• 熟悉podman
• 如何使用 Podman 对容器映像进行签名和分发

熟悉podman

此示例容器将运行一个非常基本的 httpd 服务器，该服务器仅为其索引页提供服务

[[email protected] ~]# podman ps -a
CONTAINER ID  IMAGE       COMMAND     CREATED     STATUS      PORTS       NAMES
[[email protected] ~]# podman run -dt -p 8080:8080/tcp -e HTTPD_VAR_RUN=/run/httpd -e HTTPD_MAIN_CONF_D_PATH=/etc/httpd/conf.d \
>                   -e HTTPD_MAIN_CONF_PATH=/etc/httpd/conf \
>                   -e HTTPD_CONTAINER_SCRIPTS_PATH=/usr/share/container-scripts/httpd/ \
>                   registry.fedoraproject.org/f29/httpd /usr/bin/run-httpd
Trying to pull registry.fedoraproject.org/f29/httpd:latest...
Getting image source signatures
Copying blob d77ff9f653ce done  
Copying blob aaf5ad2e1aa3 done  
Copying blob 7692efc5f81c done  
Copying config 25c76f9dcd done  
Writing manifest to image destination
Storing signatures
78dda9890d0f6cb13e47b347445ac93f43e4d993f4da5405943bf98c5bc9ab1a
[[email protected] ~]# 

由于容器在分离模式下运行（在命令中由 -d 表示），因此 Podman 将在运行后打印容器 ID。请注意，我们使用端口转发来访问 HTTP 服务器。要成功运行，至少需要 slirp4netns v0.3.0。

[[email protected] ~]# rpm -qa|grep slirp4netns
slirp4netns-1.1.8-2.module_el8.7.0+1106+45480ee0.x86_64

检查正在运行的容器您可以“检查”正在运行的容器，以获取有关其自身的元数据和详细信息。我们甚至可以使用 inspect 子命令来查看分配给容器的 IP 地址。由于容器在无根模式下运行，因此不会分配 IP 地址，并且该值将在检查的输出中列为“无”。

[[email protected] ~]# podman inspect -l|grep -i ipaddress
               "IPAddress": "10.88.0.4",
                         "IPAddress": "10.88.0.4",
[[email protected] ~]# 

注意：-l 是最新容器的便利参数。还可以使用容器的 ID 而不是 -l。

查看容器的日志您还可以使用 Podman 查看容器的日志：

[[email protected] ~]# podman logs -l
=> sourcing 10-set-mpm.sh ...
=> sourcing 20-copy-config.sh ...
=> sourcing 40-ssl-certs.sh ...
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 10.88.0.4. Set the 'ServerName' directive globally to suppress this message
[Mon Aug 15 16:09:45.049113 2022] [ssl:warn] [pid 1:tid 140289699057024] AH01882: Init: this version of mod_ssl was compiled against a newer library (OpenSSL 1.1.1b FIPS  26 Feb 2019, version currently loaded is OpenSSL 1.1.1 FIPS  11 Sep 2018) - may result in undefined or erroneous behavior
[Mon Aug 15 16:09:45.053794 2022] [ssl:warn] [pid 1:tid 140289699057024] AH01909: 10.88.0.4:8443:0 server certificate does NOT include an ID which matches the server name
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 10.88.0.4. Set the 'ServerName' directive globally to suppress this message
[Mon Aug 15 16:09:45.135165 2022] [ssl:warn] [pid 1:tid 140289699057024] AH01882: Init: this version of mod_ssl was compiled against a newer library (OpenSSL 1.1.1b FIPS  26 Feb 2019, version currently loaded is OpenSSL 1.1.1 FIPS  11 Sep 2018) - may result in undefined or erroneous behavior
[Mon Aug 15 16:09:45.136249 2022] [ssl:warn] [pid 1:tid 140289699057024] AH01909: 10.88.0.4:8443:0 server certificate does NOT include an ID which matches the server name
[Mon Aug 15 16:09:45.136619 2022] [lbmethod_heartbeat:notice] [pid 1:tid 140289699057024] AH02282: No slotmem from mod_heartmonitor
[Mon Aug 15 16:09:45.143579 2022] [mpm_event:notice] [pid 1:tid 140289699057024] AH00489: Apache/2.4.39 (Fedora) OpenSSL/1.1.1 configured -- resuming normal operations
[Mon Aug 15 16:09:45.143701 2022] [core:notice] [pid 1:tid 140289699057024] AH00094: Command line: 'httpd -D FOREGROUND'
[Mon Aug 15 16:13:55.037879 2022] [autoindex:error] [pid 49:tid 140289360692992] [client 192.168.29.1:62999] AH01276: Cannot serve directory /var/www/html/: No matching DirectoryIndex (index.html) found, and server-generated directory index forbidden by Options directive
192.168.29.1 - - [15/Aug/2022:16:13:55 +0000] "GET / HTTP/1.1" 403 4650 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.81 Safari/537.36 Edg/104.0.1293.54"
192.168.29.1 - - [15/Aug/2022:16:13:55 +0000] "GET /icons/apache_pb2.gif HTTP/1.1" 200 4234 "http://192.168.29.138:8080/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.81 Safari/537.36 Edg/104.0.1293.54"
192.168.29.1 - - [15/Aug/2022:16:13:55 +0000] "GET /icons/poweredby.png HTTP/1.1" 200 2616 "http://192.168.29.138:8080/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.81 Safari/537.36 Edg/104.0.1293.54"
192.168.29.1 - - [15/Aug/2022:16:13:55 +0000] "GET /favicon.ico HTTP/1.1" 404 209 "http://192.168.29.138:8080/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.81 Safari/537.36 Edg/104.0.1293.54"
[[email protected] ~]# 

