting `ulimit` settings in a container requires extra privileges not

6
man/docker-build.1.md
View File

@ -78,10 +78,10 @@ set as the **URL**, the repository is cloned locally and then sent as the contex
layers in tact, and one for the squashed version.
**--add-host** []
Add a custom host-to-IP mapping (host:ip)
Add a custom host-to-IP mapping (host=ip, or host:ip)
Add a line to /etc/hosts. The format is hostname:ip. The **--add-host**
option can be set multiple times.
Add a line to /etc/hosts. The format is hostname=ip, or hostname:ip.
The **--add-host** option can be set multiple times.
**--build-arg** *variable*
name and value of a **buildarg**.

6
man/docker-run.1.md
View File

@ -121,10 +121,10 @@ executables expect) and pass along signals. The **-a** option can be set for
each of stdin, stdout, and stderr.
**--add-host**=[]
Add a custom host-to-IP mapping (host:ip)
Add a custom host-to-IP mapping (host=ip, or host:ip)
Add a line to /etc/hosts. The format is hostname:ip. The **--add-host**
option can be set multiple times.
Add a line to /etc/hosts. The format is hostname=ip, or hostname:ip.
The **--add-host** option can be set multiple times.
**--annotation**=[]
Add an annotation to the container (passed through to the OCI runtime).

44
opts/hosts.go
View File

@ -161,21 +161,53 @@ func ParseTCPAddr(tryAddr string, defaultAddr string) (string, error) {
return fmt.Sprintf("tcp://%s%s", net.JoinHostPort(host, port), u.Path), nil
}
// ValidateExtraHost validates that the specified string is a valid extrahost and returns it.
// ExtraHost is in the form of name:ip where the ip has to be a valid ip (IPv4 or IPv6).
// ValidateExtraHost validates that the specified string is a valid extrahost and
// returns it. ExtraHost is in the form of name:ip or name=ip, where the ip has
// to be a valid ip (IPv4 or IPv6). The address may be enclosed in square
// brackets.
//
// TODO(thaJeztah): remove client-side validation, and delegate to the API server.
// For example:
//
// my-hostname:127.0.0.1
// my-hostname:::1
// my-hostname=::1
// my-hostname:[::1]
//
// For compatibility with the API server, this function normalises the given
// argument to use the ':' separator and strip square brackets enclosing the
// address.
func ValidateExtraHost(val string) (string, error) {
k, v, ok := strings.Cut(val, "=")
if !ok {
// allow for IPv6 addresses in extra hosts by only splitting on first ":"
k, v, ok := strings.Cut(val, ":")
if !ok || k == "" {
k, v, ok = strings.Cut(val, ":")
}
// Check that a hostname was given, and that it doesn't contain a ":". (Colon
// isn't allowed in a hostname, along with many other characters. It's
// special-cased here because the API server doesn't know about '=' separators in
// '--add-host'. So, it'll split at the first colon and generate a strange error
// message.)
if !ok || k == "" || strings.Contains(k, ":") {
return "", fmt.Errorf("bad format for add-host: %q", val)
}
// Skip IPaddr validation for "host-gateway" string
if v != hostGatewayName {
// If the address is enclosed in square brackets, extract it (for IPv6, but
// permit it for IPv4 as well; we don't know the address family here, but it's
// unambiguous).
if len(v) > 2 && v[0] == '[' && v[len(v)-1] == ']' {
v = v[1 : len(v)-1]
}
// ValidateIPAddress returns the address in canonical form (for example,
// 0:0:0:0:0:0:0:1 -> ::1). But, stick with the original form, to avoid
// surprising a user who's expecting to see the address they supplied in the
// output of 'docker inspect' or '/etc/hosts'.
if _, err := ValidateIPAddress(v); err != nil {
return "", fmt.Errorf("invalid IP address in add-host: %q", v)
}
}
return val, nil
// This result is passed directly to the API, the daemon doesn't accept the '='
// separator or an address enclosed in brackets. So, construct something it can
// understand.
return k + ":" + v, nil
}