[[email protected] ~]# podman top -l
USER        PID         PPID        %CPU        ELAPSED          TTY         TIME        COMMAND
default     1           0           0.000       6m41.225719555s  pts/0       0s          httpd -D FOREGROUND 
default     23          1           0.000       6m41.225933692s  pts/0       0s          /usr/bin/coreutils --coreutils-prog-shebang=cat /usr/bin/cat 
default     24          1           0.000       6m41.225970422s  pts/0       0s          /usr/bin/coreutils --coreutils-prog-shebang=cat /usr/bin/cat 
default     25          1           0.000       6m41.226000575s  pts/0       0s          /usr/bin/coreutils --coreutils-prog-shebang=cat /usr/bin/cat 
default     26          1           0.000       6m41.22807663s   pts/0       0s          /usr/bin/coreutils --coreutils-prog-shebang=cat /usr/bin/cat 
default     27          1           0.000       6m41.228195335s  pts/0       0s          httpd -D FOREGROUND 
default     28          1           0.000       6m41.228245362s  pts/0       0s          httpd -D FOREGROUND 
default     31          1           0.000       6m41.228288782s  pts/0       0s          httpd -D FOREGROUND 
default     49          1           0.000       6m41.228320044s  pts/0       0s          httpd -D FOREGROUND 
[[email protected] ~]# 

对容器执行检查点操作对容器执行检查点操作会停止容器，同时将容器中所有进程的状态写入磁盘。这样，容器以后可以还原，并在与检查点完全相同的时间点继续运行。此功能要求在系统上安装 CRIU 3.11 或更高版本。不支持此功能作为无根;因此，如果您想尝试一下，则需要使用相同的命令（但使用sudo）以root身份重新创建容器。要对容器使用检查点，请使用

[[email protected] ~]# podman ps
CONTAINER ID  IMAGE                                        COMMAND               CREATED        STATUS            PORTS                   NAMES
78dda9890d0f  registry.fedoraproject.org/f29/httpd:latest  /usr/bin/run-http...  8 minutes ago  Up 8 minutes ago  0.0.0.0:8080->8080/tcp  hungry_bell
[[email protected] ~]# podman container checkpoint -l
78dda9890d0f6cb13e47b347445ac93f43e4d993f4da5405943bf98c5bc9ab1a
[[email protected] ~]# ls
anaconda-ks.cfg  container-web.service

还原容器还原容器仅适用于以前检查点的容器。还原的容器将继续在检查点操作的同一时间点运行。

[[email protected] ~]# podman container restore -l
78dda9890d0f6cb13e47b347445ac93f43e4d993f4da5405943bf98c5bc9ab1a
[[email protected] ~]# podman ps -a
CONTAINER ID  IMAGE                                        COMMAND               CREATED         STATUS             PORTS                   NAMES
78dda9890d0f  registry.fedoraproject.org/f29/httpd:latest  /usr/bin/run-http...  10 minutes ago  Up 10 minutes ago  0.0.0.0:8080->8080/tcp  hungry_bell

迁移容器要将容器从一个主机实时迁移到另一个主机，容器将在迁移的源系统上执行检查点操作，传输到目标系统，然后在目标系统上还原。传输检查点时，可以指定输出文件。

停止容器
要停止 httpd 容器，请执行以下操作：
podman stop --latest
您还可以使用 ps 子命令检查一个或多个容器的状态。在这种情况下，我们应该使用 -a 参数列出所有容器。
podman ps -a