170
opts/hosts_test.go
View File

@ -2,8 +2,10 @@ package opts
import (
"fmt"
"strings"
"testing"
"gotest.tools/v3/assert"
is "gotest.tools/v3/assert/cmp"
)
func TestParseHost(t *testing.T) {
@ -146,32 +148,152 @@ func TestParseInvalidUnixAddrInvalid(t *testing.T) {
}
func TestValidateExtraHosts(t *testing.T) {
valid := []string{
`myhost:192.168.0.1`,
`thathost:10.0.2.1`,
`anipv6host:2003:ab34:e::1`,
`ipv6local:::1`,
`host.docker.internal:host-gateway`,
tests := []struct {
doc string
input string
expectedOut string // Expect output==input if not set.
expectedErr string // Expect success if not set.
}{
{
doc: "IPv4, colon sep",
input: `myhost:192.168.0.1`,
},
{
doc: "IPv4, eq sep",
input: `myhost=192.168.0.1`,
expectedOut: `myhost:192.168.0.1`,
},
{
doc: "Weird but permitted, IPv4 with brackets",
input: `myhost=[192.168.0.1]`,
expectedOut: `myhost:192.168.0.1`,
},
{
doc: "Host and domain",
input: `host.and.domain.invalid:10.0.2.1`,
},
{
doc: "IPv6, colon sep",
input: `anipv6host:2003:ab34:e::1`,
},
{
doc: "IPv6, colon sep, brackets",
input: `anipv6host:[2003:ab34:e::1]`,
expectedOut: `anipv6host:2003:ab34:e::1`,
},
{
doc: "IPv6, eq sep, brackets",
input: `anipv6host=[2003:ab34:e::1]`,
expectedOut: `anipv6host:2003:ab34:e::1`,
},
{
doc: "IPv6 localhost, colon sep",
input: `ipv6local:::1`,
},
{
doc: "IPv6 localhost, eq sep",
input: `ipv6local=::1`,
expectedOut: `ipv6local:::1`,
},
{
doc: "IPv6 localhost, eq sep, brackets",
input: `ipv6local=[::1]`,
expectedOut: `ipv6local:::1`,
},
{
doc: "IPv6 localhost, non-canonical, colon sep",
input: `ipv6local:0:0:0:0:0:0:0:1`,
},
{
doc: "IPv6 localhost, non-canonical, eq sep",
input: `ipv6local=0:0:0:0:0:0:0:1`,
expectedOut: `ipv6local:0:0:0:0:0:0:0:1`,
},
{
doc: "IPv6 localhost, non-canonical, eq sep, brackets",
input: `ipv6local=[0:0:0:0:0:0:0:1]`,
expectedOut: `ipv6local:0:0:0:0:0:0:0:1`,
},
{
doc: "host-gateway special case, colon sep",
input: `host.docker.internal:host-gateway`,
},
{
doc: "host-gateway special case, eq sep",
input: `host.docker.internal=host-gateway`,
expectedOut: `host.docker.internal:host-gateway`,
},
{
doc: "Bad address, colon sep",
input: `myhost:192.notanipaddress.1`,
expectedErr: `invalid IP address in add-host: "192.notanipaddress.1"`,
},
{
doc: "Bad address, eq sep",
input: `myhost=192.notanipaddress.1`,
expectedErr: `invalid IP address in add-host: "192.notanipaddress.1"`,
},
{
doc: "No sep",
input: `thathost-nosemicolon10.0.0.1`,
expectedErr: `bad format for add-host: "thathost-nosemicolon10.0.0.1"`,
},
{
doc: "Bad IPv6",
input: `anipv6host:::::1`,
expectedErr: `invalid IP address in add-host: "::::1"`,
},
{
doc: "Bad IPv6, trailing colons",
input: `ipv6local:::0::`,
expectedErr: `invalid IP address in add-host: "::0::"`,
},
{
doc: "Bad IPv6, missing close bracket",
input: `ipv6addr=[::1`,
expectedErr: `invalid IP address in add-host: "[::1"`,
},
{
doc: "Bad IPv6, missing open bracket",
input: `ipv6addr=::1]`,
expectedErr: `invalid IP address in add-host: "::1]"`,
},
{
doc: "Missing address, colon sep",
input: `myhost.invalid:`,
expectedErr: `invalid IP address in add-host: ""`,
},
{
doc: "Missing address, eq sep",
input: `myhost.invalid=`,
expectedErr: `invalid IP address in add-host: ""`,
},
{
doc: "IPv6 localhost, bad name",
input: `:=::1`,
expectedErr: `bad format for add-host: ":=::1"`,
},
{
doc: "No input",
input: ``,
expectedErr: `bad format for add-host: ""`,
},
}
invalid := map[string]string{
`myhost:192.notanipaddress.1`: `invalid IP`,
`thathost-nosemicolon10.0.0.1`: `bad format`,
`anipv6host:::::1`: `invalid IP`,
`ipv6local:::0::`: `invalid IP`,
for _, tc := range tests {
tc := tc
if tc.expectedOut == "" {
tc.expectedOut = tc.input
}
for _, extrahost := range valid {
if _, err := ValidateExtraHost(extrahost); err != nil {
t.Fatalf("ValidateExtraHost(`"+extrahost+"`) should succeed: error %v", err)
}
}
for extraHost, expectedError := range invalid {
if _, err := ValidateExtraHost(extraHost); err == nil {
t.Fatalf("ValidateExtraHost(`%q`) should have failed validation", extraHost)
} else if !strings.Contains(err.Error(), expectedError) {
t.Fatalf("ValidateExtraHost(`%q`) error should contain %q", extraHost, expectedError)
t.Run(tc.input, func(t *testing.T) {
actualOut, actualErr := ValidateExtraHost(tc.input)
if tc.expectedErr == "" {
assert.Check(t, is.Equal(tc.expectedOut, actualOut))
assert.NilError(t, actualErr)
} else {
assert.Check(t, actualOut == "")
assert.Check(t, is.Error(actualErr, tc.expectedErr))
}
})
}
}