移除容器删除 httpd 容器：
podman rm --latest
您可以通过运行 podman ps -a 来验证容器的删除。

[[email protected] ~]# podman rmi docker.io/alpine localhost:5000/alpine
Untagged: docker.io/library/alpine:latest
Untagged: localhost:5000/alpine:latest
Deleted: c059bfaa849c4d8e4aecaeb3a10c2d9b3d85f5165c66ad3a4d937758128c4d18
[[email protected] ~]# 

如何使用 Podman 对容器映像进行签名和分发

对容器映像进行签名源于仅信任专用映像提供程序的动机，以缓解中间人 （MITM） 攻击或对容器注册表的攻击。对图像进行签名的一种方法是使用 GNU 隐私卫士 （GPG） 密钥。此技术通常与任何符合 OCI 的容器注册表（如 Quay.io）兼容。值得一提的是，OpenShift 集成容器注册表开箱即用地支持这种签名机制，这使得单独的签名存储变得不必要。从技术角度来看，我们可以在将映像推送到远程注册表之前利用 Podman 对映像进行签名。之后，所有运行Podman的系统都必须配置为从远程服务器检索签名，远程服务器可以是任何简单的Web服务器。这意味着在映像拉取操作期间，每个未签名的映像都将被拒绝。但是这是如何工作的呢？首先，我们必须创建一个GPG密钥对或选择一个本地可用的密钥对。要生成新的GPG密钥，只需运行并按照交互式对话框进行操作即可。现在我们应该能够验证密钥是否在本地存在

[[email protected] ~]# podman run -d -p 5000:5000 docker.io/registry
Trying to pull docker.io/library/registry:latest...
Getting image source signatures
Copying blob 3790aef225b9 done  
Copying blob e2ead8259a04 done  
Copying blob 79e9f2f55bf5 done  
Copying blob 0d96da54f60b done  
Copying blob 5b27040df4a2 done  
Copying config b8604a3fe8 done  
Writing manifest to image destination
Storing signatures
673e89cc9f072e6474e59413691a2fb08af9dda10f5e9898eb827bb84e2d4388
[[email protected] ~]# ss -antl
State      Recv-Q     Send-Q         Local Address:Port          Peer Address:Port     Process     
LISTEN     0          128                  0.0.0.0:5000               0.0.0.0:*                    
LISTEN     0          128                  0.0.0.0:8080               0.0.0.0:*                    
LISTEN     0          128                  0.0.0.0:22                 0.0.0.0:*                    
LISTEN     0          128                     [::]:22                    [::]:*                    
[[email protected] ~]# podman pull docker://docker.io/alpine:latest
Trying to pull docker.io/library/alpine:latest...
Getting image source signatures
Copying blob 59bf1c3509f3 done  
Copying config c059bfaa84 done  
Writing manifest to image destination
Storing signatures
c059bfaa849c4d8e4aecaeb3a10c2d9b3d85f5165c66ad3a4d937758128c4d18
[[email protected] ~]# podman images
REPOSITORY                            TAG         IMAGE ID      CREATED        SIZE
docker.io/library/busybox             latest      7a80323521cc  2 weeks ago    1.47 MB
docker.io/library/httpd               latest      dabbfbe0c57b  7 months ago   148 MB
docker.io/library/alpine              latest      c059bfaa849c  8 months ago   5.87 MB
docker.io/library/registry            latest      b8604a3fe854  9 months ago   26.8 MB
docker.io/library/centos              latest      5d0da3dc9764  11 months ago  239 MB
quay.io/centos/centos                 latest      300e315adb2f  20 months ago  217 MB
registry.fedoraproject.org/f29/httpd  latest      25c76f9dcdb5  3 years ago    482 MB
[[email protected] ~]# podman images alpine
REPOSITORY                TAG         IMAGE ID      CREATED       SIZE
docker.io/library/alpine  latest      c059bfaa849c  8 months ago  5.87 MB
[[email protected] ~]# podman tag alpine localhost:5000/alpine
[[email protected] ~]# podman images alpine
REPOSITORY                TAG         IMAGE ID      CREATED       SIZE
docker.io/library/alpine  latest      c059bfaa849c  8 months ago  5.87 MB
localhost:5000/alpine     latest      c059bfaa849c  8 months ago  5.87 MB
[[email protected] ~]# 
[[email protected] ~]# cd /etc/containers/
[[email protected] containers]# ls
certs.d  oci  policy.json  registries.conf  registries.conf.d  registries.d  storage.conf
[[email protected] containers]# cd registries.d
[[email protected] registries.d]# ls
default.yaml  registry.access.redhat.com.yaml  registry.redhat.io.yaml
[[email protected] registries.d]# vim default.yaml 
 sigstore: http://localhost:8000
  sigstore-staging: file:///var/lib/containers/sigstore
[[email protected] ~]# gpg --full-gen-key
gpg (GnuPG) 2.2.20; Copyright (C) 2020 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
  (14) Existing key from card
Your selection? 
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 
Requested keysize is 2048 bits
Please specify how long the key should be valid.
         0 = key does not expire
      <n>  = key expires in n days
      <n>w = key expires in n weeks
      <n>m = key expires in n months
      <n>y = key expires in n years
Key is valid for? (0) 
Key does not expire at all
Is this correct? (y/N) y

GnuPG needs to construct a user ID to identify your key.

Real name: marui
Email address: marui
Not a valid email address
Email address: [email protected]
Comment: marui
You selected this USER-ID:
    "marui (marui) <[email protected]>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? 
Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
gpg: key 5FFF7EFCD429C026 marked as ultimately trusted
gpg: revocation certificate stored as '/root/.gnupg/openpgp-revocs.d/146DAAB2D98BED4A566AD5DC5FFF7EFCD429C026.rev'
public and secret key created and signed.

pub   rsa2048 2022-08-15 [SC]
      146DAAB2D98BED4A566AD5DC5FFF7EFCD429C026
uid                      marui123 (jjyy) <[email protected]>
sub   rsa2048 2022-08-15 [E]

[[email protected] ~]# gpg --list-keys marui
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
pub   rsa2048 2022-08-15 [SC]
      146DAAB2D98BED4A566AD5DC5FFF7EFCD429C026
uid           [ultimate] marui123 (jjyy) <[email protected]>
sub   rsa2048 2022-08-15 [E]

[[email protected] ~]# podman push     --tls-verify=false     --sign-by marui     localhost:5000/alpineGetting image source signatures
Copying blob 8d3ac3489996 done  
Copying config c059bfaa84 done  
Writing manifest to image destination
Signing manifest
Error: creating signature: Invalid value
[[email protected] ~]# podman push     --tls-verify=false     --sign-by marui123     localhost:5000/alpine
Getting image source signatures
Copying blob 8d3ac3489996 done  
Copying config c059bfaa84 done  
Writing manifest to image destination

Storing signatures
[[email protected] ~]# ls /var/lib/containers/sigstore
'[email protected]=a65d71e7a88c3a63246ec299abb0dcec671579ac0af199d96e2a82339f061199'
[[email protected] ~]# dnf module install python38 -y

[[email protected] ~]# cd /var/lib/containers/
[[email protected] containers]# ls
cache  sigstore  storage
[[email protected] containers]# cd sigstore/
[[email protected] sigstore]# ls
'[email protected]=a65d71e7a88c3a63246ec299abb0dcec671579ac0af199d96e2a82339f061199'
[[email protected] sigstore]# ss -antl
State       Recv-Q      Send-Q             Local Address:Port             Peer Address:Port      Process      
LISTEN      0           128                      0.0.0.0:5000                  0.0.0.0:*                      
LISTEN      0           128                      0.0.0.0:8080                  0.0.0.0:*                      
LISTEN      0           128                      0.0.0.0:22                    0.0.0.0:*                      
LISTEN      0           128                         [::]:22                       [::]:*           
[[email protected] sigstore]# python3 -m http.server
Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/) ...
[[email protected] ~]# ss -antl
State       Recv-Q      Send-Q             Local Address:Port             Peer Address:Port      Process      
LISTEN      0           5                        0.0.0.0:8000                  0.0.0.0:*                      
LISTEN      0           128                      0.0.0.0:5000                  0.0.0.0:*                      
LISTEN      0           128                      0.0.0.0:8080                  0.0.0.0:*                      
LISTEN      0           128                      0.0.0.0:22                    0.0.0.0:*                      
LISTEN      0           128                         [::]:22                       [::]:*                      
[[email protected] ~]# firewall-cmd --add-rich-rule 'rule family=ipv4 source address=192.168.29.0/24 port port=8000 protocol=tcp accept' --permanent
success
[[email protected] ~]# firewall-cmd --reload
success